fishoutawater
New member
post #185 above calls it "primary production" and "primary reduction".
How to FEED your reef tank so that your corals will really GROW, instead of ho-hum...
- Thread starter capecoral
- Start date
Gary Majchrzak
Team RC
post #185 isn't referring to dosing phytoplankton in a closed system
you must be very careful to make the distinction between closed systems (such as reef aquaria) and the ocean- they're apples and oranges.
this thread has the potential to turn so many reef aquaria into pea soup.
Greenmaster
New member
post #185 isn't referring to dosing phytoplankton in a closed system
you must be very careful to make the distinction between closed systems (such as reef aquaria) and the ocean- they're apples and oranges.
this thread has the potential to turn so many reef aquaria into pea soup.
"Pea soup" ROFL :lolspin:
jlinzmaier
Premium Member
The concept seems sound but unlikely to translate equally from oceanic reef to aquarium reef.
The general idea is building a complexly varied food chain that will manage all types of DOC's as well as POM. It would be reefkeeping nirvana to create a reef tank with such diversity of life in such perfect proportion that the tank is able to recycle every bit of food going into the tank and at the same time manage every bit of waste being generated by the animals eating that food. Starting with phyto to feed some of the smallest life forms (which then become food for larger life forms - so on and so forth) is a logical starting point but a person must understand that every change in feeding regimen or food type must be slow and deliberate so the tank can evolve. What many people overlook is that a tanks cycle is more than the first thirty days after it's been set up and it spikes ammonia then nutients slowly decline as bacterial populations become established. Every time we change a feeding regimen, add fish, add inverts, change lighting, change filtration, etc... a tank will go through a cycle with each change. That "cycle" being the tanks adaptation to the change. If we add a feeding regimen of phyto then there can be an increase in copepods and other microfauna as they feed on this phyto. The increase in copepods may induce an increase in amphipods as there is now a larger amount of food for the amphipods. With an increase in amphipods the fish have more live food to pick from and thus create more waste themselves. As that increased amount of fish waste decomposes then there will be an increase in DOC's such as N and P. That can then further fuel the growth of macroalgae "OR", if not properly managed, that increase in N and P can be detrimental as it continues to build up. That very short and extremely over-simplified example of how a tank naturally adapts to food availability is the easist way to paint a picture of what happens when we add or change a feeding regimen and please know that in reality there are thousands of variables that can affect the process and determine how the tanks inhabitants will respond to that change. It's all a very delicate balance and the diversity of life as well as the tanks ability to adapt is what can make or break a significant change in reef husbandry or feeding regimens.
Borneman did a spectacular series of articles on reef foods and "mini cycles" as food demand and/or availability changes. It's truly an awesome amount of valid information and pertains very much to the discussion on this thread.
http://www.reefkeeping.com/issues/2002-07/eb/index.php
Jeremy
Last edited:
Gary Majchrzak
Team RC
great link!
great link!
thanks for sharing your post, Jeremy!
great link!
thanks for sharing your post, Jeremy!
"Suspension Feeding in Atlantic Reef Corals, and the Importance of Suspended Particulate Matter as a Food Source. Third International Coral Reef Symposium, May 1977"
"Atlantic reef corals are able to act as suspension feeders by means of mucus nets and strands, in addition to capturing zooplankton with their tentacles. [...] The biomass of suspended particulate matter in Barbados is just enough to supply the daily maintenance requirement of corals [separate from any light]."
"This study is concerned with certain aspects of the feeding behavior, and the feeding strategies, of reef corals."
"The investigation was carried out at the Bellairs Research Institute of McGill University, St. James, Barbados, West Indies. Most of the species studied were collected from a fringing reef from the west coast of the island. In order to observe feeding behavior in the laboratory, live brine shrimp (Artemia) nauplii and finely ground fish homogenate were offered as food. Observations on feeding behavior were completed within 24 hours after collection of specimens [from the ocean]."
"Table 1. [Simplified] Mean clearance rates (in water cleared [of food particles], ml per hour per square cm of living coral tissue) of Atlantic reef corals:"
".....................................Food Clearance Rate
Diploria clivosa...................145.5
Meandrina meandrites..........139.6
Montastrea cavernosa.........111.2
Mussa angulosa..................109.6
Mycetophyllia lamarckiana....106.6
Siderastrea siderea.............106.3
Diploria strigosa..................102.1
Diploria labyrinthiformis........101.2
Agaricia agaricites...............99.5
Agaricia lamarcki.................97.2
Favia fragum......................81.2
Stephanocoenia michelinii.....63.6
Dentrogyra cylindrus...........47.7
Montastrea annularis...........41.2
Porites porites...................16.6 "
"The ability of reef corals to feed by a mucus net greatly increases the potential food sources available to them. [One researcher] considers that mucus suspension feeders are able to retain particles down to less than 1 um, and has stated that in most suspension feeders, feeding goes on more or less continuously. Thus the suspension feeding abilities of many reef corals may provide an answer to the difficulties raised [by another researcher] in regard to the poverty of zooplankton in tropical waters available to corals. Not only zooplankton, but a wide range of suspended particulate material is available for feeding corals. It has recently been shown that suspended particulate matter is found in substantial quantities on both Atlantic and Pacific reefs. [Another researcher] has shown that corals consume bacterio-plankton and aggregates of bacteria. Particulate matter may thus be an important food source for reef corals."
"Nice pics of coral mucus (bad narrative however):
http://www.youtube.com/watch?v=STzVkzuri94 "
"Attached are the top two feeders of the study, Diploria clivosa and Meandrina meandrites."
Link I found:
http://www.reefbase.org/download/download.aspx?type=10&docid=8887
"Atlantic reef corals are able to act as suspension feeders by means of mucus nets and strands, in addition to capturing zooplankton with their tentacles. [...] The biomass of suspended particulate matter in Barbados is just enough to supply the daily maintenance requirement of corals [separate from any light]."
"This study is concerned with certain aspects of the feeding behavior, and the feeding strategies, of reef corals."
"The investigation was carried out at the Bellairs Research Institute of McGill University, St. James, Barbados, West Indies. Most of the species studied were collected from a fringing reef from the west coast of the island. In order to observe feeding behavior in the laboratory, live brine shrimp (Artemia) nauplii and finely ground fish homogenate were offered as food. Observations on feeding behavior were completed within 24 hours after collection of specimens [from the ocean]."
"Table 1. [Simplified] Mean clearance rates (in water cleared [of food particles], ml per hour per square cm of living coral tissue) of Atlantic reef corals:"
".....................................Food Clearance Rate
Diploria clivosa...................145.5
Meandrina meandrites..........139.6
Montastrea cavernosa.........111.2
Mussa angulosa..................109.6
Mycetophyllia lamarckiana....106.6
Siderastrea siderea.............106.3
Diploria strigosa..................102.1
Diploria labyrinthiformis........101.2
Agaricia agaricites...............99.5
Agaricia lamarcki.................97.2
Favia fragum......................81.2
Stephanocoenia michelinii.....63.6
Dentrogyra cylindrus...........47.7
Montastrea annularis...........41.2
Porites porites...................16.6 "
"The ability of reef corals to feed by a mucus net greatly increases the potential food sources available to them. [One researcher] considers that mucus suspension feeders are able to retain particles down to less than 1 um, and has stated that in most suspension feeders, feeding goes on more or less continuously. Thus the suspension feeding abilities of many reef corals may provide an answer to the difficulties raised [by another researcher] in regard to the poverty of zooplankton in tropical waters available to corals. Not only zooplankton, but a wide range of suspended particulate material is available for feeding corals. It has recently been shown that suspended particulate matter is found in substantial quantities on both Atlantic and Pacific reefs. [Another researcher] has shown that corals consume bacterio-plankton and aggregates of bacteria. Particulate matter may thus be an important food source for reef corals."
"Nice pics of coral mucus (bad narrative however):
http://www.youtube.com/watch?v=STzVkzuri94 "
"Attached are the top two feeders of the study, Diploria clivosa and Meandrina meandrites."
Link I found:
http://www.reefbase.org/download/download.aspx?type=10&docid=8887
Attachments
"œHere is a great site that is more reefer-friendly than the research studies previously posted:"
"œCoralScience.org, 2010:"
"œSince early explorers such as Charles Darwin started to study coral reefs in the 19th century, much has been learned about the enigmatic creatures called corals. One of the most intriguing questions has always been how corals are able to survive in a seemingly empty ocean. The discovery of symbiotic algae, called zooxanthellae, in 1881 marked a key point in the understanding of coral biology. In the 1970's and 1980's, scientists determined that reef building corals may rely entirely on their symbiotic algal partners for their daily energy [not growth] intake. Without these nutritive algae, thriving in the coral's endoderm [skin], coral reefs as we know them today may never have existed."
"œFrom these findings, most aquarists have concluded that corals with symbiotic algae do not require any supplemental plankton feeding. Today, most marine aquaria are well equipped with strong lighting fixtures, but lack the technology to supply plankton or other fine particles. Relatively recent studies however have shown that the waters surrounding coral reefs are no underwater deserts at all. In fact, they are teeming with life such as bacteria, protozoa, phytoplankton and zooplankton. Although ocean water is very low in dissolved nutrients [in the top 300 feet of depth] such as ammonia, nitrate, phosphate and silica, this is on average sufficient to allow bacteria, protozoa and phytoplankton to grow. This is because many of these organisms are autotrophic, and are able to utilise the sun's energy to produce organic [food] molecules. This forms the basis of the marine food chain: phytoplankton is consumed by zooplankton, which is subsequently devoured by larger organisms. [Phytoplankton also perform nutrient primary-reduction]"
"œAll of this indicates that marine aquaria are chronically underfed in terms of plankton, which is reflected by the often poor biodiversity in these closed systems. Many highly interesting marine organisms such as sponges, tunicates, bivalves and corals that lack symbiotic algae usually do not survive for long in most marine aquaria."
"œAlthough stony corals [which use] zooxanthellae may thrive in most aquaria, even these animals still highly benefit from additional plankton feeding. This is because heterotrophy, the consumption of organic molecules [plankton], provides the necessary building blocks for animals to grow. Although zooxanthellae provide corals with ample amounts of energy by translocating carbohydrates and fats, additional food sources rich in nitrogen and other elements are crucial as well. Feeding stony corals with zooplankton has been shown to increase growth rates, and may also provide additional resilience against disease. Reproduction is likely stimulated as well, by allowing more energy to be invested in the production of gametes [for baby corals]."
"œMarine scientists currently have reached a general consensus about how corals take up nutrients, which ranges from dissolved nutrients to mega-zooplankton, and have shown the importance of a variety of nutritive sources for coral growth and survival. In addition, aquarists and hobbyists have provided detailed photographs and video footage of coral feeding behavior in the aquarium. A group of scleractinian corals however has remained controversial: the small polyped stony corals, commonly referred to as SPS corals. These animals are often wrongly believed to simply rely on strong lighting and dissolved inorganic nutrients such as ammonium, nitrate and phosphate. Scientists have clearly shown that species from this group, such as Pocillopora damicornis and Stylophora pistillata, strongly benefit from plankton consumption. Actual footage of SPS corals consuming plankton has been sparse, however."
"œThe three videos [linked at the site] clearly demonstrate zooplankton capture by two small polyped scleractinians: Seriatopora caliendrum and Stylophora pistillata. From this footage it becomes clear that at least Stylophora pistillata ingests zooplankton. Stylophora pistillata also digests zooplankton externally by expelling mesenterial filaments. Seriatopora caliendrum may also digest zooplankton externally, similar to Galaxea fascicularis and Stylophora pistillata, or internally, after uptake through the stomodeum (mouth and pharynx). Either way, scleractinian corals may highly benefit from additional zooplankton feedings."
"œCoralScience.org, 2010:"
"œSince early explorers such as Charles Darwin started to study coral reefs in the 19th century, much has been learned about the enigmatic creatures called corals. One of the most intriguing questions has always been how corals are able to survive in a seemingly empty ocean. The discovery of symbiotic algae, called zooxanthellae, in 1881 marked a key point in the understanding of coral biology. In the 1970's and 1980's, scientists determined that reef building corals may rely entirely on their symbiotic algal partners for their daily energy [not growth] intake. Without these nutritive algae, thriving in the coral's endoderm [skin], coral reefs as we know them today may never have existed."
"œFrom these findings, most aquarists have concluded that corals with symbiotic algae do not require any supplemental plankton feeding. Today, most marine aquaria are well equipped with strong lighting fixtures, but lack the technology to supply plankton or other fine particles. Relatively recent studies however have shown that the waters surrounding coral reefs are no underwater deserts at all. In fact, they are teeming with life such as bacteria, protozoa, phytoplankton and zooplankton. Although ocean water is very low in dissolved nutrients [in the top 300 feet of depth] such as ammonia, nitrate, phosphate and silica, this is on average sufficient to allow bacteria, protozoa and phytoplankton to grow. This is because many of these organisms are autotrophic, and are able to utilise the sun's energy to produce organic [food] molecules. This forms the basis of the marine food chain: phytoplankton is consumed by zooplankton, which is subsequently devoured by larger organisms. [Phytoplankton also perform nutrient primary-reduction]"
"œAll of this indicates that marine aquaria are chronically underfed in terms of plankton, which is reflected by the often poor biodiversity in these closed systems. Many highly interesting marine organisms such as sponges, tunicates, bivalves and corals that lack symbiotic algae usually do not survive for long in most marine aquaria."
"œAlthough stony corals [which use] zooxanthellae may thrive in most aquaria, even these animals still highly benefit from additional plankton feeding. This is because heterotrophy, the consumption of organic molecules [plankton], provides the necessary building blocks for animals to grow. Although zooxanthellae provide corals with ample amounts of energy by translocating carbohydrates and fats, additional food sources rich in nitrogen and other elements are crucial as well. Feeding stony corals with zooplankton has been shown to increase growth rates, and may also provide additional resilience against disease. Reproduction is likely stimulated as well, by allowing more energy to be invested in the production of gametes [for baby corals]."
"œMarine scientists currently have reached a general consensus about how corals take up nutrients, which ranges from dissolved nutrients to mega-zooplankton, and have shown the importance of a variety of nutritive sources for coral growth and survival. In addition, aquarists and hobbyists have provided detailed photographs and video footage of coral feeding behavior in the aquarium. A group of scleractinian corals however has remained controversial: the small polyped stony corals, commonly referred to as SPS corals. These animals are often wrongly believed to simply rely on strong lighting and dissolved inorganic nutrients such as ammonium, nitrate and phosphate. Scientists have clearly shown that species from this group, such as Pocillopora damicornis and Stylophora pistillata, strongly benefit from plankton consumption. Actual footage of SPS corals consuming plankton has been sparse, however."
"œThe three videos [linked at the site] clearly demonstrate zooplankton capture by two small polyped scleractinians: Seriatopora caliendrum and Stylophora pistillata. From this footage it becomes clear that at least Stylophora pistillata ingests zooplankton. Stylophora pistillata also digests zooplankton externally by expelling mesenterial filaments. Seriatopora caliendrum may also digest zooplankton externally, similar to Galaxea fascicularis and Stylophora pistillata, or internally, after uptake through the stomodeum (mouth and pharynx). Either way, scleractinian corals may highly benefit from additional zooplankton feedings."
Aquarist007
New member
Maybe this guy with particles in his water will feed his corals better?...
http://reefcentral.com/forums/showthread.php?t=1866381
http://reefcentral.com/forums/showthread.php?t=1866381
"Import and export of Net Plankton by an Eniwetok Coral Reef Community. Second International Coral Reef Symposium, Great Barrier Reef Committee, Oct 1974"
"Plankton nets were placed immediately upstream and downstream of a shallow inter-island coral community, in order to monitor the import and export of particulate material retained by a 60 micron [0.06 mm] mesh net. In this size range, there was an [overall] import [consumption] of organic carbon, nitrogen, phosphorus, benthic algal fragments, fecal pellets and zooplankton by the community. Meroplankton [eggs, larvae, etc, which settle to the bottom] dominated the imported zooplankton. (There was a net export of certain species of meroplankton however). Benthic algal fragments [from broken algae on the sea floor] constituted well over 50 per cent of the total organic matter in the samples."
"The work described here was carried out at Eniwetok Atoll, on a coral community studied extensively during Project Symbios in May and June of 1971."
"Large fragments of benthic [sea floor] algae are visible in the water over the reefs at Eniwetok. To examine the possibility that there was a net import of organic matter in this form by the coral community, we sampled with plankton nets placed upstream and downstream of the community. In addition to measuring the flux [movement] of algal fragments to and from the community by this method, we were also able to measure flux [movement] rates of other macroscopic material including individual species of zooplankton."
"The [zooplankton net] collectors were anchored in uni-directional currents on an inter-island reef [...] just north of Japtan Island. [...] Depth of the upstream and downstream stations at mean low water were 0.6 and 1.0 meters, respectively."
"The nets were anchored for 12 hour periods, corresponding to daylight and darkness between June 20 and June 27, 1971. [...] These measurements enabled us to calculate total volume transport across the [area] during our plankton collection periods. [...] Mean hourly current velocity ranged between 25 and 100 cm per second."
"Table 3. Relative weights of different types of net-caught plankton removed [eaten] by the coral community (percent of total net wet weight)"
"...................................June 20, day....June 21, day....June 21, night
Benthic algal fragments.....95.2................92.8...............57.5
Fecal pellets....................1.5.................6.5.................36.1
Meroplankton...................3.4.................0.1.................3.5
Holoplankton....................0.2.................0.1.................1.8
Fish eggs.......................-0.4.................0.4.................1.0 "
"There were consistent downstream decreases in concentration of particulate nitrogen, phosphorus and organic carbon, in the size ranges captured by the plankton nets. There was thus a consistent [overall] input of these materials [i.e., consumption] into the coral community."
"Benthic algal fragments constituted more than 90 percent (by wet weight) of the [overall] import of net-caught plankton by the coral community during the two days, and almost 60 percent during one night (Table 3). Fecal pellets constituted a minor form of input during the day, but 36 percent of the [overall] input at night."
"The fecal material ranged from about 0.1 mm to 1 cm in maximum dimension. The majority of intact fecal pellets were about 1mm long, and visually indistinguishable from those released by the larger copepods in our samples."
"Zooplankton constituted an average of only 3 percent of the [overall] input of net-caught plankton into the coral community (Table 3)."
"We have calculated the [overall] rate of removal [consumption] of zooplankton (including fish eggs) by the coral community using volume transport figures and data in Table 3. There was an hourly [overall] removal of 18.5 and 7.5 mg wet-weight of zooplankton per square meter. A much higher removal [consumption] rate of 47 mg (per square meter, per hour) was observed during the night of June 21."
"Benthic algal fragments [pieces of algae broken off from sea-floor] accounted for the bulk of the observed import of net-caught plankton (Table 3)."
"Blue-green algae [cyanobacteria] constituted over 95 percent of the drifting benthic algae in most net-caught plankton samples [taken by another researcher] at Laurel Reef, Puerto Rico."
"Benthic algal detritus [broken away from rocks and the sea floor] may be of widespread significance as an energy source in reef communities. [A previous researcher] believed it to be "the major contributor" of particulate organic carbon to the water over the reefs in Central Kaneohe Bay, Oahu, Hawaii."
"There was a rapid flux [movement] of zooplankton in and out of the reef community; several thousand individuals were consumed or released hourly, per square meter."
"Coral reef communities are apparently rather efficient at removing zooplankton from the water flowing past them. Mean numerical depletion of holoplankton [which does not settle to the bottom] in this study was 83 percent at night, and 55 percent during the day."
"This efficient removal of suspended particulate material from the water by reef communities may explain, in part, [the reef's] rather restricted width on atolls. Here the currents are more or less at right angles to the long axis of the reef, irrespective of location on the atoll (owing to wave refraction). Beyond a certain point, insufficient plankton may penetrate downstream [i.e., towards the shore] to support components of the reef community which feed primarily on this material."
"Because certain components of the plankton will be filtered out earlier than others as water crosses the reef, certain species [of coral] which feed upon plankton may drop out of the reef community for want of appropriate food, sooner than others, as one progresses [over the reef towards the shore]. Such an influence would contribute (along with various chemical and physical gradients) to the horizontal zonation observed in such reef communities."
"Conclusion:
1. There was a net import [consumption] of organic carbon, nitrogen, phosphorus, meroplankton [which settle to the floor], holoplankton [which does not settle to the floor] benthic algal detritus [mostly floating cyanobacteria particles], and fecal pellets in the net-caught plankton by an inter-island coral community at Eniwetok.
2. Benthic algal fragments [from broken cyanobacteria on rocks and the sea floor] outweighed all other imported components combined.
3. Several thousand meroplankters were exported, and several thousand holo- and meroplankters were imported, daily per square meter of the community.
4. Coral reef communities are efficient traps for net-caught plankton; this may contribute to "downstream" [closer to shore] changes in community composition, and the limited width of interisland atoll reef communities."
"Videos we like:
Plankton on sea floor, filmed by robot:
http://www.nauticvideo.com/Daisy Brittle Star.m1v
Acropora catching plankton:
http://www.youtube.com/watch?v=xtDGV5Er8aE
Fire coral catching plankton:
http://www.youtube.com/watch?v=Lpd5HRPKNAc "
Link (needs free account):
http://www.reefbase.org/download/download.aspx?type=10&docid=A0000002708_1
"Plankton nets were placed immediately upstream and downstream of a shallow inter-island coral community, in order to monitor the import and export of particulate material retained by a 60 micron [0.06 mm] mesh net. In this size range, there was an [overall] import [consumption] of organic carbon, nitrogen, phosphorus, benthic algal fragments, fecal pellets and zooplankton by the community. Meroplankton [eggs, larvae, etc, which settle to the bottom] dominated the imported zooplankton. (There was a net export of certain species of meroplankton however). Benthic algal fragments [from broken algae on the sea floor] constituted well over 50 per cent of the total organic matter in the samples."
"The work described here was carried out at Eniwetok Atoll, on a coral community studied extensively during Project Symbios in May and June of 1971."
"Large fragments of benthic [sea floor] algae are visible in the water over the reefs at Eniwetok. To examine the possibility that there was a net import of organic matter in this form by the coral community, we sampled with plankton nets placed upstream and downstream of the community. In addition to measuring the flux [movement] of algal fragments to and from the community by this method, we were also able to measure flux [movement] rates of other macroscopic material including individual species of zooplankton."
"The [zooplankton net] collectors were anchored in uni-directional currents on an inter-island reef [...] just north of Japtan Island. [...] Depth of the upstream and downstream stations at mean low water were 0.6 and 1.0 meters, respectively."
"The nets were anchored for 12 hour periods, corresponding to daylight and darkness between June 20 and June 27, 1971. [...] These measurements enabled us to calculate total volume transport across the [area] during our plankton collection periods. [...] Mean hourly current velocity ranged between 25 and 100 cm per second."
"Table 3. Relative weights of different types of net-caught plankton removed [eaten] by the coral community (percent of total net wet weight)"
"...................................June 20, day....June 21, day....June 21, night
Benthic algal fragments.....95.2................92.8...............57.5
Fecal pellets....................1.5.................6.5.................36.1
Meroplankton...................3.4.................0.1.................3.5
Holoplankton....................0.2.................0.1.................1.8
Fish eggs.......................-0.4.................0.4.................1.0 "
"There were consistent downstream decreases in concentration of particulate nitrogen, phosphorus and organic carbon, in the size ranges captured by the plankton nets. There was thus a consistent [overall] input of these materials [i.e., consumption] into the coral community."
"Benthic algal fragments constituted more than 90 percent (by wet weight) of the [overall] import of net-caught plankton by the coral community during the two days, and almost 60 percent during one night (Table 3). Fecal pellets constituted a minor form of input during the day, but 36 percent of the [overall] input at night."
"The fecal material ranged from about 0.1 mm to 1 cm in maximum dimension. The majority of intact fecal pellets were about 1mm long, and visually indistinguishable from those released by the larger copepods in our samples."
"Zooplankton constituted an average of only 3 percent of the [overall] input of net-caught plankton into the coral community (Table 3)."
"We have calculated the [overall] rate of removal [consumption] of zooplankton (including fish eggs) by the coral community using volume transport figures and data in Table 3. There was an hourly [overall] removal of 18.5 and 7.5 mg wet-weight of zooplankton per square meter. A much higher removal [consumption] rate of 47 mg (per square meter, per hour) was observed during the night of June 21."
"Benthic algal fragments [pieces of algae broken off from sea-floor] accounted for the bulk of the observed import of net-caught plankton (Table 3)."
"Blue-green algae [cyanobacteria] constituted over 95 percent of the drifting benthic algae in most net-caught plankton samples [taken by another researcher] at Laurel Reef, Puerto Rico."
"Benthic algal detritus [broken away from rocks and the sea floor] may be of widespread significance as an energy source in reef communities. [A previous researcher] believed it to be "the major contributor" of particulate organic carbon to the water over the reefs in Central Kaneohe Bay, Oahu, Hawaii."
"There was a rapid flux [movement] of zooplankton in and out of the reef community; several thousand individuals were consumed or released hourly, per square meter."
"Coral reef communities are apparently rather efficient at removing zooplankton from the water flowing past them. Mean numerical depletion of holoplankton [which does not settle to the bottom] in this study was 83 percent at night, and 55 percent during the day."
"This efficient removal of suspended particulate material from the water by reef communities may explain, in part, [the reef's] rather restricted width on atolls. Here the currents are more or less at right angles to the long axis of the reef, irrespective of location on the atoll (owing to wave refraction). Beyond a certain point, insufficient plankton may penetrate downstream [i.e., towards the shore] to support components of the reef community which feed primarily on this material."
"Because certain components of the plankton will be filtered out earlier than others as water crosses the reef, certain species [of coral] which feed upon plankton may drop out of the reef community for want of appropriate food, sooner than others, as one progresses [over the reef towards the shore]. Such an influence would contribute (along with various chemical and physical gradients) to the horizontal zonation observed in such reef communities."
"Conclusion:
1. There was a net import [consumption] of organic carbon, nitrogen, phosphorus, meroplankton [which settle to the floor], holoplankton [which does not settle to the floor] benthic algal detritus [mostly floating cyanobacteria particles], and fecal pellets in the net-caught plankton by an inter-island coral community at Eniwetok.
2. Benthic algal fragments [from broken cyanobacteria on rocks and the sea floor] outweighed all other imported components combined.
3. Several thousand meroplankters were exported, and several thousand holo- and meroplankters were imported, daily per square meter of the community.
4. Coral reef communities are efficient traps for net-caught plankton; this may contribute to "downstream" [closer to shore] changes in community composition, and the limited width of interisland atoll reef communities."
"Videos we like:
Plankton on sea floor, filmed by robot:
http://www.nauticvideo.com/Daisy Brittle Star.m1v
Acropora catching plankton:
http://www.youtube.com/watch?v=xtDGV5Er8aE
Fire coral catching plankton:
http://www.youtube.com/watch?v=Lpd5HRPKNAc "
Link (needs free account):
http://www.reefbase.org/download/download.aspx?type=10&docid=A0000002708_1
Attachments
"Reefers hopefully now have begun to understand how they can feed and filter their reef tanks using the exact same process that the ocean uses: Primary Production/Reduction. In the ocean, this process uses chlorophyll to "produce food" and "reduce nutrients" at the same time, which is why the top 300 feet of ocean water has the most food, but the lowest nutrients, of all the ocean water. But how does a reefer do such a thing in a reef tank?"
"Well, in the ocean, chlorophyll is contained mostly in the phytoplankton that covers the top 300 feet of depth of water (see attached graphics). But reef tanks are small in comparison to this depth, so the question becomes, can enough phytoplankton be grown in a typical reef tank, so that there is enough chlorophyll to do all the feeding and filtering for the amount of corals in the tanks? Let's look and see..."
"You could probably put about 10 average reef tank corals into a 1 gallon container. A typical 100 gallon reef tank has about 30 corals, so this would be about 10 gallons of corals. The live rock in a tank takes up volume too. 100 pounds of live rock would take up about 20 gallons. So in a 100 gallon reef tank, about one third (30 gallons) is taken up by rock and corals. This leaves 70 gallons of water to contain all the phytoplankton. Is this enough?"
"This answer is easy: No."
"Not even close. On a real reef, even at only 10 feet of depth, the corals have 10 feet of phytoplankton-rich water above them to do the filtering and feeding. And reefs, of course, go much deeper than that. So are there modifications that one could make to their tanks which would make it work? Well this is a brand new area of aquaria that has had almost no research done, and thus there are no studies to fall back on. So we will project from what is already known about the ocean."
"Filtering and feeding are done by chlorophyll "A", which is the material responsible for photosynthesis on the earth. The more chlorophyll "A" (which we will just call chlorophyll), the more filtering and feeding you get, as long as the chlorophyll gets enough light and water flow. In the ocean, chlorophyll is contained mostly in the planktonic diatom algae (phytoplankton) that float on the top 300 feet of depth. This phytoplankton is not packed very tight; if you filled an empty swimming pool with this water ten feet deep, it would look almost crystal clear (which is why reefs look crystal clear), because the phytoplankton is not very concentrated. But the ocean has several hundred feet of depth of this phytoplankton, and this lets the sun reach deep down into the water without being blocked. A reef tank has only about 30 inches of depth, yet has the same amount of corals per square foot on the bottom."
"One cell of chlorophyll produces the same amount of food, and reduces the same amount of nutrients, as another chlorophyll cell. The only difference is in how many cells of chlorophyll you have per unit volume. The ocean's chlorophyll concentration in the water column ("pelagic") is low, but it is very deep, and it covers the majority of the earth, so the total amount is huge. But the low concentration still lets the sun penetrate deep into the water."
"Any method that you can use to concentrate chlorophyll cells into a smaller and tighter volume will give you the same production/reduction in a smaller space, as long as it doesn't get too thick, since this would reduce the penetration of the light. In the ten-foot-deep swimming pool example, if you doubled the concentration of phytoplankton in the water, the water would start turning slightly green. But the sun would still be very strong even at the bottom of the pool, and thus you would get double the filtering and feeding in the same size (because of the doubled chlorophyll concentration). But what if you instead made the concentration ten times as much? Now the water would have a lot of green in it, and it would start blocking the light from reaching the bottom. So the bottom layers would not get much light, and you therefore would not get ten times the filtering/feeding, even though you have ten times the chlorophyll concentration."
"So how do you offset this light blockage, while still increasing chlorophyll concentration? One way is to make the water more shallow as you increase the concentration. If you increase the concentration ten times, but you make the water ten times shallower, you increase the concentration while reducing the depth at the same time (which allows the sun to still get all the way to the bottom.) In the swimming pool example, the depth would go from ten feet to one foot (12 inches). But it's still the same total amount of chlorophyll in the water. So you now have the same amount of filtering and feeding in 12 inches depth of water that you had in ten feet of water."
"What if you again reduced the depth another 12 times, but increased the chlorophyll 12 times? The amount of filtering and feeding would still be the same as the full swimming pool, but the water would only be one inch deep. The water would also be thick green, and it would block the light from going very far at all. But, the light only needs to go one inch deep."
"So the basic concept is: More concentration, but less thickness. As the concentration keeps increasing, the thickness keeps decreasing. Eventually you end up with chlorophyll so thick that it becomes a solid, and it blocks all light from going through it. This is what macro algae is."
"So considering all the concentrations and thicknesses that are possible, here are some general ideas for reefers to consider:"
"1. A Natural-Concentration Phytoplankton Reservoir: This is the easiest to understand, but the biggest and probably costliest solution to build. It actually would not be concentrated at all, and thus would require the same volume as the ocean in order to handle (for the same amount of production and reduction) a given amount of livestock. It would simply be an outdoor reservoir of some type, possibly with a clear cover to stop evaporation, and would have the same amount of water in it that the ocean would have for the amount of livestock that you were trying to feed and filter. A pond or a pool, as in the example above, comes to mind. 30,000 gallons might be a good start for a 100 gallon tank of corals. This has never been attempted or studied as far as we know, but might be a good test for someone with a pond that they can convert to salt."
"2. A High-Concentration Greenwater Tank: "Greenwater" is highly-concentrated phytoplankton. It is what commercial growers use to feed zooplankton, which then feed the baby (juvenile) fish or corals. It absorbs ("reduces") a great amount of nutrients in a much smaller volume than natural-strength seawater does, and it also feeds much more zooplankton than natural-strength seawater does. The high amount of nutrients, however, are manually fed to the phytoplankton, because "reduction of nutrients" is not a goal here; only feeding is. And feed it does. But a design problem arises when considering greenwater for use on a reef tank: You do not want greenwater in your tank, and you also do not want (nor do you have) the concentrated nutrients in your tank that are required to grow greenwater. So until an advancement is found which keeps the concentrated nutrients and phytoplankton in the greenwater tank (and out of the display tank), this route will be hard to follow."
"3. Macroalgae Growth, Exported: If a large enough tank of macro algae is grown and connected to the display tank, the amount of chlorophyll will be high enough to do all the filtering. Chlorophyll is ultra-concentrated in macro algae, which is why it is a solid green and not "clear" like ocean water. Many reefers currently use macro algae for this purpose, but do it on a scale that is much too small to do all the feeding. Some reefers do have enough to do all the filtering, because the removal ("export") of the macro algae takes the nutrients with it. But when the algae goes, so does the food production, which is why it is much harder to achieve feeding when you export. (Reefers thus compensate for this by feeding manually)"
"4. Massive Macroalgae Growth, Non-Exported: If a large enough tank of macro algae is grown and connected to the display tank, the amount of chlorophyll will be equal to the amount in hundreds of feet of ocean water. But by not exporting (removing) it, it functions exactly like it does in the ocean: It produces food, it reduces nutrients, and it slowly dies off in the darker areas as it is replaced by new growth in the brighter areas. If no manual feeding is done to your display tank, the amount of die-off will eventually equal the amount of new growth, and the system will be self-sustaining with no other filtering or feeding needed. Die-off, after all, feeds bacteria and corals directly; it's just another way that chlorophyll produces food from the sun. However since there is no export, you need massive amounts of chlorophyll in the macroalgae form, to counter-balance the die off. The exact size of such a macro algae tank cannot be recommended, because of the variables of flow and lighting and placement, etc. But when the size is sufficient, the reef tank will no longer need to be fed, or filtered, other than topping off evaporation."
"The attached picture show different levels of phytoplankton (pelagic) chlorophyll concentrations, getting thicker and thicker, until it becomes a sheet of solid (benthic) algae."
"Well, in the ocean, chlorophyll is contained mostly in the phytoplankton that covers the top 300 feet of depth of water (see attached graphics). But reef tanks are small in comparison to this depth, so the question becomes, can enough phytoplankton be grown in a typical reef tank, so that there is enough chlorophyll to do all the feeding and filtering for the amount of corals in the tanks? Let's look and see..."
"You could probably put about 10 average reef tank corals into a 1 gallon container. A typical 100 gallon reef tank has about 30 corals, so this would be about 10 gallons of corals. The live rock in a tank takes up volume too. 100 pounds of live rock would take up about 20 gallons. So in a 100 gallon reef tank, about one third (30 gallons) is taken up by rock and corals. This leaves 70 gallons of water to contain all the phytoplankton. Is this enough?"
"This answer is easy: No."
"Not even close. On a real reef, even at only 10 feet of depth, the corals have 10 feet of phytoplankton-rich water above them to do the filtering and feeding. And reefs, of course, go much deeper than that. So are there modifications that one could make to their tanks which would make it work? Well this is a brand new area of aquaria that has had almost no research done, and thus there are no studies to fall back on. So we will project from what is already known about the ocean."
"Filtering and feeding are done by chlorophyll "A", which is the material responsible for photosynthesis on the earth. The more chlorophyll "A" (which we will just call chlorophyll), the more filtering and feeding you get, as long as the chlorophyll gets enough light and water flow. In the ocean, chlorophyll is contained mostly in the planktonic diatom algae (phytoplankton) that float on the top 300 feet of depth. This phytoplankton is not packed very tight; if you filled an empty swimming pool with this water ten feet deep, it would look almost crystal clear (which is why reefs look crystal clear), because the phytoplankton is not very concentrated. But the ocean has several hundred feet of depth of this phytoplankton, and this lets the sun reach deep down into the water without being blocked. A reef tank has only about 30 inches of depth, yet has the same amount of corals per square foot on the bottom."
"One cell of chlorophyll produces the same amount of food, and reduces the same amount of nutrients, as another chlorophyll cell. The only difference is in how many cells of chlorophyll you have per unit volume. The ocean's chlorophyll concentration in the water column ("pelagic") is low, but it is very deep, and it covers the majority of the earth, so the total amount is huge. But the low concentration still lets the sun penetrate deep into the water."
"Any method that you can use to concentrate chlorophyll cells into a smaller and tighter volume will give you the same production/reduction in a smaller space, as long as it doesn't get too thick, since this would reduce the penetration of the light. In the ten-foot-deep swimming pool example, if you doubled the concentration of phytoplankton in the water, the water would start turning slightly green. But the sun would still be very strong even at the bottom of the pool, and thus you would get double the filtering and feeding in the same size (because of the doubled chlorophyll concentration). But what if you instead made the concentration ten times as much? Now the water would have a lot of green in it, and it would start blocking the light from reaching the bottom. So the bottom layers would not get much light, and you therefore would not get ten times the filtering/feeding, even though you have ten times the chlorophyll concentration."
"So how do you offset this light blockage, while still increasing chlorophyll concentration? One way is to make the water more shallow as you increase the concentration. If you increase the concentration ten times, but you make the water ten times shallower, you increase the concentration while reducing the depth at the same time (which allows the sun to still get all the way to the bottom.) In the swimming pool example, the depth would go from ten feet to one foot (12 inches). But it's still the same total amount of chlorophyll in the water. So you now have the same amount of filtering and feeding in 12 inches depth of water that you had in ten feet of water."
"What if you again reduced the depth another 12 times, but increased the chlorophyll 12 times? The amount of filtering and feeding would still be the same as the full swimming pool, but the water would only be one inch deep. The water would also be thick green, and it would block the light from going very far at all. But, the light only needs to go one inch deep."
"So the basic concept is: More concentration, but less thickness. As the concentration keeps increasing, the thickness keeps decreasing. Eventually you end up with chlorophyll so thick that it becomes a solid, and it blocks all light from going through it. This is what macro algae is."
"So considering all the concentrations and thicknesses that are possible, here are some general ideas for reefers to consider:"
"1. A Natural-Concentration Phytoplankton Reservoir: This is the easiest to understand, but the biggest and probably costliest solution to build. It actually would not be concentrated at all, and thus would require the same volume as the ocean in order to handle (for the same amount of production and reduction) a given amount of livestock. It would simply be an outdoor reservoir of some type, possibly with a clear cover to stop evaporation, and would have the same amount of water in it that the ocean would have for the amount of livestock that you were trying to feed and filter. A pond or a pool, as in the example above, comes to mind. 30,000 gallons might be a good start for a 100 gallon tank of corals. This has never been attempted or studied as far as we know, but might be a good test for someone with a pond that they can convert to salt."
"2. A High-Concentration Greenwater Tank: "Greenwater" is highly-concentrated phytoplankton. It is what commercial growers use to feed zooplankton, which then feed the baby (juvenile) fish or corals. It absorbs ("reduces") a great amount of nutrients in a much smaller volume than natural-strength seawater does, and it also feeds much more zooplankton than natural-strength seawater does. The high amount of nutrients, however, are manually fed to the phytoplankton, because "reduction of nutrients" is not a goal here; only feeding is. And feed it does. But a design problem arises when considering greenwater for use on a reef tank: You do not want greenwater in your tank, and you also do not want (nor do you have) the concentrated nutrients in your tank that are required to grow greenwater. So until an advancement is found which keeps the concentrated nutrients and phytoplankton in the greenwater tank (and out of the display tank), this route will be hard to follow."
"3. Macroalgae Growth, Exported: If a large enough tank of macro algae is grown and connected to the display tank, the amount of chlorophyll will be high enough to do all the filtering. Chlorophyll is ultra-concentrated in macro algae, which is why it is a solid green and not "clear" like ocean water. Many reefers currently use macro algae for this purpose, but do it on a scale that is much too small to do all the feeding. Some reefers do have enough to do all the filtering, because the removal ("export") of the macro algae takes the nutrients with it. But when the algae goes, so does the food production, which is why it is much harder to achieve feeding when you export. (Reefers thus compensate for this by feeding manually)"
"4. Massive Macroalgae Growth, Non-Exported: If a large enough tank of macro algae is grown and connected to the display tank, the amount of chlorophyll will be equal to the amount in hundreds of feet of ocean water. But by not exporting (removing) it, it functions exactly like it does in the ocean: It produces food, it reduces nutrients, and it slowly dies off in the darker areas as it is replaced by new growth in the brighter areas. If no manual feeding is done to your display tank, the amount of die-off will eventually equal the amount of new growth, and the system will be self-sustaining with no other filtering or feeding needed. Die-off, after all, feeds bacteria and corals directly; it's just another way that chlorophyll produces food from the sun. However since there is no export, you need massive amounts of chlorophyll in the macroalgae form, to counter-balance the die off. The exact size of such a macro algae tank cannot be recommended, because of the variables of flow and lighting and placement, etc. But when the size is sufficient, the reef tank will no longer need to be fed, or filtered, other than topping off evaporation."
"The attached picture show different levels of phytoplankton (pelagic) chlorophyll concentrations, getting thicker and thicker, until it becomes a sheet of solid (benthic) algae."
Attachments
"Dissolved Nutrients and Organic Particulates in Water Flowing Over Coral Reefs at Lizard Island [Great Barrier Reef]. Australian Journal of Marine and Freshwater Research, 1983"
"Coral reefs have often been considered as areas of high primary productivity associated with unproductive waters that are poor in dissolved and particulate nutrients. This view arose because studies of nutrients and productivity on coral reefs originally centered on oceanic atolls, rather than on reefs associated with high islands and large land masses. These studies suggested that the high benthic (sea floor) productivity of the reefs was maintained, despite low nutrient concentrations in surrounding waters, because of benthic nitrogen fixation and because of tight cycling of phosphorus. On such atolls, nitrogen and organic carbon are transported from the windward reefs to the lagoon, especially as bacteria, mucus and detrital [waste] material. The atolls may be regarded as minor sinks for phosphorus, and net exporters of small amounts of carbon and nitrogen."
"The view that coral reefs are oases in a nutrient desert is becoming less generally supportable. Upwellings [high-nutrient water coming from the deep ocean], terrestrial runoff , and inputs from groundwater, increase the levels of inorganic nutrients in waters surrounding many coral reefs, well above the levels characteristic of tropical oceanic waters. At Canton Atoll and Tarawa Atoll, the biota, especially the lagoonal biota, acts as a sink for nitrate and phosphorus introduced into surrounding waters by equatorial upwelling."
"[Note: The above is the opposite of what most reefers believe. Reefers tend to think that the ocean is providing ongoing 'waterchanges' to the reef. In reality, upwellings sometimes bring nutrients into the reef, and the reef has to reduce them with 'primary reduction']"
"[Text from Fig 2] Windward reef zonation:
I: Coral coverage to 50 percent, mostly as Acropora spp., grading to encrusting calcareous algae towards the reef crest.
II: Hard substrate covered by Marginopora vertebralis sand.
III: Small rubble with a thin algal 'slime' on sand amongst the rubble.
IV: 30-40 cm diameter, closely packed rubble bearing hard and soft corals and separated by sand covered by an algal mat
V: Large rubble bearing hard and soft corals, and filamentous brown algae; rubble widely separated by sand covered by algal 'slime'.
VI: Sand with occasional small 'bommies', and towards the rear, coral patches.
Leeward reef zonation:
I: Sand with slight algal 'slime'.
II: Reef edge of large rounded Porites spp., soft corals and Acropora spp. behind the edge grading to dense, 30-40 cm diameter rubble covered by algal 'turf'.
III: Scattered rubble with hard and soft corals covering 50-60 percent of substrate, and with sand between.
IV: Large rubble bearing hard corals on sides, and soft corals on top, sand between with 60-70 percent cover by algal 'slime'.
V: Sand with 90 percent cover by heavy algal slime, occasional large coral boulders.
VI: Raised band of hard substrate covered by algal turf and encrusting algae.
VII: Sand with 40-50 percent algal 'slime' cover, and with occasional coral boulders.
VIII: Large, flat-topped coral 'bommies' dominated by hard corals and grading into...
IX: Scoured sand and small rubble 'with' Halimeda spp. and occasional soft corals, and very thick algal 'slime' on the sand."
"In this study, part of the LIMER II expedition of 1977, dissolved organic and particulate organic nutrient distribution, and changes in waters of the Lizard Island reef system, are described. Lizard Island, in the northern sector of the Great Barrier Reef (GBR), is a nonoceanic high island about 15 km from the Australian mainland. The coral reefs at Lizard Island are bathed by waters of the GBR lagoon which, compared with tropical oceanic waters, contain relatively high levels of dissolved nutrients. Data are presented to show the characteristics of nutrient concentrations and changes over the 4-week study period."
"The [testing] stations at the windward reef front were significantly lower in nitrate than the station at the rear of the windward reef flat. This enrichment of water-column nitrate by the windward reef flat confirms earlier results. However, nitrate values of the leeward reef were not significantly different from those offshore. Thus, nitrate produced by the windward reef was either consumed [reduced] in the lagoon, or diluted by offshore water entering the lagoon through the channel."
"Analysis of nutrient concentrations on the two reef flats showed significantly greater levels of NH4, POC and PON [particles] in waters over the leeward reef flat. The concentrations of NH4, POC and PON increased within the lagoon, and were further elevated by the front region of the leeward reef [areas]. The decreased POC/PON ratio on the leeward reef compared with the windward reef indicates nitrogen enrichment of organic particulates in lagoonal waters."
"Our data suggest that the Lizard Island reef complex, as a whole, does not consume or export statistically significant amounts of inorganic nitrogen, phosphorus, silicate, organic carbon and organic nitrogen [meaning, these nutrients are created and reduced all in the same reef area, without much help from outside water]. However, the nutrient levels of portions of the reef complex do alter as water flows across the reef. Such alterations were apparent in dissolved inorganic nitrogen and POC and PON. Thus, nitrate exported into the lagoon by the windward reef was not reflected in nitrate levels over the leeward reef. Also, elevated levels of NH4, POC and PON in water moving onto the leeward reef were decreased significantly before the water left the reef. Lowered dissolved nitrogen concentrations and elevated POC concentrations in waters moving across or along the windward reef front were not maintained once water passed onto the windward reef flat. The data suggest that depletion or elevation of nutrient levels in one benthic zone or compartment is balanced by changes in downstream zones or compartments, with the result that there is little or no net influx or efflux for the reef complex as a whole [i.e., no 'water changes']."
"The lagoon appears to play an important role in nutrient balance across the reef complex. However, lack of information about sources of lagoon water and residency time make it difficult to fully assess this role. Nitrate exported by the windward reef flat decreases [reduces] in the lagoon. Relatively high concentrations of NH4 ( >100 uM ) are found in interstitial waters of lagoon sediments, and it has been suggested that lagoonal biota take up and store NH4-N that escapes from the sediments. Certainly, NH4 appears to be exported from the lagoon to the leeward reef. Lagoonal processes also appear to result in the enrichment of organic particulates with nitrogen, although the lower C/N values observed over the leeward reef could be the result of consumption of nitrogen-poor particles and production of nitrogen-rich particles in the lagoon."
"The nutrient levels measured in Lizard Island waters are of similar magnitude to those measured elsewhere in the Great Barrier Reef lagoon."
"The variability in data for stations outside the reefs is reflected by variability in data for stations across the reefs, because the reefs did not appear to make large demands upon the relatively high levels of nutrients flowing onto them. Consequently, except for nitrate, our data show no statistically significant alteration of nutrient levels as water crossed the reef flats."
"Upwelling video:
http://www.youtube.com/watch?v=ea58XTelyGs
Old classic video about plankton:
http://www.youtube.com/watch?v=443qQnUX3VI
Family-friendly plankton video:
http://www.youtube.com/watch?v=42Mw93mZkE4 "
link:
http://www.publish.csiro.au/?paper=MF9830835
"Coral reefs have often been considered as areas of high primary productivity associated with unproductive waters that are poor in dissolved and particulate nutrients. This view arose because studies of nutrients and productivity on coral reefs originally centered on oceanic atolls, rather than on reefs associated with high islands and large land masses. These studies suggested that the high benthic (sea floor) productivity of the reefs was maintained, despite low nutrient concentrations in surrounding waters, because of benthic nitrogen fixation and because of tight cycling of phosphorus. On such atolls, nitrogen and organic carbon are transported from the windward reefs to the lagoon, especially as bacteria, mucus and detrital [waste] material. The atolls may be regarded as minor sinks for phosphorus, and net exporters of small amounts of carbon and nitrogen."
"The view that coral reefs are oases in a nutrient desert is becoming less generally supportable. Upwellings [high-nutrient water coming from the deep ocean], terrestrial runoff , and inputs from groundwater, increase the levels of inorganic nutrients in waters surrounding many coral reefs, well above the levels characteristic of tropical oceanic waters. At Canton Atoll and Tarawa Atoll, the biota, especially the lagoonal biota, acts as a sink for nitrate and phosphorus introduced into surrounding waters by equatorial upwelling."
"[Note: The above is the opposite of what most reefers believe. Reefers tend to think that the ocean is providing ongoing 'waterchanges' to the reef. In reality, upwellings sometimes bring nutrients into the reef, and the reef has to reduce them with 'primary reduction']"
"[Text from Fig 2] Windward reef zonation:
I: Coral coverage to 50 percent, mostly as Acropora spp., grading to encrusting calcareous algae towards the reef crest.
II: Hard substrate covered by Marginopora vertebralis sand.
III: Small rubble with a thin algal 'slime' on sand amongst the rubble.
IV: 30-40 cm diameter, closely packed rubble bearing hard and soft corals and separated by sand covered by an algal mat
V: Large rubble bearing hard and soft corals, and filamentous brown algae; rubble widely separated by sand covered by algal 'slime'.
VI: Sand with occasional small 'bommies', and towards the rear, coral patches.
Leeward reef zonation:
I: Sand with slight algal 'slime'.
II: Reef edge of large rounded Porites spp., soft corals and Acropora spp. behind the edge grading to dense, 30-40 cm diameter rubble covered by algal 'turf'.
III: Scattered rubble with hard and soft corals covering 50-60 percent of substrate, and with sand between.
IV: Large rubble bearing hard corals on sides, and soft corals on top, sand between with 60-70 percent cover by algal 'slime'.
V: Sand with 90 percent cover by heavy algal slime, occasional large coral boulders.
VI: Raised band of hard substrate covered by algal turf and encrusting algae.
VII: Sand with 40-50 percent algal 'slime' cover, and with occasional coral boulders.
VIII: Large, flat-topped coral 'bommies' dominated by hard corals and grading into...
IX: Scoured sand and small rubble 'with' Halimeda spp. and occasional soft corals, and very thick algal 'slime' on the sand."
"In this study, part of the LIMER II expedition of 1977, dissolved organic and particulate organic nutrient distribution, and changes in waters of the Lizard Island reef system, are described. Lizard Island, in the northern sector of the Great Barrier Reef (GBR), is a nonoceanic high island about 15 km from the Australian mainland. The coral reefs at Lizard Island are bathed by waters of the GBR lagoon which, compared with tropical oceanic waters, contain relatively high levels of dissolved nutrients. Data are presented to show the characteristics of nutrient concentrations and changes over the 4-week study period."
"The [testing] stations at the windward reef front were significantly lower in nitrate than the station at the rear of the windward reef flat. This enrichment of water-column nitrate by the windward reef flat confirms earlier results. However, nitrate values of the leeward reef were not significantly different from those offshore. Thus, nitrate produced by the windward reef was either consumed [reduced] in the lagoon, or diluted by offshore water entering the lagoon through the channel."
"Analysis of nutrient concentrations on the two reef flats showed significantly greater levels of NH4, POC and PON [particles] in waters over the leeward reef flat. The concentrations of NH4, POC and PON increased within the lagoon, and were further elevated by the front region of the leeward reef [areas]. The decreased POC/PON ratio on the leeward reef compared with the windward reef indicates nitrogen enrichment of organic particulates in lagoonal waters."
"Our data suggest that the Lizard Island reef complex, as a whole, does not consume or export statistically significant amounts of inorganic nitrogen, phosphorus, silicate, organic carbon and organic nitrogen [meaning, these nutrients are created and reduced all in the same reef area, without much help from outside water]. However, the nutrient levels of portions of the reef complex do alter as water flows across the reef. Such alterations were apparent in dissolved inorganic nitrogen and POC and PON. Thus, nitrate exported into the lagoon by the windward reef was not reflected in nitrate levels over the leeward reef. Also, elevated levels of NH4, POC and PON in water moving onto the leeward reef were decreased significantly before the water left the reef. Lowered dissolved nitrogen concentrations and elevated POC concentrations in waters moving across or along the windward reef front were not maintained once water passed onto the windward reef flat. The data suggest that depletion or elevation of nutrient levels in one benthic zone or compartment is balanced by changes in downstream zones or compartments, with the result that there is little or no net influx or efflux for the reef complex as a whole [i.e., no 'water changes']."
"The lagoon appears to play an important role in nutrient balance across the reef complex. However, lack of information about sources of lagoon water and residency time make it difficult to fully assess this role. Nitrate exported by the windward reef flat decreases [reduces] in the lagoon. Relatively high concentrations of NH4 ( >100 uM ) are found in interstitial waters of lagoon sediments, and it has been suggested that lagoonal biota take up and store NH4-N that escapes from the sediments. Certainly, NH4 appears to be exported from the lagoon to the leeward reef. Lagoonal processes also appear to result in the enrichment of organic particulates with nitrogen, although the lower C/N values observed over the leeward reef could be the result of consumption of nitrogen-poor particles and production of nitrogen-rich particles in the lagoon."
"The nutrient levels measured in Lizard Island waters are of similar magnitude to those measured elsewhere in the Great Barrier Reef lagoon."
"The variability in data for stations outside the reefs is reflected by variability in data for stations across the reefs, because the reefs did not appear to make large demands upon the relatively high levels of nutrients flowing onto them. Consequently, except for nitrate, our data show no statistically significant alteration of nutrient levels as water crossed the reef flats."
"Upwelling video:
http://www.youtube.com/watch?v=ea58XTelyGs
Old classic video about plankton:
http://www.youtube.com/watch?v=443qQnUX3VI
Family-friendly plankton video:
http://www.youtube.com/watch?v=42Mw93mZkE4 "
link:
http://www.publish.csiro.au/?paper=MF9830835
Attachments
jerseyhokie
New member
Gary, youve been a strong advocate of the difference in a closed system. Would the best poential result be to introduce fresh dead plankton continuously? What if you ran a drip through a UV sterilizer to kill it and then allowed it to drift through the tank before being filtered back out.
Im guessing this will be:
A. Highly inefficient
B. Accumulate too quickly
Im guessing this will be:
A. Highly inefficient
B. Accumulate too quickly
Phyto is not a viable method for nitrate removal in aquaria. Nitrate isn't the only thing it needs and the amount it would uptake in your tank would be barely noticeable... unless your tank was a dense phyto culture, but then there would be no light for anything else.... Dense cultures can hit a PH of 12, corals and fish do not really like a PH of 12!!
"Primary production and calcium carbonate deposition rates in Acropora palmata from different positions in the reef. Third International Coral Reef Symposium, May 1977"
"[Note: The primary production of corals, described in this study, is not related to the primary production/reduction of the phytoplankton we have described previously. They both use algae, but the purpose is entirely different.]"
"Calcium carbonate deposition rates, skeletal extension [growth] rates, and primary production [of zoothanthellae, not phytoplankton] were determined for colonies of Acropora palmata growing in three different zones on a bank barrier reef east of Buck Island, St. Croix, U.S. Virgin Islands."
"For each site, we have described the typical morphologic form, determined the total calcification rate of the coral, and measured the primary productivity of the corals."
"This study was conducted at Buck Island Reef National Monument, located a half mile north of St. Croix, U.S. Virgin Islands. The immediate site of the study was a bank barrier reef dominated by Acropora palmata which encircles the eastern half of the island. Three sites were used, at the eastern tip of the reef: the shallow fore-reef and back-reef [...] were done on corals growing from .5 to 1 meter below the water's surface, while the deep fore-reef corals were growing at a depth of 8 to 10 meters below the surface."
"On August 3 and 5, 1976, colonies of Acropora palmata were stained in the field by scuba divers [...]. The dye is deposited in the coral during the calcification process, and remains as a permanent line in the skeleton. Growth after this date can then be measured as a linear extension from this mark along the polyp axes."
"Linear extension [growth] of the skeletons was greatest in colonies from the deep fore-reef [which has the least light], followed by those from the shallow fore-reef. Back-reef colonies had the smallest skeletal extension rate (Table 1)."
"Table 1: Mean skeletal extension rates of Acropora Palmata from three positions on the reef [simplified]
..........................Skeletal Extension (mm per 30 days)
Back-reef..............4.82 [2.3 inches per year]
Deep fore-reef.......8.32 [4 inches per year]
shallow fore-reef....6.33 [3 inches per year]"
"The deep fore-reef corals received about 50 to 60 percent the amount of [light] of that of the shallower forms [...] during peak hours of light, but during a 24 hour period, this percentage is probably less."
"[A previous study] reported that in nature, the relationship between calcium deposition and photosynthetic rate [of zoothanthellae, not phytoplankton] is not linear, and that rates of calcification at greater depths did not decrease as much as may have been anticipated from the [lower] photosynthetic rates and ambient light energy. [Another researcher] found that deeper growing corals (both within and between species) are more efficient photosynthetic units than shallower colonies are."
"When the light intensity was the same, the net rate of primary production [of the zoothanthellae in the coral] was higher for shallow fore-reef corals than for that of the back-reef. [...] The deep fore-reef corals have the lowest rate of primary production [because of the low light], but it should be noted that while they are receiving about 50 to 60 percent of the light available to the shallower dwelling corals, their average rate of gross primary production is 76 percent that of the shallow fore-reef, and 87 percent that of the back-reef rate. [...] When we consider calcification rate related to light intensity, a different picture emerges. [A previous study] stated that in some corals there is a [movement] of photosynthate from the zooxanthellae to the coral tissue. If this supplies a source of matrix material or a source of energy for the calcification process, the rate of calcification would be expected to increase when more photosynthate is produced (i.e., the higher the rate of prductivity)."
"Under similar light intensities, the rate of calcification of the shallow fore-reef corals is greater than that of the back-reef corals. This supports the hypothesis; since the shallow fore-reef corals have a higher rate of primary production, more photosynthate is produced and the rate of calcification is in fact greater. However, the deep fore-reef corals do not fit this pattern. The amount of [light] at this site was about half of that received by the shallow dwelling corals. The rate of primary production is the least. But the rate of calcification is intermediate between the high seen in the shallow fore-reef, and the low seen in the back-reef coral. [A previous study] observed that in three species of corals in the Red Sea, that calcification rates did not directly correlate with light intensity or photosynthetic rate. We feel that light is not the only factor which determines the rate of calcification in this coral on the reef over its normal depth range. Comparing calcification rates from the back-reef with those of the deep fore-reef, it can be seen that this coral can calcify at a greater rate in lower light intensities, even when the rate of primary production is lower."
"We believe the answer lies in the alternative sources of nutrition for the coral. [A previous study] has shown that many reef corals function as ciliary-mucoid suspension feeders. [...] In addition, polyps are extended during the daylight hours, although no actual capture of plankton has been seen. Plankton, and probably particulate detrital [waste] material, are more abundant on the fore-reef than the back-reef, as determined by student plankton studies. Also, the overwhelming majority of planktivorous fishes (diurnal, blue and brown chromis; nocturnal, cardinalfishes, big-eyes, sweepers, etc.) are observed feeding [and producing waste] on the fore-reef."
"If a heterotrophic [food] source of nutrition is important for Acropora palmata, and is utilized when available, and if it is more available to fore-reef than back-reef corals, then the differences in rate of calcification have an alternative explanation. The shallow fore-reef corals can depend on two sources of nutrition: a high rate of primary production [from the sun], and a source of heterotrophic nutrition [food]. Thus, its rate of calcification is the greatest. The deep fore-reef coral has the lowest rate of primary production [from the sun] but it can depend to a large part on a heterotrophic source of nutrition [food]. Thus, it can still maintain a moderately high rate of calcification. The back-reef corals have an intermediate level of primary production [from the sun], but probably receive very little supplemental heterotrophic nutrition [food] and thus have the lowest rate of calcification."
"Corals eating:
http://www.youtube.com/watch?v=KSb8_zYjNcc
http://www.youtube.com/watch?v=3KuFLUzrcfQ "
link:
http://www.reefbase.org/download/download.aspx?type=10&docid=8993
"[Note: The primary production of corals, described in this study, is not related to the primary production/reduction of the phytoplankton we have described previously. They both use algae, but the purpose is entirely different.]"
"Calcium carbonate deposition rates, skeletal extension [growth] rates, and primary production [of zoothanthellae, not phytoplankton] were determined for colonies of Acropora palmata growing in three different zones on a bank barrier reef east of Buck Island, St. Croix, U.S. Virgin Islands."
"For each site, we have described the typical morphologic form, determined the total calcification rate of the coral, and measured the primary productivity of the corals."
"This study was conducted at Buck Island Reef National Monument, located a half mile north of St. Croix, U.S. Virgin Islands. The immediate site of the study was a bank barrier reef dominated by Acropora palmata which encircles the eastern half of the island. Three sites were used, at the eastern tip of the reef: the shallow fore-reef and back-reef [...] were done on corals growing from .5 to 1 meter below the water's surface, while the deep fore-reef corals were growing at a depth of 8 to 10 meters below the surface."
"On August 3 and 5, 1976, colonies of Acropora palmata were stained in the field by scuba divers [...]. The dye is deposited in the coral during the calcification process, and remains as a permanent line in the skeleton. Growth after this date can then be measured as a linear extension from this mark along the polyp axes."
"Linear extension [growth] of the skeletons was greatest in colonies from the deep fore-reef [which has the least light], followed by those from the shallow fore-reef. Back-reef colonies had the smallest skeletal extension rate (Table 1)."
"Table 1: Mean skeletal extension rates of Acropora Palmata from three positions on the reef [simplified]
..........................Skeletal Extension (mm per 30 days)
Back-reef..............4.82 [2.3 inches per year]
Deep fore-reef.......8.32 [4 inches per year]
shallow fore-reef....6.33 [3 inches per year]"
"The deep fore-reef corals received about 50 to 60 percent the amount of [light] of that of the shallower forms [...] during peak hours of light, but during a 24 hour period, this percentage is probably less."
"[A previous study] reported that in nature, the relationship between calcium deposition and photosynthetic rate [of zoothanthellae, not phytoplankton] is not linear, and that rates of calcification at greater depths did not decrease as much as may have been anticipated from the [lower] photosynthetic rates and ambient light energy. [Another researcher] found that deeper growing corals (both within and between species) are more efficient photosynthetic units than shallower colonies are."
"When the light intensity was the same, the net rate of primary production [of the zoothanthellae in the coral] was higher for shallow fore-reef corals than for that of the back-reef. [...] The deep fore-reef corals have the lowest rate of primary production [because of the low light], but it should be noted that while they are receiving about 50 to 60 percent of the light available to the shallower dwelling corals, their average rate of gross primary production is 76 percent that of the shallow fore-reef, and 87 percent that of the back-reef rate. [...] When we consider calcification rate related to light intensity, a different picture emerges. [A previous study] stated that in some corals there is a [movement] of photosynthate from the zooxanthellae to the coral tissue. If this supplies a source of matrix material or a source of energy for the calcification process, the rate of calcification would be expected to increase when more photosynthate is produced (i.e., the higher the rate of prductivity)."
"Under similar light intensities, the rate of calcification of the shallow fore-reef corals is greater than that of the back-reef corals. This supports the hypothesis; since the shallow fore-reef corals have a higher rate of primary production, more photosynthate is produced and the rate of calcification is in fact greater. However, the deep fore-reef corals do not fit this pattern. The amount of [light] at this site was about half of that received by the shallow dwelling corals. The rate of primary production is the least. But the rate of calcification is intermediate between the high seen in the shallow fore-reef, and the low seen in the back-reef coral. [A previous study] observed that in three species of corals in the Red Sea, that calcification rates did not directly correlate with light intensity or photosynthetic rate. We feel that light is not the only factor which determines the rate of calcification in this coral on the reef over its normal depth range. Comparing calcification rates from the back-reef with those of the deep fore-reef, it can be seen that this coral can calcify at a greater rate in lower light intensities, even when the rate of primary production is lower."
"We believe the answer lies in the alternative sources of nutrition for the coral. [A previous study] has shown that many reef corals function as ciliary-mucoid suspension feeders. [...] In addition, polyps are extended during the daylight hours, although no actual capture of plankton has been seen. Plankton, and probably particulate detrital [waste] material, are more abundant on the fore-reef than the back-reef, as determined by student plankton studies. Also, the overwhelming majority of planktivorous fishes (diurnal, blue and brown chromis; nocturnal, cardinalfishes, big-eyes, sweepers, etc.) are observed feeding [and producing waste] on the fore-reef."
"If a heterotrophic [food] source of nutrition is important for Acropora palmata, and is utilized when available, and if it is more available to fore-reef than back-reef corals, then the differences in rate of calcification have an alternative explanation. The shallow fore-reef corals can depend on two sources of nutrition: a high rate of primary production [from the sun], and a source of heterotrophic nutrition [food]. Thus, its rate of calcification is the greatest. The deep fore-reef coral has the lowest rate of primary production [from the sun] but it can depend to a large part on a heterotrophic source of nutrition [food]. Thus, it can still maintain a moderately high rate of calcification. The back-reef corals have an intermediate level of primary production [from the sun], but probably receive very little supplemental heterotrophic nutrition [food] and thus have the lowest rate of calcification."
"Corals eating:
http://www.youtube.com/watch?v=KSb8_zYjNcc
http://www.youtube.com/watch?v=3KuFLUzrcfQ "
link:
http://www.reefbase.org/download/download.aspx?type=10&docid=8993
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