Nope. Your typical commercially made gill net is either monofilament or nylon multifilament with poly rope for the header and footer lines. Takes a nice long time for that stuff to decay.
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Nope. Your typical commercially made gill net is either monofilament or nylon multifilament with poly rope for the header and footer lines. Takes a nice long time for that stuff to decay.
That sucks. Probably turns into bits of nylon that end up floating into dead spots in oceanic gyres.
Yup, right along with the other bits of plastic.
Last year a friend of mine showed me a sample from a plankton tow in the Sargasso Sea. Along with the typical Sargasso sea weed and it's associated fauna, was an incredible amount of plastic debris. For an interesting contrast, I've a similar sample that I collected myself in 1986, no plastic at all.
Last year a friend of mine showed me a sample from a plankton tow in the Sargasso Sea. Along with the typical Sargasso sea weed and it's associated fauna, was an incredible amount of plastic debris. For an interesting contrast, I've a similar sample that I collected myself in 1986, no plastic at all.
philosophile
New member
I've always wondered why everyone is so very worried about the plastic garbage gyres in the ocean. Sure they are disconcerting... but I haven't heard much in the way of actual impact that they would have on marine life. Not to say that we should throw our plastic into the ocean, but since its been decades, you'd think we'd be able to see some kind of negative affect, if there is any at all.
Visually these garbage gyres aren't distinguishable from any other patch of the ocean. Filter feeders like whales would swallow them up and poop them out just like we would if we ate a mouthful of plastic.
I haven't done much to look into this issue, but thought maybe someone else might know.
Visually these garbage gyres aren't distinguishable from any other patch of the ocean. Filter feeders like whales would swallow them up and poop them out just like we would if we ate a mouthful of plastic.
I haven't done much to look into this issue, but thought maybe someone else might know.
Well, for one thing it's garbage that we put into the ocean. It takes a few minutes to make the plastic, and decades to break it down into it's component chemicals. There could be chemical compounds in the plastic, fluorocarbons, etc. that are detrimental to the ocean's health. Just because it appears inert to us, doesn't mean it truly is inert.
greenbean36191
Premium Member
There are lots of reasons it's a concern.
First of all, there's the role of plastics in introducing and accumulating toxins in the food chain. Some ingredients in plastics can leach out in water and interfere with the hormones of fish and inverts, rendering them sterile. Plastics are also good at adsorbing pesticides and other toxins in the water. Those are both bad news for oceanic species because in some areas of the gyres plastic bits are more abundant than plankton. Filter feeders like manta rays or whale sharks can get a stomach full of toxin-frosted plastic flakes and possibly suffer from chronic toxicity. Other critters can also mistake the small bits of plastic for real plankton and eat them. While the toxicity often isn't enough to kill the organisms that eat the plastic outright, they do absorb the toxins from it and can then accumulate it up the food chain just like mercury or DDT.
Sea birds also seem to be fond of eating plastic debris, which they then take back and feed their chicks. The chicks end up getting so much plastic in their stomachs that there's no room for real food and they starve to death. In some rookeries almost every dead chick has a stomach full of plastic.
When the plastic is old fishing gear like rope, tangled monofilament, or old nets it's bad news because floating debris in the open ocean attracts oceanic species. The old gear poses a major entanglement risk to any animals that get near it. Anything that gets caught in it, be it a fish, turtle, or mammal will drown in short order.
First of all, there's the role of plastics in introducing and accumulating toxins in the food chain. Some ingredients in plastics can leach out in water and interfere with the hormones of fish and inverts, rendering them sterile. Plastics are also good at adsorbing pesticides and other toxins in the water. Those are both bad news for oceanic species because in some areas of the gyres plastic bits are more abundant than plankton. Filter feeders like manta rays or whale sharks can get a stomach full of toxin-frosted plastic flakes and possibly suffer from chronic toxicity. Other critters can also mistake the small bits of plastic for real plankton and eat them. While the toxicity often isn't enough to kill the organisms that eat the plastic outright, they do absorb the toxins from it and can then accumulate it up the food chain just like mercury or DDT.
Sea birds also seem to be fond of eating plastic debris, which they then take back and feed their chicks. The chicks end up getting so much plastic in their stomachs that there's no room for real food and they starve to death. In some rookeries almost every dead chick has a stomach full of plastic.
When the plastic is old fishing gear like rope, tangled monofilament, or old nets it's bad news because floating debris in the open ocean attracts oceanic species. The old gear poses a major entanglement risk to any animals that get near it. Anything that gets caught in it, be it a fish, turtle, or mammal will drown in short order.
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Just talk to anyone in the business of rescue and rehab of marine life such as sea turtles. Often the plastic gets eaten. However, it doesn't just pass through like you think, it causes gut impaction
Eat enough plastic, the same would happen to you. BTW, for anyone with any amount of sea time, the visual impact of the plastic is quite noticable...and that's not just in the gyre's. Heck, just walking the beach I've seen huge changes in the debris that washes up. there is no such thing as pristine coast line anymore. I've seen plastic and old nets washed up on remote islands as well as ones close to civilization.
philosophile
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Okay, I know that plastic in large pieces are harmful for sealife, as most of you have pointed out, but the plastic in the ocean gyres are pretty small. Also they're pretty far out in the open ocean. AFAIK open oceans don't have a ton of fish, so the likelihood of fish, or manta rays, etc. eating these pieces of plastic is pretty low.
I'm not saying we should throw plastic into the oceans. I think thats wrong. But so much is being said about these gyres in the Pacific and Atlantic, as if they are a horrible stew of death, when I don't see much evidence to be concerned about them at all. They are symptomatic of what we do to the oceans, since the plastic we throw into it, breaks down into smaller pieces and create the gyres, but the gyres are also made up of plenty of plastic beads that manufacturers use to create plastic products. So its not just our plastic garbage that is to blame for the gyres themselves.
I've heard about the toxins like pesticides and such before. Does the plastic absorb the toxins from the ocean water? When fish ingest the plastic, do the pesticides stay within the plastic, or do they then leach out into the fish?
I'm just not privy enough to all the research to create an informed opinion about the gyres yet.
I'm not saying we should throw plastic into the oceans. I think thats wrong. But so much is being said about these gyres in the Pacific and Atlantic, as if they are a horrible stew of death, when I don't see much evidence to be concerned about them at all. They are symptomatic of what we do to the oceans, since the plastic we throw into it, breaks down into smaller pieces and create the gyres, but the gyres are also made up of plenty of plastic beads that manufacturers use to create plastic products. So its not just our plastic garbage that is to blame for the gyres themselves.
I've heard about the toxins like pesticides and such before. Does the plastic absorb the toxins from the ocean water? When fish ingest the plastic, do the pesticides stay within the plastic, or do they then leach out into the fish?
I'm just not privy enough to all the research to create an informed opinion about the gyres yet.
Just to be clear: plastic waste doesn't create what you're calling "the gyres." From wikipedia:
In the grand scheme of things, this is "our trash" as well, with "our" referring to humankind. sadly...
In this case, gyre refers to the Earth's natural circular oceanic currents. The trash collects in dead spots at the centers of the gyres, along with biology that is supposed to be there. The sargasso sea is a dead spot where sargassum weed proliferates, and it is home to a large biodiversity. Then you throw in a bunch of plastic trash, and there you have it.
philosophile said:
In the grand scheme of things, this is "our trash" as well, with "our" referring to humankind.
sadly...
It's not just he large pieces, but the small pieces as well that are a problem to marine life. Not all marine life out there is the large charismatic mega fauna that most non marine biologists know about, such as the ones you mentioned. In fact, much of it is smaller stuff, and even the smaller stuff can ingest small bits of plastic and run into trouble.
As thebanker mentions, the rafts of plastic are not what created the gyres, it that the gyres collect the plastic the same way they collect the normal flotsam and jetsam of seaweed.
The reason you don't see much evidence of the problem is the same most of the world doesn't see it. It's far offshore and out of sight, where few of us get to go.
philosophile
New member
Yes... I know the gyres are not rafts of plastic... Yes I know the gyres are created by ocean currents.
If you'd like I'll refer to them as the bits of plastic that collect in ocean gyres from now on, but that rather cumbersome to type out.
I know that most of the larger marine creatures are completely unaffected by the plastic in the gyres. That was sort of my point earlier.
This was my question.... How does ingestion of the plastic affect these creatures? When a krill eats some plastic, does it die? And so what? Does the pesticides and toxins in the plastic get digested when its eaten or does it stay within the plastic? If it never leaves the plastic, then it seems like it would be kind of beneficial to put more plastic into the oceans, then harvest them out again removing toxins and pesticides. (I'm not actually suggesting this.)
My point is that people are freaking out about plastic collecting in these ocean gyres, when we really have no idea if it is all that detrimental to marine life. Flotsam and Jetsam can sometimes provide a valuable oasis to many marine organisms, just like Sargasso does. (Not suggesting that we should throw a bunch of floating garbage in the ocean).
When it comes to a lot of moral issues, people just react with knee-jerk hysteria without understanding the issue. I'm just trying to understand here.
If you'd like I'll refer to them as the bits of plastic that collect in ocean gyres from now on, but that rather cumbersome to type out.
I know that most of the larger marine creatures are completely unaffected by the plastic in the gyres. That was sort of my point earlier.
This was my question.... How does ingestion of the plastic affect these creatures? When a krill eats some plastic, does it die? And so what? Does the pesticides and toxins in the plastic get digested when its eaten or does it stay within the plastic? If it never leaves the plastic, then it seems like it would be kind of beneficial to put more plastic into the oceans, then harvest them out again removing toxins and pesticides. (I'm not actually suggesting this.)
My point is that people are freaking out about plastic collecting in these ocean gyres, when we really have no idea if it is all that detrimental to marine life. Flotsam and Jetsam can sometimes provide a valuable oasis to many marine organisms, just like Sargasso does. (Not suggesting that we should throw a bunch of floating garbage in the ocean).
When it comes to a lot of moral issues, people just react with knee-jerk hysteria without understanding the issue. I'm just trying to understand here.
You know this how?
Please reread what greanbean and myself wrote about this. I believe we've both seen firsthand examples of what we've mentioned.
There is no nutritional benifit to eating plastic. Ingested plastic (even if it manages not to cause impaction) means that less actual food is eaten. This leads minimally to malnutrition, which in turn leads to shortened life spans and reduced reproductive potential. "So what?" you ask, well when you cause problems to the lower levels of the food chain, those problems go on up to the higher levels. Less food, less nutritious food, bio accumulated toxins from said plastic, and so on and so forth.
Some remains locked up till it degrades, but some also leaches out and leads to problems in the food chain. Both in terms of direct toxicity and disruption of hormone systems in the critters exposed.
Plenty of reasons it isn't good, and they are well known within the Marine Science community. Many of these reasons have already been mentioned. BTW the plastic in those gyres started out in our estuaryies and near coastal zones, where much of our seafood comes from. So it's not just the plastic being in the gyres that is the problem, it is the plastic being in our oceans in the first place.
That is always a good thing :thumbsup:
BTW, both greenbean and myself happen to be marine biologists
clownfreak
New member
I agreewholeheartedly Bill. Plastic and nets should NOT be in the ocean, if for any other reason then not being natural, or simulating any natural enviroment. There is almost nothing worse than a lose/lost net, any fish that gets caught attracts other fish and it cycles (like crab/lobster pots). In my case it is rare to lose a net (but not unheard of) the sad part is a fisherman that has a net get tangled up, and even if it's full of fish just cutting it lose. This, fortunately is rare but some will dump old webbing and that is what really causes the damage. Due to the high price of nets (about $1000 a shackle) luckily there isn't too much of an issue up in AK. And no, nets are not biodegradable, like Bill said ours were monofiliment or a braided filament. Mono is the new stuff (now most typically used) and braided the old stuff (fish can see it more easily). On the bright side we recycled our old webbing :thumbsup:
philosophile
New member
So compared to the toxins that they get from pesticides being in the water, vs the toxins that they get from plastic, is one significantly worse than the other? e.g. If we could clean out all the plastic tomorrow, would the ocean's creatures have more toxins or less toxins in them?
Sea turtles ingesting plastic from the gyres.... doesn't the plastic pass right through them? (I'm not talking about larger pieces of plastic, clearly this doesn't, but the plastic in the gyres are usually millimeters in size no?)
I know the larger pieces of plastic break down into the smaller pieces of plastic, which collect in the gyres, So large plastic pieces that the turtles eat eventually will become the plastic in the gyres. But I want to focus specifically in on the plastic in the gyres. I'm not sure anyone would defend large plastic pieces in the ocean.
Will the plastic in the gyres collect things like algae eventually? Create a pseudo-sargasso?
Sea turtles ingesting plastic from the gyres.... doesn't the plastic pass right through them? (I'm not talking about larger pieces of plastic, clearly this doesn't, but the plastic in the gyres are usually millimeters in size no?)
I know the larger pieces of plastic break down into the smaller pieces of plastic, which collect in the gyres, So large plastic pieces that the turtles eat eventually will become the plastic in the gyres. But I want to focus specifically in on the plastic in the gyres. I'm not sure anyone would defend large plastic pieces in the ocean.
Will the plastic in the gyres collect things like algae eventually? Create a pseudo-sargasso?
greenbean36191
Premium Member
The toxins on the plastic have been measured at concentrations over 1 million times those found in the water, so yes, eating plastic significantly increases their exposure.
Just to be clear, the plastic in the gyres isn't distinct in makeup from the plastic anywhere else. It's simply more concentrated there. It's still got all of the large constituents like plastic bags, nets, floats, ropes, cigarette lighters, bottle caps, etc. in there. By sheer numbers, yes, the majority of it is only a few mm in size, but that's true anywhere.
However, with sea turtles the main concerns are plastic bags and balls of monofilament, which they mistake for jellyfish, and fishing gear which they get tangled in. About the only way they would eat significant amounts of the small stuff is by taking in Sargassum with a lot of plastic bits in it. In that case, the very small pieces might pass right through adults. Hatchlings and juveniles might have more trouble passing them, but it's hard to say since we know essentially nothing about that part of their lives.
Most flotsam will grow some sort of algae and encrusting life on it, but the open oceans are pretty low in nutrients, so growth of real algae is limited.
Things like nets, rope, and mono will tend to snag other wayward bits of junk and form mats that perform essentially the same fish aggregating function as real Sargassum, but with the nasty exception that they can snag and drown any animals that get a little too close.
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watchguy123
New member
Nobody wants either plastic or garbage in their front yard or as their main course.
After the plastic is ingested by the turtle, the turtle's gut becomes impacted and the turtle dies, yes that plastic does end up leaving the sea turtle to once again float freely in the water. Of course, that's after the dead turtle as decayed enough. Same with sea birds and other animals that might ingest that plastic.
Yup, that's the primary mechanism of breakdown for stuff at the surface.
That earlier plastic laden sample from the Sargasso Sea I mentioned is a good example of this. Many of the plastic bits were certainly big enough to support fouling growth, but were very clean of any such growth.
Indeed. In my case, I call Long Island Sound my front yard, and the Atlantic Ocean is my back yard. Naturally I don't want trash in my yard
Luiz Rocha
Salty Dog
Check the link below:
http://plasticmanners.wordpress.com/about-plastics/
And here stomach contents of A SINGLE albatross from Hawaii:
Will help you understand why plastic is detrimental to marine life of ALL sizes.
http://plasticmanners.wordpress.com/about-plastics/
And here stomach contents of A SINGLE albatross from Hawaii:
Will help you understand why plastic is detrimental to marine life of ALL sizes.
philosophile
New member
Do Albatrosses swallow stones like other birds to aid in digestion? A lot of that look like rocks. I mean on the surface, that looks horrifying, but I wonder how much actual harm that did to the bird. Again, I'm not expert.
Ick looks like there is a lighter in there. Purple left off center a bit.
Heh I feel like I should make it known that I really do care a lot about the environment. I just don't want my constant questioning to make it seem as if I don't actually think plastic in the ocean is harmful. I don't think I've ever denied it.
Ick looks like there is a lighter in there. Purple left off center a bit.
Heh I feel like I should make it known that I really do care a lot about the environment. I just don't want my constant questioning to make it seem as if I don't actually think plastic in the ocean is harmful. I don't think I've ever denied it.
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