Edwin-
Hermit crabs, are omnivores. Bears are omnivores. If you give a bear a choice between a nice deer, a dead dear, or vegetation...he will take the live meat every time.
Hermit crabs are the same way, they would rather eat live prey, or carrion than algae. What they are primarily feeding upon are small fauna, such as the type we want in our sand beds. Also things like juvenile snails, juvenile worms, etc.
I personally think a smattering of hermits are okay, it adds bio-diversity. But there are people that are advocating a concentration as high as 1 hermit per every 2/3 gallons of tank volume. You'll notice that most of these people are selling hermits. As far as the
"I've heard tons of people and LFS say hermits", ya, the LFS is selling hermits. The tons of people are just passing along what they were told. I think this is one of those less filling/tastes great scenario. But, in our case it's less hermits/more hermits. Guess who is shouting "more hermits". People primarily add hermits to clean up uneaten meaty foods, and dead animals. The Nassarius snails will do that just as efficiently as the hermits. The plus with them is that's all they will eat.
What Ron was trying to convey with the
"meteor crashing into the ocean that killed them. I didn't understand why he was talking about that and those pigeons" bit was simply to give the audience actual comparisons that related to what he feels is a faunal extinction event actually happening now, during our lifetime.
"I didn't get too much info in what we could do to try and help.... I kinda got the idea of more that the reefs are in trouble and they are all going to die away. But I don't remember anything on what we could do...."
Ron's presentation laid out that there are two primary factors that will lead to the extinction of coral reefs within the next 20-30 years. The first is a history of over-fishing that goes back a couple of hundred years. I was able to find some information online in regards to this theory. There is quite a bit out there supporting Ron's theory that the long term over-fishing of Keystone species will eventually lead to a downward spiral leading to the coral reefs extinction as we know it. The reef will still be there, but the major players will be bivalves (clams, muscles, etc) and algae. The coral will be gone. I did find some papers/articles that disputed this theory, and interestingly enough...most of them were backed in one way or another by commercial fishing interests (IMO, sort of like the crack dealer telling you all that hype about just say NO is wrong, and that it has therapeutic properties).
The ocean acidification aspect, once you delve into it is sort of of funny, in a way. Global Warming! We've all heard about it, but Global Warming is not a root cause issue as so many are trying to make it to be. Global Warming is a symptom of the excess amount of "green house" gasses that have accumulated in the past 100 or so years. Primarily we are talking about Carbon Dioxide. The buildup of CO2 in the atmosphere is what is causing Global Warming...it's also what is causing the plummeting pH of the oceans as they start acidifying. There is a lot of people refuting Global Warming as just another cycle in the Earth's history, and that it is natural. It isn't from human impact! But everyone, EVERYONE, agrees that the build up of CO2 that is causing the Ocean Acidification is being caused by the worlds industrial centers, cars, planes etc. as they spew forth the waste gas CO2. No one refutes that the ocean is acidifying, nor is anyone refuting it's cause.
Do we all see the Catch 22 here? You have people, like our current President, that feel that we just don't know everything we need to about this "Global Warming" thing...but has a task force looking into what we can do to stop the increasing acidification of our oceans.
