Common Misconceptions In the Hobby

[Tu Ku]

Originally posted by tydtran
Explain to me how the "coral reefs are dying" is a misconception.

Mind you this is only what I've read and so I don't know that they aren't dying, but they have died off before and so will probably die again. The ocean's reefs are so unfathomably vast that to say that it is all dying or going to die for ever would be like saying all the mammals are dying, or all of the plants are dying and will never exist again in any form. The reef will be there as long as any other part of natural life will be there, for as long as there is a place to be. It may become extinct in the sense that we know of it today, but it would be a misconception to think that it will all just disappear.

[tydtran]

I disagree.
The history of life on earth is the history of extinction. Many species have disappeared never to be seen again. Think about the dinosaurs for example. The question is this: are coral reefs facing a potentially catastrophic, extinction level event or are they simply in a cyclical downturn from which they will eventually recover. I agree with you that this is an open question. My bias is towards the first possibility but I acknowledge that is insufficient data to really answer the question. However, I think calling it a misconception is a mistake because it minimizes the problem and leads to inaction. If we all believed it and did nothing, one day we may have the definitive data in hand and then it may just be too late to do anything.

[fantastic4]

my misconception is that my wife will someday say....

"Honey I want a 300 gallon in-wall aquarium with a lavish fish room just behind it"

In reality my wife will someday say....

"Honey I know you want a 300 gallon in-wall aquarium and that fish room thingy, but let's take the money and redo the kitchen... or no sex for you"

[Tu Ku]

[samtheman]

Big tough guy!

[samtheman]

Big tough guy!

[Rosseau]

Though at first it may be easy to jump on Tu Ku and start attacking there is a valid point raised here in my opinion.

What do we measure as the baseline and "natural" level of biodiversity, extent of reefs etc. ?

Definitely these ecosystems have changed in the past and will continue to do so regardless of human activity.

However, modern reefs are facing more stressors which are changing more rapidly than in the past (most of the past). It's the rapidity of the envrionmental changes which probably face the biggest threat to these system.

Destroying all life is a tricky task and so certainly much will survive rapid change yet the effects of the change will be complex and widespread.

[capn_hylinur]

Originally posted by Rosseau
Though at first it may be easy to jump on Tu Ku and start attacking there is a valid point raised here in my opinion.

What do we measure as the baseline and "natural" level of biodiversity, extent of reefs etc. ?

Definitely these ecosystems have changed in the past and will continue to do so regardless of human activity.

However, modern reefs are facing more stressors which are changing more rapidly than in the past (most of the past). It's the rapidity of the envrionmental changes which probably face the biggest threat to these system.

Destroying all life is a tricky task and so certainly much will survive rapid change yet the effects of the change will be complex and widespread.

I think everyone on this length thread is discussing--not attacking
Attacking brings a negative and personal perspective to things. Nothing said on all 20 some pages has been personal or negative.
Personally I am glad Tu Ku has joined in even though his entrance was so subtle

I disagree that there is not enough expertise on this thread to dispell some common misconceptions. One needs to look at the experince of alot of the contributors, the success they have had, and their occupations. There are marine biologists, and near to be biologists among us. There are authors , there are divers and there are those that possess high degrees of scientific skills.
If you believe in the process and importance of science period, let alone in this hobby then you have to give the advice and statments by these people a high level of trust.
I would hope that someone new to this thread would read it from the beginning and get a more global feel of this thread.

[Paul B]

but let's take the money and redo the kitchen... or no sex for you"

Amazing, she must know my wife.

As for the reefs I have been lucky enough to dive on many of them for the last 40 years and I was very impressed, or depressed in some areas in the South Pacific where I saw and photographed many acres of dead tongue corals. I don't think Isaw any living ones. In the Caribbean it is more near shore reefs which are obviousely dying from run off of the Islands.
Besides that, most of the reefs that I have seen seem fairly healthy.
Of course, my tank looks pretty good even though I recently had a tankwide "global warming" and some massive pollution spills . I have not yet had a fuel spill or runoff from the wall but I am sure one is coming in the future.

[greenbean36191]

I've been to reefs in the Pacific that were in great shape. I've been to reefs in the Pacific and Caribbean that were in terrible shape. I've also been to reefs in both oceans that looked great, but were really in terrible shape. This summer I even got to work on a reef in the Caribbean that was in bad shape but was actually recovering. So certainly the current health of reefs runs the full spectrum and not all are currently dying. However, the recent trend towards reef death has been pretty strong.

Over the last 30 years in the Jamaica there's been an 80% decline in coral cover. In most areas of the Caribbean studied coral diversity and cover has dropped, though not quite as dramatically. The dominant herbivores have become functionally extinct in many areas. Within a 10 year period 95-97% of the dominant species of coral there died off and nearly 20 years later still aren't showing significant recovery. For several reasons it's unlikely they ever will. That type of change has never happened before at least in the last 3,000 years that we can look at. The study of reef ecology in the Pacific is a lot younger, so it's harder to measure the trends there, but from what people have looked at there seem to be dramatic declines going on there too.

Ultimately the thing that spell disaster for all coral reefs is CO2. It's a 1-2 punch for reefs. Of course everyone has heard about how it contributes to warming, which increases bleaching. This isn't just theory either. Over the last 50 years there has been a measurable increase in average ocean temps in the tropics. Mass bleaching events used to be a decadal event but within the last 15 years or so have started creeping closer and closer to the biannual scale, which is just about the limit corals can take. Taken alone, this is something corals could probably adapt to fairly quickly and there is evidence that they've started. However, probably the bigger threat from CO2 is the effect of driving the ocean's pH down. As CO2 dissolves in the water it forms carbonic acid and lowers the pH and the saturation point of Ca in the water, which makes it less energetically favorable for corals and other animals that form aragonite to form their shells. Again, this has already had a measurable effect. This threat is a lot harder to adapt to, especially when the corals are already sapped for energy due to bleaching and other threats.

If the current trend of increasing CO2 continues, within the next 50 years there will be nowhere in the ocean that's favorable for reef formation. That's often reported as "reefs will be gone within 50 years" which isn't the case. Increasing temps are pushing corals toward the poles, while pH and Ca are pushing them toward the equator. When the two boundaries meet corals will still be around and still growing. However that's when they'll enter what's called a "fall behind" state. That means that they aren't growing fast enough to keep up with disturbances that knock them back. Essentially what will happen is that as colonies die off they won't be replaced by new coral like they have been in the recent past, but they'll be replaced by something like algae or seagrass. This is already the trend in many places. This happened before several million years ago and resulted in a few million years with no reefs at all. The good news here is that we still have about 10 years or so to make a change before we reach the point of no return.

When you talk about changes to the reef in the geologic past it's important to keep in mind a few things. Corals haven't always been the dominant reef forming organisms. For a while it was sponges, then clams, then corals. When one group couldn't keep up, another group rose to dominance, so it's not a fair assumption that corals will adapt and keep on trucking. They have done it in the past, (like 125,000 years ago) and have even dealt with changes occurring at the rate they're occurring now. The big difference though was that then they didn't have so many stressors working synergisticly.

What do I think the near future hold for reefs? Based on what we know of the past and current trends it looks like within my career I'll be documenting the end of coral reefs as we know them. Corals will fizzle out and lose to green algae as the dominant reef organisms. Because the algae don't significantly contribute to the reef structure the reefs themselves will eventually erode and subside and we'll enter another gap of a few million years with no reef forming organisms. Corals as a group will still survive, but they won't be reef formers.

[capn_hylinur]

a very good article--thanks Greenbean---- very troublesome but at the same time a bit of optimism.

What do you see the role of our hobby in all of this--will it contribute to the preservation of the worlds coral species.

[greenbean36191]

This certainly takes us into the realm of informed opinion again rather than hard fact, but if the current trends in the hobby continue I don't believe it will provide any real conservation value. In a best case scenario I think it's simply a way to preserve corals to show our grandchildren what we messed up for them.

For several reason, the animals in the hobby are essentially dead ends for conservation. They aren't suitable for restoring reefs. One big reason is the possibility of introduced pathogen prevents animals from being suitable for reintroduction once they've entered the trade and especially after they've been kept in mixed tanks.

Another big reason is the lack of diversity. You really can't understate the importance of diversity in preserving ecosystems. Species diversity is important in preserving ecosystem function, but the trouble is that we really don't have a grasp on what the minimum level of diversity is to preserve that functionality. In the hobby we only see a tiny fraction of the diversity of the reefs and of that tiny fraction, the majority can't be propagated long-term in captivity. If we were to lose our supply of wild specimens in the near future the species diversity in the hobby would drop drastically. It's extremely unlikely that we would be able to re-establish a functioning ecosystem with even the current level of diversity available in the hobby, much less a reduced level.

Another diversity problem is the lack of genetic diversity. One big thing that has to be considered in long-term conservation plans is genetic diversity, which is important for adapting to changes. It's going to be especially important in the near future. As a general rule you need to start with at least 50 genetically distinct, reproductive individuals to preserve enough genetic diversity to give a species long term chances of survival. There are probably few species in the hobby that we can say that for since there's so much asexual propagation done and so much inbreeding with captive fish. There may be thousands of a given species, but most can be traced back to only a few original individuals.

The really big question for reintroduction though is if conditions get so bad that wild corals die off where do we reintroduce the captive ones?

There's also been a huge push within the hobby over the past decade or so to reduce the impact on wild reefs by propagating corals at home. The problem is that this approach doesn't address the economics behind collecting. It removes our demand from the reefs but doesn't replace it with anything that produces equal value for the collectors. There are plenty of more distructive industries like coral mining that are ready to fill that void. We need to replace current collecting practices with equally valuable industries that use the reef more responsibly.

Also, besides our direct impacts we're huge contributors to environmental change. We use huge amounts of electricity to run our tanks. Even though some people like myself can say that all of our electricity comes from nuclear or hydro, we still keep animals and rock that's been flown thousands of miles on one of the most polluting forms of transportation we have.

Ultimately if the hobby wants to have any conservation value we need to make a few big changes:
1) Close the lifecycle of the animals we keep. That means sexual reproduction from large starting populations to preserve diversity.
2) Reduce our indirect impact by more efficient equipment, better power sources, and cleaner shipping methods.
3) Promote in situ aquaculture. We need to get away from the idea that if we stop demanding goods from the reef people will stop collecting them. Instead we need to provide a market for animals that are produced sustainably while still giving the collectors jobs.

[MiddletonMark]

Great points, Greenbean.

I'd like to reinforce the point you made about how corals [geologically speaking] are not the only reef-building organism. My reading on the subject really suprised me, as I never expected clams+such to be a primary reef-building [and most abundant] creature at various periods of Earth's history... yet there are many of millions of years where `reefs' meant huge agglomerations of shellfish and the like. [not stony corals]

Sure, maybe there will be `reefs' in a few generations ... but to any of us [esp divers] ---- giant mounds of shellfish are not what I would ever label reef. [nor algae beds]
As far as I'm concerned, corals are `reefs' ... even though anyone who knows oceanic geology/history would certainly correct my misguided impression. [Heck, reef-building organisms created/used calcite at one period, not the CaCO3 that we know + love]


I also fear the long-term ramifications of CO2 % changes is by far the most concerning issue with any global system changes that are occuring. If the pH drops, calcification will halt and a vast array of ocean-creatures will be affected.

That, personally, is very concerning as despite how humans may do, the loss of a wide range of ocean life is not an ok outcome IMO.

[capn_hylinur]

great answers guys----I guess there is no Noah's ark for our reefs