Input on Herbivorous Fishes

[Ret_Talbot]

I am looking for some perspective on herbivorous fishes that are commonly seen in the marine aquarium hobby. In particular, I am interested in rabbitfishes, surgeonfishes, parrotfishes, and batfishes in terms of their ecological function as reef grazers. If you are interested in any of these fishes or issues related to the resiliance of tropical reefs based on algae-grazing fishes or the use of algae-grazing fishes in marine aquaria, I'd love to hear from you.

Thanks!

 

[Ret_Talbot]

ok...how about this:

How would people in the industry feel about excluding parrotfishes from the trade until this herbivore's ecological function in terms of reef resiliance is better understood?

 

[JeremyR]

I don't buy/sell parrotfish anyways. Or batfish for that matter.

 

[Ret_Talbot]

I don't buy/sell parrotfish anyways. Or batfish for that matter.

Yes, but many many still do. Marine Depot, for example, has queen parrotfishes in stock. Do you think people in the industry would be willing to self-regulate and not sell these animals (except to public aquaria, researchers, etc.)?

 

[JeremyR]

Of course they won't.. or they would have already. What's your angle here?

 

[Ret_Talbot]

Of course they won't.. or they would have already. What's your angle here?

My angel always is that it's better to self-regulate from the inside rather than have poorly thought-out legsislation (like Hawaii this winter) come down on the industry's head. Wouldn't it be great if the major retailers came out in support of a self-imposed parrotfish ban? Might earn some points with the environmentalists and would certainly help to educate aquarists about what it means to be a true contientious marine aquarist today...

 

[Anonymous]

WIBG thread

It would be great, but it's not going to happen. Besides, the environmentalists that want to shut down the trade don't care if we self regulate parrot fishes. Nemo's message wasn't it's OK if we don't take the herbivores.

 

[Ret_Talbot]

WIBG thread

It would be great, but it's not going to happen. Besides, the environmentalists that want to shut down the trade don't care if we self regulate parrot fishes. Nemo's message wasn't it's OK if we don't take the herbivores.

lol...Thanks, Gresham...

So convince me why I should abandon my optimism here. If it's a fish with very high captive mortality inappropriate for most home aquarists AND if its ecological role is not well understood, why wouldn't everyone be on board with keeping it out of the trade until such time as more is known regarding husbandry and the fishes' ecological function?

By the way, I'm not suggesting it would be in any way appropriate to include all herbviroes here. The parrotfishes and batfishes may deserve some attention as a special subset of herbivores.

Regarding Nemo, much of the testomony in favor of the Hawaii Bill (ah to be a journalist--yes, I read every word...lol) was not the misguided Nemo rheoric; it was the misguided rhetoric based on shoddy and incomplete so-called scientific date, and herbivores came up more than once (although usually in error).

Thoughts?

 

[Anonymous]

Um... I thought that parrotfishes were corallivores, not herbivores. :?

 

[Fish_dave]

The few smaller parrot fish that the trade takes would go virtually un-noticed by the reef. The trade takes very few and the few that we do are generally juv. or very small adults. Only the public aquariums want large ones and again that is very few. If you go to the San Pedro fish market you will see many large adults there for sale as food fish. If you go to the fish markets in any tropical location you will probably see hundreds of large adults for sale as food. The food market takes many orders of magnitude more parrot fish biomass than the aquarium trade does. I know that it sometimes makes you feel good to think that you making a difference to the reef but in this instance I think that your energies would have more impact if you focused them on something that will have an impact. Yellow tang collection for instance would have much more impact than the few parrot fish that are collected for our hobby.

Dave

 

[Ret_Talbot]

Um... I thought that parrotfishes were corallivores, not herbivores. :?

Parrotfishes do consume a fair bit of coral--you are correct--but they do so to get at the algae. In the wild, they target dead coral skeletons and bite off large chunks, extract the food energy from the algae and "poop" out sand. They will also eat live coral, especially in the aqurium where few aquarists provide them with enough algae covered dead coral skeletons. When they eat live coral, they are after the algae hosted within the coral rather than the coral itself. At least that's my understanding.

 

[Ret_Talbot]

The few smaller parrot fish that the trade takes would go virtually un-noticed by the reef. The trade takes very few and the few that we do are generally juv. or very small adults. Only the public aquariums want large ones and again that is very few. If you go to the San Pedro fish market you will see many large adults there for sale as food fish. If you go to the fish markets in any tropical location you will probably see hundreds of large adults for sale as food. The food market takes many orders of magnitude more parrot fish biomass than the aquarium trade does. I know that it sometimes makes you feel good to think that you making a difference to the reef but in this instance I think that your energies would have more impact if you focused them on something that will have an impact. Yellow tang collection for instance would have much more impact than the few parrot fish that are collected for our hobby.

Dave

Thanks, Dave. I always appreciate your thoughtful input to threads here. Believe me when I say that I am fully aware that overfishing for food is an expodentially larger problem then the aquarium trade when it comes to most herbivorous fishes. That needs to be addresses, and I have addressed it elsewhere and will continue to do so. I guess my thought here is not to save the reefs by stopping the trade of parrotfishes; rather it's about retailers taking the lead in educating consumers.

While I appreciate that it is mostly juvs that are wild collected for the trade, the bottom line is that many of those juvs die within a few months. The ones that don't die from stravation or stress, have their growth severely stunted in most home aquaria, and, as a result, die a slow death. These simply are not great aquarium fish at present, and their role on tropical reefs needs to be much better understood. Sure, I wish I could wave a magic want and regulate food fishing for adult parrotfishes, but I can't. Anyway, it's always easy to point at the other guy and say, "well he's doing more harm," but that's not really a logical argument if we within the marine aquarium industry believe that these fishes generally make poor aquarium species.

Further, the opportunity to educate aquarists about the fishes functional capabilities will make aquarists more informed, and I strongly believe that marine aquarists should be on the front line of science-based reef conservation.

Thoughts?

 

[rgbmatt]

My 2c:

The biggest reason why some people want to shut down the aquarium industry is very simple - they think it's morally wrong to take a fish from the ocean and put it in a box. This is purely an emotional issue and has little to do with how we affect the environment.

So, this sort of thing will never go away, no matter how environmentally conscious we are. Ironically, what is most upsetting to many people is the poor survival rate of some species - some of which might not be particularly significant ecologically. Is it worse to collect a bunch of large surgeonfish that will live happily for years in captivity (while no longer grazing their native reef), or a bunch of butterflies that will probably die in a couple of months but didn't have much effect on their environment? Obviously, it depends on your perspective.

That said, however, it's hard to get laws passed based purely on somebody's sympathy for cute fish. So, when this type of thing is brought up to politicians and the general public, environmental issues are always emphasized; without them their arguments fall flat. It's something that will come up in the future and the industry needs to be conscious of it if we are to survive.

 

[Ret_Talbot]

My 2c:

The biggest reason why some people want to shut down the aquarium industry is very simple - they think it's morally wrong to take a fish from the ocean and put it in a box. This is purely an emotional issue and has little to do with how we affect the environment.

So, this sort of thing will never go away, no matter how environmentally conscious we are. Ironically, what is most upsetting to many people is the poor survival rate of some species - some of which might not be particularly significant ecologically. Is it worse to collect a bunch of large surgeonfish that will live happily for years in captivity (while no longer grazing their native reef), or a bunch of butterflies that will probably die in a couple of months but didn't have much effect on their environment? Obviously, it depends on your perspective.

That said, however, it's hard to get laws passed based purely on somebody's sympathy for cute fish. So, when this type of thing is brought up to politicians and the general public, environmental issues are always emphasized; without them their arguments fall flat. It's something that will come up in the future and the industry needs to be conscious of it if we are to survive.

Thanks for your thoughts. All this input is great! I want to be very clear on a couple of points, as I am painfully aware of how these threads can wander...lol:

• I do not want to shut down the marine aquarium industry. I am both a serious hobbyists and someone who writes quite a bit about the marine aquarium industry and its value.
  
  I do not think that the importation of all herbivorous fishes should be shut down either by outside regulation/legislation or by self-regulation.
  
  I am not terribly interested in the emotional appeal arguement (e.g. Nemo). My work and writing is based on hard data, and I believe that, if educated, marine aquarists can become some of the most important proponents and advocates for tropical reefs and tropical reef species.
  
  I do know that some researches in the field have expressed concerns about lack of regulation for some species based on ecosystem sustainability and what we know (and more importnatly don't know e.g. batfishes) about some fishes functional roles.
  
  My point, I suppose, is that the big retailers are in an excellent position to educate marine aquarists, which, in turn, will stregthen the industry and insure its sustainability and the sustainability of tropical reefs and tropical reef species.

 

[Fish_dave]

I agree that parrot fish do not make good aquarium fish for most home aquariums. That is an argument that I would support. I don't think that the few that are taken for the home aquarium market have any impact on the reef.

Taking the thought a little farther it may be that the attention that parrot fish get from the aquarium trade ( negative and otherwise) may help the cause of better understanding the relationship that parrot fish have on the reef. In some cases it may actually be better to take a few from the reef to increase awareness of the species. I think that this is definitly true with public aquariums, is there some bleed over to home aquariums ? Maybe.

Dave

 

[Ret_Talbot]

I agree that parrot fish do not make good aquarium fish for most home aquariums. That is an argument that I would support. I don't think that the few that are taken for the home aquarium market have any impact on the reef.

Taking the thought a little farther it may be that the attention that parrot fish get from the aquarium trade ( negative and otherwise) may help the cause of better understanding the relationship that parrot fish have on the reef. In some cases it may actually be better to take a few from the reef to increase awareness of the species. I think that this is definitly true with public aquariums, is there some bleed over to home aquariums ? Maybe.

Dave

Dave,

I really agree with most of this, and I think parrotfishes in public aquaria are critical in terms of education. I do think the retail side of the marine aquarium industry can also play a key role, especially online retailers, by providing rational in the species descriptions on their websites about why they only offer certain species to public aquaria, scientists and, in rare circumstances, to serious advanced aquarists who are fully aware of the animal's husbandry needs and the functional role they play on the reef.

I didn't mean to ever imply that the number of individuals being collected for the aquarium trade prove a serious threat to wild populations, especially when compared to food fisheries. Nonetheless, that statement seems to have little bearing on a postive argument on why the industry might agree to not commonly offer these fishes in the aquarium trade. I know analogies are fraught with contradictions and problems, but the same could be said for why I don't throw my old laptop in the garbage can as opposed to recycling it. Will my one little laptop really have an impact compared to the tons of computer hardware legally disposed of in landfills every year by business? No? Does that mean I should just send it out with the trash?

I choose not to.

 

[Fish_dave]

I think that we pretty much agree on this. Of 2,000 fish that I bring in it would be very rare to find more than 2 parrot fish. I do not sell many parrot fish. I see them offered quite often but from my experience there is not much demand for them. I will get 1 or 2 juv. bicolor parrots in once in awhile. I saw one offered on our Solomon list this week. We certainly do not target them but once in awhile a collector will bring one in that must have run into his net and we will accept it and put it up for sale rather than reject it and send it home with the collector. I see them available on the internet quite often but have no idea how many are actually sold, the demand for them from me is almost non-existant.

I agree with the laptop comparison. I walk my plastic bottles over to the recycle bin (although we still throw hundreds of pounds of plastic in the trash can).

Dave

 

[dizzy]

Might as well mention a book called "Surgeonfishes Rabbitfishes and their relatives" by by Kuiter and Debelius. You might find some useful information in this book.

 

[JeremyR]

I'm curious where you write for and where your previous articles are published?

 

[jhemdal1]

Better to protect Diadema urchins as opposed to vertebrate herbivores...In the Caribbean, loss of Diadema through disease and environmental problems is a much bigger problem than removing parrotfishes. The patch reefs off Belize are covered in thallose algae and still have huge numbers of parrots - few Diadema though.

Jay

p.s. - batfishes are omnivores with a strong tendency towards being carnivores.