Boycotting the Trade in Parrotfish
Voluntary Boycott Based on Science May Help Conserve Tropical Reefs
Algae-grazing parrotfishes are not protected and are often available in the tropical aquarium trade. Conservation-minded aquarists should, however, boycott their sale.
Parrotfishes are poor aquarium fishes. Bob Fenner, author of The Conscientious Marine Aquarist, writes, “[The parrotfishes] would seem to have everything going for it as far as desirability to marine aquarists; many are spectacularly colorful, they have almost comical fusiform-torpedo body shapes, and they are numerous and easy to catch…. Their only downside, and it's a big one, is that [parrotfishes] rarely live for anytime in captivity.”
In addition to the fact that parrotfishes rarely survive in the home aquarium, scientists are learning that they serve an absolutely crucial, albeit little understood, ecological function on tropical reefs. Given the plight of tropical reefs the world over, it is essential to insure a sustainable population of herbivorous fishes like the parrotfish on reefs. Marine aquarists can do their part by boycotting these fishes and urging retailers to not engage in their sale.
Poor Survivability in an Aquarium
The most prevalent reasons why parrotfishes do not survive in aquaria have to do with diet, adult size and stress. Mark Martin, the Director of Marine Ornamental Research at Blue Zoo Aquatics, explains, “The only parrotfishes that can be recommended with any degree of integrity are the queen parrotfish (Scarus vetula), the spotlight parrotfish (Sparisoma viride) and the bicolor parrotfish (Cetoscarus bicolor).” Even these three species, Martin says, generally do not survive in the home aquarium and, as such, are only recommended for public aquaria, scientists and expert aquarists who can provide them with the environment they require.
In the wild, parrotfishes graze primarily on algae by using their specialized teeth to scrape it off dead coral skeletons. In the process, they swallow large pieces of the calcareous skeleton and process whatever algae are on that skeleton inside their digestive system.
Parrotfishes Will Eat Live Coral
Because the typical reef aquarist does not keep dead coral skeletons in his or her system, the aquarium parrotfish will usually turn to living coral in a reef tank. The fish does not differentiate the live coral from the dead coral skeletons it is accustomed to consuming. “It will be more than happy to take chunks out of the living coral and process and utilize the zooxanthellae in the tissue of the coral as food energy,” Martin explains. “This would, of course, be a nightmare to most reef aquarists who keep expensive and difficult to find corals.”
The alternative to keeping a parrotfish in a reef tank is to keep it in a fish only system. Unfortunately, this also does not usually work out, since most home aquarists cannot keep up with the fish’s dietary needs in a fish only system. ”The reality,” Martin says, “is that keeping a parrotfish in an aquarium will usually lead to starvation.”
Ecological Importance of Parrotfishes
If the parrotfishes’ poor survivability in the aquarium is not a good enough reason for marine aquarists to boycott their use in the hobby, than consider their ecological role as reef grazers. Marine scientists have recently shown that we don’t know nearly enough about these fishes’ ecological role, but it is clear that herbivorous fishes are critical to the health of tropical reefs. When grazing fishes are overfished, whether for food or for the marine aquarium industry, reefs suffer because algae outcompetes sessile invertebrates such as coral.
Self-Regulation is the Key to a Sustainable Hobby
In the final equation, conscientious aquarists should take note of the ecosystems from which the species they desire to keep are collected. As recent research has shown, aquarists need to learn a lot more about herbivorous fish species in light of degraded tropical reefs. Further, aquarists should consider self-regulation based on science, even when these species have not been identified for protection by CITES or other regulating bodies. Building closer ties with the scientific community will provide the best opportunity for a sustainable hobby based on the conservation of sustainable wild populations.
