Aquarium fish: Let science guide decision-making

Unlimited fishing, reef destruction, species extinction, illegal trafficking, complaints of “no fish” — the blame for all these accusations is heaped upon Hawaii aquarium fish collectors by a small but vocal group determined to shut down the aquarium fishery. Recently, 12 coral reef biologists wrote to legislators supporting the Hawaii aquarium fishery. Why are coral reef biologists largely unconcerned? Because scientists follow the data published in peer-reviewed journals and government reports, none of which has demonstrated negative impacts from aquarium fish collecting in Hawaii. In fact, 18 years of extensive monitoring on the Kona coast has shown that the fishery there is sustainable at the current level of fishing and reef health. A few biologists working against aquarium fish collecting cite their own beliefs, unsupported by Hawaii-based research, and offer as facts untested assumptions and anecdotal stories of environmental harm.

In 2016, there were 43 collectors on Oahu, and 35 active licensees in West Hawaii. This is a very small, limited fishery, but in dollar value it is the most valuable nearshore fishery in the Hawaiian Islands. Oahu and West Hawaii island account for almost all of the collecting activity; aquarium fish populations on the remaining islands are largely untouched.

In February 2017, the National Oceanic and Atmospheric Administration published a report citing a decline in populations of some Hawaii reef fishes. None of the species of concern was an aquarium fish species. And, after 50 years of aquarium fishing in Hawaii, no aquarium fish species is endangered or threatened with extinction; in fact populations of the two most heavily fished species have increased.

The yellow tang is the most popular aquarium fish collected and has been extensively monitored on the Kona coast where just over 35 percent of the coastline is off-limits to aquarium fishermen. State Department of Natural Resources (DLNR) scientists, and other researchers, report fewer aquarium fish species in areas where collecting occurs, but this impact is not producing a significant negative effect on the populations or on the environment. No reef degradation has been attributed to fish collecting on these Kona reefs despite intensive observation and research.

How can it be that collectors can catch over 300,000 yellow tangs per year and not negatively affect the species? Collectors target juvenile fish, not adults, so the breeding population is left intact. The adult population of yellow tangs on the Kona coast is estimated at over 2.5 million. One adult female Yellow Tang can produce over 1 million eggs per year. This phenomenal reproductive effort is part of the equation that allows this fishery to persist. Fish collectors target juveniles that often settle on reefs in large numbers (young fish are subject to high natural mortality in the ocean). One Hawaii biologist remarked that it is like a bank account where you remove some of the interest (juveniles), but leave the principal untouched (brood stock).

Preservationists want zero collecting everywhere which is an elitist, selfish position. Conservation biologists recognize the need for “shared resource use,” and also the educational value of aquariums, especially for those too young, too old, or otherwise unable to swim in the ocean. These conservationists have worked diligently to ensure that Hawaii’s aquarium fishery is well- managed and sustainable; it should be a model for all fisheries in this state, not a pariah, as it has been portrayed.

In today’s world we should be making decisions based on good science, not anecdotes, hearsay and inflammatory rhetoric. Instead, we are entering an absurd new reality where killing any of these fishes will be legal without a permit, but collecting them alive for an aquarium will be impossible.

(Scientific studies have been conducted on this fishery, and on the yellow tang, by researchers from: the University of Hawaii (Manoa and Hilo), DLNR Division of Aquatic Resources, Oceanic Institute, Washington State University, Oregon State University, the National Marine Fisheries Service and the NOAA Fisheries Pacific Science Center. )

Bruce Carlson, Ph.D. (retired), is former director of the Waikiki Aquarium and former director of conservation at the Georgia Aquarium.