Reef aquariums may cause collapse of marine invertebrate fishery

Blue-legged hermit crab (Clibanarius tricolor), the top catch of the Florida ornamental fishery at over 2.3 million indviduals. Image credit, RevolverOcelot.Scientists have warned of a possible upcoming collapse in the Florida invertebrate fishery that supplies home and public aquariums. They reached their conclusions based on a review of Florida ornamental fishery catches from 1994 through 2007.

Andrew Rhyne and fellow researchers found that the fishery has grown from a catch of nearly 1.8 million individuals in 1994 to nearly 9 million individuals collected in 2007.  That represents a growth of 13.3% or 500,000 individuals per year.

Most interesting, the types of species caught have shifted dramatically from mostly ornamental creatures (e.g. anemones) and curios (e.g sea stars and sand dollars) to those that provide ecosystem services in reef aquariums (e.g grazers such as hermit crabs and snails). The researchers hypothesize that this change reflects a shift in the preferences of aquarium hobbyists over the years from fish-only tanks to miniature reef ecosystems.

Unfortunately, these same species that are desirable for providing ecosystem functions in the home tank are important for maintaining natural reefs by providing those same functions in the wild. The catch numbers alone do not conclusively show that the fishery is collapsing but they certainly raise some serious red flags.

In my opinion the shift in hobbyists preferences from fish-only aquariums to miniature reef ecosystems is a good thing. For me, it represents a growing public appreciation of marine ecosystems and interest in how they work. However, just as the case with whale watching, sometimes hobbies that involve an appreciation for nature, ironically, have unintended negative consequences for the resource.

As the study authors address, there needs to be better management of the Florida ornamental fishery. Right now the state regulates the fishery largely through restricting the number of people who can participate rather than setting limits on what they catch. Yet, the amount of catch has increased dramatically since 1994 while the number of licenses have decreased.

The study goes into much more detail on the problems of current management and possible solutions than I am able to present here. You can find the original paper in the always FREE open source journal PLoS ONE.  So, I highly recommend you check it out.

--Reviewed by Rob Goldstein

Rhyne, A., Rotjan, R., Bruckner, A., & Tlusty, M. (2009). Crawling to Collapse: Ecologically Unsound Ornamental Invertebrate Fisheries PLoS ONE, 4 (12) DOI: 10.1371/journal.pone.0008413