Ecosystem Effects of Collecting from the Wild Hawaii Audubon Society, 2004
Hawaii Audubon Society, 2004
“Preferences for particular sizes, color forms, or rarity can produce extremes in selective harvesting. (Sativa and Vincent, 2002 at 394) Animals that are 2 - 10 cm in length are the most popular (Id.). Taking juvenile fishes or male wrasses because of their distinctive coloring can cut off the reproductive cycle. Removal of significant numbers of particular species of sub reproductive reef fish for the aquarium trade can interrupt food chains, cause reproductive failure and alter habitat. Because of this there is a concern that the continued removal of marine ornamental organisms will not only impact target species, but will also have irreversible effects on components of the entire ecosystem
The two major ecological problems with the current regulation of marine ornamental collection in Hawaii are the lack of information on the impact of the collection of rare and endemic organisms, many of whose populations have been decimated by over-collection (Gulko, pers. comm.), and the complete lack of recognition of trophic significance and life history stages in regulations regarding take of marine ornamentals. In 1998, a group of Hawaiian reef experts were brought together by the DLNR to discuss the state of Hawaiian reef species and recommend those that should be investigated as to the need for increased protection. This group came up with a list of twenty-six species, most of which were endemic, that they felt needed some form of immediate protection. The majority of species on this list were targeted by the marine ornamental trade; in fact, for a number of the species, the only known impact was marine ornamental collection With overall coral reef endemism rates approaching 25% (Gulko, 1998), there is no replacement pool for many of the targeted species should over-collection or a habitat shift occur as a result of the marine ornamental trade. (Friedlander, 2001). For example, removal of large numbers of herbivores such as the yellow tang can cause reef areas to be overrun and smothered with algae. The removal of cleaner fishes may result in higher parasite load on other reef fishes. The removal of coral and live rock can destroy reef habitat.
While strong rules protect against the use of destructive gear and methods for food fishing in Hawaii (DLNR, 2003), such controls are minimal in the marine ornamental trade; for example, many of the benthic invertebrates collected (featherduster worms, crabs, shrimp, brittle stars, sea urchins, anthozoans, etc.) involve destruction or alteration of live rock and coral to gain access (something which is against existing Hawaii State law), but is completely ignored when considering limits on collection of these organisms. From a benthic perspective, many of the fishers collect a wide range of organisms from a wide variety of habitats employing a wide variety of techniques, many of which are specific to the organisms being targeted. Furthermore, minimum sizes are used for collection of a wide variety food fish species in recognition that removal of pre-reproductive fish and invertebrates can severely affect viability of the population as a whole, yet such standards are completely absent for over 350 species of Hawaiian organisms collected for the marine ornamental trade. The result is that the Hawaiian marine ornamental trade represents a relatively small fishery that has wide ranging impacts across a wide spectrum of trophic levels and habitats disproportional to either its economic value or its number of participants.
Because aquarium fish collectors are highly selective and often capture large quantities of individuals of high value, the potential for overexploitation is high (Wood, 1985). Species of interest to the aquarium trade are often absent or in low abundance in areas frequented by collectors (Albaladejo and Corpuz, 1981; Wood, 1985, Tissot and Hallacher, 1999). The enormous increase in the trade of marine aquarium species has led to questions about the long term sustainability of this industry (Friedlander, 2001). If harvesting effort continues to increase, growth and recruitment will not be able to keep up and aquarium stocks will decline, just like any other fishery.
Furthermore, there is a common misconception that fish populations will always recover when fishing pressure is released. Recovery has occurred in many cases, but in other cases it has not, even after many years…Even effectively enforced no-take marine reserves may not bring back a population if so many individuals were taken that the species can no longer successfully spawn (Birkeland and Friedlander 2002).” The Marine Aquarium Trade in the Western Hemisphere and the Indo-pacific Region, Hawaii Audubon Society 2004
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