Study Links Aquarium Collection to Decline of Reef Fish on O‘ahu

posted in: Fisheries, Marine, October 2020 | 0

Some 17 years ago, Leon Hallacher and Brian Tissot undertook to assess the impact of aquarium fish collectors on the population of reef fish along the Kona coast of the Big Island. To collect the data needed, undergraduates were trained to identify the fish and then made underwater surveys along transects in sites known to have been subject to col- lection and others where such collection was banned.

They found that seven of the 10 species popular with collectors were lower in areas where collection occurred than in the control areas. Also, “several lines of evidence suggest that the current system of catch reporting underestimates actual removals.”

Following that, Gail Grabowsky, director of the Environment Program and interim dean of Natural Sciences and Mathematics at Honolulu’s Chaminade University, along with Daniel Thornhill, director of Auburn University’s Biological Oceanography Program, undertook to apply Hallacher and Tissot’s study methods to reef fish along O‘ahu’s coast. Grabowsky trained six Pacific Islander undergraduates who then surveyed dozens of reef sites around Oahu during the summer months from 2009 through 2011.

Grabowsky presented their findings at this year’s Conservation Conference sponsored by the Hawai‘i Conservation Alliance. (Owing to the coronavirus pandemic, the conference was conducted virtually September 1- 3.)

Unlike the Kona Coast, O‘ahu has few areas where aquarium fish collection is banned. As their control site, Grabowsky and Thornhill used Hanauma Bay, even though at the time of their survey, the bay was still open to use by thousands of visitors a day.

“On O‘ahu,” Grabowsky noted, “we have very few fully no-take zones, less than one percent. … Those are the Marine Life Conservation Districts. Hanauma Bay is one of them, as is Pupukea and Coconut Island. We initially used all three as control sites, but because we heard of poaching and saw some poaching, we were left with just Hanauma Bay as a fully protected site.” Even that wasn’t perfect, she added, given the heavy recreational use of the bay, sunscreen pollutants, and other disturbances.

“We started out with a whole bunch of sites,” she said, “but not all sites made it into this paper, because there was some legitimate criticism that habitat sites were not the same.” Grabowsky consulted NOAA maps that showed geomorpho- logical and biological characteristics of the sites considered and winnowed down the list of sites comparable to conditions at Haunama Bay to just 17.

Some 16 species of reef fish were censused. The results: Six of those species were significantly more abundant at Hanauma Bay.

To determine which reef fish were most popular among collectors, Grabowsky sought from the Department of Land and Natural Resources the reports submitted by those collectors to the state and determined that four of those six species were also those that were most commercially collected. Just one of those four is also collected as a food fish, meaning that its depletion at the survey sites cannot be definitively laid at the door of aquarium collectors.

Grabowsky noted the challenges in her study. “There is no good baseline data for O‘ahu,” she noted. “We can’t go back and look at records. … The methods for counting fish are so different, we decided it was better to use the methods on the Big Island. Also, there are shifting trends in the aquarium trade and poaching on protected sites. Also, Hanauma Bay is not really pristine.

“Nevertheless, our statistically significant results … do make a convincing case for collection-driven declines in reef fish abundance.”

“In these days of nutrient pollution and climate change and overfishing, this is possibly another stressor we’re putting on our reefs,” she concluded. “To make an ethical statement, is it right that we decide that fish sold for money are more valuable than their value on the reef when the reefs are so challenged?”

“Given the potential for negative impacts to both fish populations and coral reef conditions in this time of escalating anthropogenic threats,” she continued, “it seems pertinent to increase protective measures to safeguard fish populations from overexploitation.”

A Bill for O‘ahu

The state Department of Land and Natural Resources has continued to issue permits allowing for the commercial collection of reef fish destined for confinement in private aquariums, even though a Supreme Court decision three years ago was thought by many to put an end to the practice, at least until an environmental impact statement could be completed and accepted.

On Maui, an ordinance that took effect in January 2011 curtailed much of the commercial aquarium collection by requiring the humane treatment of fish caught for the trade. Common practices that were banned include puncturing the swim bladders, trimming their fins or spines, and holding them for extended periods without food. Also prohibited is the transport of aquarium fish in a manner that results in injury or death to the fish. Collectors were required to submit biannual reports on mortality rates to the Maui Humane Society.

Now a similar bill has been proposed to the Honolulu City Council. Bill 66, introduced by council member Ron Menor on September 2, would ban deflating the swim bladders of fish and cutting or trimming their fins as well as their transport in a manner resulting in injury or death.

Menor’s bill would also require reports to the city on a monthly basis, including data on mortalities, by species, and cause of death. For each shipment of aquarium fish out of state, the city would also require the copy of the packing list, invoice, or other document “listing the species contained within the shipment by common and scientific name.” Finally, the city would require any business entity selling the aquarium fish to obtain state and federal tax clearances.

At its first reading, on September 9, almost all testimony was in strong support. Earthjustice attorneys Kylie Wager-Cruz and Mahesh Cleveland, who were part of the team representing Native Hawaiians and other organizations that won the Supreme Court decision. The bill, they testified, “would fill a critical gap in regulating the aquarium trade on O‘ahu which in the past few years has become a hotbed for the industry since West Hawai‘i was temporarily closed to collectors. Although statutes and rules under the state Department of Land and Natural Resources’ purview … purport to address the aquarium trade’s impacts on Hawai‘i’s marine ecosystems, none of these management tools specifically regulate how animals are handled during collection, storage, and transport. Thus Bill 66 is necessary to prevent mistreatment and waste of these public natural resources.”

Earthjustice endorsed amendments, initially proposed by the group For the Fishes, that would make monthly reports required only for mortality by species and out-of-state shipments.

Testimony in opposition was received from Chatham Callan of the Oceanic Institute at Hawai‘i Pacific University and Tom Bowling, an aquaculturist. Callan objected to the language that would prohibit the withholding of food from aquarium fish for more than 24 hours in transport.

“As written,” Callan stated in his testimony “this bill would effectively prohibit the transport or shipping of marine life, AT ALL.”

“We have extensive data,” he said, “to show that marine fish need to purge their digestive systems prior to be transported, or they will pollute their shipping water with toxic waste products. These waste products are far more harmful to the fish than being without food for a short time period. With herbivorous species, such as Yellow Tang, this fasting period can take up to 48 hours.

“We have shipped over 15,000 cultured juvenile Yellow Tang in over 100 separate shipments over the past several years. In all these shipments, fish were fasted for 48 hours prior to shipping. We are pleased to report the survival rate of these fish in these shipments is always greater than 90 percent and in most cases is greater than 99 percent. …

“Further, we feel the enforcement of this arbitrary time period will negatively impact OI’s ability to generate revenue and would restrict the development of new technologies for the captive rearing of aquarium fish to take pressure off the reefs.”

Bowling, whose company partners with Oceanic Institute, repeated many of the same concerns raised by Callan. “Although the idea of ‘starving’ an animal does come across as inhumane and cruel, it is done for much the same reason you are told not to eat for 24 hours prior to surgery. If you do eat, it could put your life in danger … Similarly, the fish must not be fed 24 hours prior to transit, as this means they would defecate in their small volume of transit water and this WILL kill them,” Bowling wrote.

The bill received unanimous approval on its first reading and now awaits further hearing from the Committee of Public Safety and Welfare. 

— Patricia Tummons

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