The Department of Land and Natural Resources has rejected a recent demand from environmental groups for a temporary ban on the collection of aquarium fish in Hawaii waters as a response to unprecedented coral bleaching.
Instead, the state has embarked on a comprehensive coral reef management plan, which may include new restrictions and educational outreach.
“Coral bleaching in some parts of Hawaii is unprecedented in recorded history, placing our corals at much greater risk of dying,” said Bruce Anderson, the administrator for the DLNR Division of Aquatic Resources, in a statement Monday.
DLNR Chair Suzanne Case says a temporary ban on aquarium fish collection isn’t the answer to unprecedented coral bleaching.
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“We need to ensure our reefs are as healthy and resilient as possible to maximize the chances of recovery,” he said. “Aquarium fish collecting is not thought to contribute significantly to the problem, while declines in populations of large-scale coral scraping herbivores such as parrot fish (uhu) are a significant issue for our reef health.”
In October, 16 environmental groups and two state entities asked Gov. David Ige and DLNR Chair Suzanne Case to issue an emergency moratorium on the collection of reef wildlife for aquarium purposes.
Jessica Wooley, who was then head of the Office of Environmental Quality Control, and members of the state Environmental Council underscored the dramatic changes Hawaii’s nearshore waters are experiencing from record high temperatures, ocean acidification and massive coral bleaching.
DLNR officials said at the time that they would consider the request based on the best science available.
“Commercial aquarium fish collecting, in fact, does not occur to any great extent off most of the Hawaiian Islands,” Case said in a statement Monday.
Yellow tang are a type of grazing herbivorous fish that the aquarium industry targets off the west coast of the Big Island.
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Aquarium fish collectors have said their impact is negligible and that the opposition really comes from people who are morally opposed to taking marine life for ornamental purposes.
Scientific studies have shown that protecting herbivorous fish is one of the best ways to help bleached coral recover because they eat the algae that takes over as a result. But not all herbivores are created equal.
In Hawaii, yellow tang are by far the most common fish targeted by the aquarium industry, with the vast majority caught off the west coast of the Big Island.
Yellow tang, and other types of surgeonfish, are “grazers” that eat low-lying turf algae, according to William Walsh, a Division of Aquatic Resources biologist who has studied coral reefs on the Big Island for years. They don’t eat the algae, or limu, down far enough to kill it though, which lets it grow back so they can keep eating it there.
But another type of herbivore — called a “scraper” or “excavator” — behaves differently. This type, which includes parrotfish, or uhu, eats the algae down to the point that it exposes the rocky base of the coral, which lets new coral regenerate there, he said. That’s the key aspect scientists say can help bleached coral.
An uhu, or parrotfish, is an excavating type of herbivore that can help bleached corals recover by eating the fleshy algae to expose areas for new corals to grow.
Courtesy: Randy Chiu/Flickr
Aquarium fishers don’t go after parrotfish at all on the Big Island and very little elsewhere throughout the state; they’ve averaged five per year recently on Oahu. But uhu are caught for food.
“We anticipate Hawaii’s management plan might address protection of grazers/excavators as well as certain species of sea urchin,” Walsh said.
Urchins play a similar role as the parrotfish, but their impact is less significant due to their limited mobility.
The state’s reef management plan is expected to cover much more than the collection of certain types of fish.
“Coral reef resilience and recovery is very complex, so the plan will have to address site-specific stressors; this can’t be a one size fits all approach,” Anderson said.
Case said addressing large-scale stressors like pollution from runoff is a tough but important challenge. She hopes the management plan will reiterate steps that every Hawaii resident and visitor can take to help the coral reefs.
“It’s all on the table,” Anderson told Civil Beat.
Hawaii was under the National Oceanic and Atmospheric Administration’s highest alert levels for coral bleaching for most of October and September. As of Monday, some of the state was under a watch but the outlook was “no stress” for the next three months.
One of Walsh’s concerns was that people easily noticed the coral bleaching when it was happening because the reefs were a ghostly white. But as algae grows on the dying corals, he said it can look like they are getting healthy again because the color is changing.
He said cauliflower corals that grow in shallower, wave-exposed areas, and large mounding corals that are decades old suffered “massive mortality” during the bleaching.
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