DLNR: Comprehensive Coral Reef Management Planning

A comprehensive coral reef management plan for near-shore water in the main Hawaiian Islands is underway in response to mass coral bleaching across the entire Hawaiian archipelago.

“Coral bleaching in some parts of Hawai’i is unprecedented in recorded history, placing our corals at much greater risk of dying,” said Dr. Bruce Anderson, administrator for the Department of Land and Natural Resources Division of Aquatic Resources. “We need to ensure our reefs are as healthy and resilient as possible to maximize the chances of recovery.”

In October, the State Office of Environmental Quality Control requested that the Department of Land and Natural Resources consider a temporary moratorium on commercial aquarium fish extraction in response to Hawai’i’s extensive coral bleaching event.

“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,” Anderson said.

As a result of the October request, DLNR Chair Suzanne Case wrote back, noting that commercial aquarium fish collecting was not happening in large numbers off most of the Hawaiian Islands.

“The fishery is primarily centered in West Hawai’i. Fifteen years of data shows that the herbivores making up most (92%) of the catch have increased over the years and are now more numerous there than any other place in the Hawaiian archipelago,” Case said. “Significantly, no parrotfishes are taken by West Hawai’i aquarium collectors.  On Oahu, less than 20% of all the aquarium animals collected are herbivorous fishes. Again, parrotfishes are essentially not taken by collectors, averaging only 5/year recently.

“Addressing large-scale stressors like land pollution is a tough, but important, challenge. In the management plan, we hope to reiterate steps that every Hawai’i resident and visitor can take to help our coral reefs.”

Dr. Anderson says the development of a statewide coral reef management plan is a major priority for DAR. He noted the extent and severity of coral bleaching across Hawai’i over the past two years.

“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,” Dr. Anderson said.

On the Big Island, Dr. William Walsh, a DAR Aquatic Biologist, has a long history collecting data on coral reefs. His expertise notes that herbivores are not created equally and ocean scientists categorize them based on what they feed on, their role on a reef, and their role in coral health and recovery.

“Grazers are the main fish collected by the aquarium industry.  They crop the low-lying turf algae and include many species of surgeon fish like yellow tang.  The other two categories are browsers and scrapers/excavators,” said Dr. Walsh. “It’s this last category that current global scientific research suggests are the key players in overall coral reef health, by regenerating coral reefs and controlling invasive algae. These include parrot fish. We anticipate Hawai’i’s management plan might address protection of grazers/excavators as well as certain species of sea urchin.”