������Ƶ

Divers in bays off of South Kohala on the Big Island can’t miss the spectacularly beautiful fish that do laps around the reefs. There are brightly speckled wrasses, pink goatfish with whiskers, and intricately patterned yellow and white butterflyfish with a mask of black around their eyes.

Such sights have long highlighted the awe-inspiring natural diversity of the islands. And that is why a steep decline in the number of such fish, as well as a notable depletion of the coral cover that they feed on, seems so troubling.

How bad is the situation? Recently released data from Hawaii’s Department of Aquatic Resources indicates that the overall number of reef fish off the coast of Puako has fallen by between 43 percent and 69 percent over the last quarter-century, and off of Pauoa, the fish population dropped between 49 and 76 percent. Specifically, the study shows declines in 10 different families of fish. In Pauoa, there are 90 percent less goatfish than there were a generation ago, and 38 percent fewer wrasses.

“It’s almost spooky,” said William Walsh, a marine biologist with the state’s aquatic resources division who conducted the study.

There are other disturbing signs. Up to one-third of the coral there has disappeared in just 25 years. And perhaps most ominously, 87 percent of the hard, colorful algae, which is a building block of reef recovery, is gone at Pauoa. At Puako, the number 64 percent.

“When you see this type of algae going down it’s not a good sign,” the marine biologist said.

Interestingly, the water there is nice and clean, not the sort of wasteland that people might expect, given the data.

Eric Conklin, a scientist with Hawaii’s Nature Conservancy, said that the study provides a good historical snapshot of the reefs. “I think one thing that has surprised a number of us is how healthy and productive we think that stretch of coastline is, and it is, relative to other places,” he said. “And yet, it is a shadow of its former self.”

Without swift intervention, Walsh warns that the coral reefs might never recover, and he laments that state and county agencies, including his own, have failed to make protecting reefs a priority.

Meanwhile, green algae is flourishing and may one day cover reefs that will one day be largely bereft of coral.

Globally, some scientists say that coral reefs are on a trajectory to collapse within a generation, due to acidification from warming waters, pollution and overfishing.

The decline of Hawaii’s coral reefs and fish is occurring around the islands, on Kauai and in on Oahu.

But the findings in South Kohala on the Big Island are particularly unnerving because the leeward coast has some of the richest coral reefs in the state and the area is relatively undeveloped. “It’s going to be known as the last best place,” said Walsh, who has spent four decades studying Hawaii’s coral.

The data highlights several mysteries. For one, what does it mean for the islands?

It could be a troubling bookmark for major reef fish declines throughout the islands. But while Walsh was able to compare the present fish numbers in Puako and Pauoa to data collected by the University of Hawaii between 1979 and 1981 by repeating the original study, such specific data from that era is rare in Hawaii. In other words, it will be difficult to document the evolution elsewhere.

And then there is the crucial question of what is causing the decline?

The study only points out the problem, it is not descriptive. But the findings indicate that the entire ecosystem is stressed. (Species that are often fished are declining alongside fish that are never targeted for food or the aquarium trade.)

Because of the breadth of the shrinking fish population, Walsh said, it is clear that there “is a major system stressor or combination of stressors.”

There are numerous candidates for the origins of the decline. It could be from cesspools that leak sewage into underground streams that ultimately empty into the ocean. Or perhaps it is due to underground injection wells that similarly pollute near-shore waters. Other possible factors are runoff, fishing or the changing climate. Or the disappearing fish could be the result of natural cycles, or due to the volcano.

Philip McGillivary, an oceanographer who worked as an environmental consultant in Hawaii, said that climate change and reduced soil moisture could also be a factor. Abundant groundwater flows through underground streams and out into the ocean on the Big Island’s leeward side. With decreased rainfall and warmer conditions the amount of water in the soil could be decreasing. This could disrupt areas of brackish water that are important for some fish to spawn. Or not. It is just a theory, McGillivary notes. (Studies documenting changes in soil moisture haven’t been conducted.)

Another theory suggests that increases in development upland from the bays could be diverting fresh water. But William Aila, chair of the Department of Land and Natural Resources, said that he didn’t think this was the case. “It’s not like Oahu where streams are diverted for agriculture,” he said.

Until further studies are conducted the mystery is likely to continue.

After all, Walsh said his division does not even have the capacity to study water quality.

And while the Department of Health is responsible for carrying out the federal Clean Water Act, spokeswoman Janice Okubo did not a respond to questions from Civil Beat as to whether the department had looked into the problems at South Kohala. Nor did she say whether or not there were plans to look into the problem. She did suggest, however, that the best agency to contact was the Department of Land and Natural Resources, which oversees the aquatic resources division.

There is one area where there may be action. Aila said that the department would likely seek additional funding from the Legislature to study the problem.

Regardless of the reason for the disturbing trend, Cindi Punihaole, an educational director at the Kohala Center who grew up fishing, said that the community needs to take better care of the reefs and be more mindful about fishing practices.

“There’s no one answer. I think it is because we are all a part of the problem,” she said. “It’s the aquarium collectors, it’s the fishermen, it’s the pollution. It shows a lot of people not being educated about the reefs.”