THE DECLINE OF HAWAII’S MULLET FISHERY AND THE IMPACT ON LOKO I?A

Prior to western contact ancient Hawaiian fishponds (loko i'a) were operated with minimal management. Restocking of ponds occurred naturally, each species entering the pond according to their own season. The estuarine environment attracted species that sought that habitat for food and protection. The nearshore fishery has changed drastically since the first western contact in 1778. There was very little written documentation on the health and structure of Hawaii's fishery until John N. Cobb produced "The Commercial Fisheries of the Hawaiian Islands in 1903". That report serves as the basis for assessing the changes in Hawaii's nearshore fisheries with its current status.

In 1948 the Territory of Hawaii's Division of Fish and Game (currently Division of Aquatic Resources or DAR) began maintaining annual catch reports of all commercial fishing activities throughout Hawaii. "Commercial Marine Landings Summary Reports" are currently available online from 1997 through 2018. Recreational and subsistence fisheries are not monitored so those impacts cannot be assessed. The nearshore fisheries for species reared in loko i'a has changed since 1903 and those changes mirror the fish population in Waikalua Loko I'a.

Sampling of Waikalua Loko in June 2019 generated a list of species. The barracuda (kaku) was the dominant predator. Herbivores (`ama`ama, awa) dominated the fishery and ponds in 1903. In 2019 the pond is still dominated by herbivores; the non-native tilapia and kanda. Fishery data (2014-2018) on these species indicate that the kaku is present in high numbers relative to the more desirable `ama`ama and awa. This suggests that kaku will continue to enter Waikalua Loko in high numbers. As the top predator they remain trapped and feed on all species. Tilapia have become established in Waikalua Loko I'a with survival mechanisms that allow them to proliferate in spite of predation by kaku and other carnivores.