In Pupukea on the north shore of Oahu, I follow Carl Meyer, a graduate student at the University of Hawaii, into the water. He shows me how easy it is to catch fish at night, bare-handed. Shine a light into their eyes and they freeze like deer on a road. He grabs a striped convict tang. In one study, Meyer caught dozens of fish, tagged them with ultrasonic transmitters and released them. Then, to learn their movement patterns, he paddled after them in his hydrophone-equipped kayak.
He discovered that the three species he tracked (blue spine unicorn fish, yellowstripe goatfish and blue jack) all had well-defined home ranges. With the regularity of bank employees, they commuted daily between their sleeping areas in the reef and their feeding grounds. While unicorn fish stayed within the reserve, the goatfish and jack had home ranges three times the reserve size, exposing them to daily danger. Meyer concluded that tripling the reserve’s size, which is currently a mere tenth of a square mile, would protect these mobile species.
In a statement issued last autumn, 161 of the nation’s leading marine scientists suggested that reserves strung together like pearls would provide maximum protection, reseeding each other as well as the nearby fishing areas. Designing optimal reserves therefore requires knowledge of current patterns, larval transport routes and fish movement—there is still much left to learn.
by Bernice Wuethrich