Stock assessment surveys of marine preserves and control sites

Gutierrez, Jay

During FY98, initial planning for the Marine Preserve Fish Assessment Surveys had begun. Of Guam’s five marine preserves, fish assessment surveys will be conducted at the Piti Bomb Holes Preserve and the Achang Reef Flat Preserve. The surveys will be divided into two habitat types: the reef flat and the fore reef slope. The reef flat habitat will be divided into microhabitats such as sandy bottom, seagrass beds, and coral/rubble habitats. The control site chosen for the reef flat at the Piti Bomb Holes Preserve is Cocos Lagoon, the control site chosen for the Piti Bomb Holes Preserve fore reef slope is the Asan fore reef slope (area closer to Adelup), the control site chosen for the Achang Reef Flat Preserve reef flat was the Pago Bay reef flat, and the control site chosen for the Achang Reef Flat Preserve fore reef slope was the Atao Beach fore reef slope. Field surveys were conducted at a variety of sites until suitable control sites could be selected. Fish assessment surveys will also be conducted near the Piti Observatory since feeding practices appear to be aggregating fish. A visual fish survey was chosen: reef flat surveys and fore reef slope surveys will consist of 50 m X 5 m strip transects. To augment the results of these surveys, interval counts, filming with an underwater video camera, and photo-sampling of substrate will be conducted. The fish species to be surveyed are the important food fishes and the butterflyfishes since they usually serve as indicators of coral cover.