Ocean Research Equipment for the Coral Reef Research Foundation

Coral Reef Research Foundation, San Diego CA

Investigators

Abstract

With the oceanographic equipment funded by this project, the Coral Reef Research Foundation in Palau will be able to examine the physical environment associated with coral reefs, fish spawning aggregations and marine lakes with endemic jellyfish. The multibeam sonar mapping system will allow the creation of bottom maps of the entire perimeter of Palau's outer reef slope (300 km) to 200 m depths, allowing a better understanding of deep coral reef communities. The ocean current profiler will track water movement on and adjacent to reefs, information that can help track where fish eggs and larvae go after spawning. This important aspect of the life history of fish will help to estimate where young fishes come from after spending their larval life in the open ocean. The CTD profiler will be used to measure how the temperature and salinity of the ocean and lagoon varies with depth. In Palau's marine lakes these instruments can also provide information leading to important work on climate change, where bottom cores from the lake provide a historical record of past climates. All of these instruments are used to measure important physical characteristics of the ocean, lagoon and marine lakes. Overall this project will improve the understanding of highly diverse tropical marine environments and their resources which are under increasing stress from climate change and human population pressure. The project will purchase 1) a multibeam sonar system for bathymetric mapping, 2) two Acoustic Doppler Current Profilers (ADCP) and 3) two Conductivity Temperature Depth (CTD) profilers. All equipment will be used by visiting researchers and staff at the Coral Reef Research Foundation (CRRF) in Koror, Palau (coralreefpalau.org). The multibeam system will be used to map outer slope reef environments and deep lagoon areas to benefit broad studies of mesophotic environments, topography of reef fish spawning aggregations, and marine lakes. The current profiles will be used to study fish spawning aggregations, fish vortices, and marine lake hydrodynamics while the CTDs will complement other location specific data collection. The equipment will enhance long-term data collection efforts stimulated by major events such as coral bleaching (1998, 2010) and jellyfish population crashes (1999, 2016). Broad impacts of the work include addressing the suggestion that mesophotic coral reefs are possible "lifeboats" for shallow water (less than 30 m depth) coral reefs, and help move beyond the relatively simple considerations of deep reef refugia presently being debated. Deep reefs also hold various organisms usable as proxies for questions of climate change, including ocean warming and sea level rise, and mapping will help delineate where such organisms occur. The health and fate of reef fish spawning aggregations, critical for fisheries in developing countries and understanding human impacts on reef fisheries, will be examined in new ways to quantify the locations and number/sizes of fish present. Marine lake investigations will benefit from improved understanding of the physical and biological dynamics. Surveys of lake bathymetry will drive selection of locations for sediment coring of their bottoms, which hold multi-thousand year records of El Nino conditions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.