USVI Larval Distribution and Supply

Fisheries oceanography research cruises were conducted aboard the NOAA Ship Nancy Foster. The research conducted was aimed at answering the following three questions:

1) How do the abundance and composition of ichthyoplankton around Grammanik Bank and other similar banks change with space and time?

2) How much of this variation in abundance and composition can be explained by the oceanographic setting?

3) How do the oceanography and ichthyoplankton assemblages' interface with the boundary areas of seasonally or permanently closed MPAs?

We sampled settlement-stage larvae in conjunction with an oceanographic (biological, physical and chemical) survey of the bank system, coral reef environs, and inshore waters of the USVI, with emphasis on present and possible future MPAs. Surveys included bongo and one meter multiple open and closing net environmental sampling system (MOCNESS) trawl tows, as well as CTD02/LADCP casts profiling, temperature, salinity, dissolved oxygen, light transmission, chlorophyll, and water velocity. Continuous surface measurements of temperature, salinity, light transmission, chlorophyll, and water velocity were collected via the ship's flow-through system and hull-mounted ADCP. Independent temperature profiles were obtained using XBT.

Finally, satellite-tracked, Lagrangian surface drifters were deployed to assess regional ocean circulation. Stations directed at the Virgin Islands were designed along transects that allowed for sampling near shore, along the shelf edge, and offshore. Depending on the location along the sampling transects, various biological and/or physical oceanographic sampling methods were used.

To observe variation in ichthyoplankton abundance and composition in the region due to oceanographic processes