2011 NSF RAPID cruise Pt 1: Macroalgae, macrocrustaceans and associated fauna offshore LA, MS, AL

The NSF RAPID grant (DEB-1045690) awarded to Suzanne Fredericq and Darryl Felder from the University of Louisiana at Lafayette (http://biology.ucs.louisiana.edu/) and entitled "RAPID: Impacts of the Deepwater Horizon crude oil spill on the diversity of macroalgae and macrocrustaceans inhabiting deepwater hard banks in the NW, NE and SE Gulf of Mexico" is facilitating critical assessment of pre- and post-oil spill impacts on the diversity, vitality, and distribution of these offshore organisms. This video shows part 1 of the 2011 April 20-23 RAPID sampling cruise offshore Louisiana (Sackett Bank), Mississippi and Alabama. Part 1 documents in situ video of the muddy bottom at Sackett Bank filmed with an SeaViewer underwater camera, deployments of a box dredge and benthic skimmer, and examples of macrocrustaceans and associated fauna (sponges, sea cucumbers, molluscs, nemertine worms, cephalopod, fish). 1) April 20, 2011, Box dredging at Sackett Bank, 60-64 m depth
~28o.37.995'N, 89o33.370'W (in) ~28o.38.004'N, 89o33.187'W(out); 2) Benthic Skimmer dredging, 307-560 m depth, ~28o.32.439'N, 89o29.373'W (in), ~28o.29.224'N, 89o30.525'W; 3) April 21, 2011, ~28o.23.935'N, 89o22.508'W (in), ~28o.20.939'N, 89o20.779'W(out) 675-765 m depth.

The Hourglass-design box dredge provides a now standardized method of semi-quantitative sampling. It is an effective tool only on substrata of low relief that consist of loose rocks and rubble, shells or shell hash, and calcareous nodules (rhodoliths), the typical substrata of Gulf deep banks.

A benthic skimmer provided an ancillary tool for work on lower slopes of hard banks and surrounding bottom, taking advantage of ship access to these locations in the northern Gulf of Mexico, and allowing a comparison to established data sets for especially deep benthos. While operated below depths inhabited by most macroalgae, it provided excellent intact samples of benthic macrocrustaceans and associated fauna. The skimmer is constructed precisely in accord with those used in the most extensive previous surveys of such Gulf environs by the R/V Alaminos in the 1960's through early 1970's (Pequegnat et al. 1970). This standardization of tools potentially allows comparisons of new collections to a substantial published record of deep Gulf benthos in proximity to the oil spill. Reference: Pequegnat, W. E., T.J. Bright & G.M. James. 1970. The benthic skimmer, a new biological sampler for deep-sea studies. TAMU Oceanographic Studies 1: 17-20.

The expedition departed from LUMCON in Cocodrie LA, on board the R/V Pelican, a 32 m (105ft) ABS Class "A-1+ Oceanographic, steel-hull coastal research vessel operated by UNOLS.

Filmed and edited by S. Fredericq.

Category:

Science & Technology

Tags:

• National Science Foundation
• BP
• oil spill
• seaweeds
• crustaceans
• taxonomy
• northern
• Mississippi
• Alabama
• rhodoliths
• mud
• evolution
• biogeography
• systematics
• exploration