The Deep Gulf of Mexico Benthos Cruise

Biweekly report number 3
May 15, 2000

This is our third bi-weekly report. It is Monday and our 13th day at sea. We are now on our 13th site, which means we are right on schedule with an average of one station per day. We are in the middle of a camera lowering, which is our 131st activity. The first week we went south down across the slope doing stations designated WC, B or NB. This reflects west central stations that were done by LGL in NGOMCS or the testing of our basin vs. non-basin hypothesis (B and NB). Following this set of stations, we proceeded back up north to the shallow end of the "W" or western transect done on NGOMCS by LGL. Of these, we have now completed 3 sites: W1 through W3, and are nearing the middle (in time) of W4 at a depth of 1.4 km. After this we will continue offshore to our deepest stations, W5 and W6, the latter at 3.2 km. It is on the 26 North Lat. line, which is the standard demarcation of our EEZ bordering Mexican waters.

Success with the box core continues to be excellent. Subsamples continue to be taken for bacteria, meiofauna, trace metals, hydrocarbons, geology and geochemistry. We were able to obtain a good pinger [sent to us on a supply boat which we met Saturday morning at AUGER], and hence the camera lowerings have resumed with good success at determining bottom contact. Having digital images is a satisfying advance over previous work we have done with film cameras.

We continue to do CTD's with a 12 bottle rosette.

Our best trawl sample was at W1. Numerous photos were made of the diverse catch of both fishes and invertebrates. It was also characterized by high biomass. Some of the specimens were photographed and can be seen on our web site. An 8th grade class in Wichita Falls is using the web site as a teaching tool.

This great success of the trawl at W1 however was followed by a complete severing of the net off the boards at W2. By W3 we had re-rigged the boards with the backup net. On this tow the backup net was sliced extensively in two places, but not lost. At this time it is being sewn up on the fantail. We are looking into the options available to us in Port Aransas and the surrounding area for finding additional backups for the trawl. Our beam trawl is available, but is not expected to fish as well as the the otter trawl with semi-balloon net. Known bottom obstructions have been plotted on our mapping system, but none can be seen at the depths at which we are operating. The causes of our nets' being sliced up remains open to speculation.

Following this transect (W), we will steam up slope doing RW (really west)6 through RW 1, and including a station in Alaminos Canyon (AC1). From RW1, we will terminate Leg 1 in Port Aransas.