DISCOVRE 2008

Cruise Log: 10/17/2008

Leg 1 Summary: The Sea has the Final Word

Steve W. Ross, Chief Scientist

No matter neither the size of the ship nor the skill of the crew, there are seas and weather that dictate an end to productive work in the ocean. And so with seas increasing beyond 7-8 ft., we called a halt to our work and ran for port on Monday evening. Although we ended this cruise two days early, our general feeling was that we had conducted about as much sampling as possible between 5-13 October. The crew was tired. We worked 24 hr shifts and deployed many types of gear. While we did not completely finish our many objectives (that will require the next 2-3 years), we have made a good start.

One of our main goals was to test and deploy the two benthic landers provided by the Dutch and UK scientists (see 10/08 blog). Despite some rough seas and the fact that the ship had never done this, the initial deployment went smoothly. We were even able to find one of the landers on the bottom and film it with the ROV, which was exciting for our collaborators as they had never done this. Both landers were recovered four days later, yielding very interesting data on bottom currents and sediment flow. The data were so intriguing that we have already started a paper describing the benthic processes. Because of deteriorating weather, the European crew quickly downloaded data, cleaned parts, charged batteries, recalibrated and reprogrammed instruments, and prepared for the final launching the next day. We chose new settling sites for the landers and dropped them from the surface into 450 meters+ of water. All went smoothly and we will return to retrieve these instruments in one year. Such observatories, gathering high frequency data on long term variability of benthic parameters, are critical in helping us understand these deep-sea coral habitats.

Besides the two lander operations, a big part of the cruise was spent occupying the 83 other stations, as well as conducting some seismic sonar survey lines to help interpret bottom observations. These stations represented the use of a variety of sampling gear, including small bottom trawls (17 stations), opening/closing midwater nets (18 stations), plankton nets (11 stations), benthic traps (4 sets), light traps, and CTD instruments. Much of this important sampling would have been impossible without the large winch loaned to us by our cooperating group, TDI Brooks, Inc. Using this gear was not without hazard, and we lost one benthic trawl, ripped a midwater net, and bent two steel support bars. That is why we bring spares for everything. Great credit goes to our night crew, lead by Andrea Quattrini, who spent long hours on little sleep conducting deck operations all night. Collecting the animals is just the beginning. From these methods we collected hundreds of specimens of fishes and invertebrates, some we had never seen from this area. We took subsamples for microbiology, genetics (278 samples), and stable isotopes (773 samples to help in studies of feeding). We tried to take photographs of all unique specimens, ending up with photos of 352 specimens. The remaining animals were preserved for later identification and other data collection. We will spend the next year in several laboratories identifying, counting, examining stomach contents and reproductive conditions, and gathering other biology data, plus analyzing and writing.

During the cruise we completed six ROV dives (see 10/07 blog). This type of equipment is essential for studying these rugged, deep reef habitats. While we collected some very good video and over a thousand digital still photographs with this vehicle, it had considerable difficulty with conditions on these study sites. The ROV operators worked hard to meet our objectives, but we learned that we will need a bigger vehicle in the future. We appreciate the efforts of SeaVision in keeping up their spirits, remaining cooperative, and helping in many ways through the three cruise legs of this large project.

As of now (Friday, 17 Oct), all of the science crew has departed except me and our GIS technician, Mike Carlson. The ship has been cleaned inside and out. The ROV van and borrowed winch were removed by crane. New stores and fuel have been loaded. The remaining two members of the science crew will come aboard tomorrow. We are ready for our next and final leg of this expedition, which will be to conduct multibeam sonar mapping of deep reef targets off the west Florida coast. One last item is to acknowledge the dedication and skill of the crew and officers of the NOAA ship Nancy Foster, who were a critical part of our mission. Stay tuned for the next installment of our mission.

Drs. Nizinski & Duineveld sorting animals in the wet lab. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge

Crabs and shrimps (left) and rattail fish and flatfish (right) sorted from a trawl catch. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge

A few of our samples: left, the deep-sea isopod; right, a sea urchin common to coral habitat. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge

A few of our samples: left, the hard coral Lophelia pertusa; right, lobsteret crustaceans. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge

THE SCIENCE CREW (5-13 Oct 2008). From left to right, front row: Steve Ross, Amanda Demopoulos, Martha Nizinski, Adela Roa-Varon, Andrea Quattrini, Mike Carlson, Furu Mienis. Back row: Gerard Duineveld, Andy Davies, Tjeerd van Weering, Steve Artabane. Unfortunately another crew member, Mike Gray, had to leave early and missed this photo. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge