Thursday, May 12, 2011

Burdwood bank – the work begins!

11th May 2011

The ARV N.B. Palmer arrived at our first station, Burdwood Bank, at 3am this morning, and work began in earnest. The first thing to do was to put down a couple of trawls. One of the main aims of this cruise is to sample deep-sea corals of the Drake Passage and we can do this either by dredge or trawl. Our favorite type of trawl for collecting benthic marine life is the Blake Trawl, which has a heavy frame attached to a net to scoop up biology from a small area of seafloor. We deployed two Blake trawls in the early hours of the morning, both of which brought up some goodies for us, including some living corals, echinoderms, sea-spiders, sponges, bryozoans and even a few fossil corals.

Our next target for Burdwood Bank was to retrieve some sediment cores using a Box Core. Unfortunately, the corer came up empty, even on the third try – it seemed that the sandy sediments here are just not right for this coring device. In this business it’s definitely a case of “win some, lose some”!

Not downhearted, the next step was to try out the WHOI TowCam system (see link on the right). This camera is purpose built to be towed behind the ship, very carefully to avoid hitting the seafloor and at a very slow speed, to taking photos and water samples along the way. It allows us to really understand the diversity and ecology of the corals growing on Burdwood Bank: do the corals form reefs, or do the corals grow in isolation? Do they grow in association with other animals, or particular types of seafloor rocks and sediment? We hope to be able to answer all of these questions, and more, by looking at the photos that the TowCam brings up. The TowCam team had a very successful day, taking photos and bringing up water samples for chemical analysis.

As the day watch shifted over to the night watch, a dredge was recovered, bringing up a large haul of biology, fossils and rocks, which pleased all the science team. So, although the swell has been fairly fiendish, making walking around on deck tricky at times ,everyone on board is in good spirits, after a good first day of science!

By: Kate

Weather: 41°F, 25°F windchill, 5-15 knots, sunny intervals!

The Marine Techs (Stian and Marc) deploy the Blake Trawl early this morning amidst some very large sea swell (R. Waller).

The Towcam in full splendor, on the starboard A-frame of the ARV N.B. Palmer (A. Margolin).

Towcam disappears into the water to take photos of the seafloor at 300m depth (A. Margolin).

Recovering material from the Hein dredge this afternoon (A. Margolin).

Biologist Sebastian with a primnoid octocoral recovered in the Hein dredge (A. Margolin).

1 comment:

  1. I was a girl, but clumsy things. I do not know how to cook, sew, above, ca. I have too insipid and tedious, but that's my personality. It's hard to change