Life Aboard Ship, Dispatches From South of the "Roaring Forties"
Wednesday, June 30, 2004
We are on the verge of leaving Bouvet and heading to Tristan da Cunha. (see “Cruise Track,” http://www.icefish.neu.edu/) We are pulling our last strings of fish traps now (0930). Afterwards we are going to do some surveying with a small ROV (Remotely Operated Vehicle), and after that, we will head north to warmer (and sunnier) waters. Sampling here has been difficult, and we did not succeed in getting any samples below about 650 meters (2122 ft.), having lost the cod end of one 30 foot otter trawl (unrepairable here) and one complete 30-foot otter trawl at 1500 m (4875 ft.) while trying.
Yesterday we had beautiful sea conditions. When I got up for breakfast (0730) the sea was calm, even glassy in places, and there was only a low swell running. We were trawling in very shallow water (about 50 m or 162 ft. deep, 3/4 mile off the beach) on the eastern side of Bouvet. We had discussed trying to land to use a beach seine to collect intertidal fishes, and decided to try it.
The nav chart shows three landing spots, one in the middle of the eastern side. Of course, these were sites of reported landings, most of them made long ago. Given the instability of the ice cliffs, and the power of the surf and the currents, we figured that conditions on Bouvet probably change rapidly, so maybe these were no longer viable landing spots. So, around noon, the crew got out our two Zodiac inflatables, set them up, and put them in the water. One would be used to trawl in shallow water (we used it the same way in the Falklands) and the other would land a seining party on the beach. First, however, we had to find a place to go ashore.
Both Zodiacs are being prepared for deployment, one to land on Bouvet, the other to trawl for fish off the beach. The trawler has the steel A-frame and block.
The inflatable went down the beach slowly, and (we later learned) anchored offshore in at least one spot so they could watch the breakers. Then they came back to the ship and reported that although it was possible to land (with just the right timing) it would not be possible to leave the beach safely. Appearances were deceptive: Bouvet could be the ideal description for "shore break" as applied to swells. The beach was narrow and moderately steep, but at the water's edge there was a very steep drop off, and the swell would build up very high right there and break directly onto the beach. In fact, while I was watching them move along the beach line, I could see the boat drop out of sight as large swells would build off shore of them.
Here is what it looked like from the inflatable. No scale, but the beach is about 10 feet wide!
Photo: David McPike
The trawl boat was more successful in that they were able to find good bottom and tow a net there at least an hour, but they caught nothing. That was disappointing, but not too surprising. One of the things we have learned about Bouvet is that it has what we would call a depauperate fauna (that is, not many species and not many of each). We suspect this is the result of several factors: 1) distance from nearest land to the west (e.g., the South Sandwich islands) means that drifting eggs and larvae from these shores would have to drift over a thousand miles to reach Bouvet; and 2) strong currents, ice erosion, and loose bottom means that most animals could not survive on the bottom for any length of time before being swept away or destroyed.
So as we head north to Tristan, which is supposed to be "the world's most remote inhabited island" (as opposed to Bouvet, which is supposed to be the most remote place on earth), I'm actually sorry to leave. I think we could have learned much more if we had only had more time (and more nets)!