On-board Diary: July 29, 2008
Author: Ana de la Torriente
Date: July 29, 2008
Today was an intense day of work with Rov. During the first dive, in the canyon off Ondarroa, we documented a muddy bottom where the following creatures dwell: prawns of the genus Pleisonika, octopi (Eledone cirrhosa), catsharks (Sciliorhinus canicula), four-spotted megrims (Lepidorhombus boscii), silver pout (Gadiculus argenteus) and color tube anemones (Cerianthus membranaceus). These last ones formed abundant bunches.
Something notable about the dive is that we documented the shark Galeus atlanticus for the first time since the beginning of the expedition. This is a never before described species in the Bay of Biscay. This shark is a deepwater species whose distribution has been confirmed in Mediterranean Spanish waters from the Strait of Gibraltar to Cabo de Gata, and is especially abundant in the Alboran Sea. In Atlantic Spanish waters, it is found from the Strait of Gibraltar to Cabo de San Vicente and on the Northwestern coast of Africa at Cape Spartel in Morocco and in Mauritania. The problems identifying this shark and confusing it with other two species of the same genus, G. melastomus and G. polli, have probably been one of the reasons its true distribution has been unknown.
The second task with Rov was also performed on a muddy bottom in the canyon off Ría de Orio. Besides silver pout, anemones, greater forkbeards (Phycis blennoides) and pennants (Anseropoda placenta), we found Norway lobsters (Nephrops norvegicus), which were the dive's great find, and once again, a new record for the expedition.
Along the transect, we recorded just 10 specimens of this species. Some crayfish stocks are in a relatively good situation. However, in the Cantabrian area, the stock is close to collapsing. Therefore, the low number of crayfish specimens we found was no surprise.
As always, when we approached the canyons, we are always accompanied by a group of common dolphins (Delphinus delphis), that stayed nearby, displaying feeding behavior.
Already back in port, while arriving in Zumaia, we found a bonito boat from Getaria catching live bait with nets. The amazing thing was that even though it is a practice permitted within legal margins, the ship was very close to the shore - at a distance of 0.25 nautical miles from the Zumaia breakwater. We trust that little by little, we will evolve toward restricting this type of practices in possible areas of fish hatcheries for many fish species.