On-board Diary: From Galicia to Asturias

Author: Silvia García
Date: June 24, 2008



Today was our last day in Galician waters. We take a couple of dives with the ROV, on a seamount 30 miles from the coast and on a continental shelf 25 miles from Ribadeo. These distances require almost 4 hours of sailing, so we leave the port of Viveiro at 6 a.m. Luckily, the weather looks good and we will have perfect working conditions.

We are in cold, clear waters, with high visibility. We can see the ROV's ballast (weights that helps to maintain the robot's position underwater) up to 20 meters depth, and it is at 130 meters depth. And yet again, after various attempts to find the seamount, we must accept the fact that it does not exist, because we haven’t found anything except very deep waters. The second dive, off the shelf at 180 meters depth, lasts more than 3 hours. We find a large quantity of echinoderms, such as the goose foot starfish (Anseropoda placenta), which is usually found in very deep waters. We also see large quantities of mysids everywhere, small shrimps that constitute an important source of nutrients for many species.

Sightings of cetaceans have been especially numerous today, more than any other day. We’ve seen bottlenose dolphins (Tursiops truncatus) and common dolphins (Delphinus delphis), various large groups throughout the day, some swimming fast and others playing with the bow our boat. Twice, in the morning, we've also spotted cetaceans we haven’t been able to identify, because they were too far away. In one of the cases, the specimen had a dorsal fin that was much longer than a bottlenose dolphin, perhaps a pilot whale (Grampus sp.). In the other case, the two specimens sighted were larger and darker than any dolphin, so they might have been pilot whales, too.

At the end of the day, we anchored in a cove, west of Busto Cape, in Asturian waters, where the divers carried out a night dive. Five minutes after the divers plunge down, a couple of cetaceans come out of the water to breathe only a few meters away from the us, and we suppose they are dolphins. We hear them for a few minutes. We hope the divers are able to photograph and record them, but there was no luck. What they did document, though, was the frenetic nocturnal activity of the cephalopods, including squids (Loligo sp.), cuttlefish (Sepia sp.) and octopus (Octopus sp.), as they were feeding. We also spotted many fish, such as mackerel (Scomber sp.) and jack mackerel (Trachurus sp.), mullets (Mullus sp.), streaked gurnards (Trigloporus lastoviza) and pouts (Trisopterus luscus), amongst others.