Lophelia filmed by the deep-sea ROV Aglantha below 1000 metres.
"Caring male" of Entelurus carrying eggs (Photo by David Shale)
Echogram collected by lander (see text for details)
Date:22 of July 2004
Author: Ricardo Serrão Santos (DOP-University of the Azores, Horta, Portugal), Atle Totland (IMR, Bergen, Norway)
Most of the day was focused on the ROVs. The ship went back to some of the stations that had been missed owning to technical problems and we started to catch up with the missing dives. During the afternoon the ROV AGLANTHA dived to 1400 metres deep. During the descent a small squid was caught using the special suction sampling device. Later we were able for the first time to study this creature alive and close up in the aquarium on board the ship.
The dive was made in a region with some sediment and an elevation of pillow lava rising up to 150 metres above the bottom. It is not particularly easy to navigate in these areas. The rocky area was particularly interesting showing a diverse colourful sessile fauna of sponges (in blue, orange, yellow and even green), corals, anemones, etc.
Today we found again a profusion of Lophelia, one of the cold corals, standing on rocky outcrops, emerging from the rocks but also on soft bottoms in small tuffs, not forming large reefs as know for other places. What is amazing in these kinds of dives is to discover such diverse and colourful associations of organisms where no sun-light penetrates.
It is not always is the deep sea that calls our attention. There are the birds, the marine mammals and even sharks that we see at the surface. There are also other small pelagic organisms that we sometimes catch in the net. During this leg we have caught three "pipefish", of the family Syngnathidae. The Syngnathidae are widely distributed around the world, mostly in coastal and inshore areas. The best well known are the seahorses of the genus Hippocampus, considered endangered species in great part of their distribution. The "pipefish" we caught belong to the genus Entelurus. The specimens caught two days ago were a female and a "pregnant" male. In this family of fishes the eggs are transferred by the female to the male. He then keeps them inside pouches, as in the case of the seahorses, or glued to the belly as in the case of the pipefish. Our observation of Entelurus above the MAR proves the wide open ocean pelagic distribution of this genus, which is not surely accidental drift by currents. The pelagic wide north-eastern Atlantic is certainly a habitat for the species. It gives birth, grows, feeds, mates and reproduces in the open ocean without ever having to go near any shore or island. Our photographer on board, David Shale, has captured the beauty of this unlikely fish in the vast ocean domain.
The wide Atlantic is an immense tridimensional puzzle of habitats, with proof of life at all levels being found by means of photography, video and by acoustic instrumentation. After we depart the environment will continue to be monitored by special acoustic instruments. Last night of our three acoustic landers was deployed on one of the highest ridge peaks (900 meters deep) in this area. The lander has an upward looking echo sounder as its main instrument. Detailed data on the diurnal and even annual changes in distribution of fish and other creatures will be stored on board. It will take at least one year before the lander can be retrieved and the data analysed. To allow the system to operate for a long period of time, it has been packed with large batteries. To save power, the instruments and the lander's PC will have a cycle of one week operating and 10 days in "sleep" mode. The figure to the left shows an echogram collected by one of the landers used earlier during the cruise. Fish and other organisms (blue dots are animals) migrate from the surface as the sun rises (the surface echo is red) retreating to the safety darkness down at 300-600 meters for the duration of the day.