13. June


Pelagic shrimps caught in the Egersund trawl.


Sperm whale blowing.


The powerful fluke of the sperm whale.

Todays Highlights

Date:June 13, 2004
Author:  Tone Falkenhaug and Henrik Sřiland, Institute of Marine Research, Norway

Sampling on our fourth station, located east of the MAR, started yesterday evening. Work on station continued through the night and was completed early in the morning. On the first haul a small zooplankton net was attached to the Macrozooplankton trawl in order to sample fish eggs and zooplankton. The sample contained various species of small crustaceans (copepods), planktonic molluscs and arrowworms (chaetognatha). The arrowworms are voracious predators on smaller zooplankton, such as copepods, which are seized with grasping spines located on either side of the head (see plankton video here). Until now, 7 species of arrow worms have been recorded during the cruise, many of which are deep living species.

One of the today’s highlights was the deployment of the large pelagic “Egersund trawl” (75 m wide). The trawl was towed at depths ranging from 1500 to 1200 meters. The scientists were excited by the large catch, which had a high diversity of species. After several hours of identification, and measurements, they can report 24 fish species, 7 species of squids and 7 different species of pelagic shrimps from this single haul. A 44 cm long specimen of the Black dragonfish (Trigonolampa miriceps) was caught, which is the largest ever registered. There were also several Pelican eels (Eurypharynx pelicanoides). This bizarre fish is able to swallow prey that are larger than themselves, and attracts their prey by using a light-producing organ at the tip of the tail.

Today we observed a large dense group of about 15 sperm whales above a seamount around 1200 m below the surface. The whales were found just above this underwater mountain structure, and were probably feeding on squid. These whales are specialists in very deep diving and hunting for fast swimming squid. Other marine mammals observed were sei whales and leaping dolphins.

We are now steaming southwest, heading for our fifth station, located at the ridge. Sampling on this station will continue throughout the night with the Macrozooplankton trawl, the underwater video profiler (UVP), and the CTD.

 

Weather Conditions

It has been cloudy all day, with good visibility. A strong SW breeze early in the morning has diminished to gentle breeze in the afternoon and the sea is calmer.

 

Tomorrows expected highlights

Encouraged by the today’s successful trawling with the large Egersund trawl, this trawl will be deployed on our way to the sixth station, situated west of the ridge.