RRS Discovery D255

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD255
Cruise period2001-08-14 — 2001-09-03
Port of departureSouthampton, United Kingdom
Port of returnGovan, United Kingdom
ObjectivesThe cruise was funded from two sources:

1. 21 days by a NERC grant (GR3/12789: Metabolism, activity, and distribution patterns of deep-sea demersal fishes: In situ oxygen consumption, activity and fast starts in relation to depth, season and temperature in the NE Atlantic and Eastern Mediterranean) awarded to Priede, Collins & Bagley;
2. 2 days by Tim Minshull to undertake dredging. During CD124 (September 2000) dredging was unsuccessfully attempted due to weather constraints. Funding had been secured to make another attempt sampling at sites south west of the Porcupine Seabight (40 30 N; 15 00 W).

This was the third in a series of 5 cruises. The main objectives of the project are:

1. Determine routine metabolism and activity of demersal fishes in relation to seasonal and environmental parameters. This objective to be achieved using autonomous lander vehicles to conduct experiments in situ on the ocean floor. The Aberdeen University Deep Ocean Submersible (AUDOS) will collect data on routine swimming speed and three new systems will collect data on:
a) Resting metabolism (FRESP:- Fish RESPirometry Lander);
b) Fish fast start (SPRINT lander);
c) Long term scavenger abundance and activity (DOBO: Deep Ocean Benthic Observatory).

2. Temporal changes in demersal fish populations in the Porcupine Seabight. This objective to be achieved using trawl sampling (OTSB) and baited camera data (AUDOS) to examine seasonal and inter-annual changes in the composition of the ichthyofauna.

Specific Objectives

1. Test a new version of the FRESP lander targeting depths around 2500m and 4000m. This new version had a reduced bow wave, timed release and gravity deployed respirometry chamber.
2. Test the new DOBO lander on a short (7 day) deployment. If successful deploy DOBO on a long-term (7 month) deployment to be recovered during our next cruise in March 2002.
3. Deploy AUDOS at depths ranging from 1000m to 4800m to determine bathymetric trends in scavenging fauna.
4. Deploy the ISIT lander to investigate and quantify bioluminescent light at different depths.
5. Use the OTSB to determine the distribution and abundance of fish and invertebrates in the Porcupine Seabight. In addition samples will be used for molecular analysis, enzyme assays and work on brain morphology and visual pigments.
6. Recover Bathysnap
7. Perform 2 days dredging for Tim Minshull
Chief scientistPhilip Bagley (University of Aberdeen, Oceanlab)
Coordinating bodyNERC
Cruise reportRRS Discovery D255 cruise report d255.pdf (0.61 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
SpecificPorcupine Bight
Track chartsRRS Discovery D255 cruise track — d255trk.pdf (0.11 MB)