Cruise inventory

FRV Explorer 4B/77

Cruise summary report

Cruise Info. 
Ship name (ship code)FRV Explorer (74EX)
Cruise identifier4B/77
Cruise period1977-05-17 — 1977-05-31
StatusCompleted
Port of returnAberdeen, United Kingdom
PurposeResearch
ObjectivesPart I
1) To determine the horizontal variability of salinity, temperature, chlorophyll and zooplankton by continuous measurement along a line from Rattray Head to Fladen. Two hydrographic stations will be worked to determine vertical distribution
2) To determine the horizontal variability of salinity, temperature and chlorophyll only, on the journey from Fladen to Lerwick

Part II
1) To conduct instrumented engineering trials of a trawl designed for the blue whiting fishery and to evaluate handling procedures for 4 pannel pelagic trawls with long cod-ends on a side trawler.
2) To study the dynamic characteristics of large four panel pelagic trawls in deep water using long warp lengths.

Part I of the cruise was cancelled due to delays in recruiting crew and passage was made for deep water west of Shetland. A mid cruise break in Lerwick took place on the 21/05/1977 to exchange staff.
Chief scientistRichard S T Ferro (Department of Agriculture and Fisheries for Scotland Aberdeen Marine Laboratory)
Cruise reportFRV Explorer 4B/77 cruise report explorer4_77.pdf — access key 'C' (0.08 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
Specificwest of Shetland
Measurements 
Biology and fisheries 
Pelagic fishQuantity: number of hauls = 22
Description: Made at warp lengths varying from 200 to 600 fathoms. The gear configuration for several different rig combinations was monitored. Measurements were made of the dynamic response of the trawl when warp length and speed were increased and decreased during towing. Information was also obtained on the sensitivity of the gear to relatively small differences between the lengths of the 2 warps.
Gear researchQuantity: number of hauls = 22
Description: Made at warp lengths varying from 200 to 600 fathoms. The gear configuration for several different rig combinations was monitored. Measurements were made of the dynamic response of the trawl when warp length and speed were increased and decreased during towing. Information was also obtained on the sensitivity of the gear to relatively small differences between the lengths of the 2 warps.