FRV Mara 6/70
Cruise summary report
|Ship name (ship code)||FRV Mara (74MR)|
|Cruise period||1970-07-27 — 1970-08-29|
|Port of departure||Buckie, United Kingdom|
|Port of return||Buckie, United Kingdom|
|Objectives||1) Observation and photography of the behaviour of round and flatfish during the process of demersal seining
2) Recording the change in shape of the seine net by means of instrument spread, headline height and photographs of warp divergence. Reading to be taken of the warp tension developed during fishing, and further studies made of the sinking rates of ropes and the behaviour of ropes during fishing.
3) Underwater photometry to correlate underwater visibility with fish behaviour
4) Tagging of flatfish to determine behaviour in relation to tide, and estimation of catching efficiency of the gears.
The first 2 weeks of the cruise were carried out from Buckie. During the final 3-week period of the cruise, FRV ''Mara'' worked jointly with ''Boy Andrew.'' No tagging of flatfish was carried out
|Chief scientist||C C Hemmings (Department of Agriculture and Fisheries for Scotland Aberdeen Marine Laboratory)|
|Cruise report||(0.12 MB)|
|Specific||Spey Bay, 'Bellings' ground, N side of Moray Firth, Sinclair Bay|
|Optics (eg underwater light levels)||Description: Some samples of underwater 'black body visibility' and records of surface light intensity were taken. No. of records taken not recorded.|
|Current profiler (eg ADCP)||Quantity: number of deployments = 1|
Description: A Plessey current meter was deployed during the cruise, but proved to be non-functional.
|Biology and fisheries|
|Demersal fish||Description: Observation and recordings made within the 1st 2 weeks were restricted to flatfish due to the absence of haddock at certain depths. Instrument readings were taken, along with cine film recordings. No. of hauls not specified.|
|Demersal fish||Description: Several hauls were made in the 2nd part of the cruise. The hauls were to obtain haddock samples. No. of samples was not specified.|
|Gear research||Description: Two forms of groundline rigged for rough ground operation were observed. No. of trials not noted.|