Cruise inventory

Thalassa EVHOE2015

Cruise plan

Cruise Info. 
Ship name (ship code)Thalassa (35HT)
Cruise identifierEVHOE2015
Cruise period2015-10-17 — 2015-12-01
StatusCompleted
Port of departureBrest, France
Port of returnBrest, France
PurposeResearch
ObjectivesFrench Bottom Trawl Surveys in Bay of Biscay and Celtic Sea.

Objectives
- obtain abundance indices per age group and annual recruitment estimates for the sampled species
- build a reliable time series of those indices
- follow the evolution of the demographic structures of the main exploited fish populations
- map the spatio-temporal distribution of the fisheries resources per age group

Methodology
The GOV 36/47 bottom trawl is used with a 20 mm mesh codend liner. The trawl is deployed with plane oval trawl boards of 1300 kg and with 10-20 cm rubber discs on the footrope. The haul duration is 30 minutes and the towing speed 4 knots. Trawling is carried out during day time only. In the Bay of Biscay (ICES division VIII) and in the Celtic Sea (ICES division VII), a stratified sampling scheme is used. The area is divided according to latitude into 5 blocks and the hauls were distributed in seven depth zones (15-30, 31-80, 81-120, 121-160, 161-200, 201-400, 401-600 m). 160 stations will be occupied. Catch weight and catch numbers are recorded for all species, only selected finfish and shellfish are measured.
Chief scientistMichele Salaun (IFREMER, Lorient Station)
Ocean/sea areas 
GeneralCeltic Sea
Bay of Biscay
SpecificICES areas VII e-j; VIII a-d