Data on the distribution and feeding of fin whales off the Galician coasts

• Main Authors: Lens, Santiago, Santos, María Begoña, Miranda, Ana
• Format: Still Image
• Language: Spanish
• Published: 2007
• Subjects: Medio Marino; Centro Oceanográfico de Vigo; Fin whale
• Online Access: http://hdl.handle.net/10508/8780; http://hdl.handle.net/10261/323229

One ofthe aims of a next CODA (Cetacean Offshore Distribution and Abundance in the European Atlantic)-IEO survey, is to investigate the presence of fin whales and their prey off the Galician coast. As a preparation it was considered useful to look at the available historical information regarding fin whale presence off GaIicia. Some observations about fin whaIe feeding are aIso presented here. The catch statistics for 1952 - 1985 were analysed for pattems of seasonal distribution. Information about the geographic distribution of fin whaIes was obtained from positions in the catch statistics, from sightings made by the whaling boats and from severaI sighting surveys. These positions were represented in charts with bathymetric profiles to visualise the distribution of whales in relation with the sea bottom topography. The prey species found in the stomachs of 17 individuaIs caught during the 1983 season were identified and their degree of digestion and semi-quantitative abundance evaIuated. Throughout the historie series more than 70 % ofthe catches occur between July and September. Some temporal distributional pattems can be described along the time series and in relation with annual values ofNAO and Gulf Stream indices. Positions of catches and sightings data were plotted by months and compared to show the seasonal distribution and reIative movements of fin whaIes. Only 3 of the 17 stomachs were empty. The prey most commonly found (85.7 % of the stomachs with food) was the euphausiid Meganycthiphanes norvegica. One whale has only the gadoid fish Micromesistius poutassou and another whale a mixture of both items. The degree of digestion and the amount of food in the stomachs suggest a moming feeding periodo The position and dates of the catches of these specimens could also indicate areas where euphausiids and fish were locally abundant in that particular year.