|Ref.||Working Document for WGHANSA (Lorient, 24-29 June.2016)|
|Copyright||2016 Ifremer, CNPMEM, Université de La Rochelle|
|Author(s)||Duhamel Erwan1, Doray Mathieu2, Huret Martin1, Sanchez Florence5, Lespagnol Patrick1, Doremus Ghislain4, Lemerre Charlotte3|
|Affiliation(s)||1 : IFREMER, lab. Fisheries Research, 8 rue François Toullec 56100 LORIENT, France
2 : IFREMER, lab. Fisheries Ecology, BP 21105, F- 44311, Nantes, France.
3 : CNPMEM, 134 avenue de Malakoff, 75116 PARIS, France
4 : Observatoire PELAGIS - UMS 3462 - Université de La Rochelle – CNRS - Pôle Analytique – 5 allée de l’Océan - 17000 LA ROCHELLE, France
5 : IFREMER, Allée du Parc Montaury 64600 Anglet, France
|Abstract||The Pelgas16 acoustic survey has been carried out with very good weather conditions (regular low wind, medium temperatures) for the whole area, from the South of the bay of Biscay to the west of Brittany. The help of commercial vessels (two pairs of pelagic trawlers and a single one) during 18 days provided about 120 valid identification hauls instead of about 60 before 2007 when Thalassa was alone to identify echotraces. Their participation increased the precision of identification of echoes and some double hauls permitted to confirm that results provided by the two types of vessels (R/V and Fishing boats) were comparable and usable for biomass estimate purposes. These commercial vessels participated to the PELGAS survey in a very good spirit of collaboration, with the financial help of "France Filière Pêche" which is a groupment of French fishing organisations.
The PELGAS16 survey observed a medium level of anchovy biomass, which seems to be a medium biomass compared to previous year's, comparable to 2010 and far away from the 2015 biomass. The biomass estimate of sardine observed during PELGAS16 is decreasing compared to the last years level of biomass. It confirms that this specie shows a variable abundance in the bay of Biscay at this period.
Duhamel Erwan, Doray Mathieu, Huret Martin, Sanchez Florence, Lespagnol Patrick, Doremus Ghislain, Lemerre Charlotte (2016). Direct assessment of small pelagic fish by the PELGAS16 acoustic survey. Working Document for WGHANSA (Lorient, 24-29 June.2016). https://archimer.ifremer.fr/doc/00344/45546/