FN Archimer Export Format
PT J
TI Do survey design and wind conditions influence survey indices ?
BT 
AF POULARD, Jean-Charles
   TRENKEL, Verena
AS 1:1;2:1;
FF 1:PDG-DOP-DCN-EMH;2:PDG-DOP-DCN-EMH;
C1 IFREMER, Dept Ecol & Models Fisheries, F-44311 Nantes, France.
C2 IFREMER, FRANCE
SI NANTES
SE PDG-DOP-DCN-EMH
IN WOS Ifremer jusqu'en 2018
IF 2.058
TC 16
UR https://archimer.ifremer.fr/doc/2007/publication-2690.pdf
LA English
DT Article
CR EVHOE 2000
   EVHOE 2001
   EVHOE 2002
   EVHOE 2003
   EVHOE 871
   EVHOE 882
   EVHOE 883
   EVHOE 894
   EVHOE 905
   EVHOE 916
   EVHOE 927
   EVHOE 948
   EVHOE 959
   EVHOE 97
   EVHOE 98
   EVHOE 99
BO Thalassa
DE ;Bay of Biscay;survey conditions;time trends;catchability;survey index
AB Survey indices play an important role in stock assessments as they provide information on stock trends. In certain cases large interannual variations have been observed which are unlikely to reflect true underlying stock changes but are rather outliers. When survey indices for several species appear to be outliers for the same year, the suspicion is raised that something happened during the survey of that year. This is called a year-effect in survey catches. To study the potential year-effect in survey catches for the French autumn groundfish survey taking place in the Bay of Biscay, several indicators for survey design and wind conditions were derived as explanatory variables and Principal Component Analysis was used to study the relationship between these variables. Using multiple linear regression models we found that, on average 20% of interannual variation in abundance indices could be explained by survey conditions for benthic species, 11% for demersal and none for pelagic species. In contrast, survey conditions explained a smaller and decreasing part of the interannual variability in the coefficients of variations of these abundance indices and in species mean weight for benthic, demersal and pelagic species. Thus survey indices of benthic species seemed most affected by survey design and wind conditions.
PY 2007
PD JUL
SO Canadian journal of fisheries and aquatic sciences
SN 0706-652X
PU NRC
VL 64
IS 11
UT 000251595100008
DI 10.1139/F07-123
ID 2690
ER

EF