DAtabase TRAwl Survey (DATRAS) ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

introduction data: output from database: how are data collected? what are data used for? what problems should users care about? output from database: data files the web page data access ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

data collection catch by length sub sample ALK ICES OBI Conference HL,1,DEN,DAN2,GOV,001,2004,N,8791030402,059,2 HL,1,DEN,DAN2,GOV,001,2004,N,8791031301,023,6 HL,1,DEN,DAN2,GOV,001,2004,N,8791031301,034,2 HL,1,DEN,DAN2,GOV,001,2004,N,8791031301,038,4 HL,1,DEN,DAN2,GOV,001,2004,N,8791031301,039,2 HL,1,DEN,DAN2,GOV,001,2004,N,8791031801,011,2 HL,1,DEN,DAN2,GOV,001,2004,N,8791031801,014,2 HL,1,DEN,DAN2,GOV,001,2004,N,8791031801,015,2 HL,1,DEN,DAN2,GOV,001,2004,N,8791031801,017,6 HL,1,DEN,DAN2,GOV,001,2004,N,8791031801,019,2 HL,1,DEN,DAN2,GOV,001,2004,N,8791031801,021,2 catch by length sub sample ALK ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

why data collection provide ICES assessment WG with indices describe species distribution biodiversity studies ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

data IBTS North Sea (1965) IBTS Northern BTS BITS (1985) (1994) (1991) All quarterly based and by stratum; area or/and depth IBTS Western (2001) ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

IBTS-North Sea IBTS 30 min all fish species GOV whole NS History: International Young Herring Survey (IYHS). By the Dutch in 65. information for other fish species, such as cod and haddock => the survey was renamed into the International Young Fish Survey (IYFS). Now 8 standard species where there are collected data as age and maturity be length Decide on 30 min hauls in 1977, took until 1998 before all countries followed the recommendation Decided on GOV trawl in 1977 – was implemented by 1983 In 1990 ICES decided to combine the international and the national surveys into the IBTS. The IBTS was carried out on a quarterly basis in the period 1991-1996. since 1997 twice per year (1st and 3rd quarter) GOV whole NS IBTS hauls 1. q, 2004 ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

data flow in DATRAS ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

standard output tables Whiting 1. q NS-IBTS,2004,1,1,44F0,164712,Gadus morhua,0.02,20.62,5.24,5.63,4.27,2.20 NS-IBTS,2004,1,1,44F1,164712,Gadus morhua,1.39,27.10,3.31,2.14,0.63,0.40 NS-IBTS,2004,1,1,45F0,164712,Gadus morhua,0.66,7.65,3.36,4.13,0.51,0 NS-IBTS,2004,1,1,45F1,164712,Gadus morhua,0.35,22.32,10.99,15.19,3.10,2.01 CSV files CPUE per length CPUE per age mean CPUE per age by statistical rectangle mean CPUE per length by statistical rectangle indices ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04

access to data www.ices.dk ICES OBI Conference Lena I. Larsen 29.11.04 – 01.12.04