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

2. 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 –

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

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

5. 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 –

6. 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
since 1997 twice per year (1st and 3rd quarter)
GOV
whole NS
IBTS hauls 1. q, 2004
ICES OBI Conference
Lena I. Larsen –

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

8. 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 –

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