Baseline study Fish, fry and commercial fishery Nysted Offshore ...

Bio/consult as Page 18
3.5. Information recorded
In all, the total number of samples obtained during the Spring and Autumn programme
was 236, consisting of 192 biological survey gill nets, 96 turbot gill nets, 236 standard
fyke nets and 236 fry fyke nets.
The following information was recorded for each net:
• Station
• Date
• Net
• Time of activity
• Position
• Depth
• Species of fish
• Number of each species
• Total weight of each species
• Length (total length) of each individual rounded down to the nearest half centimetre
• Corresponding values of length (mm) and weight (1/10 g) for each individual of the
important species
In the fish study, the gonad index was also determined for important species and was
classified on the basis of five developmental levels:
1. Juvenile gonads undeveloped and impossible to tell the sex of the fish
2. Sexually differentiated – the sex of the fish could be determined from the gonads
3. Intermediary – gonads in development with differentiation of roe cells and milt
4. Mature – roe and milt flow freely when the abdominal cavity is pressed
5. Spent – gonads empty or partly empty, slack and bloodshot
Figure 3.5.1 From each sample species was identified and sorted. Each individual was measured and
weighted and notes were carefully taken down.
The following meteorological data for May, June, September, October and November
was obtained from Danish Meteorological Institute and included for station 06149
Gedser Odde:
SEAS. Baseline study – Fish, fry and commercial fishery Dok. nr. 2148-03-001-rev3 2P.doc