Lecture 2 Flashcards
How can age of a fish be calculated?
Otoliths (ear bones) have growth rings
What can research vessel surveys show?
Validation on what is being observed in fish markets
What does TAC stand for?
Total allowable catch
How can scientists influence management of fisheries?
Make catch forecasts which are transformed into official ICES advice to the EU Science
How can larvae surveys help with stock assessments?
Number of fish eggs and larvae found in plankton can provide insights into fish spawning
What can information from fishermen show?
Catch per unit effort from log books
What is a problem with TACs?
If you catch fish over the quota have to be thrown back = discards
What are the three issues that complicate the tasks of fisheries stock assessment?
Cannot count all fish Fish move around Number of young produced annually varies
What can satellite tracking provide?
Insights into location of fisheries and allow seabed and resources to be managed spatially
What does MSY stand for?
Maximum sustainable yield
Why estimate fish stocks?
Develop management plans to exploit species Investigate different degrees of mortality Manage an annual quota Manage eu fleets
What are the two main tasks of fisheries stock assessment?
Estimating how many fish there are Forecasting how many fish there will e
What is MSY?
Target reference point. Level of fish catch that may be made each year without endangering the capacity to regenerate
What is the goal of MSY in the eu?
Produce stable and sustainable catch levels
What are the key values to estimate?
Fishing mortality Spawning stock biomass Recruitment Fish landings
