DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009

DEEPFISHMANStakeholder worskshop

Brussels

29-30 June 2009

Data availability

DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009

Type of Data ProblemsFishing

Times series of fleet, catch and effort

Start time of time-series, resolution, completeness

Biology (biological parameters, stock structure)

Uncertainty

Biodiversity

By-catch, benthos, VMEs, fishing impact,

Often limited, observation data provide by-catch, not all fleet covered

Economy See G. Haraldsson’s presentation

Social See G. Haraldsson’s presentation

Assessment methodologies Most assessment exploratory, not validatedeven for redfish “data rich” stock

Management Data on management procedure,regulation available

Impact on fleet poorly known

DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009

More data allow more realistic assessment and management

Example 1:

Tally book data provide haul by haul catch and effort

The view of the fishery is different for that for EU logbook data (hauls aggregated per day and statistical rectangle)

Tally books allow : - better estimates of CPUEs

- account of fishing strategies on trends in landings and CPUEs

DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009

Example 2.

-the effect on fishing on both exploited species and other species in the ecosystem is primarily a matter of mortality- for benthos mortality can be assessed from the frequency of trawling

DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009

Example 2.

-the effect on fishing on both exploited speices and other species in the ecosystem is primarily a matter of mortality- for benthos mortality can be assessed from the fequency of trawling

When data resolution increases a large proportion of the seabed appears no to be fished:

% of unfished bottom (% unimpacted benthos) estimated lower from VMS

No change in estimated fishing mortality for target species

From Piet and Quirijns (2009). The importance of scale for fishing impact estimations. can. J. Fish. Aquat. Sci.

DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009

Questions

Which data can be made available for stock and ecosystem assessment

- VMS data: which are available?

what can de done with?

- Tally book data: main use might be stock assessment?

- Data availability in the future (e.g. electronic logbook)