Understanding harbour porpoise (Phocoena phocoena) and fisheries interactions in the north-west Iberian Peninsula

Project ID:
PP/2010/06
Activity start date:
Activity end date:
Contract number:
SSFA/ASCOBANS/2010/4
Contract signed date:
Closed on date:
Executive summary

The proposed project aims to:
1) Quantify life history parameters (age structure, age and length at sexual and asymptotic maturity, pregnancy rate, etc) in harbour porpoises for the NWIP.
2) Use age-at-death data to estimate total and fisheries mortality rate for porpoises in the NWIP.
3) Examine evidence for temporal trends in age at sexual maturity, reproductive output and mortality rates.
4) Compare life history parameters for Iberian porpoises with those from northern Europe.
5) Investigate seasonal, geographic, annual and ontogenetic variation in the diet of NWIP in relation to prey abundance and thus define their trophic role in the area.
6) Provide recommendations on conservation of porpoises along the north-west Iberian Peninsula.

Conservation

The by-catch rate in NWIP porpoises is currently unknown and there is currently no nationally funded strandings monitoring in the area, this role being taken by NGOs. Analysis of diet and life history parameters for stranded animals, coupled with diagnosis of cause of death provides a mechanism to both directly estimate by-catch mortality and to provide
basic parameters for monitoring of population status and trends. The recent recognition of this population as genetically distinct and the recommendation by ICES WGMME to treat it as a separate management unit makes this work particularly timely.

Objective
Habitat conservation and management
Surveys and Research
Use of by-catches and strandings
Budget line (BAC)
Fund:
BAL
Organizational unit:
2236
Programme:
2661
Object code:
220100
Activity

Age determination by counting growth layer groups in the dentine. Age data will be used to construct life tables and thus estimate mortality rate

Stomach content analysis and comparison with fishery catch data to determine the potential for competition between cetaceans and fisheries e.g. catch composition, minimum landing size and geographical overlap

Determination of individual reproductive status and history, which together with age data will be used to construct maturity ogives (to establish age and size at sexual maturity), and determine the pregnancy rate and the annual reproductive cycle.

Statistical analysis of trends in life history parameters to detect any strong trends in life history parameters over time, permitting inferences about population status. Comparison with equivalent data for other populations (notably for Scotland) for bet

Schedule of payments
Amount:
7500
Date:
Comments:

1st Instalment (75%)

Amount:
2500
Date:
Comments:

2nd Instalment (25%)

Country:
Portugal
Spain
Group:
Instrument:
Threats: Unsustainable fishing and harvesting aquatic resources, Bycatch, Prey depletion