Harbour seal monitoring AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 • Much more limited movements than grey seals -> more genetic structuring • 2-3 aerial surveys covering all haulout sites within two weeks in August • Seals are photographed and number of individuals are counted from the photographs • As an abundance index, ”a trimmed mean” (average of 2 highest daily counts out of 3) has been used
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY Harbour seal eal abundance ce trends COPENHAGEN JUNE 27TH 2019
Harbour seal abundance trends AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Abundance index in 2017 and increase (%/year) during 2003-2017 2 (4) HELCOM management units: 6 500 - Kattegat + Southern Baltic, +7.4 % Kalmarsund, (Limfjord) 10 500 1 300 Abundance index estimated to 1 100 +6.1 % +8.3 % represent 65 % of total population size +2.7 % (70-80 % in Kalmarsund) . 1 000 ⇒ Estimated total population sizes: +6.3 % Skagerrak 10 000 Kattegat 16 000 Southern Baltic 1 500 Kalmarsund 1 900
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Summary • Baltic seal populations are recovering • There are some indications of approaching carrying capacity in grey seal and harbour seal • Climate warming is an increasing challenge for ringed seals • Improving monitoring methods for better understanding on seals abundance and its variations
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Targets for Good Environmental Status sensu MSFD under HELCOM
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Favourable Conservation Status - Habitats directive • Annex II - core areas of their habitat must be protected under the Natura 2000 Network and the sites managed in accordance with the ecological requirements of the species • Annex V – member states to take measures to ensure that their exploitation and taking in the wild is compatible with maintaining them in a favourable conservation status
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Habitats directive assessments – seal species • Is assessed and reported by each nation • Actual abundance and distribution are compared to ‘favourable reference values’
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Recommendations from HELCOM: • Implementation of General Management Principles and management units , development and implementation of national management plans. • National management plans are the most important tool for obtaining ‘Favourable conservation status’ for seal management units
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 ‘General Management Principles’ • population size (with the long-term objective to allow seal populations to recover towards carrying capacity levels) • distribution (with the long-term objective to allow breeding seals to expand to suitable breeding distribution in all regions of the Baltic) • health status (with the long-term objective of attaining the health status that secures the continued existence of the populations)
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Recommendation: Precautionary Approach Level (PAL) •no allowances for deliberate killings. •licenses for anthropogenic removals can be issued provided that the long-term objectives of the General •licenses for anthropogenic removals Management Principles are not can only be issued if in the compromised population a significant positive long-term growth rate can be observed; •special care has to be taken so that the positive long-term growth rate is not jeopardized Target Reference Limit Reference Level Levels (TRL) (and (LRL) above) Exemption from the General Management Principles can be issued for specific scientific purposes, animal welfare reasons and for removing identified individuals specialising on depredation of captured or farmed fish.
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM recommendations: • For CP’s to carry out monitoring programmes for the respective species. • For CP’s take effective measures for all populations in order to prevent illegal killing , and to reduce incidental bycatches to a minimum level and if possible to a level close to zero. • For CP’s to develop and to apply , where possible, non-lethal mitigation measures for seals to reduce bycatch and damage to fishing gear, as well as to support and coordinate the development of efficient mitigation measures.
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Recommendations for HELCOM Expert Group on Marine Mammals (EG MAMA): • to develop and co-ordinate monitoring programmes and assess the population structure , size and growth , reproduction and breeding distribution , contaminant burden and health status , fisheries interactions and bycatches , and evaluate their results; • to quantify the Limit Reference- , Precautionary Approach- and Target Reference Levels for populations of the described Management Units; • to define and quantify similar reference levels with regard to seal distribution and health status; • to assist in harmonising National Management Plans for those cross-boundary Baltic Sea Seal Management Units described above; • to draft HELCOM Guidelines for exemptions to the General Management Principles • to collaborate within the HELCOM seal expert group to identify and establish a network of protected areas for important actual and potential seal habitats across the Baltic Sea area (re. the EU Habitat Directive, Annex II), and attempt to harmonize the regulations and monitoring of these conservation areas. • to report annually on progress and evaluate every 5 years
AARHUS UNIVERSITY ‘PAL’ • Precautionary Approach Level : Point of ‘maximum production’ of the population
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 ‘TRL’ • Target Reference Level : the level where the growth rate starts to level off and the population asymptotically approaches the current carrying capacity level (e.g. 0.8 K) • HELCOM SEAL : Precautionary Approach Level and Target Reference Level can only be quantified retrospectively
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 ‘LRL’ • Limit Reference Level: (the Safe Biological Level): the Minimum Viable Population Size, which is to be defined for each of the management units • Population Viability Analysis (VORTEX) : assumptions: panmixia, no immigration, 1% extinction risk over 100 years, life history parameters for seals, mortality rates = 7 000-8 000 grey seals • Genetic diversity : at 10 000 seals 5% loss of diversity over 100 generations • LRL set at 10 000 individiuals
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Population abundance in practical management Precautionary Approach Level (PAL) •licenses for anthropogenic •no allowances •licenses for removals can be for deliberate anthropogenic issued provided that killings . removals can only be the long-term issued if in the objectives of the population a significant General positive long-term Management Limit growth rate can be Principles are not Reference observed; compromised Level (LRL) •special care has to be taken so that the positive long-term Target growth rate is not jeopardized Reference Levels (TRL) (and above)
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Less elbow room for harbour seal management? Limfjord/Kalmarsund
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Seal Abundance & Distribution – HOLAS II • HOLAS II – overall state of ecosystem health in the Baltic Sea, 2014- 2018 • HELCOM core indicators form the basis for the assessment of environmental status
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Seal Abundance & Distribution – HOLAS II • Seal indicators: • Nutritional status • Reproductive status • Population trends and abundance • Distribution
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY Population trends and abundance of seals COPENHAGEN JUNE 27TH 2019 Thresholds for GES: • Abundance of population > LRL • For populations below TRL: at least 7-9% annual growth rate • For populations at/above TRL: no decline >10% over a period up to 10 years
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Distribution of seals Thresholds: • Breeding distribution on land or ice: all available sites/area are occupied • Moulting distribution on land or ice: all available sites/area are occupied • At sea distribution: seals are not hindered in their movements for travelling and foraging
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Integrated assessment, grey seals
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Integrated assessment, harbour seals
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Integrated assessment, ringed seals
AARHUS HELCOM WORKSHOP SEAL-FISHERIES UNIVERSITY COPENHAGEN JUNE 27TH 2019 Thank you
Recommend
More recommend
