Harbour seal monitoring AARHUS HELCOM WORKSHOP SEAL-FISHERIES - - PowerPoint PPT Presentation

Harbour seal monitoring

• 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
• f 3) has been used

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Harbour seal eal abundance ce trends

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

6 500 +7.4 % 10 500 +6.1 % 1 300 +8.3 %

Abundance index in 2017 and increase (%/year) during 2003-2017

1 000 +6.3 %

Harbour seal abundance trends

Abundance index estimated to represent 65 % of total population size

(70-80 % in Kalmarsund).

⇒ Estimated total population sizes: Skagerrak 10 000 Kattegat 16 000 Southern Baltic 1 500 Kalmarsund 1 900 2 (4) HELCOM management units:

• Kattegat + Southern Baltic,

Kalmarsund, (Limfjord)

1 100 +2.7 %

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

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 UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Targets for Good Environmental Status sensu MSFD under HELCOM

• 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

Favourable Conservation Status - Habitats directive

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

• Is assessed and reported by each nation
• Actual abundance and distribution are compared to ‘favourable

reference values’

Habitats directive assessments – seal species

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

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
• btaining ‘Favourable conservation status’ for seal management units

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

• 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)

‘General Management Principles’

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Recommendation:

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.

• no allowances for deliberate killings.

Limit Reference Level (LRL)

• licenses for anthropogenic removals

can only be issued if in the population a significant positive long-term growth rate can be

• bserved;
• special care has to be taken so that

the positive long-term growth rate is not jeopardized

Precautionary Approach Level (PAL)

• licenses for anthropogenic removals

can be issued provided that the long-term objectives of the General Management Principles are not compromised

Target Reference Levels (TRL) (and above)

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 UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

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 COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

• Precautionary Approach Level:

Point of ‘maximum production’

• f the population

‘PAL’

AARHUS UNIVERSITY

• Target Reference Level: the level where the growth rate starts to level
• ff 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

‘TRL’

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

• 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

‘LRL’

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Population abundance in practical management

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

• no allowances

for deliberate killings.

Limit Reference Level (LRL)

• licenses for

anthropogenic removals can only be issued if in the population a significant positive long-term growth rate can be

• bserved;
• special care has to be

taken so that the positive long-term growth rate is not jeopardized

Precautionary Approach Level (PAL)

• licenses for

anthropogenic removals can be issued provided that the long-term

• bjectives of the

General Management Principles are not compromised

Target Reference Levels (TRL) (and above)

Less elbow room for harbour seal management?

Limfjord/Kalmarsund

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

• 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

Seal Abundance & Distribution – HOLAS II

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

• Seal indicators:
• Nutritional status
• Reproductive status
• Population trends and abundance
• Distribution

Seal Abundance & Distribution – HOLAS II

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

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

Population trends and abundance of seals

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

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

Distribution of seals

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Integrated assessment, grey seals

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Integrated assessment, harbour seals

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Integrated assessment, ringed seals

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES

Thank you

AARHUS UNIVERSITY COPENHAGEN JUNE 27TH 2019 HELCOM WORKSHOP SEAL-FISHERIES