TMAP Monitoring Handbook

1 Introduction

Marine mammals regarded as indigenous species in the Wadden Sea are the harbour (or common) seal Phoca vitulina, grey seal Halichoerus grypus, and harbour porpoise Phocoena phocoena.

In 1991 the Agreement on the Conservation of Seals in the Wadden Sea (Seal Agreement, 1991) was enacted as the first agreement of the Convention on the Conservation of the Migratory Species of Wild Animals (Bonn Convention), concluded between the countries adjacent to the Wadden Sea – Denmark, Germany and the Netherlands. Pursuant to Article 4 of the Seal Agreement, the Parties have to develop, on the basis of scientific knowledge, a conservation and management plan for the seal population. This plan has to contain a comprehensive statement of actions, which are or are to be undertaken by the Parties.

General remark on Seal Management Plan (SMP, 1996, 2002): The SMP will be revised on a regular basis. Monitoring has to be carried out to understand population dynamics and population response to Phocine Distemper Epidemics (Reijnders et al., 2003b).

2 Objectives

Trilateral policy and management aims “to achieve, as far as possible, a natural and sustainable ecosystem in which natural processes proceed in an undisturbed way” (Guiding Principle).

The following Target (Wadden Sea Plan) applies to marine mammals:

• Viable stocks and a natural reproduction capacity of common/harbour seal, grey seal and harbour porpoise in the tidal areas and the offshore zone.

The monitoring of harbour seal, grey seal and harbour porpoise is carried out to assess trends in population size and pup production.

3 Monitoring requirements

Wadden Sea Plan (WSP)

WSP

Targets on “Marine Mammals”

• Viable stocks and a natural reproduction capacity of the harbour seal, including juvenile survival.
• Viable stocks and a natural reproduction capacity of the grey seal, including juvenile survival.
• Viable stocks and a natural reproduction capacity of the harbour porpoise.
• Conservation of habitat quality for conservation of species.

EC Habitats Directive (HD)

HD

Article 11: Monitoring of conservation status of habitat types and species.

Species in Annex II, IV, V, according Article 1(e)

• Harbour seal - Phoca vitulina (Annex II, V)
• Grey seal - Halichoerus grypus (Annex II, V)
• Harbour porpoise - Phocoena phocoena (Annex II, IV, V)

Water framework directive (WFD)

WFD

Not relevant.

Oslo Paris convention (OSPAR)

OSPAR

Biological Diversity and Ecosystems Strategy, Annex V and Appendix 3

Initial OSPAR List of Threatened and/or Declining Species and Habitats (Ref-Nr. 2004-06): Harbour porpoise.

Ecological Quality Objectives:
EcoQO Issue 2: Marine mammals.
2.1 Seal population trends in the North Sea

• Harbour seal population size (no decline in population size of >10% as represented in a five-year running mean)
• Grey seal pup production (no decline in pup production of >10% as represented in a five-year running mean)

2.2 By-catch of harbour porpoises (annual by-catch level below 1.7%)

EcoQO 7.1 Presence and extent of threatened and declining species in the North Sea: Harbour Porpoise.

Agreement on the Conservation of Small Cetaceans of the Baltic and North Seas (ASCOBANS)

ASCOBANS

[Only relevant for harbour porpoise]

Achieve and maintain a favourable conservation status for small cetaceans (ASCOBANS, 1992, 2003).

Annex “Conservation and management plan”:

1. Habitat Conservation and management

2. Surveys and research
Investigation shall be conducted in order to
(a) assess the status and seasonal movements of the populations and stocks concerned,
(b) locate areas of special importance to their survival, and
(c) identify present and potential threats to the different species.

3. Use of by-catches and stranding

• reporting and retrieving by-catches and stranded specimens,
• carry out full autopsies (collect tissues for further studies, reveal possible causes of death, document food composition),
• information shall be made available in an international database.

Convention on Migratory Species (CMS)

CMS

Seal Agreement 1991: first agreement under the Convention on the Conservation of Migratory Species of Wild Animals (CMS-Bonn Convention).

• Contracting Parties: The Netherlands, Germany, Denmark;
• Aim: to cooperate closely in achieving and maintaining a favourable conservation status for the harbour seal population in the Wadden Sea;
• Provisions: amongst others, on research and monitoring, (implemented in the Seal Management Plan);
• TSEG in charge of the coordination, supervision of the implementation of the monitoring activities and assessment of the results.

4 Definitions

[to be added]

5 TMAP Monitoring Strategy

The existing monitoring scheme for harbour seals should be continued and the current monitoring of grey seals should further be coordinated and trilaterally harmonized by the TSEG.

Monitoring of harbour porpoise should be done within a North Sea wide framework (Hammond et al., 2002). The results of the MINOS project in Schleswig-Holstein (Eskildsen et al., 2002) will be evaluated before deciding whether it is useful to include the harbour porpoise monitoring in the TMAP; this concerns the trilateral Offshore Area of the Schleswig-Holstein and the Lower Saxon Wadden Sea.

(Table 5.1) Parameters with monitoring locations and frequencies and the relation to the other monitoring requirements.

Remarks:

5.1 Parameters

• number and distribution of seals (adult and pups)
• calculation of population dynamics:
• population size,
• breeding success,
• recruitment / survival.

In addition, monitoring of marine mammals regarding migration, diseases, age structure, sex ratio should be carried out on the national level according to the Seal Management Plan (SMP).

5.2 Monitoring locations

For harbour seals:
- entire Wadden Sea

For grey seals:
- entire Wadden Sea or areas with grey seal colonies

For harbour porpoise:
- offshore area of the Wadden Sea Area
- entire North Sea

6 Methods

Monitoring is carried out by aerial survey, ship survey, manual counting and mapping (according to national monitoring guidelines).

The result is the counted number of marine mammals used as an index of the seal/whale populations.

7 Parameter

8 Frequency and time

For harbour seals:

• population size: a minimum of five surveys per year in a trilaterally coordinated way (three during the pupping and two during the moulting period);
• more flights in one year (a few more flights in the pupping season) should be carried out in the trilaterally coordinated way in case of emergency or because of special local/regional reasons on the basis of agreed scientific requirements.

For grey seals:

• synchronous counts (at least twice) during the moulting period (March – April) preferably by aerial survey;
• at least three counts of pups born in December and January, either from plane of from land.

For harbour porpoise:

To be carried out in a North Sea wide framework in cooperation with the other North Sea countries according to ASCOBANS (1992).

[to be elaborated]

For details see [Table 5.1].

9 Assessment

The assessment is based on the targets, as formulated at the 7th Trilateral Governmental Conference (November 1994) for the Wadden Sea (Wadden Sea Plan).

The assessment shall be carried out in accordance with the stipulations of the EU Habitats Directive and the approach defined in the North Sea EcoQO (OSPAR, 2007) as described by Meesters et al. (2007) (see Annex).

Table 9.1 Assessment of marine mammals in the Wadden Sea

Fig. 9.1 Number of counted Harbour Seals in the Wadden Sea (1975-2009)

10 Reporting

All data obtained from aerial and field surveys should be transferred into a geographical information system (GIS) for the analysis and assessment of the data (spatial and temporal development) and in combination with other GIS based information.

The counting results should be delivered together with information on used methods and any other information relevant for an assessment of the data. The data should be reported annually to the national TMAP databases in accordance with the regulations at the national level.

The frequency for monitoring and reporting will be linked to the 6-year reporting period (in accordance with the HD) by the expert group (TSEG). The trilateral evaluation of the monitoring data will be performed by the Trilateral Seal Expert Group (TSEG) (Reijnders, 1996; Reijnders et al., 2003a, 2003b; Siebert, 2003; TSEG plus, 2002) and the TMAG (for example TMAG, 2006) at least every third year as part of the Quality Status Report of the Wadden Sea (Jong et al., 1999).

11 Quality assurance

Evaluation of the monitoring data and methods will be carried out by the Trilateral Seal Expert Group (TSEG) every year. The Seal Management Plan (SMP) will be revised on a regular base.

12 Monitoring authorities

Denmark

Ministry of the Environment, The National Forest and Nature Agency (BMU)

National Environmental Research Institute, Roskilde

Fiskeri-og Søfartsmuseet, Esbjerg

Germany

Federal Ministry for the Environment, Nature Conservation and Nuclear Safety

Landesbetrieb für Küstenschutz, Nationalpark und Meeresschutz (LKN)

Niedersächsisches Landesamt für Verbraucherschutz und Lebensmittelsicherheit (LAVES)

Nationalparkverwaltung Niedersächsisches Wattenmeer (NLPV)

FTZ Büsum der Universität Kiel

Netherlands

Dutch Ministry of Agriculture, Nature and Food Quality (LNV)

Institute for Marine Resources and Ecosystem Studies (IMARES) Yerseke / Texel

13 Literature

Agreement on the Conservation of Seals in the Wadden Sea (Seal Agreement), 1991: http://www.waddensea-secretariat.org/management/SMP/Seals-Agreement.pdf.

ASCOBANS, 1992: Agreement on the Conservation of Small Cetaceans of the Baltic and the North Sea. United Nations, New York, 17 March 1992.

ASCOBANS, 2003: Proceedings of the 4th Meeting of Parties to ASCOBANS. Esbjerg, Denmark, 19-22 August 2003.

Eskildsen, K., D. Adelung, H. Benke, G. Dehnhardt, S. Garthe, A. Kellermann, K. Lucke, M. Scheidat, U. Siebert, U. Verfuß & R. Wilson, 2002: MINOS - Marine Warmblüter in Nord- und Ostsee: Grundlagen zur Bewertung von Windkraftanlagen im Offshore-Bereich. In: Forschungszentrum Jülich PTJ (Eds.) Ökologische Begleitforschung zur Offshore-Windenergienutzung : Fachtagung des Bundesumweltministeriums des Projektträgers Jülich, Bremerhaven 28.-29.5.2002 ; Tagungsband.

Hammond, P.S., P. Berggren, H. Benke, D.L. Borchers, A. Collet, M.P. Heide-Jørgensen, S. Heimlich-Boran, A.R. Hiby, M.F. Leopold & N. Øien, 2002: Abundance of harbour porpoise and other cetaceans in the North Sea and adjacent waters. J. Appl. Ecol. 39, 361-376.

Härkönen, T., K.C. Harding & M.-P. Heide-Jørgenssen, 2002: Rates of increase in age structured populations, a lesson from the European harbour seal. Can. J. Zool. 80, 1498–1510.

Jong, F.F xde, J.F. Bakker, C.J.M. van Berkel, N.M.J.A. Dankers, K. Dahl, C. Gätje, H. Marencic & P. Potel. 1999: Wadden Sea Quality status report. Wadden Sea Ecosystem No. 9, Common Wadden Sea Secretariat, Trilateral Monitoring and Assessment Group, Quality Status Report Group. Wilhelmshaven, Germany.

Meesters, E., P. Reijnders, S. Brasseur, U. Siebert, M. Stede, S. Tougaard & T. Härkönen, 2007: An effective survey design for harbour seals in the Wadden Sea: tuning Trilateral Seal Agreement and EU-Habitat Directive requirements. Trilateral Seal Expert Group, 2007. Seal Management Plan: Monitoring Scheme. TWG 07/1/5-1, 22 March 2007.

OSPAR, 2007: EcoQO Handbook - Handbook for the application of Ecological Quality Objectives in the North Sea. First Edition 2007. Ref.-No. 2007/307

Reijnders, P.J.H., 1996: Development of grey and harbour seal populations in the international Wadden Sea: reorientation on management and related research. Wadden Sea Newsletter 1996(2), 12–16.

Reijnders, P.J.H., J. van Dijk & D. Kuiper, 1995: Recolonization of the Dutch Wadden Sea by the grey seal Halichoerus grypus. Biol. Conserv. 71, 231–235.

Reijnders, P.J.H., K.F. Abt, S.M.J.M. Brasseur, S. Tougaard, U. Siebert & E. Vareschi, 2003a: Sense and sensibility in evaluating aerial counts of harbour seals in the Wadden Sea. Wadden Sea Newsletter 28, 9-12.

Reijnders, P.J.H., S.M.J.M. Brasseur & A.G. Brinkman, 2003b: The phocine distemper virus outbreak of 2002 amongst harbour seals in the North Sea and Baltic Sea: spatial and temporal development, and predicted population consequences. In: Management of North Sea harbour and grey seal populations. Proceedings of the International Symposium at Eco-Mare, Texel, The Netherlands, November 29-30, 2002. Wadden Sea Ecosystem No. 17, Wadden Sea Secretariat, Wilhelmshaven, Germany. pp.19-25.

Seal Management Plan, 1996: Conservation and Management Plan for the Wadden Sea Seal Population, 1996-2000, including Additional Measures for the Protection of the Grey Seal (Adopted by Senior Officials, March 1996). Common Wadden Sea Secretariat, March 1996. In: Wadden Sea Newsletter 1996,No. 2, 41-54.

Seal Management Plan, 2002: Seal Management Plan, 2002. Conservation and Management Plan for the Wadden Sea Seal Population, 2001-2006, including Additional Measures for the Protection of the Grey Seal inthe Wadden Sea. In: Ministerial Declaration of the 9th Trilateral Governmental Conference on the Protection of the Wadden Sea, Esbjerg, October 31, 2001, Annex 1 (English version). Common Wadden Sea Secretariat, Wilhelmshaven, 25-37.

Siebert, U., 2003: Monitoring the health status of harbour seals: pathological investigations before and during the PDV-virus outbreak. Proceedings of the International Symposium at EcoMare, Texel, The Netherlands, November 29-30, 2002.Wadden Sea Ecosystem No. 17, Wadden Sea Secretariat, Wilhelmshaven, Germany, 33-36.

TMAG, 2006: Report on Monitoring of marine mammals in the Wadden Sea. Version 9. October 2006

Trilateral Seal Expert Group-plus, 2002: Common and Grey seals in the Wadden Sea. Evaluation of the Status of Common and Grey Seal Populations in the Wadden Sea including an Assessment as to whether the Seal Management Plan needs to be revised and amended. TSEG-plus report to the TWG/SO, March/June 2001. Wadden Sea Ecosystem No. 15, 81-93. Common Wadden Sea Secretariat, Wilhelmshaven, Germany.

Wadden Sea Newsletter, 1996, No. 2 : Joint Trilateral Project on Conservation and Management of Common Seals in the Wadden Sea (1989 - 1994).