NAMMCO - the North Atlantic Marine Mammal Commission - is an international body for co-operation on conservation, management and study of marine mammals in the North Atlantic. The NAMMCO Agreement focuses on contemporary approaches to the study of the marine ecosystem as a whole, and to understanding better the role of marine mammals in this system. Through regional co-operation, the member countries of NAMMCO aim to strengthen and further develop effective conservation and management measures for marine mammals. Such measures are based on the best available scientific evidence, and taking into account both the complexity and vulnerability of the marine ecosystem, and the rights and needs of coastal communities to make a sustainable living from what the sea can provide. NAMMCO provides a mechanism for co-operation on conservation and management for all species of cetaceans (whales) and pinnipeds (seals and walruses) in the region, many of which have not before been covered by such an international agreement.

  The Agreement to establish NAMMCO was signed in 1992 by the current members of the Commission - the Faroe Islands, Greenland, Iceland and Norway. NAMMCO had its beginnings in earlier international conferences on marine mammals, first held in Reykjavik in 1988 and also attended by Canada, Japan and Russia. At the 1990 meeting of the conference in Troms�E a memorandum of understanding was signed by the four Nordic North Atlantic countries to establish an informal North Atlantic Committee for Co-operation on Research on Marine Mammals (NAC). The Parties to NAC agreed to work towards the development of mechanisms to ensure the conservation and management of marine mammals. From this process evolved NAMMCO.

  The recent activities of NAMMCO include new abundance estimates for a number of North Atlantic whale stocks based on the North Atlantic Sighting Surveys conducted in 2001. These international surveys, which began in 1987, have provided a unique source of information on the distribution, abundance and trends in abundance of several whale stocks, including fin, minke, pilot, sei, northern bottlenose and blue whales. This information is crucially important in the management of whale stocks, and also in the assessment of their role in the ecosystem.

  One desired objective identified in the NAMMCO Agreement is the ecosystem approach to management of living marine resources, placing NAMMCO at the forefront of efforts to implement such approach. Based on the on-going work of the NAMMCO Scientific Committee on marine mammal - fisheries interactions a broad-based approach is needed to identify the changes in management systems that might be required when using a multispecies, ecosystem-based approach. As a result a new Working Group on Enhancing Ecosystem-based Management has been established this year under the Management Committee. This Working Group will consider recent developments in this area, identify the challenges faced in adapting management systems to ecosystem-based approaches, and recommend what kinds of principles and measures can be applied. In addition the Working Group will investigate the progress that has been made in other fora in implementing such an approach.

  Under the Scientific Committee a series of Working Groups have been considering pertinent scientific questions on marine mammal - fisheries interactions. In the early stages one Working Group considered bio-economic models of varying complexity and ecosystems, but with no conclusive results due to lack of data. At its 8th meeting, in 1998, the NAMMCO Council tasked the Scientific Committee with providing advice on the economic aspects of marine mammal-fisheries interactions, with a particular focus on the harp and hooded seals and minke whales, the species of economic interest to some of the NAMMCO member countries. A Working Group on the Economic Aspects of Marine Mammal - Fisheries Interactions met in 2000 to consider parts of the request. One of the conclusions of the Working Group was that significant uncertainties remain in the calculation of consumption by marine mammals, and this uncertainty was the most important factor hindering the development of models linking consumption with fishery economics (NAMMCO 2001). Considering this conclusion, the Scientific Committee decided to convene a workshop to further investigate the methodological and analytical problems in estimating consumption by marine mammals. This workshop, held in 2001, resulted in, among other things, a list of research priorities to refine existing estimates of consumption by North Atlantic marine mammals (NAMMCO 2001). The list included a focus on distribution of prey species in place and time, spatial and temporal distribution of the diet composition of harp and hooded seals and of minke whales in areas where such information is lacking, and the diet composition of the white-sided, white beaked and bottlenose dolphins.

  The NAMMCO Scientific Committee viewed the next logical step in this process to be a review of how presently available ecosystem models can be adapted in order to increase our understanding of and quantifying marine mammal - fisheries interactions. A Workshop held in 2002 was tasked with choosing a preferred modelling approach for analysing the ecological role of minke whales, harp and hooded seals, and other marine mammal species in the North Atlantic, identifying required input data, and recommending a process for further development. The Working Group considered descriptions of the range of available multispecies modelling tools. This include two general classes of models typified by the Minimum Realistic Models (MRM) on the one hand and the ECOSIM/ECOPATH approach on the other. The MRM class includes MULTISPEC, BORMICON/GADGET and Scenario Barents Sea. These models share the characteristics of being system specific, modelling only a small component of the ecosystem for a specific purpose, and treating lower trophic levels and primary production as constant or varying stochastically. In contrast, ECOPATH/ECOSIM is an all-inclusive approach that incorporates lower trophic levels and primary production. Mass balance equations are used, essentially relating production by some species to predation by others under the assumption that the system is in a steady-state. ECOSIM builds upon this approach, but drops the equilibrium assumption so that the system is modelled by a set of coupled differential equations. Potentially ECOSIM, like the MRM class of models, could provide a basis to provide advice on marine mammal-fisheries interactions. Considering the data available or likely to become available in the foreseeable future, the Working Group favoured the Minimum Realistic-type model, as exemplified by Scenario Barents Sea, MULTSPEC and BORMICON approach of using a limited model that encompassed only the major species of interest, as opposed to an all-encompassing model where all or most species are included, as a basis for potential management advice in the short to medium term (NAMMCO 2002).

  In reviewing the amount of multispecies modelling work and associated applications to management decisions that had been conducted world-wide over the past several years, the Working Group noted a much lower than expected activity in this area. This was considered surprising given the emphasis politicians and management authorities have placed on multispecies (ecosystem) approaches to the management of marine resources. While the principle of multispecies management seems to be widely accepted, the practical aspects of putting it into practice lag far behind the rhetoric. Progress in this area will not be made unless significant additional resources are dedicated to it. Finally the discussion of the economic aspects of marine mammal-fisheries interactions would be premature until at least one of the Minimum Realistic Models have been developed. Once models are available that can predict the variation in target species in response to management measures, linkages to simple economic models that assess the economic consequences of the responses can be made (NAMMCO 2002). The next steps forward will include a focus on assessing modelling results from Minimum Realistic Models, and to consider the feasibility of connecting the multispecies models with simple economic models.

  North Atlantic Marine Mammal Commission, 2001.
  NAMMCO Annual Report 2001. North Atlantic Marine Mammal Commission, Troms�E Norway, 335 pp.
  North Atlantic Marine Mammal Commission 2002
  NAMMCO Annual Report 2002. North Atlantic Marine Mammal Commission, Troms�E Norway, 357 pp.