The Spatial Dimension of Ecosystem Structure and Dynamics
Conveners: Maria Borges (Portugal), Jason Link (USA), and Einar Svendsen (Norway) (Session L) (Abstract) (Timetable) (Report)

Multidisciplinary Approaches to the Identification of Stock Structure of Small Pelagics: Implications for Assessment and Sustainable Management (Session K)

The concept of the stock is fundamental to fisheries management. Identifying stocks, discriminating among them, and determining the stock composition of mixed stocks are integral elements of both assessment and management. Failure to recognise the existence of stock structure in exploited species can lead to overfishing and the depletion of less productive units.

The strongest inferences on stock structure are drawn from a suite of complementary techniques that cover multiple aspects of the biology of a fish species. This is partly because the definition of a stock, for management purposes, is not strictly a genetic construction, but refers to a semi-discrete group of fish with some definable attributes of interest to managers. A multidisciplinary approach to fish stock identification appears to be particularly pertinent for those species with complex, and frequently subtle, stock identities.

In the Atlantic, some of the earliest questions about stock structure and identification began with stock concept issues formed in the late nineteenth century, on herring. Some key issues still remain unresolved. In the Pacific, issues about stock identification have developed with herring and some other small pelagic species such as anchovy, sardine, and smelt, in recent decades. Pelagic species continue to provide a challenge to both biologists and fisheries managers, due to their highly variable life history traits, variable population size and, commonly, strong schooling habit. Many species straddle several management areas, but may comprise one, or more, stocks that may not match the imposed political stock boundaries. Additionally many species are seasonally migratory. These species, therefore, are primary candidates for a multidisciplinary approach, with a suite of methods giving a higher chance of detecting structure.

This Theme Session aims to provide a forum for the presentation of results of individual stock identification methods as components of multidisciplinary studies, as well as those employing a combination of different methods. One possible outcome might be the development of methodological guidelines of particular utility for discrimination of small pelagic stocks. Additionally, recommendations on the appropriate incorporation of stock identification data into the assessment and management process will be generated, most likely through relevant case studies. Other studies of implicit relevance, on non-pelagic species, may be considered.

It will draw together contributions of relevance from the ICES, PICES, and wider academic communities and act as a conduit for exchange of information between these communities.

Contributions are therefore invited on the individual methods performed within a multidisciplinary structure, such as:
• Life history comparisons between stocks;
• Morphometrics and meristics;
• Parasites as biological tags;
• Tagging studies;
• Otolith techniques (e.g. microstructure, microchemistry) ;
• Genetic techniques; and the combined analyses resulting from these methods, such as:
• Mixed stock analyses;
• Temporal stability of traits;
• Threshold decisions for meaningful stock separation;
• and ultimately, the implications for assessment and sustainable management.

The Spatial Dimension of Ecosystem Structure and Dynamics
(Session L)

Questions to address:

• Spatial scales of the ecosystem: Downscaling global atmospheric–oceanic interactions to basin and local habitat scales;
• Putting spatial pattern into population and ecosystem models;
• Spatial relationships among biotic communities and their habitat;
• The spatial aspects of human activities

In order to make progress on addressing anthropogenic impacts via ecosystem-based approaches, we need to recognise that ecosystem processes occur at multiple scales. Thus, it is essential for ecosystem-based approaches to examine the multiple spatial and temporal dimensions on which abiotic, biotic, and human processes occur. Key developments in coupled physical-biological numerical models still need to be applied more broadly. Defining habitat across a suite of variables also poses several challenges, particularly for fisheries issues at appropriately resolved spatial scales. Recognising that ecosystem processes operate at multiple temporal and spatial scales is critical, but incorporating spatial explicitness into ecosystem and population models remains a key challenge.

Impact of External Forcing on Flows in Marine Trophic Networks (Session M)

Elasmobranch Fisheries Science (Session N)

Elasmobranchs: sharks, rays, and skates, are a poorly understood group of fishes. They are considered to be vulnerable to exploitation on account of their conservative life-history strategies, and there are documented cases of depletions. However, there are also cases where abundance appears to be increasing. Scientists in ICES and neighbouring areas have been working to improve the scientific basis for the assessment of these species, both in terms of fisheries management and conservation related issues. This has been conducted through the ICES Working Group on Elasmobranch Fishes and through various international meetings and projects.

In order to further ICES’ goals in the science of elasmobranch fisheries, it will be necessary to have a Theme Session in 2005, to provide a forum for researchers to exchange information and pool scientific experience of these data-deficient stocks in the ICES and other areas. By 2005, there will be the opportunity to draw on the results of new biological studies carried out by European countries, and to consolidate on the progress made under the EU-funded DELASS project.

Basic biological studies viz. growth, mortality, and reproduction are important topics, placing emphasis on how these data can improve traditional and novel assessment methods. Assessment methodologies, for fisheries assessment and vulnerability status, will be important topics, along with information on stock structure and migrations.

Connecting Physical-Biological Interactions to Recruitment Variability, Ecosystem Dynamics, and the Management of Exploited Stocks (Session O)

The interplay between physical and biological processes, at all scales, is critical for understanding the dynamics of marine ecosystems. As such, the development of predictive capacities for these processes is necessary for assessing and mitigating the effects of climate change on marine ecosystems. In particular, these processes affect interannual variability in recruitment, and the distribution and feeding interactions of all life stages of exploited fish populations as well as their prey. Effects are manifested via modification of vital rates by physical processes at small scales (e.g. turbulence), mesoscale (e.g. hydrographic fronts, eddies, jets and river plumes), and large scales (e.g. currents, transport). Recent progress in field, laboratory, and modeling research has resulted in advances in empirical descriptions and numerical parameterizations of physical-biological interactions influencing lower trophic level production, and early-stage and adult dynamics of exploited fish populations. The improved understanding and predictive ability provided by these advances will enhance our understanding of the influence of climate forcing on ecosystems and fish stocks. This understanding is necessary to improve the state-of-the-art of ecosystem-based fisheries management. For example, a better understanding of the physical conditions that promote organism aggregations or modify nursery habitat will enhance management by improving the identification of suitable marine protected areas, design of stock assessment surveys, and determination of predator-prey interactions.

This Theme Session solicits the results of modelling, laboratory, and field studies focused on understanding physical-biological interactions, predicting their implications for distribution, abundance, and interactions of species assemblages relative to climate forcing, and determining their potential for incorporation in ecosystem-based management strategies.

Regional Ecosystem Pilot Projects, Ecosystem Forecasting, and Operational Oceanography: Comparing and Contrasting Scientific Tools, Strategies, Outputs, and Applications (Session P)

Operational oceanography and the development of ecosystem forecasting (and hindcasting) tools depend as much on the physical-biological models and conceptual tools as they depend on consistent, high quality sample and data collection. Sampling and survey plans and designs are in turn dependant on good theory and models. One way of implementing operational oceanography and ecosystem forecasting in a practical way is through regional ecosystem pilot projects. The GOOS-endorsed definition of a “pilot project”: “an organised, planned set of activities with focused objectives designed to provide an evaluation of technology, methods, or concepts within a defined schedule and having the overall goal of advancing the development of the sustained, integrated ocean observing system.” Increasingly operational oceanography and regional ecosystem pilot projects are being established throughout the ICES/IOC/PICES area, aimed at delivering information in order to support an ecosystem approach to fisheries and environmental management. There are lessons to be learnt by comparing and contrasting the differing approaches taken in different regions. The session aims at drawing together experiences obtained from different regional ecosystem pilot projects and generating useful recommendations for future developments. The aim is to enhance and review this dialog between marine scientists contributing in these areas, and to promote practical suggestions and outcomes relevant to requirements of marine resource managers. Also the Theme Session could provide a forum for individuals involved in the policy and practise of marine resource management to give input into the processes they depend on so much for advice and assessment tools.

Advances in Reproductive Biology: Methodology and Applications for Fisheries Science (Session Q)

Within management advice for a fishery is a need to be able to estimate the number of new individuals that will enter the population or the fishery. In many instances this is still based on the classic stock and recruit relationships or on a slightly more complex model that incorporates some aspect of the status of the spawning stock or prevalent environmental conditions. It is essential that if progress is to be made toward being able to predict ‘recruitment’ then there must be a better understanding of the processes that underpin the quantity and quality of egg production in a stock. There is also a need to understand how different environmental conditions will impact egg production. In addition, the backward projection of spawning stock biomass from methods such as the Annual Egg Production Method relies on reliable estimates of the realised (viable) egg production from a given stock.

The overall aim is to develop our understanding of the importance of reproductive biology to fisheries science, explicitly being able to incorporate the individual level responses into stock level responses. This Theme Session seeks papers on the reproductive biology of fish, shellfish, or squids, focused on a methodology for better stock assessment and applications to investigate the relationship between stock size and ‘viable egg’ production.

Topics to be addressed include:

• Experimental biology on reproduction, aimed at discovering the factors which are important for determining the viable egg production in the field;
• Evidence for and against an invariant reproductive potential in response to changes in the environment that arise, for example, from short- to long-term fluctuations or as a consequence of climatic change or anthropogenic effects;
• Advances in methodology aimed at providing a more accurate assessment of realised fecundity, both male and female reproductive potential, in relation to stock biomass. The advances can be presented as the current state of development or as part of other programs designed to estimate spawning stock biomass independent of fishery data, e.g. egg production models or survey techniques;
• Modelling approaches to incorporate biologically relevant data into forecasting population dynamics and biological reference points in response to a fishery or environmental change.
  

Marine Mammals: Monitoring Techniques, Abundance Estimation, and Interactions with Fisheries (Session R)

The role of seals and cetaceans as top predators in marine ecosystems has been the focus of increasing discussion in recent years. Marine mammals interact with fisheries in a number of ways. Direct interactions include commercial and aboriginal subsistence hunting and bycatch of marine mammals in a variety of fishing gears, and damage by seals to fishing gear and fish catch. Indirect interactions involve the impact of large and/or increasing populations of marine mammals on fish stocks and fisheries yield and, conversely, the impact of reduced fish stocks due to overfishing on marine mammal populations.

To quantify interactions between marine mammals and fisheries (and the impact of direct removals) we need, at a minimum, data on abundance, spatial distribution, and diet of marine mammal populations. In most cases, even this information is lacking so that it is possible to make only very crude assessments. To develop dynamic models of interactions, we need life history data including population growth rates, and data on how the consumption of fish by marine mammals varies with the size of fish stocks – their functional response.

Several approaches have been applied to estimate the abundance of whales and seals (e.g., total counts, mark-recapture experiments, line transect sampling), their distribution (e.g. visual sightings, tag returns, satellite telemetry), and their diet (e.g. stomach contents analysis, faecal analysis, fatty acid analysis), and there has been considerable development in both data collection and analytical methodology in recent years. In addition, there is new work on dynamic modelling of marine mammal–fish interactions. The present Theme Session will allow researchers with experience of abundance, distribution, and diet estimation of different marine mammal species and of modelling these data to meet and discuss the advantages and disadvantages of the different approaches used. Issues raised will include data requirements and availability, the validity and realism of the various assumptions required for each method, sensitivity of the results to these assumptions, and how uncertainty is dealt with and quantified.

Oil Spills in Marine Ecosystems: Impacts and Remediation (Session S)

Coastal and offshore waters of the ICES area have been impacted by numerous large spills from tankers, such as the recent Prestige spill. More importantly, perhaps, large volumes of oil are spilled into the sea continuously through chronic spillage from numerous sources. This Theme Session will highlight the results of investigations from the Prestige spill but will also encourage papers describing the impacts from other major spills, as well as papers describing the impacts of chronic spills. In addition to the impact from the spilled oil, efforts to clean up the oil in the environment can have significant impacts. Papers will be solicited on the impacts of clean-up operations and the description of low-impact remediation techniques.

Besides large spills, the Theme Session will include the effects of smaller persistent spills, long-term impacts of drilling muds, produced water, the impact on the biology of marine species, and the inclusion of the coastal zone.

Integrating/Implicating Genetics into Fisheries Management
(Session T)

Effective fisheries management relies on the integration of diverse approaches such as biological sciences, oceanography, climatology, and information technology. Foremost among developments have been technological and conceptual advances in genetics, affording new insights into stock discrimination, population structure, ecosystem functioning, selective fishing, exotic species, food tracing, conservation, and impacts of climate change. In addition, progress in genomics is poised to advance our understanding of natural marine resources further. The focus of this Session will be to consider how recent developments in genetics may contribute to key challenges in fisheries management, with emphasis on practical implementation.

Acoustic Techniques for Three-dimensional Characterization and Classification of the Pelagic Ecosystem (Session U)

Comprehension of the three-dimensional and dynamic features of pelagic marine ecosystems is important for developing effective methodology to support ecosystem-based management of marine resources. To achieve this goal, there is an increasing need for efficient tools to conserve the ecosystem integrity when studying fish populations. Acoustics techniques are non-intrusive, and may be used to look at aquatic ecosystems over a broad range of spatial and temporal scales. Powerful 3-D visualisation systems can be applied on 2-D and 3-D acoustic devices to observe marine ecosystems with a new perspective.

The three-dimensional scales of aquatic ecosystems range from the smallest (centimetres) to the widest areas (hundreds of nautical miles). Physical, chemical, and biological properties show strong gradients (e.g. coast/offshore, north/south, high/low temperature) and complex structures (e.g. fronts, eddies) along the vertical and the horizontal planes, forming specific habitats for pelagic organisms. The improved understanding of the relation between the environmental characteristics and the organisms, as well as their intra- and inter-specific interactions, preserving the three-dimensional context where these interactions take place is important. New technologies and approaches to efficiently collect, compute, display, and validate three-dimensional multivariate data on aquatic ecosystems are now available. This Session aims at presenting the current state of methodology for characterization and visualisation of spatial and temporal dynamics in marine pelagic ecosystems while preserving the 3-D spatial context. Case studies presenting applications and future potentials of these methodologies would also be strongly appreciated in this Session.

Fishers’ Perceptions and Responses in Management Implementation (Session V)

Effective fisheries management is dependent on compliance and industry adaptations not counteracting the objectives of management. A wide discussion is required to agree on the scientific principles and required knowledge as basis for evaluations of management performance
and fisheries agreements. The aim of the session is to discuss the role of fishers' perception of the management issues and their adaptation to management implementation in the evaluation of fisheries management decisions. Fishers' perception of the management issues and management implementation has important consequences as to the legitimacy of management and thus also for compliance. Furthermore, fishers will adapt to management regulations by choosing harvest tactics that pursue their own objectives as individual operators. These responses to management implementation can from a technical point of view be seen as a source of uncertainty in reference points and prediction which has the same effect as any other scientific uncertainty. It is likely that a better understanding of this uncertainty in many cases would enable a better basis for determining justified management actions. Furthermore, the uncertainty may be reduced by increased participation of fishers in the management decision processes, which will increase legitimacy and contribute to regulations being better adapted to the practical realities of fishers. Various initiatives and re-defined user rights have been taken for increased participation of fishers in management decisions. In the technical domain there are no agreed rules for the estimation of the uncertainty associated with adaptations or lack of compliance. The understanding of compliance and adaptations is clearly a multidisciplinary task. Strong cooperation is needed between sociologists, economists, legal experts, stock assessment scientists, and managers to understand compliance and adaptations and how the institutional setup of management can be modified in such a way that outcomes will better fulfil objectives with high compliance when the adaptation takes place.

Various aspects of management (participation of users in both policy and management decisions and regulatory tools which are more appropriate to the realities of fisheries) may be developed and implemented to reduce management uncertainty and make fisheries management more effective in achieving objectives. The Theme Session is of a strongly multi-disciplinary nature and requires active participation from many fields of applied sciences. Presentations from various stakeholders (fishers, managers, and other stakeholders) are also expected.

Contributions are invited on:
• Role of implementation uncertainty in the definition of reference points;
• Case studies on fishers' adaptations to management actions;
• Case studies and methodology to study user participation, legitimacy and compliance;
• Methodological solutions to estimate and model implementation uncertainty;
• Management instruments which are participatory and appropriate to the realities of fisheries practices;
• Stakeholders’ experiences about successful and unsuccessful management operations related to implementation;
• Fishers' decisions regarding risk-taking and investments in relation to various harvest control rules.

Rebuilding Programmes for Threatened Fish Populations (Session W)

There have been substantial declines in the abundance of many fish stocks in recent years, and many diadromous species in particular have been classified as vulnerable, threatened, or endangered throughout all or part of their ranges. However, while the status of the main commercial species receives considerable publicity, much less attention is paid to other species that are still important from a conservation perspective. The management of many rare and endangered species may also be constrained by the lack of data, and there is therefore an urgent need to combine information between research agencies. The objective of this Theme Session is therefore to share best practice on the development and management of programmes to rebuild threatened or depleted fish populations.

The short-term management response to declining stock abundance is generally to reduce or eliminate exploitation. In many cases this will address only part of the problem, and there will be a need to develop a more comprehensive programme of management and research activities to address the causes of the stock decline in the longer term. This is particularly true for diadromous species, which are more often affected by a range of human activities at various stages in their lives. Such stock rebuilding programmes may involve a number of processes, including perhaps: the development of assessment procedures and harvest rules; evaluation of natural and anthropogenic factors affecting the stock; instigation of insurance measures (e.g. gene banks); engagement with stakeholder groups; assessment of social and economic factors; development of plans to prioritise management actions and research; and monitoring and evaluation of progress against forecast recovery trajectories.

Papers are invited on any of these topics, but are particularly sought on:
• Guidance for the development of integrated rebuilding programmes;
• Evaluation of alternative stock rebuilding strategies;
• Identification and involvement of stakeholder groups in recovery programmes;
• Results of both successful and unsuccessful rebuilding programmes and the lessons to be learnt;
• Plans and proposals for new rebuilding and recovery plans.

Mitigation Methods for Reduction of Marine Mammal and Sea Turtle Bycatch in Fisheries (Session X)

The incidental bycatch of cetaceans, pinnepeds, and sea turtles associated with commercial fishing operations is an issue of global concern. Fisheries managers are under increasing pressure from governments, NGOs, and the general public to protect these large marine mammals and turtles from fishing activities. There are a number of high-profile fisheries where, from an ethical and/or biological perspective, such bycatches are unacceptable. Some examples include the capture of dolphins during pelagic trawling, the entanglement of whales in marker ropes, and the bycatch of turtles in both longline and tropical shrimp trawl fisheries. In some instances, managers have closed viable fisheries due to marine mammal issues, and some fisheries have suffered economic downturn due to consumer boycots, for example the Eastern Pacific tuna purse seine fishery that resulted in the concept of ‘dolphin-friendly’ tuna. However, modifications to fishing gear and/or fishing practices can, in many instances, provide practical and workable alternatives for fisheries managers, allowing the continuation of fishing activities while preventing the unnecessary capture of cetaceans, etc. Worldwide, there are a number of successful examples where technical conservation measures have greatly reduced fisheries impacts. The use of turtle excluder devices (TEDs) in many tropical shrimp fisheries has reduced the mortality rates of several turtle species, while modification of hook shape has reduced bycatches associated with longline fisheries. Considerable research has focussed on technical modifications to fishing gears to minimise such bycatch, the development of acoustic deterrents, and on operational changes. This Theme Session is intended to provide scientists the opportunity to present their research into mitigation measures to reduce bycatch; to provide examples where such measures have been applied and to produce a summary review.

Contributions to the Session should address any of the following themes:
• Current management practices for reducing bycatch of pinnipeds, marine mammals, and sea turtles;
• Behavioural studies and observations on the interaction of bycatch species with fishing gear;
• Gear modifications, acoustic deterrent devices, and alternative fishing tactics to reduce bycatch;
• Predicted impacts of gear modifications and operational changes on populations of cetaceans, pinnepeds, and sea turtles;
• The effectiveness of mitigation measures in terms of acceptability to the fishing industry, considering economic impact and additional costs and including enforcement;
• Identification of potential solutions in other fisheries to reducing bycatch by employing similar technologies or methods.

An Interactive Forum with the Fishing Industry (Session Y)

Until recently fisheries science, and especially stock assessment, was carried out entirely by scientists, without fishers themselves taking part. Fishers were seen as providers of data, but not as active participants. There was a perception that stock assessment should be independent from fishers’ concerns and isolated from fishers’ lobbying. Fisheries science was the responsibility only of specialised experts.

Indeed, fishers were excluded from the whole system of fisheries management. Again, management was seen as the province of experts. Fishers were placed firmly on the sidelines as scientists and managers played the game of fisheries management. It was considered that only the results should concern the fishing industry.

Those circumstances are now changing. The results gained through this system of fisheries management have not been impressive, even to the players themselves. Fisheries science has been increasingly difficult to carry out as fish stocks have declined. Both the fisheries themselves and the management regimes are changing rapidly. Fishers are refusing to support the game and are withholding information on their catches. The assessments themselves are becoming uncertain and retrospective. It has become evident that there is a need for a different approach, incorporating new paradigms and based on the wider use of data from fishers themselves; data which are both accurate and up-to-date. At the same time, the rigid game-plan of fisheries management has itself changed. Fishery managers are increasingly seeking advice directly from fishers and other stakeholders.

It is time for fishery managers and the scientists who support them to engage more closely with fishers and other stakeholders – to involve them in the game. The help of fishers is needed both to improve the stock assessments and to arrive at successful management measures.

There have been many successful recent examples of fishers working closely with scientists. The Theme Session will start by considering examples of these and seeking out examples of good practice. The Session will then move on to look at future collaboration between fishers and scientists in the context of the new, more participatory forms of fisheries management currently being introduced.

How to Improve Environmental Monitoring and Biological Studies – Integrating Ecology and Statistics (Session Z)

This Theme Session will solicit papers dealing with environmental monitoring, environmental impact, and other biological studies using statistics such as:

• the probability of detecting environmental impacts and biological effects;
• methods for spatial and temporal trend studies;
• the probability of detecting point sources or episodic events;
• cost-effective sampling design using statistics.

The Session will document the essential use of a statistical approach to the design and assessment of environmental monitoring. Papers will be solicited that demonstrate the effective use of power analyses for sampling design to insure cost effectiveness while achieving the desired level of probability of detecting an impact. This session will provide practical examples of how statistics can be implemented in planning and assessing the results of monitoring programs.

Chairs should actively look for relevant papers, including case studies.

Cod in a Changing Climate (Session AA)

Conveners: Keith Brander (ICES/GLOBEC) and Ken Drinkwater (Norway)

This Theme Session will coincide with the 2005 publication of the book on Cod in a Changing Climate and will contribute to the Cod and Climate Change strategic plan.

The book and the Theme Session are intended to make information on status and trends in cod stocks available to a wider public and to make them aware of the contribution of ICES to international marine science. The biological and life history processes underlying climate-driven changes in fish stocks include recruitment (i.e. the number of young fish produced), growth, maturation, natural mortality, and migration. Thanks to the commercial importance of North Atlantic cod, a long history of research, and a dedicated programme within ICES on Cod and Climate Change over the past decade, much has been learned about these processes and about their interaction with each other and with the food chain, predators, and other components of the marine ecosystem. Cod is probably the most comprehensively studied marine fish species, occupying a key role in several North Atlantic ecosystems. An understanding of its dynamics is of direct and indirect relevance to other species and to gaining insight into the response of the marine ecosystem to climate change and variability. The Cod and Climate Change programme is a regional component of the Global Ocean Ecosystem Dynamics (GLOBEC) programme of IGBP. Speakers will be invited to present the subjects on which they have contributed in the book. They will review many aspects of our knowledge of cod, but will also report new results and analyses. They will use a comparative approach to draw conclusions from differences and similarities between the many stocks, which occupy a range of different physical and biological situations.

Ecosystem Approach to Fisheries Management Worked Examples (Session BB)

Through instruments such as the Bergen Declaration and Reykjavik Declaration, ICES, its member states, and major client commissions have all embraced movement to an Ecosystem Approach to management of human activities in the seas. The Ecosystem Approach to fisheries management is more than an abstract concept for the future; it is emerging as practical reality today. The full impact of this broadening of the basis for managing fisheries has yet to be felt in much of the ICES area, and much remains to be consolidated to provide the scientific basis for taking an Ecosystem Approach to fisheries. Nonetheless there are concrete examples of moving towards an Ecosystem Approach in a number of fisheries in the North Atlantic and globally. ICES needs to learn from these global practical examples, and apply the lessons quickly in its own science and advice. This Theme Session will be built around several selected examples of practical implementations of an ecosystem approach to contemporary fisheries management and supporting scientific advice. Authors will be recruited by the conveners for case histories and will be provided with sufficient speaking time to illustrate exactly both what was done, with the existing knowledge, to move fisheries management to a more inclusive ecosystem approach, and how the management and prosecution of the fisheries was changed. Contributed papers will also be considered for the Theme Session, but selection will apply stringent standards of truly operational examples rather than just discussions of concepts and possibilities.