The meeting was supported by the Namibian Fisheries Ministry and was held in the National Marine Information and Research Center (NATMIRC) of Namibia in Swakopmund. It was sponsored by NATMIRC, the Scientific Committee of Oceanic Research (SCOR), the Intergovernmental Oceanographic Commission (IOC) of Unesco, the German Agency for Technical Cooperation (GTZ) and the U.S. GLOBEC Office.
The meeting was attended by 36 scientists from 16 countries (Namibia, South Africa, Angola, Ghana, Morocco, Turkey, Romania, Italy, Spain, France, Germany, Denmark, Sweden, Norway, Russia and USA; see Table 1).
The objectives of the meeting were to:
The working group assignments and terms of reference evolved over the meeting. The focus of Working Group I, Decadal Ecosystem Changes, was on the use of retrospective data to answer fundamental questions regarding DECADAL variability of small pelagic fish populations and atmospheric teleconnections between systems. Working Groups II and III focused on using comparative process studies to understand the links between climatic, zooplankton and fish population dynamics, but their approach differed. Group II used a "bottom up" while group III used a "top down" approach to design a minimum core programme. Working Group II, Fish Growth and Zooplankton Distribution, examined existing surveys and research programmes in six West African or Mediterranean countries to define a common minimum core programme that could lead to significant insight without a major outlay of new resources. Working Group III, Process-oriented Studies on Zooplankton and Fish Dynamics in Relation to Hydrography, considering the full range of measurements needed for a comprehensive comparative programme addressed a wide range of questions concerning fish productivity and then defined the minimum core programme. Working Group IV, Implementation of Modeling, focused on strategies for implementing modeling in SPACC.
Biological Data Bases: Appropriate time series of information for populations of small pelagic fish need to be collated. The time series data should be prepared in a spreadsheet format as described by SCOR WG 98 on World-wide Large-scale Fluctuations of Sardine and Anchovy Populations. It was recommended to convene soon a workshop at which the data sets be presented, clarified and collated in a standard format. A wealth of proxy series exists for both environmental and biological phenomena of interest including deposits of fish scales in sediments, records of harvests of seabird guano, width of annual tree rings from related areas and qualitative anecdotal records of fish catches. All these data are essential for comparison with the biological, physical and meteorological time series mentioned above and for the extension of these time series into the past for which time series data are nor available.
Hydrographic and climatic time series: Data series on physical hydrographic and climatic factors that may drive small pelagic fish populations need to be available for comparison with the biological time series. A catalogue of the available time series and where they may be obtained needs to be prepared. This should be done by a small group of experts.
A formal assessment of satellite imagery as a retrospective tool: The Working Group recommended a formal assessment of the usefulness of satellite imagery for decadal-scale studies. Data giving spatial resolution are available for the last 15 years.
Investigations of teleconnections: Teleconnection patterns can be investigated through comparison of climatic indices such as SOI, NAO, air pressure anomalies between St. Helena High and South African Low, variations in the position of the ITCZ, and precipitation patterns or other meteorological parameters.
Modeling: Modeling can provide insight into many of the key questions concerning decadal changes in ecosystem productivity. They will help to identify the studies that have the greatest chance of improving our understanding of decadal-scale changes and provide forecasts.
The group concluded that somatic growth was the most informative and practical ecological response to study in this context. Changes in fish growth during the critical first months of life, or shifts in birthdate distribution from the norm, are early indicators of ecosystem shifts affecting the productivity of small pelagic fish populations. Comparisons of growth and birthdate shifts in present ecosystems in different productivity states (indicated by declining, increasing, or stable population trends of target fish stocks and differences in size structure and distribution of zooplankton populations) will help to identify the critical links between somatic growth, zooplankton production and physical forces affecting stock productivity.
The group proposed to use daily somatic growth in the first 6 to 12 months of life, and the mapping of acoustic backscatter from zooplankton in relation to fish distribution and physical structure as a field measurement programme. Modeling, particularly fish growth energy models, and ones needed to facilitate comparisons between ecosystems would be essential as well as training in the use of such models. It was considered that the acoustic measurements of zooplankton would reflect prey abundance often enough to be used in comparing food distribution in certain areas with that of the fish, which would be mapped synchronously. The acoustic measurements would have to be supplemented by quantitative net hauls to identify targets and confirm a relationship between back-scattering strength and prey abundance in the various zooplankton regimes encountered during the survey.
Enhancements to this most basic field programme are highly desirable and would be expected in many SPACC countries or regions.
The fundamental question of a SPACC program is to understand the causal mechanisms responsible for the fluctuations in abundance of small pelagic fish populations. To understand these causal mechanisms, the SPACC programme will, with respect to process-oriented studies, incorporate and integrate a number of elements, including: field surveys of standardized core measurements at critical periods in the life history of the fish; more frequent monitoring of a subset of the core measurements at a few points (coastal or offshore) or transects; and development of biophysical models. Where resources allow, additional parameters will be measured on the core surveys and monitoring stations and intensive studies will focus on specific processes for shorter periods.
Measurements and sampling strategy were identified for a core SPACC Sampling Programme. The major processes to be determined are:
From the standpoint of implementation, the modeling needs of the SPACC Programme can be broadly categorized into two classes: (1) advanced models for general application and (2) models for regional application and training. Each is discussed below.
Advanced models for general application: Advanced models are needed as tools to integrate and compare the results from different SPACC regions. General circulation models (GCMs) should be coupled with biological models of different complexity to create generic ecosystem models. This requires the participation of modelers with existing state-of-the-art expertise. To initiate this aspect of the modeling studies, biologists and modelers should meet at a workshop to identify a minimum group of specific models that need to be developed. A hierarchy of generic models will be developed which can be made available for application to different SPACC regions. In this way, results from field programmes would be synthesized and the models would facilitate intersystem comparisons.
Models for regional application and training: Given the general paucity of regional modeling expertise and the large number of SPACC-related regions, training and education should proceed immediately and in conjunction with the development and implementation of simple models such as individual-based energy budgets or trophic flow models of ecosystems. Initial training could start with a workshop addressing a specific ecological problem, such as the development of an energy-budget (e.g. individual-based) model for small pelagic fish or an energy flow budget model, summarizing the existing knowledge on the various components in the ecosystem of interest in a clear manner. A workshop such as this could help identify potential key individuals for further training in modeling.
Training, Education and Mutual Assistance (TEMA) is an important part of SPACC and most research elements of SPACC will have training components. Given the paucity of modeling expertise in many participating countries and the dependance of SPACC process studies on the application of models, training in the use of simple models receives a high priority in SPACC. A training and education component in the use of simple models appropriate to SPACC is a certainty and shall be a key part of SPACC implementation. Priorities for training and education in other fields cannot be set until the characteristics of the core programmes are finalized.
It is important to resolve the issue of a SPACC office as soon as possible as the need is urgent (current efforts of Hunter, Alheit and their secretaries cannot be sustained much longer). Precedents exist for such an office; three of the four International GLOBEC sponsors (SCOR, ICES, PICES) are currently hosting offices for GLOBEC Programmes. It was suggested in Swakopmund that SPACC could approach IOC regarding support of the future SPACC office. This seemed appropriate because SPACC is the GLOBEC activity with the by far largest number of developing countries participating and because the goals of SPACC are at the heart of the OSLR (Ocean Science in Relation to Living Resources) Programme of IOC.
A SPACC-GLOBEC Newsletter will be established which serves to rapidly disseminate information to the SPACC community. The information will be given in "bullet" form indicating a source for further information. The issues will be published as soon as sufficient information has been accumulated. Ramiro Sanchez, Argentina, is the editor of the Newsletter. The first issue was distributed in late December 1995.