Driving Forces Affecting Resource Sustainability in Large Marine Ecosystems

Located around the coastal margins of the Atlantic, Pacific and Indian Oceans are 64 Large Marine Ecosystems (LMEs). Within the boundaries of the LMEs, 95% of the world’s marine fisheries biomass is produced, ocean pollution is most severe, and coastal habitats are most seriously degraded. The LMEs are also important economic areas of the world, producing goods and services valued at $10.6 trillion annually. It is in the collective interest of civil society to ensure that resources at risk are protected and sustained for present and future generations. A pragmatic approach is being applied by countries in Africa, Asia, Latin America and eastern Europe, supported by $650 million in start-up funds from the Global Environment Facility (GEF) and other donors. This LME approach uses suites of indicators to assess physical, biological, and human forcing on ecosystem productivity, fish and fisheries, pollution and ecosystem health, socioeconomics and governance. Applications of the approach for identifying and, where appropriate, mitigating the affects of principal driving forces on sustaining goods and services of four LMEs are compared and evaluated in the ecosystem context. LME DELINEATION AND MAJOR STRESSORS Large marine ecosystems are natural regions of ocean space encompassing coastal waters from estuaries to the seaward boundary of continental shelves and the outer margins of coastal currents. They are relatively large regions of 200,000 km or greater, the natural boundaries of which are based on four ecological criteria: bathymetry, hydrography, productivity, and trophically related populations. The concept that critical processes controlling the structure and function of biological communities can best be addressed on a regional basis (Ricklefs 1987) has been applied to the ocean by using large marine ecosystems as the distinct units for 8/24/2005 4:14:26 PM 2 marine resources assessment, monitoring, and management (Duda and Sherman 2002). In turn, the concept of assessment, monitoring, and management of renewable resources from an LME perspective has been the topic of a series of ongoing national and international studies, symposia case studies and workshops initiated since 1984; in each instance, the geographic extent of the LME has been defined on the basis of bathymetry, hydrography, productivity, and trophodynamics. A list of peer reviewed published volumes of LME case studies is given in Table 1. The marine areas of the world most stressed from habitat degradation, pollution, and overexploitation of resources are the coastal ecosystems. Ninety-five percent of the usable annual global biomass yield of fish and other living marine resources is produced in 64 LMEs (Figure 1) identified within, and in some cases extending beyond, the boundaries of the EEZs of coastal states (Sherman 1994); Levels of primary production are persistently higher around the margins of the ocean basins than in the open-ocean pelagic areas (Figure 2). High population density characterizes these coastal ocean areas and contributes to the pollution that has its greatest impact on natural productivity cycles through eutrophication from high levels of nitrogen and phosphorus effluent from estuaries or air-born sources. The presence of toxins, in harmful algal blooms, and loss of wetland nursery areas to coastal development are ecosystem-level problems that also need to be addressed. Taken together, the goods and services provided to civil society from LMEs on an annual basis are estimated at $10.6 trillion (Costanza et al. 1997). It is important to ensure that resources at risk are protected and sustained for present and future generations Efforts are underway to meet the challenges of forecasting changing biotic and abiotic conditions within the boundaries of LMEs (USEO 2004; USOAP 2004; UN General Assembly 2001). Given the multi-sectoral and multi-disciplinary demand for time-series data, consideration should be given to the use of standard and inter-calibrated protocols for measuring changing ecological states of the watersheds, bays, estuaries, and coastal water of LMEs. Long-term historical time series data on living marine resources (some up to 40-yr), coupled with measured or inferred long-term pollutant loading histories, have proven useful for relating the results of intensive monitoring to the quantification of ‘cause and effect’ mechanisms affecting the changing ecological states of LMEs. Temporal and spatial scales influencing biological production and changing ecological states in marine ecosystems have been the topic of a number of theoretical and empirical studies. The selection of scale in any study is related to the processes under investigation. An excellent treatment of this topic can be found in Steele (1988). Steele indicates that in relation to general ecology of the sea, the best known work in marine population dynamics includes studies by Schaefer (1954), and Beverton and Holt (1957), following the earlier pioneering approach of Lindemann (1942). However, as noted by Steele (1988), this array of models is unsuitable for consideration of temporal or spatial variability in the ocean. A heuristic projection was produced by Steele (1988) to illustrate scales and ecosystem indicators of importance in monitoring pelagic components of the ecosystem including phytoplankton, zooplankton, fish, frontal processes, and short-term but large-area episodic effects (Figure 3). Advances in technology allow for cost effective methods for measuring the changing states of LMEs using suites of indicators including those depicted in Figure 3, supplemented with other modular suites of indicators. 8/24/2005 4:14:26 PM ICES CM 2005/M:07 3 LME INDICATOR MODULES A five-module indicator approach to the assessment and management of LMEs has been proven to be useful in ecosystem-based projects in the United States and elsewhere. The modules provide time-series data to support forecasting efforts. They are customized to fit the situation within the context of a transboundary diagnostic analysis (TDA) process and a strategic action plan (SAP) development process for the groups of nations or states sharing an LME. These processes are critical for integrating science into management in a practical way and establishing appropriate governance regimes. The five modules consist of 3 that are science-based indicators focused on: productivity, fish/fisheries, pollution/ecosystem health; the other two, socio-economics and governance, are focused on economic benefits to be derived from a more sustainable resource base and implementing governance mechanisms for providing stakeholders and stewardship interests with legal and administrative support for ecosystem-based management practices. The first four modules support the TDA process while the governance module is associated with periodic updating of the Strategic Action Program (SAP). Adaptive management regimes are encouraged through periodic assessment processes (TDA updates) and updating of SAPs as gaps are filled (Figure 4) ( Duda and Sherman 2002; Wang 2004). Productivity Module Indicators • Primary productivity can be related to the carrying capacity of an ecosystem for supporting fish resources (Pauly and Christensen 1995). Measurements of ecosystem productivity can be useful indicators of the growing problem of coastal eutrophication. In several LMEs, excessive nutrient loadings of coastal waters have been related to algal blooms implicated in mass mortalities of living resources, emergence of pathogens (e.g., cholera, vibrios, red tides, and paralytic shellfish toxins), and explosive growth of nonindigenous species (Epstein 1993, 1996). • The ecosystem parameters measured and used as indicators of changing conditions in the productivity module are hydrography, nutrients, primary production, zooplankton biomass and species composition (Edwards et al. 2000a, 2000b). Plankton inhabiting LMEs have been measured over decadal time scales by deploying continuous plankton recorder systems monthly across ecosystems from commercial vessels of opportunity as well as from fixed stations. Advanced plankton recorders can be fitted with sensors for temperature, salinity, chlorophyll, nitrate/nitrite, petroleum, hydrocarbons, light, bioluminescence, and primary productivity, providing the means for in situ monitoring and for calibrating satellite-derived oceanographic data. Properly calibrated satellite data can provide information on such ecosystem aspects as physical state (i.e. surface temperature), nutrient characteristics, primary productivity and chlorophyll concentration (Berman and Sherman 2001; Aiken et al. 1999). Fish and Fisheries Module Indicators • Changes in biodiversity and species dominance within fish communities of LMEs have resulted from excessive exploitation, naturally occurring environmental shifts due to climate change and coastal pollution. Changes in biodiversity and species dominance in a fish community can rise up the food web to apex predators and cascade down the food web to plankton components of the ecosystem (Frank et al. 2005; Choi et al. 2004; Pauly and Christensen 1995). • The Fish and Fisheries Module includes both fisheries-independent bottom-trawl surveys and pelagicspecies acoustic surveys to obtain time-series information on changes in fish biodiversity, population dynamics, and abundance levels. Standardized sampling procedures, when employed from small calibrated trawlers, can provide important information on changes in fish populations (NOAA 1993; NEFSC 1999, 2002) Sherman et al. 2002, 2003). Commercial fish catch provides biological samples for stock identification, stomach content analyses, age-growth relationships, fecundity, as well as data for preparing stock assessments and for clarifying and quantifying multispecies trophic relationships and pathological conditions. The survey vessels can also be used as platforms for obtaining water, 8/24/2005 4:14:26 PM 4 sediment, and benthic samples for monitoring harmful algal blooms, diseases, anoxia, and changes in benthic communities. Pollution and Ecosystem Health Module Indicators • In several LMEs, pollution and eutrophication have been important driving forces of change in biomass yields. Assessing the changing status of pollution and health of an entire LME is scientifically challenging. Ecosystem health is a concept of wide interest for which a single precise scientific definition is difficult. The health paradigm is based on multiple-state comparisons of ecosystem resilience and stability, and is an evolving concept that has been the subject of a number of meetings (NOAA 1993). To be healthy and sustainable, an ecosystem must maintain its metabolic activity level and its internal structure and organization, and must resist external stress over time and space scales relevant to the ecosystem (Costanza 1992). • The Pollution and Ecosystem Health Module measures pollution effects on the ecosystem through the bivalve monitoring strategy of the U.S. Environmental Protection Agency’s (EPA’s) Mussel-Watch Program, through the pathobiological examination of fish; through the estuarine and nearshore monitoring of contaminants and contaminant effects in the water column, the substrate, and in selected groups of organisms, through similar efforts. Where possible, bioaccumulation and trophic transfer of contaminants are assessed, and critical life history stages and selected food web organisms are examined for indicators of exposure to, and effects from, contaminants. Effects of impaired reproductive capacity, organ disease, and impaired growth from contaminants are measured. Assessments are made of contaminant impacts at both species and population levels. Implementation of protocols to assess the frequency and effect of harmful algal blooms, emergent diseases, and multiple marine ecological disturbances (Sherman 2000) are included in the pollution module. In the United States, the EPA has developed a suite of 5 coastal condition indicators: water quality index, sediment quality index, benthic index, coastal habitat index, and fish tissue contaminants index. The 2004 report, “National Coastal Condition Report II,” includes results from EPA’s analyses of coastal condition indicators and NOAA’s fish stock assessments by LMEs aligned with EPA’s National Coastal Assessment (NCA) regions (USEPA 2001, 2004). Socioeconomic Module Indicators • This module emphasizes the practical application of scientific findings to managing LMEs and the explicit integration of social and economic indicators and analyses with all other scientific assessments to assure that prospective management measures are cost-effective. Economists and policy analysts work closely with ecologists and other scientists to identify and evaluate management options that are both scientifically credible and economically practical with regard to the use of ecosystem goods and services. • In order to respond adaptively to enhanced scientific information, socioeconomic considerations must be closely integrated with science. This component of the LME approach to marine resources management has recently been described as the human dimensions of LMEs. A framework has been developed by the Department of Natural Resource Economics at the University of Rhode Island for monitoring and assessment of the human dimensions of LMEs and for incorporating socioeconomic considerations into an adaptive management approach for LMEs (Sutinen et al. 2000). One of the more critical considerations, a method for economic valuations of LME goods and services, has been developed using framework matrices for ecological states and economic consequences of change (Hoagland et al. 2005). Governance Module Indicators • The Governance Module is evolving, based on demonstration projects now underway in several ecosystems, such that ecosystems will be managed more holistically than in the past. In LME assessment and management projects supported by the Global Environment Facility for the Yellow Sea, the Guinea Current , and the Benguela Current LMEs, agreements have been reached among the environmental ministers of the countries bordering these LMEs to enter into joint resource assessment and management activities as part of building institutions. One of the major goals of the Benguela Current LME (BCLME) Programme is to establish a Benguela Current Commission which will enable Angola, Namibia and South Africa to engage constructively and peacefully in resolving the transboundary fisheries and environmental issues that threaten the integrity of the BCLME. 8/24/2005 4:14:26 PM ICES CM 2005/M:07 5 • A preliminary study has found that the establishment of a Benguela Current Commission (BCC) can be justified on several grounds. These include the need for an appropriate institution to implement an ecosystem-based management approach in the BCLME and the need to fulfill the international obligations and undertakings of the three countries of the Benguela. Other motives for the establishment of a regional commission include the need to develop a better understanding of the BCLME, to improve the management of human impacts on the BCLME, to facilitate regional capacity building and to increase the benefits derived from transboundary management and harvesting of fish stocks. • A phased approach towards establishing a Benguela Current Commission has been recommended. The first priority would be to draft the necessary agreement between the three countries of the Benguela region. Thereafter, working groups and joint management committees could be brought into operation to address the most pressing transboundary concerns. • An Interim Benguela Current Commission (IBCC) is seen as a preliminary step towards a permanent Commission. It would provide the three countries with an opportunity to test and strengthen the institutional structures that will be required for a permanent Commission. It is envisaged that the BCLME Programme’s existing structures would support the IBCC until new structures are made operational. • Elsewhere, the Great Barrier Reef LME and the Antarctic LME are also being managed from an ecosystem perspective, the latter under the Commission for the Conservation of Antarctic Marine Living Resources. Governance profiles of LMEs are being explored to determine their utility in promoting long-term sustainability of ecosystem resources (Juda and Hennessey 2001). In each of the LMEs, governance jurisdiction can be scaled to ensure conformance with existing legislated mandates and authorities. • Agreement was reached recently by UNEP to engage GEF-supported LME projects as the assessment and management components of the UNEP Regional Seas Programme (IOC 2005) APPLICATION OF ECOSYSTEM INDICATORS TO LME ASSESSMENT AND MANAGEMENT For this report we examined the forces driving changes in biomass yields of four LMEs based on the studies currently in progress for the Yellow Sea in Asia, the Benguela Current in Africa, and the U.S. Northeast Shelf and the Canadian Scotian Shelf LMEs in North America. In each case, the stewardship agencies responsible for the long term sustainability of the fishery resources at risk, applied information consistent with two or more of the 5 LME modules and their indicators to assess the changing states of the ecosystems under investigation. In each case, the identification of root causes for the biomass yield changes were identified by the principal investigators and reported in the literature. Legally mandated management actions were implemented following deliberations on the broader ecosystem considerations made possible from the indicator assessments of LME productivity, fish and fisheries, pollution and ecosystem health, socioeconomics and governance.