From aquatic science to ecosystem health: a philosophical perspective

The development of an ecosystem (social, economic, environmental) approach to water management is traced from its origins in the Great Lakes of North America. The focus on health and integrity of ecosystems is an outgrowth of the Lamarckian concept of The Biosphere as a global system of matter, life, and mind. The driving forces behind the development of an ecosystem approach have been negative feedback from excessive demotechnic growth and faith that we can maintain a healthy relationship with Mother Earth.     

The development of ecosystem objectives for the Laurentian Great Lakes

Historically management of human use of ecosystems has been based around engineering and chemical approaches and through the construction of treatment facilities, effluent controls and setting chemical concentrations, both at end of pipe and in the aquatic environment. However, the general continued degradation of many ecosystems shows these approaches alone are insufficient. In the Laurentian Great Lakes the Great Lakes Water Quality Agreement was first signed in 1972 and ratified in 1978 and in 1987 tacitly acknowledged the problems with a chemical only approach by requiring the development of ecosystem objectives in the 1978 agreement. Furthermore, the agreement specifically identified numerical ecosystem objectives in the 1987 agreement. The evolution of ecosystem objectives in the Great Lakes has expanded from the strictly numerical objectives such as production of lake trout and abundance of the amphipod Pontoporeia hoyi. More recent developments in ecosystem objectives have been the inclusion of indicators for wildlife, habitat, human health and stewardship.Prepared as a discussion paper presented to the United Nations Economic Commission for Europe's seminar on an Ecosystems Approach to Water Management (May 27–31, 1991).     

The ecosystem approach to environmental assessment: moving from theory to practice

The ecosystem approach to environmental management is viewed by many as being fundamental to the development of appropriate management strategies. While this approach represents a major advance in the way researchers view environmental assessment, the approach in itself does not provide practical information as to what questions to ask and what tools to use in assessing and managing ecosystems. Similarly, the concept of ecosystem health, as it is usually defined, has little practical value for ecosystem managers. We suggest the next stage in environmental assessment will be the development of specific frameworks designed to assess individual ecosystems. Of primary importance is the need to consider the basic structure and function of the ecosystem itself. Such consideration, together with explicit identification of anthropogenic stresses particular to the system, serves to identify those components most at risk and those issues most deserving of attention. Researchers should explore critical linkages between environmental stressors and their observable, measurable and predictable effects on ecological parameters and use this understanding to develop a management strategy that incorporates appropriate ecological indicators. The importance of these considerations will be illustrated using examples from the Northern River Basins Study.     

Predator-prey dynamics in an ecosystem context

Evaluating the role of fishes at the food web and ecosystem scales profits from an iterative process. At the community and population scales, prey selection by predators alters habitat selection behaviours of prey species as well as their abundance, size distributions, life histories and the consequent effects on their own prey. At the whole system scale, predation by fishes alters community structure and nutrient cycling. Thus, both direct and indirect predation effects are expressed in population structure, community composition and production processes at all trophic levels. These are the central tenets of the trophic cascade argument.
Examples are abundant and diverse. We know that predators are size selective, that resource partitioning occurs, that functional responses link the density dependence of predator and prey populations, and that predator avoidance behaviours are common. A more significant challenge exists when attempting to use this knowledge.
This presentation attempts to link theory and empiricism in forecasts of what will happen next in response to a management action or a planned experiment. Examples are drawn from whole system experiments conducted in small lakes and from large-scale manipulations of predator populations in North America's Laurentian Great Lakes. Rapid and discontinuous or non-linear responses are common. Extrapolating the lessons of mechanistic process studies proves insufficient because the context is dynamic. Inferences built from the whole ecosystem scale yield equally misleading results because the scale is too general, Resolving these problems will require a clever mix of selective applications of predator-prey theory and astute empiricism.     

Developing ecosystem objectives for the Great Lakes: policy,progress and public participation

Under the Great Lakes Water Quality Agreement of 1978 between the United States and Canada, as amended in 1987, an ecosystem objective with associated indicators for Lake Superior was adopted, and a commitment was made to develop ecosystem objectives and indicators for each of the other Great Lakes. Building upon a history of activities within the International Joint Commission related to the development of ecosystem indicators for Lake Superior and for mesotrophic waters, a binational Ecosystem Objectives Work Group (EOWG) has been established by the U.S. and Canada and charged with developing ecosystem objectives for the Great Lakes, beginning with Lake Ontario. These objectives are primarily biological in nature, in contrast to chemical objectives. The approach of the EOWG is to identify in sequence: (1) broad ecosystem goals, (2) a suite of objectives whose attainment would ensure achievement of the goals, and (3) one or more measurable indicators of progress toward meeting each objective. Societal values are reflected in the goals and objectives following consultation with competing users of ecosystem resources. Identification of appropriate indicators requires the assistance of technical experts. The experience of the EOWG in developing ecosystem objectives for Lake Ontario illustrates the application of this process.     

Towards defining aquatic ecosystem health for the Great Lakes

The Canada — U.S. Great Lakes Water Quality Agreement defines Areas of Concern as geographic areas that fail to meet the general or specific objectives of the Great Lakes Water Quality Agreement where such failure has caused or is likely to cause impairment of beneficial use or the area's ability to support aquatic life. Impairment of beneficial use is defined by the Agreement as a change in the physical, chemical or biological integrity sufficient to cause any one of 14 designated use impairments. In 1987 the International Joint Commission's Great Lakes Water Quality Board (GLWQB) recommended that criteria be developed to determine when ecosystem conditions have been impacted enough to warrant designation as an Area of Concern and when conditions have improved sufficiently to be delisted. Based on scientific input and policy considerations, the GLWQB adopted, in principle, a set of quantitative and qualitative listing/delisting criteria for each of the 14 use impairments. These criteria can be uniformly applied throughout the basin. Further, the GLWQB recommended future refinement of these criteria based on advances in science and public input.     

Ecosystem integrity in the Great Lakes Basin: an historical sketch of ideas and actions

The concepts of ecosystem and integrity effectively entered the binational political arena in the Great Lakes Basin in the early 1970's. They were brought together explicitly in the statement of the purpose of the 1978 Great Lakes Water Quality Agreement. The 1987 Protocol to that Agreement has helped to specify the practical meaning of ecosystem integrity of the Great Lakes Basin. The proceedings of a binational workshop in 1988, titled An Ecosystem Approach to the Integrity of the Great Lakes Basin in Turbulent Times, helped to clarify the conceptual meaning. An Ecosystem Charter for the Great Lakes-St. Lawrence River Basin was proposed in 1989 to help achieve more thorough implementation of the commitment to ecosystem integrity. The evolutionary emergence of this political concept and related practice is described in the paper.List of abbreviations used in the text CUSIS Canada-U.S. Inter-University Seminar Series - LAA Environmental Lakes Area - EPA Environmental Protection Agency - GLBC Great Lakes Basin Commission - GLC Great Lakes Commission - GLER Great Lakes Ecosystem Rehabilitation - GLFC Great Lakes Fishery Commission - GLSAB Great Lakes Science Advisory Board - GLU Great Lakes United - GLWQA Great Lakes Water Quality Agreement - HASP Heritage Area Security Plan - IBP International Biological Program - IJC International Joint Commission - IZAP Inundation Zone Adaptive Plan - LAMP Lake-wide Management Plan - LLRS Lake Levels Reference Study - MAB Man and the Biosphere program - NEPA National Environmental Policy Act - PLUARG Pollution from Land Use Activities Reference Group - RAP Remedial Action Plan - SCOL Salmonid Communities in Oligotrophic Lakes - SGLFMP Strategic Great Lakes Fishery Management Plan - SPOF Strategic Plan for Ontario Fisheries - UNESCO United Nations Educational, Scientific and Cultural Organization Aquatic Ecosystem Health and Management Society. Symposium at the University of Waterloo, July 23–25, 1990.     

基于生态系统方法的大海洋生态系管理

大海洋生态系是指海洋中具有独特海洋学和生态学特征的一个较大的区域,其自然特性要求采用基于生态系统的方法对其进行管理.一系列的国际条约和章程均明确或间接支持采用基于生态系统方法管理大海洋生态系,实现海洋资源的可持续利用.实践方面,加拿大、澳大利亚、美国等采用了基于生态系统方法对其海洋进行管理,全球环境基金会等国际组织实施了一些基于生态系统方法的大海洋生态系项目,加勒比共同体等区域组织建立了旨在实现其渔业可持续发展的区域渔业机制.而基于生态系统方法的大海洋生态系管理能否最终成功实施,不仅是一个科学和法律问题,而且在很大程度上也是一个政治问题,依赖于相关国 家的政治意愿与相互合作的程度.     

Embracing thresholds for better environmental management

Three decades of study have revealed dozens of examples in which natural systems have crossed biophysical thresholds (‘tipping points’)—nonlinear changes in ecosystem structure and function—as a result of human-induced stressors, dramatically altering ecosystem function and services. Environmental management that avoids such thresholds could prevent severe social, economic and environmental impacts. Here, we review management measures implemented in ecological systems that have thresholds. Using Ostrom''s social–ecological systems framework, we analysed key biophysical and institutional factors associated with 51 social–ecological systems and associated management regimes, and related these to management success defined by ecological outcomes. We categorized cases as instances of prospective or retrospective management, based upon whether management aimed to avoid a threshold or to restore systems that have crossed a threshold. We find that smaller systems are more amenable to threshold-based management, that routine monitoring is associated with successful avoidance of thresholds and recovery after thresholds have been crossed, and that success is associated with the explicit threshold-based management. These findings are powerful evidence for the policy relevance of information on ecological thresholds across a wide range of ecosystems.     

Linking fish population dynamics to habitat conditions: insights from the application of a process-oriented approach to several Great Lakes species

One of the major challenges facing fishery scientists and managers today is determining how fish populations are influenced by habitat conditions. Many approaches have been explored to address this challenge, all of which involve modeling at one level or another. In this paper, we explore a process-oriented model approach whereby the critical population processes of birth and death rates are explicitly linked to habitat conditions. Application of this approach to five species of Great Lakes fishes including: walleye (Sander vitreus), lake trout (Salvelinus namaycush), smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens), and rainbow trout (Onchorynchus mykiss), yielded a number of insights into the modeling process. One of the foremost insights is that processes determining movement and transport of fish are critical components of such models since these processes largely determine the habitats fish occupy. Because of the importance of fish location, an individual-based model appears to be a nearly inescapable modeling requirement. There is, however, a paucity of field-based data directly relating birth, death, and movement rates to habitat conditions experienced by individual fish. There is also a paucity of habitat information at a fine temporal and spatial scale for many important habitat variables. Finally, the general occurrence of strong ontogenetic changes in the response of different life stages to habitat conditions emphasizes the need for a modeling approach that considers all life stages in an integrated fashion.     

Variations of ecosystem gas exchange in the rain forest mesocosm at Biosphere 2 in response to elevated CO2

The effects of elevated CO₂ on tropical ecosystems were studied in the artificial rain forest mesocosm at Biosphere 2, a large-scale and ecologically diverse experimental facility located in Oracle, Arizona. The ecosystem responses were assessed by comparing the whole-system net gas exchange (NEE) upon changing CO₂ levels from 900 to 450 ppmV. The day-NEE was significantly higher in the elevated CO₂ treatment. In both experiments, the NEE rates were similar to values observed in natural analogue systems. Variations in night-NEE, reflecting both soil CO₂ efflux and plants respiration, covaried with temperature but showed no clear correlation with atmospheric CO₂ levels. After correcting for changes in CO₂ efflux we show that the rain forest net photosynthesis increased in response to increasing atmospheric CO₂. The photosynthetic enhancement was expressed in higher quantum yields, maximum assimilation rates and radiation use efficiency. The results suggest that photosynthesis in large tropical trees is CO₂ sensitive, at least following short exposures of days to weeks. Taken at face value, the data suggest that as a result of anthropogenic emissions of CO₂, tropical rain forests may shift out of steady state, and become a carbon sink at least for short periods. However, a better understanding of the unique conditions and phenomena in Biosphere 2 is necessary before these results are broadly useful.     

Ecosphere,biosphere, or Gaia? What to call the global ecosystem

The terms biosphere, ecosphere, and Gaia are used as names for the global ecosystem. However, each has more than one meaning. Biosphere can mean the totality of living things residing on the Earth, the space occupied by living things, or life and life-support systems (atmosphere, hydrosphere, lithosphere, and pedosphere). Ecosphere is used as a synonym of biosphere and as a term for zones in the universe where life as we know it should be sustainable. Gaia is similar to biosphere (in the sense of life and life-support systems) and ecosphere (in the sense of biosphere as life and life-support systems), but, in its most extreme form, refers to the entire planet as a living entity. A case is made for avoiding the term Gaia (at least as a name for the planetary ecosystem), restricting biosphere to the totality of living things, and adopting the ecosphere as the most apt name for the global ecosystem.     

Impact of environmental factors on couplings between bacterial community composition and ectoenzymatic activities in a lacustrine ecosystem

This study examined the effects of temporal changes in bacterial community composition (BCC) and environmental factors on potential ectoenzymatic activities (α-glucosidase, β-glucosidase, alkaline phosphatase and leucine aminopeptidase) in a lacustrine ecosystem (Sep reservoir, France). BCC was assessed by terminal restriction fragment length polymorphism. Physical parameters, and inorganic and organic nutrient concentrations (dissolved carbohydrates and proteins) were measured in lakes and tributaries. According to the multivariate statistics (redundancy analysis), physical and chemical factors explained the largest part of leucine aminopeptidase activity, whereas the temporal changes of other ectoenzymatic activities were partly dependent on the variations in the BCC. In particular, the occurrence of occasional bacterial populations seemed to explain a lot of the variation in rates and patterns of polymer hydrolysis. The relation observed in this study between the bacterial structure and activity is discussed within the framework of biodiversity–ecosystem functioning.     

Fisheries in the Southern Ocean: an ecosystem approach

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is bound by its Article II, 3 to follow an ecosystem approach to management. This approach has been extended to the application of a precautionary approach in the late 1980s. In our review, we deal primarily with the science-related aspects of CCAMLR and its development towards an ecosystem approach to the management of the living resources of the Southern Ocean. To assist the Commission in meeting its objectives, as set out in Article II, 3, the Scientific Committee established the CCAMLR Ecosystem Monitoring Programme to detect possible effects of krill fishing on the performance of top-level predators, such as albatrosses, penguins, petrels and fur seals. Fisheries in the Southern Ocean followed the fate of other fisheries worldwide in which target species were depleted to low level one after the other. Currently, two types of fisheries are open: the longline fisheries on Patagonian toothfish (Dissostichus eleginoides) and Antarctic toothfish (Dissostichus mawsoni) and the trawl fisheries on mackerel icefish (Champsocephalus gunnari). Both fisheries are managed in a single-species context, however, with conservation measures in place to protect by-catch species, such as rattails (Macrouridae) and skates and rays (Rajidae). Two major problems still exist in fisheries in the Southern Ocean: the by-catch of birds in longline fisheries primarily in the Indian Ocean and the high level of IUU fishing again in the Indian Ocean. Both, the by-catch of birds and high IUU catches undermine the credibility of CCAMLR to safeguard the marine living resources in the Southern Ocean.     

Parasites of Aquatic Exotic Invertebrates: Identification of Potential Risks Posed to the Great Lakes

Exotic species typically lose most of their associated parasites during long-distance spread. However, the few parasites that are co-introduced may have considerable adverse impacts on their novel hosts, including mass mortalities. We present a comprehensive inventory of parasites known to infect 38 species of exotic invertebrates established in the Great Lakes, as well as 16 invertebrate species predicted to arrive in the near future, all of them crustaceans. Based on a literature analysis, we identified a total of 277 parasite taxa associated with the examined invertebrates in their native ranges and/or invaded areas. Of these parasites, 56 species have been documented to cause various pathologies in their intermediate or final hosts, with humans and fishes being the most frequently affected host categories. Potentially harmful parasites were identified in 61% of the invaders for which published information was retrieved (in their ranges outside of the Great Lakes), with molluscs and crustaceans hosting the highest numbers of such parasites. The results of our study provide a baseline for further assessment and management of the parasitological risks posed by exotic species to the Great Lakes.     

Adaptive management of coastal ecosystem restoration projects

There is a clear need to apply better and more effective management schemes to coastal ecosystem restoration projects. It is very common for aquatic ecosystem restoration projects not to meet their goals. Poor performance has led to a high degree of uncertainty about the potential success of any restoration effort. Under adaptive management, the knowledge gained through monitoring of the project and social policies is translated into restoration policy and program redesign. Planners and managers can utilize the information from the monitoring programs in an effective way to assure that project goals are met or that informed and objective decisions are made to address both ecological and societal needs. The three main ingredients of an effective adaptive management plan in a restoration project are: (1) a clear goal statement; (2) a conceptual model; and (3) a decision framework. The goal ‘drives’ the design of the project and helps guide the development of performance criteria. The goal statement and performance criteria provide the means by which the system can be judged. With the conceptual model, the knowledge base from the field of ecological science plays an active and critical role in designing the project to meet the goal. A system-development matrix provides a simple decision framework to view the alternative states for the system during development, incorporate knowledge gained through the monitoring program, and formulate a decision on actions to take if the system is not meeting its goal.     

锡林郭勒生物圈保护区草原生态系统服务间接价值动态评估

草地是我国面积最大的陆地生态系统类型,对于维持我国北方的生态安全具有重要价值。北方草原的大面积退化已引起人们的极大关注。以内蒙古锡林郭勒生物圈保护区为研究区域．利用2个年份的遥感数据,结合地面样方调查,在GIS的支持下,绘制出草原退化空间分布图。选取草原生态系统在控制土壤侵蚀、减少土壤肥力流失、营养物质循环、CO2储存和O2释放方面的功能指标,对草原生态系统服务间接价值进行了动态评估。1985年和1999年草原退化面积分别为7190．9和7689．3km^2,占研究区总面积的67．19％和71．86％。2个年份草原生态系统间接服务总价值分别为28．24和26．75亿元．下降了5．28％,单位面积间接服务价值分别为2990和2830元。下降了5．35％。人类的过度放牧是导致草原大面积退化,生态系统功能降低和服务价值下降的主要原因。     

Environmental quality assessment of the St. Clair River as reflected by the distribution of benthic macroinvertebrates in 1985

A benthic macroinvertebrate and sediment chemistry study of the St. Clair River from Lake Huron to Lake St. Clair was conducted in the spring of 1985. The purpose of the. study was to evaluate the environmental quality of the nearshore areas and assess the effectiveness of industrial and municipal abatement programs that have been implemented since 1977.A total of 112 macroinvertebratd taxa was collected from the river. Classification analysis indicated that 7 macroinvertebrate communities were evident in the river. Discriminant analysis suggested that physical habitat characteristics explained the distribution of 4 benthic communities, while sediment contaminants explained the distribution of 3 benthic communities. These analyses showed that the environmental quality of a 12 km stretch of the river along the Canadian shoreline had been degraded, probably by industrial waste discharges and spills. Toxic conditions were evident along the waterfront of Dow Chemical Canada Inc., probably a result of the combined effects of chlorinated organics, oils and greases, and mercury (historical contaminant) in the sediments. In contrast, the invertebrate fauna throughout the remainder of the St. Clair River reflected meso-eutrophic conditions, typical of a large, unstressed river.A comparison of the environmental quality as reflected by the benthic invertebrate fauna in 1985 with that in 1977 suggests that the abatement programs implemented over the past decade have improved the environmental quality along the Canadian side of the river. The total length of river adversely affected by waste discharges from Canadian industries and municipalities decreased from 21 km in 1977 to 12 km in 1985.     

Comparative analysis of European wide marine ecosystem shifts: a large-scale approach for developing the basis for ecosystem-based management

Abrupt and rapid ecosystem shifts (where major reorganizations of food-web and community structures occur), commonly termed regime shifts, are changes between contrasting and persisting states of ecosystem structure and function. These shifts have been increasingly reported for exploited marine ecosystems around the world from the North Pacific to the North Atlantic. Understanding the drivers and mechanisms leading to marine ecosystem shifts is crucial in developing adaptive management strategies to achieve sustainable exploitation of marine ecosystems. An international workshop on a comparative approach to analysing these marine ecosystem shifts was held at Hamburg University, Institute for Hydrobiology and Fisheries Science, Germany on 1-3 November 2010. Twenty-seven scientists from 14 countries attended the meeting, representing specialists from seven marine regions, including the Baltic Sea, the North Sea, the Barents Sea, the Black Sea, the Mediterranean Sea, the Bay of Biscay and the Scotian Shelf off the Canadian East coast. The goal of the workshop was to conduct the first large-scale comparison of marine ecosystem regime shifts across multiple regional areas, in order to support the development of ecosystem-based management strategies.