Ecosystem Health of the World’s Great Lakes and Its Influence on the Sustainability of Their Fisheries
Norine E. Dobiesz and Robert E. Hecky
Created through different geological processes and occupying a board range of climates, the world’s great lakes naturally exhibit a broad range of physical, chemical, and biological properties. These large aquatic ecosystems support vital fisheries that provide substantial economic value to humans and ecological importance to the environment. To varying degrees, all global great lakes are facing ecologically relevant challenges associated with invasive species, climate change, contaminants, excessive nutrient loading, and overexploitation of fisheries. Activities associated with social and economic development, such as human population growth, urbanization, deforestation, and increasing demand and use of natural resources, often further aggravate these conditions. Indeed, an ecosystem faces a wide variety of stressors that can reduce its functionality and negatively impact its health.
The term “ecosystem health” is generally defined by analogy to human health (Costanza et al. 1992), which is familiar and therefore helpful for communicating ecosystem status to the public (Ryder 1990; Lackey 2001). Researchers prefer a definition based on ecological principles and therefore define a healthy ecosystem as being stable and sustainable with resilience to stress that allows it to maintain its organization (Costanza et al. 1992). Because humans benefit from ecosystem resources and services and exercise control over ecosystem processes, healthy ecosystems are also identified as those capable of sustaining economic activity and human health while maintaining organization, resilience, and vigor (Rapport et al. 1998).