Ecosystem classification and mapping of the Laurentian Great Lakes

Abstract

Owing to the enormity and complexity of the Laurentian Great Lakes, an ecosystem classification is needed to better understand, protect, and manage this largest freshwater ecosystem in the world. Using a combination of statistical analyses, published knowledge, and expert opinion, we identified key driving variables and their ecologically relevant thresholds and delineated and mapped aquatic systems for the entire Great Lakes. We identified and mapped 77 aquatic ecological units (AEUs) that depict unique combinations of depth, thermal regime, hydraulic, and landscape classifiers. Those 77 AEU types were distributed across 1997 polygons (patches) ranging from 1 to >48 000 km 2 in area and were most diverse in the nearshore (35 types), followed by the coastal margin (26), and then the offshore (16). Our classification and mapping of ecological units captures gradients that characterize types of aquatic systems in the Great Lakes and provides a geospatial accounting framework for resource inventory, status and trend assessment; research for ecosystem questions; and management and policy-making. Résumé : En raison de l'énormité et de la complexité des Grands Lacs laurentiens, une classification des écosystèmes est nécessaire pour mieux comprendre, protéger et gérer ce plus grand écosystème d'eau douce du monde. En utilisant une combinaison d'analyses statistiques, de connaissances publiées et d'opinions de spécialistes, nous avons cerné des variables clés et leurs seuils importants sur le plan écologique, et délimité et cartographié les systèmes aquatiques pour l'entièreté des Grands Lacs. Nous avons cerné et cartographié 77 unités écologiques aquatiques (UEA) qui représentent les différentes combinaisons de profondeur, de régime thermique et de variables hydrauliques et du paysage importantes pour la classification. Ces 77 types d'UEA sont répartis sur 1997 polygones (parcelles) de superficies allant de 1 à >48 000 km 2 , la région sublittorale en présentant la plus grande diversité (35 types), suivie des bandes côtières (26), puis de la zone extracôtière (16). La classification et la cartographie des unités écologiques font ressortir les gradients qui caractérisent les types de systèmes aquatiques dans les Grands Lacs et fournissent un cadre géospatial de référence pour l'inventaire des ressources, l'évaluation des statuts et tendances, la recherche sur des questions touchant aux écosystèmes et la gestion et l'élaboration de politiques. [Traduit par la Rédaction]

Space and Species Interactions in Welfare Estimates for Invasive Species Policy

“…The lake is split into five ecologically differentiated zones (Figure 1) -zone 1 (southern Green Bay), zone 2 (northern Green Bay and Northern Lake Michigan), zone 3 (northwest Lake Michigan), zone 4 (southwest Lake Michigan), and zone 5 (southeast Lake Michigan) -following the ecological classifications of Riseng et al (2017) and the Level III Omernick classification of adjacency (EPA NHEERL, 2003). Riseng et al (2017) use five variables to represent four classification factors: bathymetry, thermal regime, mechanical energy associated with water motion, and tributary influence and identified 77 aquatic ecological units across the entire Great Lakes, which provided a geospatial accounting framework for research and resources management.…”

Modeling the interactive effects of nutrient loads, meteorology, and invasive mussels on suitable habitat for Bighead and Silver Carp in Lake Michigan

“…We defined the nearshore and offshore zones based on established bathymetric thresholds (nearshore: \ 30 m; offshore: C 30 m) that are commonly used to delineate biophysically-distinct habitats in the Great Lakes (Riseng et al 2018).…”

Lake level oscillations recorded in Buracica Stage (Barremian, Early Cretaceous) of Recôncavo Basin, Bahia State (N.E. Brazil)

“…Sediments deposited by high-energy and storm event are common in shallow marine environments due to wave activity and also in lakes from regions submitted to severe storms. The production of lake storm deposits is common; it is observed, for example, in the Great Lakes of North America or in the Paraná Basin, in central-eastern South America (Riseng et al 2018). Cohen (1984) reported the presence of near-shore sandy bodies in the Lake Turkana Basin, Africa (Galana Boi Layers), which have been formed by storm.…”