The Physical, Biological, and Human Interactions Shaping the Ecosystems of Freshwater Bays and Lagoons

Project overview

The Lake Ontario Biocomplexity Project focused on distinct and enclosed freshwater bays and lake-level lagoons along the New York coast of Lake Ontario including the associated watersheds, wetlands, and human settlements. The principal theme organizing the research effort is biocomplexity in open ecosystems. The main hypothesis is that the average time water takes to move through an aquatic system is a key variable defining the extent that ecosystems are self-organized or dominated by outside influences. The effort produced a large number of findings (57) covering many natural and human properties and processes of the eight embayment ecosystems. Overall, we found no simple pattern or single factor strongly shaping ecosystem character and this general conclusion refutes our main hypothesis. Dominant factors influencing many ecosystem properties differed among our eight systems with water dynamics important in some ecosystems or at times of large hydrologic events. Nutrient loading, aquatic macrophyte changes, and human activities were other factors that had widespread ecosystem effects. Therefore, we now see a multiple driver perspective as necessary to explain the nature of coastal bay and watershed ecosystems even though they exist in a single climate and are connected by a common waterbody (Lake Ontario).

The scale and importance of many ecosystem properties were detailed. Human community interests and patterns of change were included in our analyses. Extensive information was assembled to characterize key properties and processes of the nearshore environment: invertebrate correlates, fish-physicochemical relations, water circulation in and through embayments as well as on the Lake Ontario shore, aquatic vegetation and its role in shaping shallow water habitats, plankton dynamics, and food webs in different settings. Productivity for some taxa groups were clearly linked to water residence, nutrient inputs, and bay morphology. These relations are important for interpreting biological changes among bays and through time. Land cover was analyzed at decade time steps and paleo core records for plankton, land cover, chemistry, and wetland communities were developed. The major factors influencing the biota of embayments, tributaries, and wetlands were analyzed and described. Extensive data relating land use, agriculture, stream water quality, and embayment quality were assembled, interpreted, and refined. The consequences on aquatic life were well characterized providing thorough knowledge of non-point source pollution on biological and chemical properties of our ecosystems. GIS modeling of these processes on the landscape scale provide broad spatial information on streams and provides a framework for tracking and displaying information. The large array of information we assembled indicates what environmental and human factors are linked to ecosystem scale properties. Therefore, we obtained diverse and valuable findings on the nature of coastal ecosystems in the Great Lakes.

The Lake Ontario Biocomplexity Project was designed to interface with agencies and organizations responsible for Lake Ontario and is coastal zone. Many activities and additional funded studies built strong connections to managers and conservationists. The project contributed relevant data and new understanding on some of the issues important to practitioners and decision-makers: aquatic communities and habitats, non-point source pollution, and climate change. Some information was developed on exotic species, tributaries, and sustainable development. Our project did not assist agencies on contaminant issues. Overall, our strongest record of contribution were on broad issues consistent with our ecosystem orientation, and we were less valuable on topics of recent or local interest.

Aquatic communities are shaped by many factors acting together in coastal embayments: water circulation, residence time, nutrient inputs, mixing, inflow of cold water from lake, and others. Shallow vegetated bays have food webs based on in-bay energy sources (vegetated shallow, pelagic) while deep and open bays are based on energy from phytoplankton. The most important factors for the productivity and quality of embayments and coastal wetlands are hydrodynamics, nutrient loading, and bay morphology. Very clear data were obtained showing close link between agricultural land on water quality. Land cover change has reduced agricultural land and increased forest cover. These changes suggest declining threat from non-point source pollution. Methods for effective monitoring of coastal wetlands were assessed and a protocol developed. Paleoecology core analyses provide an understanding of long-term (1000s years) trends in environmental conditions that can help put climate changes in perspective. Perhaps our largest contribution was assembling diverse information in a way that provided a more complete picture of common coastal management issues.

 

The final report for this project was submitted to the National Science Foundation in Spring 2007.