Saint Michaels College
Middlebury College University
of Vermont
Johnson State College
Green Mountain College
Castleton State College
State University of New York - Plattsburgh
Return to LCRC Home page
contact us at LCRC@smcvt.edu
Summary of April 30 Discussion of Community Structure of Missisquoi Bay
(participants: Brian Chipman, Doug Facey, Tom Manley; summary by Doug Facey)
Background
Some information is available about the relative abundance and distribution of some common species of fish, wildlife, and plants in the Bay, tributaries, and wetlands of the Missisquoi Ecosystem (including the Refuge). The Missisquoi River supports several rare species, and also is a spawning area for migratory fishes, including game species and endangered species. The Bay and wetlands also support other rare aquatic, wetland, and terrestrial species, and the entire ecosystem is used by a variety of migratory waterfowl and neotropical birds. There is much, however, that we do not know particularly with regard to recent changes in the ecosystem. We need much fuller assessment of the overall community structure of the ecosystem and the status of the various species in order to make appropriate decisions regarding future uses and impacts, and in order to detect changes as they occur so that appropriate action may be taken. This assessment should include the status of aquatic, wetland, and terrestrial invertebrates, vertebrates, and plants with a special emphasis on rare species and those likely to be connected to or affected by recent water quality issues in the Bay.
We need a better understanding of the role of various species of phytoplankton, zooplankton, larger invertebrates, and fishes in the aquatic food web; some of these food web links may be associated with recent noxious blooms of cyanobacteria, and others are likely to be affected by arrival of alewife if that species increases in the next few years. White perch, another invasive species, is now among the most common fish in the bay and we should learn more about its impact on other fishes and on invertebrate and plankton communities. Non-native plants including Eurasian watermilfoil, frogbit, purple loosestrife, yellow iris, flowering rush, water chestnut also have become established in Vermont, and a better knowledge of their abundance, distribution, and impact on other species is important. Other important questions include the impact of barriers on aquatic species and the role of wetlands to rare species.
Although much is known about various aspects of the overall community of Missisquoi Bay Ecosystem, there are some large gaps in the information available that should be addressed. In addition, further improvement in the sharing of information between Vermont and Quebec will help all involved with research and management to make more informed decisions.
Future Research Needs The discussion identified several main areas of need for future research.
Fish Community More information is needed about the relative abundance, distribution and movement, and trophic interactions of the fishes in the Missisquoi Bay ecosystem (including the Bay, tributaries, and wetlands). This is particularly important given the explosion of the white perch population in the Bay within the last 10 years and the apparent arrival of alewife (confirmed from collections made in 2003). A complete assessment is needed of the fish community, the movement of fishes in and out of tributaries (including for spawning), the fish exchange between the Bay and the rest of Lake Champlain, and the relative importance of barriers (dams on the rivers, and the Route 78 causeway) on fish movement. One important question that could be answered by studies of fish movement and exchange is whether the Missisquoi Ecosystem is a significant nursery area for fishes that subsequently move to other parts of Lake Champlain. The status of several rare species should be assessed, including eastern sand darters, brook lamprey, sturgeon, and redhorses. In addition, a thorough analysis of the food web is needed to assess the trophic interactions among fishes and the benthic and pelagic invertebrates. This could help address questions about potential links between foods web interactions and recent problems with blooms of toxic cyanobacteria. It could also help understand the movement of toxins through the food web, the impact of these toxins on fish and wildlife, and their potential impact on human consumers.
Benthic Community - An overall understanding of the benthic community is needed, including benthic invertebrates, aquatic macrophytes, and substrate. Information from sediment cores should help provide information about the historical changes in some of these parameters, which would also be quite valuable in understanding the ongoing changes in the Bay. We also need a better understanding of the distribution and relative abundance of aquatic macrophytes on the Vermont side of the Bay (similar information is already available on the Quebec side). The impacts of non-native macrophytes and wetland plants should be studied. Also important to understanding the overall community structure of the ecosystem is a thorough analysis of the benthic invertebrate community, including zebra mussels and other bivalves, snails, crayfish, and aquatic insects. This could provide information about invertebrate indicators of water quality as well as provide better ecological information about the community as whole.
Plankton - Also important to understanding the overall community structure of the ecosystem is a thorough analysis of the plankton community, including phytoplankton and zooplankton. Noxious, and sometimes toxic, blooms of cyanobacteria in recent years have dramatically impacted use of the Bay and hurt the local economy. These events are likely linked to nutrient inputs, but it is possible that changes in the overall plankton community, perhaps linked with trophic dynamics of the fishes, may be contribute to abundance of cyanobacteria during periods in the summer.
Vertebrates other than fishes - We need a better understanding of the populations and distributions of other vertebrates that use the Missisquoi Bay Ecosystem including turtles and migratory waterfowl and neotropical birds. The status of several rare vertebrates should be assessed, including spiny softshell turtle, map turtle, mudpuppy, chorus frog, Indiana bat, and black tern. The impact of the expanding cormorant population on other nesting birds, such as the blue heron rookery in the Missisquoi Wildlife Refuge, should also be monitored. In addition, a better understanding of the impact of human shoreline development on wildlife (especially rare species) is needed.
Wetlands and Riparian Woodlands - The extensive wetlands and riparian forests of the Missisquoi Bay Ecosystem also provide a good opportunity to study the importance of these habitats to the community as a whole, including their role as sediment and nutrient traps for the lake, their importance to fish and wildlife reproduction (including migratory neotropical birds), and the impacts of invasive vegetation.
Data Management - As is the case throughout the Lake Champlain Basin, improved data management to ensure the sharing of information in a timely manner will be critical in helping the support continued research and management efforts.
Multidisciplinary linkages - The issues of better understanding the community structure of the Missisquoi Bay Ecosystem cover a wide range of areas, and thus provide opportunities form multidisciplinary linkages among several major areas of research interest such as Lower Food Web/Plankton, Middle Food Web, Invertebrates, Fishes, Wildlife, Exotic Species, Land Use, Ecosystem Health, Toxics, Algae Blooms, Toxins, Hydrodynamics, Atmospherics, and Cultural issues (including hunting, fishing, other outdoor recreation, interest in the Wildlife refuge, and local indigenous human culture).