Carp Exclusion, Food-web Interactions, and the Restoration of Cootes Paradise Marsh

Carp were excluded from Cootes Paradise Marsh (Lake Ontario) in 1997 in order to improve water clarity and promote submerged plant growth. On average, turbidity at open water and vegetated areas was reduced by 40 and 60 percent, respectively, following carp exclusion. However, responses by plants and other trophic levels have been both spatially and temporally variable due in part to annual variation in environmental conditions and fish-zooplankton interactions. In 1997, an unusually cool spring delayed the migration of spawning fish, including a usually abundant planktivore population, into the marsh. This had three main effects: 1) large Daphnia were released from predation in early summer and reached unprecedented numbers (530 Daphnia/L) in open water areas, 2) despite the lack of vegetated marsh habitat, larval fish production was high due to reduced predation and abundant zooplankton prey, and 3) zooplankton grazing initiated a spring clear-water phase which, together with carp exclusion, promoted submerged plant growth in shallow areas previously devoid of vegetation. These newly vegetated areas showed the greatest improvements in clarity and macrophyte growth in the first 2 years following exclusion. Currently, however, the future of the biomanipulation remains uncertain, due in part to natural climatic confounding factors, and further remedial actions will be required before this wetland represents a stable, clear-water, macrophyte dominated state.

[1]  G. Houen,et al.  Allelopathic effects on phytoplankton by substances isolated from aquatic macrophytes (Charales) , 1982 .

[2]  P. Chow-Fraser,et al.  Cootes Paradise Marsh , 1995, Restoration & Management Notes.

[3]  E. Jeppesen,et al.  Impact of submerged macrophytes on fish-zooplankton-phytoplankton interactions : large-scale enclosure experiments in a shallow eutrophic lake , 1995 .

[4]  M. Hanson,et al.  Responses of Plankton, Turbidity, and Macrophytes to Biomanipulation in a Shallow Prairie Lake , 1994 .

[5]  H. Pincus,et al.  Great Lakes Basin , 1963, Soil Science Society of America Journal.

[6]  M. Meijer,et al.  Effects of biomanipulation in the large and shallow Lake Wolderwijd, The Netherlands , 2004, Hydrobiologia.

[7]  P. Chow-Fraser,et al.  Primary determinants of macrophyte community structure in 62 marshes across the Great Lakes basin: latitude, land use, and water quality effects , 2001 .

[8]  J. K. Leslie,et al.  Distribution and Abundance of Larval Fish in Hamilton Harbour, a Severely Degraded Embayment of Lake Ontario , 1992 .

[9]  Patricia Chow-Fraser,et al.  Percentage land use in the watershed determines the water and sediment quality of 22 marshes in the Great Lakes basin , 1999 .

[10]  R. Greenberg.  Biometry , 1969, The Yale Journal of Biology and Medicine.

[11]  Patricia Chow-Fraser,et al.  Development and use of a zooplankton index of wetland quality in the Laurentian Great Lakes Basin , 2002 .

[12]  P. Chow-Fraser,et al.  Long-term response of the biotic community to fluctuating water levels and changes in water quality in Cootes Paradise Marsh, a degraded coastal wetland of Lake Ontario , 1998, Wetlands Ecology and Management.

[13]  J. Magnuson,et al.  Seasonal regulation of Daphnia populations by planktivorous fish: Implications for the spring clear‐water phase , 1990 .

[14]  R. Bachmann.  A guide to the restoration of nutrient‐enriched shallow lakes , 1999 .

[15]  T. Whillans.  Changes in Marsh Area Along the Canadian Shore of Lake Ontario , 1982 .

[16]  Spatial variability in the response of lower trophic levels after carp exclusion from a freshwater marsh , 2001 .

[17]  J. Lundholm,et al.  Wetland Vegetation Monitoring in Cootes Paradise , 2001, Ecological Restoration.

[18]  Ioannis K. Tsanis,et al.  Mass balance modelling and wetland restoration , 1997 .

[19]  Hakumat Rai,et al.  Phytoplankton control by grazing zooplankton: A study on the spring clear‐water phase1 , 1986 .

[20]  B. Moss,et al.  Prevention of growth of potentially dense phytoplankton populations by zooplankton grazing, in the presence of zooplanktivorous fish, in a shallow wetland ecosystem , 1984 .

[21]  P. Chow-Fraser,et al.  Predictions on the effect of common carp (Cyprinus carpio) exclusion on water quality, zooplankton, and submergent macrophytes in a Great Lakes wetland , 1998 .

[22]  E. Jeppesen,et al.  Fish manipulation as a lake restoration tool in shallow, eutrophic, temperate lakes 2: threshold levels, long-term stability and conclusions , 1990, Hydrobiologia.

[23]  T. Whillans.  Historic and comparative perspectives on rehabilitation of marshes as habitat for fish in the lower Great Lakes basin , 1996 .

[24]  Whole-lake food-web manipulation as a means to study community interactions in a small ecosystem , 1990 .

[25]  Ellen van Donk,et al.  Can macrophytes be useful in biomanipulation of lakes? The Lake Zwemlust example , 1990, Hydrobiologia.

[26]  Gregory Nolan.  Stage 2 Report , 2000 .

[27]  Fish manipulation as a lake restoration tool in shallow, eutrophic, temperate lakes 2: threshold levels, long-term stability and conclusions , 1990 .

[28]  S. E. HOLLINGWORTH,et al.  The Great Lakes , 1959, Nature.

[29]  David P. Hamilton,et al.  An empirical model for sediment resuspension in shallow lakes , 2004, Hydrobiologia.

[30]  J. Lundholm,et al.  Regeneration of Submerged Macrophyte Populations in a Disturbed Lake Ontario Coastal Marsh , 1999 .

[31]  P. Chow-Fraser.  Seasonal, Interannual, and Spatial Variability in the Concentrations of Total Suspended Solids in a Degraded Coastal Wetland of Lake Ontario , 1999 .

[32]  Robert G. Randall,et al.  An Index of Biotic Integrity (IBI) for Fish Assemblages in the Littoral Zone of Great Lakes' Areas of Concern , 1994 .

[33]  Patricia A. Chambers,et al.  Depth distribution and biomass of submersed aquatic macrophyte communities in relation to Secchi depth , 1985 .

[34]  M. Scheffer.  Ecology of Shallow Lakes , 1997, Population and Community Biology Series.

[35]  B. McCune,et al.  Analysis of Ecological Communities , 2002 .

[36]  P. Chow-Fraser,et al.  Factors that regulate the zooplankton community structure of a turbid, hypereutrophic Great Lakes wetland , 1998 .

[37]  P. Chow-Fraser.  A conceptual ecological model to aid restoration of Cootes Paradise Marsh, a degraded coastal wetland of Lake Ontario, Canada , 1998, Wetlands Ecology and Management.