5.0 Submerged Aquatic Plants on Long Point Bay

5.5 Information gaps

The research conducted by LPWWRF and others at Long Point has provided important information pertaining to changes in distribution and abundance of aquatic plants over space and time. While changes in the distribution and abundance of aquatic macrophytes has been well documented, the causative agents of those changes are still largely unknown. It is difficult, but certainly not impossible to confidently ascertain which factor or group of factors have influenced aquatic plant dynamics. While it is known that non-point agricultural sources of nutrients and contaminants can have a profound effect on plant growth, little is known about the long-term ramifications of Big Creek discharge on aquatic plant growth in Long Point Bay. More specifically, we need to further assess:

1/ the potential long term effects that Lake Erie water level stabilization would have on aquatic plant biomass and species composition.

2/ the short and long term impacts of agriculturally-derived nutrients and contaminants on aquatic plant growth and succession.

3/ what aquatic plant species are consumed by waterfowl at Long Point during the spring.

4/ the availability of preferred waterfowl plant foods, particularly during spring and fall when large numbers of birds are staging at Long Point. This requires long term monitoring of selected vegetation transects.

5/ the influence of herbivore predation (carp, ducks, swans etc.), changes in sediment composition and quantity, storm and ice damage, and introduced exotics (including Eurasian milfoil and zebra mussels) on aquatic plant species distribution and abundance.

6/ the availability of wild celery. Being a particularly important food for Canvasbacks, this plant species requires special attention with respect to changes in its availability for migrating waterfowl.

However, environmental and anthropogenic factors can often act synergistically in their effect on the distribution and abundance of a particular plant species at any particular time. Therefore, long term, comprehensive research is required to gain a predictive understanding of the factors that are regulating aquatic plant communities at Long Point.