Current Research
       1999 Lake Macropyhte Study
       Pictures from Summer 2000 

Introduced species into the Conesus Lake ecosystem

Alewife (Alosa pseudoharengus)

The alewife (Alosa pseudoharengus) is a planktivorous fish introduced into Conesus Lake in 1984.  The alewife feeds predominately on Daphnia, a zooplankton that feeds on phytoplankton helping to keep algal blooms in check.  The alewife had a drastic effect on the Daphnia population in the lake, preying so heavily upon them as to totally decimate their population.  As a consequence the Daphnia are no longer present to graze upon the phytoplankton allowing for expanded growth.  Due to the introduction of the alewife the algal blooms during the summer months in Conesus Lake cause the water to turn a pea soup color, having a negative effect on recreation in and on the lake.

Zebra Mussels (Dreissena polymorpha)

Zebra mussels (Dreissena polymorpha) from eastern Europe have recently invaded North America and are colonizing many inland lakes of New York, including the Finger Lakes.  The zebra mussel was identified in Conesus Lake in 1992, approximately 6 years after their introduction into the lake's ecosystem.  Zebra mussels have the potential to clog municipal and industrial water intake facilities; disrupt food webs and ecosystem balances; and interfere with sport and commercial fishing, navigation, recreational boating, beach use and agricultural irrigation. Most importantly for shoreline owners, they can clog residential water intakes and cause much frustration and added cost for homeowners.  Zebra mussels attach themselves to hard surfaces by using a tough elastic fiber tipped with an adhesive, called byssal thread. Once attached, the mussels can form a dense colony on whatever substrate it has attached to. The waterline is an ideal habitat providing a continuous source of food and oxygen while carrying away mussel wastes, and protecting the mussels from predation and storm waves.
      The introduction of the zebra mussel has also had a negative effect on the the existence of the native unionids in the lake.  Unionids are benthic invertebrates and their hard shells are ideal for the zebra mussel byssal threads to attach to and colonize. All species in North America that have been heavily infested for two to four years have experienced near mortality.  There are two main ways zebra mussels affect the unionids. The mating season of the zebra mussels coincides with the unionid's mating season.  For information on zebra mussel reproduction click here. When the unionids leave their burrows, the mussels colonize on the unionid shell. The byssal threads that the mussels use to anchor themselves to substrate pull hard on the shell, and often cause deformities which result in the inability of the unionid to open or close its shell. Once the unionid has come out of its strata and been colonized by mussels, it cannot rebury itself because of the new shape and weight caused by the mussels.  The zebra mussels also locate themselves near the food gathering siphons of the unionid, and take advantage of the incurrent flow to steal the food before it enters the unionid’s siphons.  The mussels covering the unionid have a choking effect on the unionid, because often there are so many that the flow of food to the unionid is blocked, starving the unionid.
    While there are many downsides to the presence to zebra mussels, there is a positive reason for their presence in the lake.  Zebra mussels like many other bivalves are filter feeders.  They extend their siphons out of their shell and filter the water to collect phytoplankton (their primary food source).  By filtering the water and consuming the phytoplankton, the zebra mussels increase the water by making it cleaner and clearer.
    For further information on zebra mussels refer the 2000 Lake Research Report, and the Lake Links page.

 Eurasian Milfoil (Myriophyllum spicatum)

With the introduction of the zebra mussel and increased water clarity arose a new problem - 'weeds'.  These so called 'weeds' are aquatic plants called macrophytes.  Serving as a primary producer and shelter for the lakes fauna these 'weeds' are very important to the equilibrium in the lake.  The reason macrophytes have gained this negative connotation is because of their negative effects on recreation.  The increased water clarity meant that the macrophytes could grow bigger and at a deeper water depth because the light could now penetrate the water.  The increased growth led to the formation of dense beds of macrophytes and are an irritation to the residents of the lake.  However, there is one species of macrophyte that out competes the others - Eurasian milfoil.
    Its is uncertain when Eurasian milfoil (Myriophyllum spicatum) was introduced into Conesus Lake, however, studies have shown it to be around since 1927.  Eurasian milfoil is a vigorous plant that favors eutrophic waters and regularly reaches the surface of the water shading much of the waters below and effectively excludes other species from its habitat.  GIS (geographic information systems) maps have been created showing the distribution of the 12 major weed beds in Conesus Lake, click here to view them.  For further information refer to the 1999 Lake Macrophyte Study and the Lake Links page.

Current Research
 

    A continuation of the initial survey of the distribution of dense Eurasian milfoil beds throughout the lake was completed using global positioning systems (GPS).  Eleven major beds were identified, all near the mouth of streams in areas with a predominately south/southwest exposure.  Using these GPS coordinates, geographic information systems (GIS) maps where created.  To view the maps created by these high tech programs click here.  The GIS maps represent the GPS coordinates of the principal milfoil beds in an illustrative manner in order to present the data in a clear and precise manner.  Furthermore, the GIS maps show an unmistakably positive correlation between streams and macrophyte beds, strengthening the hypothesis that the macrophyte beds occur in areas of high nutrient loading, found at the streams and rivulets of Conesus Lake's Watershed.  The GIS program used also allows for an analysis of total area per macrophyte bed and can be used in biomass studies.  Quadrats were taken from each major macrophyte bed.  The samples were taken from various depths and were used for analysis of species diversity and biomass.
    A continuation of Conesus Lake's zebra mussel population was also conducted over the course of this summer's macrophyte survey.

Roster of the research teams:

2002 Lake Research Team	Team Leader	Dr. Isidro Bosch
	Lead Researcher, SCUBA diver	Liz Miz
	Research Assistant	Tom Balzer
	Research Assistant	Eric Caruana