Estimate the total relative density of larval fish exchanged between Lake Erie and Metzger Marsh (net flux).
Estimate the relative density of each larval fish taxon exchanged between Lake Erie and Metzger Marsh.
Describe the progression of the larval fish assemblage through the season.
Correlate the relative abundance of larval fish and their assemblage with measures of environmental factors.
Test the outwelling hypothesis on a large-lake system by comparing Metzger Marsh's larval fish assemblage and densities exchanged with Lake Erie under present conditions to pre-restoration assemblage and densities of the degraded marsh.

Metzger Marsh is a 367-ha restored coastal wetland, connected to Lake Erie by an engineered opening in a man-made dike. After a severe storm destroyed the marsh's natural barrier beach in 1973, wave action scoured the marsh; vegetation losses exceeded 111-ha. The dike was constructed to mimic the function of the original barrier beach. It allows a hydrologic connection with the lake by incorporating a 10-m wide opening.

We sampled larval fish at the marsh's mouth from April through August 2001. If we can provide evidence that larval fish benefit from this hydrologic connection influenced by wind-driven seiches, i.e. that Odum's (1968) outwelling hypothesis may apply to seiche-driven systems (analogous to tides), this has the potential to provide a scientific basis to re-evaluate current management policies for coastal wetlands along Lake Erie and possibly throughout the Great Lakes.

The mean ichthyoplankton export to Lake Erie was 7.44 fish/m³; mean import to the marsh was 3.99 fish/m³. Although observed export exceeded import, the difference is not significant when considering the entire assemblage. Analysis of individual taxa is in progress. Coinciding taxa averaged greater than a 30-fold increase in densities represented in post-restoration samples of larval flux over standing densities sampled in the pre-restoration marsh. Such increases in larval recruitment were likely driven by a massive increase in productivity within the restored marsh over its degraded state.

We need preliminary data to support proposals studying interconnected systems of wetlands and adjacent large bodies of water. We hypothesize that "coupled systems" such as Metzger Marsh to Lake Erie will prove to be important for fish production and nutrient additions to Lake Erie. However, little work has been done in fresh water to test the outwelling concept. The existence of hydrological interdependence between aquatic systems and their adjacent systems is well know in regards to streams and riparian zones as well as oceans in association with coastal marine wetlands.

Ninety percent of lake Erie's wetlands are diked, removing them from the watershed and isolating them from the lake in regards to fish production. We need information on the contribution of larval fish from freshwater systems to connected lakes in order to propose more functional wetland management of those wetlands.

Our research to date shows that the fish diversity in Metzger Marsh is two to three times greater than traditional diked wetlands, and also undiked nearshore areas. In addition, we find a rapid and nearly complete switch from open lake fish species to wetland (plant loving) species when hydrologically connected wetlands are created. However, our research on larval fish movement has been limited to weekly samples for short time periods. We have examined those data and realize that a much more intensive method must be developed. This small-grant application, if funded, will allow us to determine if the method described here will give us that much needed information. We will then be in a much stronger position to propose both fish and nutrient flux work to the National Science Foundation, Sea Grant, Great Lakes Protection Fund, and the Lake Erie Protection Fund. We are submitting a small grant request to the Lake Erie Protection Fund for development of a method to sample juvenile fish a

We sampled larval fish at the marsh's mouth from April through August 2001. Paired plankton nets ( 303-micron mesh) were deployed at random start times for 10 min each hr over the duration of one full seiche cycle per week. The abiotic factors of water current speed and direction, dissolved oxygen, pH, turbidity, water temperature, light level, and wind speed and direction were collected with each ichthyoplankton sample for analysis of their effect on the density of sampled larval fish.

Larval fish were counted, identified to lowest practical taxon, and classified by developmental stage. Ichthyoplankton densities were calculated as fish/m³ of water sampled.

Future analysis will test the significance of abiotic factors on densities of fish taxa. We will describe larval fish assemblages through the season using multivariate techniques. Pre- and post-resotration assemblages and densities will be compared in an effort to provide evidence in support of Odum's (1968) outwelling hypothesis.