October 2004 – LCRC update on Research Priorities in the areas of Fishes & Fisheries

Priorities in 1999

• What contribution does walleye stocking make to the adult population?
• Chet Mackenzie - considerable progress evaluating the contribution of stocked walleye to spawning populations in the Missisquoi and Winooski Rivers, and this will continue in the future; planning to continue marking all fry and fingerlings stocked into Lake Champlain
• How should we sample walleye?
• Donna Parrish - progress on sampling early life stages of walleye
• Are smelt populations different among basins?
• What level of predation can smelt sustain in Lake Champlain?
• Are lake trout naturally reproducing, and if not, why not?

• Ellen Marsden - good evidence of successful lake trout reproduction in the Lake, but recruitment still seems low. Questions for future research - Is this due to low post-emergent survival, or perhaps fish haven’t yet gotten large enough to show up in sampling gear.

Priorities in 2004 (for the next several years)

· Top two priorities/themes were

o Begin assessment and long-term monitoring of fish populations/communities in Lake Champlain and its major tributaries. LCRC should seek new funding for establishment of a lake-wide fish community monitoring program similar to the ongoing water quality/ plankton monitoring done by the two states. This should include fish species in the lake and those dependent upon lower reaches of large Lake Champlain tributaries. This latter group would include species that require these areas for spawning or passage to upstream spawning areas (e.g. walleye, salmonids, sturgeon); and also rare species that reside in these areas throughout their life (e.g. eastern sand darters, channel darters, quillback, redhorses). Perhaps begin with Missisquoi Bay and its tributaries, given the many issues of current concern in that part of the Basin.

o What is the status of alewife in Lake Champlain, and what would be the effect of an alewife invasion on the Lake Champlain ecosystem and the economy in the basin? Part of this would be dependent upon the previous priority listed – and it would be good to begin in Missisquoi Bay, given the apparent finding of alewife in the Bay in 2004.

· Additional priorities

o Detailed investigations into the food web structure of Missisquoi Bay, to assess whether food web interactions play a role in the severity, frequency, and species composition of blue-green algae outbreaks. For example – could decline in esocids due to disease, or impacts of white perch (an invasive species) be related to algal blooms through a trophic cascade?

o What affects lake trout post-emergent survival, given that we have lots of successful reproduction. Or, is recruitment beginning to occur and the fish are not yet old enough to show up in assessment gear? What are the impediments to restoration of this species?

o Alternative methods for lamprey control - particularly, can we use pheromones as a method for improving trapping efficiency of spawning adults.

o What is the status of sauger in the Lake? Populations of this smaller relative of the walleye have declined dramatically, particularly in the southern part of the lake.

o Investigate opportunities for American eel restoration given that passage has been restored on the Richelieu River.

Interdisciplinary Research Opportunities

• Work with Wildlife/Biodiversity, Middle Food Web/Exotics, Ecosystem Health, and Toxics groups on a plan for extensive sampling/monitoring of species in the lake, wetlands, and lower reaches of large tributaries – with particular focus on those species about which know very little. Begin with Missisquoi Bay and its tributaries, but address other part of the lake in turn – this would have to be a multi-year, long-term commitment.
• Work with Middle Food Web/Exotics, Nutrients/Lower Food Web, and Ecosystem Health groups on a plan to investigate the food web of Missisquoi Bay to see if food web dynamics or trophic cascades might be in some way linked to recent algal blooms. (This could be the initial phase of the previous point.)
• Work with Land Use and Ecosystem Health groups on a plan to evaluate the effects of land use on water quality, flow, and substrate composition of large tributaries – and the effects of these factors on sensitive fish species that rely on those tributaries. Also relevant to Missisquoi Bay and tributaries, as a starting point, but expand to other parts of the basin.