Great Lakes Fishery Commission

Previous attempts to rehabilitate Great Lakes coregonines (Coregonus spp.) have been unsuccessful due to the reliance on fry and stocking on top of existing populations that made evaluations difficult. After the demise of cisco and deepwater coregonines during 1940-50, non-native alewife (Alosa psuedoharengus) and rainbow smelt (Osmerus mordax), replaced native species as forage of top predators. A basin-wide decline of both rainbow smelt and alewive has generated broad inter-lake, international interest and urgency in re-establishing species such as cisco (C. artedii), bloater (C.

RATIONALE: In a recent study we found that the timing of reproductive maturation in siscowet populations in southern Lake Superior was synchronized within populations east and west of the Keweenaw Peninsula, and occurred from August to October as observed in an adjacent lean lake trout population (Goetz et al., 2011). However, historical and more recent accounts strongly suggest that siscowets and possibly humpers, reproduce at other times of the year in other locations, particularly areas surrounding Isle Royale.

Restoration of self-sustaining lake trout populations in the Great Lakes has been slow, except in Lake Superior and local populations in Lake Huron. Potential reasons may be related to the inability of hatchery-reared lake trout to select appropriate spawning habitat where eggs can successfully incubate and hatch.

The proposed research seeks to better understand downstream migration (i.e., outmigration) of newly metamorphosed sea lamprey larvae (transformers) to inform development of new trapping methods for control of this invasive species in the Great Lakes. Our current understanding of behavior during outmigration is limited to studies focused on when migration occurs seasonally (Applegate 1950, Applegate and Brynildson 1952, Applegate 1960). Little information is available describing diel or spatial movement patterns of sea lamprey transformers.

The muskellunge (Esox masquinongy) is a native Great Lakes apex predatory fish that has experienced declines and extirpations in many areas resulting in numerous restoration efforts. Despite localized understanding of genetic diversity in some locations, a broader understanding of genetic differences among most major Great Lakes spawning aggregates is lacking. Historic and ongoing stocking of Great Lakes and non-Great Lakes strain muskellunge poses a threat to the genetic integrity of remnant populations.

RATIONALE: In addition to the olfactory system, lampreys contain solitary chemosensory cells, termed oligovil-lous cells, located along the surface of the body, oral disc and gills (Whitear and Lane, 1983); as well as multicellular taste buds on the pharynx and gill arches (Barreiro-Iglesias et al., 2010). In 1985, Baatrup and Døving found that chemical stimuli for oligovillous cells in brook lamprey, included trout conditioned water.

Renibacterium salmoninarum (Rs) is the causative agent of bacterial kidney disease (BKD), a significant disease of Chinook salmon in the Great Lakes. Rs can cause a long-term persistent infection and infected fish may not necessarily show disease. The standard susceptible-infected-recovered (SIR) population framework for disease does not model Rs infection dynamics well. Fenichel et al. 2009 (Ecol. Apps V19:747) proposed a conceptual framework for Rs, which we have modified here as the ‘susceptible-latent-diseased-latent’ (SLDL) model.

In spawning streams, sexually mature males release 3kPZS (7α, 12α, 24-trihydroxy-5α-cholan-3-one-24-sulfate), the main component of the mating pheromone that attracts ovulatory females and is indispensable for sea lamprey reproduction. Blocking the female detection of 3kPZS will likely halt the reproductive cycle. Recently we have identified a repertoire of 60 olfactory receptor genes from the draft sea lamprey genome and characterized a receptor (SLOR1) that specifically detects 3kPZS.