Research about Chaumont Bay

USGS2020

Spatial segregation of cisco (Coregonus artedi) and lake whitefish (C. clupeaformis) larvae in Chaumont Bay, Lake Ontario

Abstract Two of the remaining coregonine species in Lake Ontario, cisco (Coregonus artedi) and lake whitefish (C. clupeaformis), spawn in Chaumont Bay, NY. Larvae co-occur in the spring but are difficult to distinguish morphologically. We applied genetic species identification using microsatellite DNA loci of 268 larvae from known locations in nearshore and offshore habitats in Chaumont Bay to determine the extent of mixing of these species in each habitat. Cisco dominated (95% of larvae) the larvae in offshore habitats and lake whitefish dominated (84%) in nearshore habitats, where seven of eight putative hybrids occurred. Habitat segregation between these two species at the larval stage has implications for productivity estimates. Discrimination between cisco and lake whitefish larvae helps to characterize habitat and basic life history needs and to focus research collections. Genetic species identification should be applied to larger samples of larvae to evaluate changes in larval distributions and associations with environmental conditions.

Chaumont Bay↗

USGS2009

Feeding ecology of lake whitefish larvae in eastern Lake Ontario

We examined the feeding ecology of larval lake whitefish ( Coregonus clupeaformis ) in Chaumont Bay, Lake Ontario, during April and May 2004-2006. Larvae were collected with towed ichthyoplankton nets offshore and with larval seines along the shoreline. Larval feeding periodicity was examined from collections made at 4-h intervals over one 24-h period in 2005. Inter-annual variation in diet composition (% dry weight) was low, as was spatial variation among collection sites within the bay. Copepods (81.4%), primarily cyclopoids (59.1%), were the primary prey of larvae over the 3-year period. Cladocerans (8.1%; mainly daphnids, 6.7%) and chironomids (7.3%) were the other major prey consumed. Larvae did not exhibit a preference for any specific prey taxa. Food consumption of lake whitefish larvae was significantly lower at night (i.e., 2400 and 0400 h). Substantial variation in diet composition occurred over the 24-h diel study. For the 24-h period, copepods were the major prey consumed (50.4%) and their contribution in the diet ranged from 29.3% (0400 h) to 85.9% (1200 h). Chironomids made up 33.4% of the diel diet, ranging from 8.0% (0800 h) to 69.9% (0400 h). Diel variation in the diet composition of lake whitefish larvae may require samples taken at several intervals over a 24-h period to gain adequate representation of their feeding ecology.

Journal of Great Lakes Research↗