more information
Search within Results:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author (up) Lee, A.H.; Eme, J.; Mueller, C.A.; Manzon, R.G.; Somers, C.M.; Boreham, D.R.; Wilson, J.Y. file  url
openurl 
  Title The effects of increased constant incubation temperature and cumulative acute heat shock exposures on morphology and survival of Lake Whitefish (Coregonus clupeaformis) embryos Type Journal Article
  Year 2016 Publication Journal of Thermal Biology Abbreviated Journal J Therm Biol  
  Volume 57 Issue Pages 11-20  
  Keywords Climate change; Coregonus clupeaformis; Great Lakes; Heat shock; Morphology; Survival; Temperature; Thermal effluent  
  Abstract Increasing incubation temperatures, caused by global climate change or thermal effluent from industrial processes, may influence embryonic development of fish. This study investigates the cumulative effects of increased incubation temperature and repeated heat shocks on developing Lake Whitefish (Coregonus clupeaformis) embryos. We studied the effects of three constant incubation temperatures (2 degrees C, 5 degrees C or 8 degrees C water) and weekly, 1-h heat shocks (+3 degrees C) on hatching time, survival and morphology of embryos, as these endpoints may be particularly susceptible to temperature changes. The constant temperatures represent the predicted magnitude of elevated water temperatures from climate change and industrial thermal plumes. Time to the pre-hatch stage decreased as constant incubation temperature increased (148d at 2 degrees C, 92d at 5 degrees C, 50d at 8 degrees C), but weekly heat shocks did not affect time to hatch. Mean survival rates and embryo morphometrics were compared at specific developmental time-points (blastopore, eyed, fin flutter and pre-hatch) across all treatments. Constant incubation temperatures or +3 degrees C heat-shock exposures did not significantly alter cumulative survival percentage (~50% cumulative survival to pre-hatch stage). Constant warm incubation temperatures did result in differences in morphology in pre-hatch stage embryos. 8 degrees C and 5 degrees C embryos were significantly smaller and had larger yolks than 2 degrees C embryos, but heat-shocked embryos did not differ from their respective constant temperature treatment groups. Elevated incubation temperatures may adversely alter Lake Whitefish embryo size at hatch, but weekly 1-h heat shocks did not affect size or survival at hatch. These results suggest that intermittent bouts of warm water effluent (e.g., variable industrial emissions) are less likely to negatively affect Lake Whitefish embryonic development than warmer constant incubation temperatures that may occur due to climate change.  
  Call Number Serial 1227  
Permanent link to this record
 

 
Author (up) Marty, J.; Bowen, K.; Koops, M.A.; Power, M. file  url
openurl 
  Title Distribution and ecology of Hemimysis anomala, the latest invader of the Great Lakes basin Type Journal Article
  Year 2010 Publication Hydrobiologia Abbreviated Journal Hydrobiologia  
  Volume 647 Issue 1 Pages 71-80  
  Keywords Hemimysis anomala; Great Lakes; United States; Feeding; Carbon; Food source; Water temperature; Diet; Food webs; Stable isotopes  
  Abstract Since 2006, the known distribution of Hemimysis anomala has greatly expanded in the Great Lakes ecosystem, with, to date, 45 sites of occurrence among 91 monitored sites, located in four of the Great Lakes and the upper St. Lawrence River. By means of carbon and nitrogen stable isotopes, a first assessment of the feeding ecology of Hemimysis was completed. The δ13C values of 18 individuals collected in Lake Erie (Port Mainland) on a single date (Sept. 23, 2008) ranged from −30.2 to −24.5, indicating that Hemimysis could feed on multiple carbon sources including pelagic and littoral autochthonous and terrestrial carbon. In Lake Erie, variation in δ13C was related to δ15N, indicating the importance of food source for determining the trophic position of Hemimysis. The δ15N signatures of individuals were strongly related to their C/N ratios, suggesting that variations in the nutritional value of Hemimysis may depend on trophic position. Isotopic variation among individuals in Lake Erie was complemented by temporal variation in Lake Ontario. Monthly changes (from June to December 2008) in carbon isotope signatures were observed and related to changes in water temperature, highlighting the variations in the baseline prey signatures that fuel Hemimysis diets. The observed variation in stable isotope signatures occurring among individuals within a localized Hemimysis assemblage and temporally should be considered as a key design feature in further studies attempting to identify the possible effects of Hemimysis on nearshore food webs in the Great Lakes.  
  Call Number Serial 588  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations: