Ecological tracers reveal resource convergence among prey fish species in a large lake ecosystem
| Autor: | G.D. Haffner, Brian F. Lantry, Timothy B. Johnson, Daryl J. McGoldrick, Scott A. Rush, Gord Paterson, Michael T. Arts, Craig E. Hebert, Sean Backus, Aaron T. Fisk, Ken G. Drouillard |
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| Rok vydání: | 2014 |
| Předmět: |
nearshore
Osmerus Neogobius biology offshore Ecology Alosa pseudoharengus Dreissena spp stable isotopes Life Sciences Alewife Aquatic Science biology.organism_classification fatty acids Dreissena Rainbow smelt Forage fish Physical Sciences and Mathematics Sculpin Biology Biochemistry Biophysics and Structural Biology |
| Zdroj: | Biological Sciences Publications Great Lakes Institute for Environmental Research Publications |
| Popis: | SUMMARY 1. We measured stable isotopes of carbon (d 13 C) and nitrogen (d 15 N) and fatty acid profiles inLake Ontario alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), slimy sculpin (Cottuscognatus) and round goby (Neogobius melanostomus) collected from 1982 to 2008 to investigate howtemporal variability in these ecological tracers can relate to ecosystem-level changes associated withthe establishment of highly invasive dreissenid mussels.2. Prey fish d 15 N values remained relatively constant, with only slimy sculpin exhibiting a temporalincrease in d 15 N. In contrast, d 13 C values for alewife, rainbow smelt and, especially, slimy sculpinbecame less negative over time and were consistent with the benthification of the Lake Ontario foodweb associated with dreissenids.3. Principal components analysis revealed higher contributions of 14:0 and 16:1n-7 fatty acids andincreasingly negative d 13 C values in older samples in agreement with the greater historical impor-tance of pelagic production for alewife, rainbow smelt and slimy sculpin.4. Temporal declines in fatty acid unsaturation indices and Σn-3/Σn-6 ratios, and also increased24:0/14:0 ratios for alewife, rainbow smelt and slimy sculpin, indicated the increasing importance ofnearshore production pathways for more recently collected fish and resulted in values more similarto those for round goby.5. These results indicate a temporal convergence of the food niche, whereas food partitioning hashistorically supported the coexistence of prey fish species in Lake Ontario. This convergence is con-sistent with changes in food-web processes associated with the invasion of dreissenid mussels.Keywords: Dreissena spp., fatty acids, nearshore, offshore, stable isotopes |
| Databáze: | OpenAIRE |
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