Event Title

Using Stable Isotope Analyses to Assess Benthic-Pelagic Coupling in Arctic Lakes

Location

Space Dynamics Laboratory

Event Website

http://water.usu.edu/

Start Date

3-25-2004 3:40 PM

End Date

3-25-2004 4:00 PM

Description

Comparison of stable isotopes of nitrogen and carbon of organisms can provide information on the trophic level and food sources of given species. Analysis of 15N and 13C values from a suite of organisms living in lakes of the Arctic Lakes Long Term Ecological Research site in northern Alaska indicated that the trophic position of given species varied with the type of community present in the lake. The degree of herbivory exhibited by planktonic copepods was greater in lakes where fish were present. Analysis of fish tissue indicated that over 90% of fish consumption originated from benthic production pathways. An 15N addition to the pelagic region of two lakes indicated that dissolved nitrogen was immediately assimilated into the pelagic components of the food web, but that benthic organisms assimilated the 15N the following year. These results indicated that the pelagic food web initially subsidized benthic organisms, but then benthic organisms then provided the food base for pelagic fishes.

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Mar 25th, 3:40 PM Mar 25th, 4:00 PM

Using Stable Isotope Analyses to Assess Benthic-Pelagic Coupling in Arctic Lakes

Space Dynamics Laboratory

Comparison of stable isotopes of nitrogen and carbon of organisms can provide information on the trophic level and food sources of given species. Analysis of 15N and 13C values from a suite of organisms living in lakes of the Arctic Lakes Long Term Ecological Research site in northern Alaska indicated that the trophic position of given species varied with the type of community present in the lake. The degree of herbivory exhibited by planktonic copepods was greater in lakes where fish were present. Analysis of fish tissue indicated that over 90% of fish consumption originated from benthic production pathways. An 15N addition to the pelagic region of two lakes indicated that dissolved nitrogen was immediately assimilated into the pelagic components of the food web, but that benthic organisms assimilated the 15N the following year. These results indicated that the pelagic food web initially subsidized benthic organisms, but then benthic organisms then provided the food base for pelagic fishes.

https://digitalcommons.usu.edu/runoff/2004/AllAbstracts/40