Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes
The importance of fish nutrient recycling for lake primary production increases with lake productivity. However, fish in low-productivity lakes may have substantial indirect effects on nutrient recycling from lower trophic levels. We measured nutrient excretion rates from fish and zooplankton in oli...
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ftutahsudc:oai:digitalcommons.usu.edu:wats_facpub-1224 2023-05-15T14:53:31+02:00 Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes Johnson, C. R. Luecke, Chris Whalen, S. C. Evans, M. A. 2010-01-01T08:00:00Z https://digitalcommons.usu.edu/wats_facpub/225 unknown Hosted by Utah State University Libraries https://digitalcommons.usu.edu/wats_facpub/225 Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact the Institutional Repository Librarian at digitalcommons@usu.edu. PDM Watershed Sciences Faculty Publications fish pelagic nitrogen phosphorus oligotrophic arctic Aquaculture and Fisheries Environmental Sciences Fresh Water Studies text 2010 ftutahsudc 2022-08-11T17:19:37Z The importance of fish nutrient recycling for lake primary production increases with lake productivity. However, fish in low-productivity lakes may have substantial indirect effects on nutrient recycling from lower trophic levels. We measured nutrient excretion rates from fish and zooplankton in oligotrophic Arctic lakes and investigated direct and indirect fish effects on consumer nutrient recycling. Fish nutrient excretion rates were small relative to phytoplankton nutrient demand. Zooplankton excretion, however, supplied 19%–130% and 37%–200% of phytoplankton nitrogen and phosphorus demand, respectively. Fish had a significant effect on zooplankton biomass; in lakes with fish, this was approximately 80% lower than in lakes without fish. The difference in zooplankton biomass was due primarily to a decrease in zooplankton density; no significant difference in average zooplankton size was observed between fish and fishless lakes. Fish also impacted zooplankton community composition; communities in lakes with fish were dominated by copepods compared with cladoceran dominance in lakes without fish. Because of lower zooplankton biomass, lakes with fish showed lower rates of zooplankton nitrogen and phosphorus excretion relative to lakes without fish. Thus, our results support the hypothesis that fish have major indirect effects on lake nutrient cycles, even when direct excretion from fish is minimal. Text Arctic Phytoplankton Zooplankton Copepods Utah State University: DigitalCommons@USU Arctic |
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Utah State University: DigitalCommons@USU |
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topic |
fish pelagic nitrogen phosphorus oligotrophic arctic Aquaculture and Fisheries Environmental Sciences Fresh Water Studies |
spellingShingle |
fish pelagic nitrogen phosphorus oligotrophic arctic Aquaculture and Fisheries Environmental Sciences Fresh Water Studies Johnson, C. R. Luecke, Chris Whalen, S. C. Evans, M. A. Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes |
topic_facet |
fish pelagic nitrogen phosphorus oligotrophic arctic Aquaculture and Fisheries Environmental Sciences Fresh Water Studies |
description |
The importance of fish nutrient recycling for lake primary production increases with lake productivity. However, fish in low-productivity lakes may have substantial indirect effects on nutrient recycling from lower trophic levels. We measured nutrient excretion rates from fish and zooplankton in oligotrophic Arctic lakes and investigated direct and indirect fish effects on consumer nutrient recycling. Fish nutrient excretion rates were small relative to phytoplankton nutrient demand. Zooplankton excretion, however, supplied 19%–130% and 37%–200% of phytoplankton nitrogen and phosphorus demand, respectively. Fish had a significant effect on zooplankton biomass; in lakes with fish, this was approximately 80% lower than in lakes without fish. The difference in zooplankton biomass was due primarily to a decrease in zooplankton density; no significant difference in average zooplankton size was observed between fish and fishless lakes. Fish also impacted zooplankton community composition; communities in lakes with fish were dominated by copepods compared with cladoceran dominance in lakes without fish. Because of lower zooplankton biomass, lakes with fish showed lower rates of zooplankton nitrogen and phosphorus excretion relative to lakes without fish. Thus, our results support the hypothesis that fish have major indirect effects on lake nutrient cycles, even when direct excretion from fish is minimal. |
format |
Text |
author |
Johnson, C. R. Luecke, Chris Whalen, S. C. Evans, M. A. |
author_facet |
Johnson, C. R. Luecke, Chris Whalen, S. C. Evans, M. A. |
author_sort |
Johnson, C. R. |
title |
Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes |
title_short |
Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes |
title_full |
Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes |
title_fullStr |
Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes |
title_full_unstemmed |
Direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic Arctic Alaskan lakes |
title_sort |
direct and indirect effects of fish on pelagicnitrogen and phosphorus availability in oligotrophic arctic alaskan lakes |
publisher |
Hosted by Utah State University Libraries |
publishDate |
2010 |
url |
https://digitalcommons.usu.edu/wats_facpub/225 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Phytoplankton Zooplankton Copepods |
genre_facet |
Arctic Phytoplankton Zooplankton Copepods |
op_source |
Watershed Sciences Faculty Publications |
op_relation |
https://digitalcommons.usu.edu/wats_facpub/225 |
op_rights |
Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact the Institutional Repository Librarian at digitalcommons@usu.edu. |
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PDM |
_version_ |
1766325116099100672 |