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Effects of fish density and river fertilization on algal standing stocks, invertebrates communities, and fish production in an Arctic River

Canadian Journal of Fisheries and Aquatic Sciences

By:
, , , , and
DOI:10.1139/f96-268

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Abstract

This study examined the relative importance of bottom-up and top-down controls of an arctic stream food web by simultaneous manipulation of the top predator and nutrient availability. We created a two-step trophic system (algae to insects) by removal of the top predator (Arctic grayling, Thymallus arcticus) in fertilized and control stream reaches. Fish abundance was also increased 10 times to examine the effect of high fish density on stream ecosystem dynamics and fish. We measured the response of epilithic algae, benthic and drifting insects, and fish to nutrient enrichment and to changes in fish density. Insect grazers had little effect on algae and fish had little effect on insects. In both the control and fertilized reaches, fish growth, energy storage, and reproductive response of females declined with increased fish density. Fish growth and energy storage were more closely correlated with per capita insect availability than with per capita algal standing stock

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of fish density and river fertilization on algal standing stocks, invertebrates communities, and fish production in an Arctic River
Series title:
Canadian Journal of Fisheries and Aquatic Sciences
DOI:
10.1139/f96-268
Volume:
54
Issue:
2
Year Published:
1997
Language:
English
Publisher:
NRC Research Press
Description:
15 p.
First page:
269
Last page:
283
Online Only (Y/N):
N
Additional Online Files (Y/N):
N