Sea lamprey carcasses exert local and variable food web effects in a nutrient-limited Atlantic coastal stream

Canadian Journal of Fisheries and Aquatic Sciences
By: , and 

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Abstract

Resource flows from adjacent ecosystems are critical in maintaining structure and function of freshwater food webs. Migrating sea lamprey (Petromyzon marinus) deliver a pulsed marine-derived nutrient subsidy to rivers in spring when the metabolic demand of producers and consumers are increasing. However, the spatial and temporal dynamics of these nutrient subsidies are not well characterized. We used sea lamprey carcass additions in a small stream to examine changes in nutrients, primary productivity, and nutrient assimilation among consumers. Algal biomass increased 57%–71% immediately adjacent to carcasses; however, broader spatial changes from multiple-site carcass addition may have been influenced by canopy cover. We detected assimilation of nutrients (via δ13C and δ15N) among several macroinvertebrate families including Heptageniidae, Hydropsychidae, and Perlidae. Our research suggests that subsidies may evoke localized patch-scale effects on food webs, and the pathways of assimilation in streams are likely coupled to adjacent terrestrial systems. This research underscores the importance of connectivity in streams, which may influence sea lamprey spawning and elicit varying food web responses from carcass subsidies due to fine-scale habitat variables.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Sea lamprey carcasses exert local and variable food web effects in a nutrient-limited Atlantic coastal stream
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/cjfas-2015-0506
Volume 73
Issue 11
Year Published 2016
Language English
Publisher NRC Research Press
Contributing office(s) Coop Res Unit Leetown
Description 10 p.
First page 1616
Last page 1625
Online Only (Y/N) N
Additional Online Files (Y/N) N