Mainstem‐tributary linkages by mayfly migration help sustain salmonids in a warming river network. (6th August 2015)

• Record Type: Journal Article
• Authors: Uno, Hiromi; Power, Mary E.; Sih, Andrew
• Is Part Of: Ecology letters. Volume 18:Number 10(2015:Oct.)
• Page Start: 1012
• Page End: 1020
• Publication Date: 2015-08-06
• Subjects: Ecology -- Periodicals; 577
• DOI: 10.1111/ele.12483
• Languages: English
• ISSNs: 1461-023X

Abstract

<abstract abstract-type="main" id="ele12483-abs-0001"> <title>Abstract</title> <p>Animal migrations can link ecosystems across space. We discovered an aquatic insect that migrates between a river mainstem and its tributaries, and provides an important trophic subsidy for tributary predators. A mayfly, <italic>Ephemerella maculata</italic>, rears in a warm, sunlit productive river mainstem, then migrates as adults to cool, shaded unproductive tributaries where they oviposit and die. This migration tripled insect flux into a tributary for 1 month in summer. A manipulative field experiment showed that this <italic>E. maculata</italic> subsidy nearly tripled the growth of the young of the year steelhead trout (<italic>Oncorhynchus mykiss</italic>) in the recipient tributary over the summer months, and was more important than terrestrial invertebrate subsidies, which have been considered the primary food source for predators in small, forested creeks. By delivering food subsidies from productive but warming river mainstems to cool but food‐limited tributaries, aquatic insect migrations could enhance resilience to cool‐water predators in warming river networks.</p> </abstract>