Restoration of rapids habitat in a Great Lakes connecting channel, the St. Marys River, Michigan

Autor: Terry Heatlie, Eric Ellis, Kevin L. Kapuscinski, Alejandro Molina-Moctezuma, Edward F. Roseman, Ashley H. Moerke
Rok vydání: 2020
Předmět:
Zdroj: Restoration Ecology. 29
ISSN: 1526-100X
1061-2971
DOI: 10.1111/rec.13310
Popis: Aquatic habitat has been extensively altered throughout the Laurentian Great Lakes to increase navigation connectivity. In particular, the St. Marys River, a Great Lakes connecting channel, lost >50% of its historic rapids habitat over the past century. In 2016, the natural flow was restored to the Little Rapids area of the St. Marys River. The goal of our study was to evaluate physical and ecological responses to the restoration of the Little Rapids area. Extensive habitat and biological data were collected prior to restoration (2013 and 2014), and after restoration (2017 and 2018). Measured parameters included total suspended solids, current velocity, benthic macroinvertebrates, and larval, juvenile, and adult fishes. Total suspended solids stayed low ( 90% reduction). We observed a 45% increase in richness of larval fish 2 years after restoration and a 131% increase in catch per unit effort. For adult fishes, the proportion of individuals with a preference for fast‐moving waters increased from 1.5 to 45% in the restored area, and from 7 to 15% upstream of the restored area; a similar response was observed for lithophilic spawners. The physical and biological conditions of the Little Rapids improved and resembled conditions typical of rapids habitat extent in other areas of the river and other systems.
Databáze: OpenAIRE
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