Rearing in natural and recovering tidal wetlands enhances growth and life-history diversity of Columbia Estuary tributary coho salmon Oncorhynchus kisutch population.
J Fish Biol. 2014 May 28;
Authors: Craig BE, Simenstad CA, Bottom DL
This study provides evidence of the importance of tributary tidal wetlands to local coho salmon Oncorhynchus kisutch populations and life-history diversity. Sub-yearling and, to a lesser extent, yearling O. kisutch life histories utilized various estuary habitats within the Grays River, a tidal freshwater tributary of the Columbia Estuary, including restoring emergent wetlands and natural forested wetlands. Migration timing data, size distributions, estuary residence and scale patterns suggest a predominance of sub-yearling migrant life histories, including several that involve extended periods of estuary rearing. Estuarine-rearing sub-yearling O. kisutch exhibited the greatest overall growth rates; the highest growth rates were seen in fish that utilized restoring emergent wetlands. These results contrast with studies conducted in the main-stem Columbia Estuary, which captured few O. kisutch, of which nearly all were hatchery-origin yearling smolts. Restoration and preservation of peripheral and tributary wetland habitats, such as those in the Grays River, could play an important role in the recovery of natural O. kisutch populations in the Columbia River and elsewhere.
PMID: 24890886 [PubMed – as supplied by publisher]
via pubmed: school of aquatic an… http://ift.tt/1iTDqjz