Decreased Growth Rate Associated with Tissue Contaminants in Juvenile Chinook Salmon Out-Migrating through an Industrial Waterway
journal contributionposted on 2021-07-12, 23:44 authored by Jessica I. Lundin, Paul M. Chittaro, Gina M. Ylitalo, John W. Kern, David R. Kuligowski, Sean Y. Sol, Keri A. Baugh, Daryle T. Boyd, Mary C. Baker, Robert M. Neely, Kennith G. King, Nathaniel L. Scholz
The industrial waterway in Portland Harbor, Oregon, is a migration corridor for a distinct population segment of Chinook Salmon (Upper Willamette River) currently protected by the U.S. Endangered Species Act. Juveniles are exposed to a suite of contaminants during outmigration including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and dichlorodiphenyltrichloroethanes. We collected natural origin subyearling Chinook salmon from sites in and around the industrial harbor to evaluate growth (otolith microstructural analysis) in relation to measured chemical concentrations in tissue. A reduced growth rate was associated with higher tissue contaminant concentrations, particularly mixtures represented by PAHs and certain PCBs, which were elevated in juvenile Chinook collected throughout sites within Portland Harbor relative to those captured upstream. First-year growth is an established predictor of individual survival and eventual reproductive success in Chinook salmon. Therefore, our results indicate that legacy pollution may be limiting the population abundance of threatened Willamette River Chinook salmon, and future habitat remediation or restoration actions may benefit ongoing species recovery efforts.
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otolith microstructural analysisPAHorigin subyearling Chinook salmonWillamette River Chinook salmonspecies recovery effortsUpper Willamette RiverEndangered Species Acttissue contaminant concentrationsDecreased Growth Rate AssociatedJuvenile Chinook Salmon Out-Migratingfuture habitat remediationU.SPortland Harbor