Graduate Thesis Or Dissertation
 

Mercury accumulation in fish from Cottage Grove Reservoir and its tributaries

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/4b29b8493

Descriptions

Attribute NameValues
Creator
Abstract
  • A fish sampling program was initiated at Cottage Grove Reservoir in June of 1974 to investigate mercury accumulation in the fish. Samples were collected periodicallv from June to November, 1974, and from June, 1975 through January, 1976 from both the reservoir and its tributaries. Species collected included spring chinook salmon Oncorhynchus tshawytscha, rainbow trout Salmo gairdneri, cutthroat trout Salmo clarki clarki, largemouth bass Micropterus salmoides, and brown bullhead Ictalurus nebulosus. Cutthroat trout and spring chinook salmon sampled from a tributary of Cottage Grove Reservoir in 1974 and 1975 had significantly less mercury in their muscle tissue than similar fish collected from the reservoir (P < 0.05). All species of fish except the 1+ brown bullheads collected in 1974, tended to accumulate mercury with time. Many of the fish sampled had mercury levels two to three times the FDA guideline of 0.5 [mu] Hg/g. It also appeared that predatory fish accumulated higher mercury levels than non-predatory species. The percent of mercury as methylmercury in all species ranged from 4.3 to 100, with most fish containing between 60% and 90% methylmercury. Mercury uptake from the food accounted for a significant percentage of the total mercury uptake of the 0+ spring chinook collected in 1974. The average methylmercury concentration in the diet of the fish was estimated to be 0.23 [mu]g Hg/g. The significant difference in mercury concentration and total body burden of mercury of the spring chinook collected from the Coast Fork of the Willamette River and Cottage Grove reservoir suggested that two separate populations of chinook might exist (P < 0.05). Yearling chinook salmon collected from the reservoir in the spring of 1976 with greater than 0.20 [mu] Hg/g in the muscle tissue had greater mortality in saltwater than the control fish which had mercury concentrations below 0.10 [mu]g Hg/g.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details WorcesterThomasC1980.pdf 2017-08-08 Public Download