Proceedings - Teaching and Learning Centre - Simon Fraser ...

Fraser River Action Plan 3rd Research Workshop
Chlorophenol Effects on the Early Development and Growth of White Sturgeon
Objective
B. Bennett and A.P. Farrell
Biological Sciences
Simon Fraser University
To quantify specific effects of selected chlorinated guaiacol, catechol, and vanillin compounds on early
development stages of white sturgeon under controlled conditions of exposure in a laboratory setting.
Rationale
White sturgeon are regarded as a valued component of the Fraser River ecosystem. Sturgeon have been lost from
other large river systems through anthropogenic impacts. There is no toxicological information on the sensitivity
of juvenile sturgeon to components of pulp mill effluents. There is insufficient information to determine whether
or not juvenile sturgeon might act as a sentinel species for the Fraser River.
Approach
The large quantity of fertilized eggs that are required for toxicity testing cannot be obtained in B.C. We,
therefore, had to secure a supplier and transportation method to bring fertilized eggs rapidly from California to
B.C. since hatching is completed in about one week.
There are no published methods for toxicity testing with juvenile sturgeon. We, therefore, developed our own
testing techniques through trial and error, and based on advice from others.
The selection of test chemicals, made by Environment Canada, was intended to reflect chemicals of concern in
the Fraser River. The test chemicals in 1994 were 5-monochlorovanillin, 4-chlorocatechol and 3,4,5,6tetrachloroguaiacol.
The test chemicals in 1995 were 6-monochlorovanillin, 4,5-dichlorocatechol and 4,5tetrachloroguaiacol.
In addition, the anti-sapstain, DDAC, was tested in both years and pentachlorophenol was
tested as a reference chemical in 1995.
Conclusions
1. We were successful in transporting, hatching and rearing several thousand eggs during the two-year
period. The transplant permit required that all fish were killed upon completion of the experiments.
2. In contrast to our experience with salmonid eggs, sturgeon eggs and larvae are very sensitive to
environmental changes and handling, which can both lead to mass mortality. The transition from feeding
larvae to feeding fry invariably is associated with a high mortality.
3. Toxicity testing with eggs was deemed unsuccessful due to variability in the results. In part, the problem
may relate to eggs clumping even after the de-adhesion process.
4. The toxicity testing with larvae and fry was more successful. Estimates for LC0, LC50 and LC100 are
presented in Table 1. We have greater confidence in the 1995/96 results because methods were refined
by the second year of testing. Nonetheless, there is good agreement between the test results in 1994 and
1995 for DDAC.
5. The data for 1995 show a clear and substantial decrease in sensitivity towards the test chemicals with
increasing development age. Larvae were one to two orders of magnitude more sensitive than the feeding
fry.
Page 47