Sturgeon Fry Research Articles

Acute Toxicity Testing with Juvenile White Sturgeon (Acipenser transmontanus)

Abstract The primary goal of this study was to investigate the possibility of using early life stages of white sturgeon (Acipenser transmontanus) (eggs, larvae and fry) as a species relevant to the Fraser River, B.C., for the acute and sublethal toxico-logical testing of forest industry effluents. Here we report the first successful acute toxicity tests for 8-day-old larvae and 42-day-old fry exposed to several chemicals known to be released into the Fraser River (i.e., 6 monochlorovanillin [6 MVAN], 4,5 dichloroguaiacol [4,5 DCG], 4,5 dichlorocatechol [4,5 DCAT], pentachlorophenol [PCP], and didecyldimethylammonium chloride [DDAC]). In most cases, white sturgeon fry were at the lower end of the range for acute toxicity values for chlorinated phenolic compounds, when compared with other juvenile fish species, and they were extremely sensitive to DDAC. The larval stage was usually more sensitive than the fry stage. Acute toxicity tests with fertilized eggs were unsuccessful. A postexposure growth study was inconclusive because neither control nor toxicant-exposed larvae and fry withstood the additional handling used for measuring body mass. At 62-days-old, fry were more tolerant of handling. This allowed measurement of their swimming performance. Although we have concerns about the reliability of using larvae for acute toxicity testing at this time, 60-day-old white sturgeon fry would appear to be both a sensitive and relevant species for assessing environmental impacts relevant to the Fraser River.

ACUTE TOXICITY OF A DIDECYLDIMETHYLAMMONIUM CHLORIDE-BASED WOOD PRESERVATIVE, BARDAC 2280, TO AQUATIC SPECIES

The acute toxicity of the antisapstain wood preservative Bardac 2280 (principal active ingredient 80% didecyldimethylammonium chloride, DDAC) was tested with four fish and four aquatic invertebrate species. White sturgeon fry (Acipenser transmontanus) were the most sensitive fish species tested with a 24-h 50% lethal concentration (LC50) value between 1 and 10 ppb Bardac 2280. The 96-h LC50 values for the three other fish species ranged from 0.39 ppm for fathead minnows (Pimephales promelas) to 2.0 ppm for juvenile starry flounder (Platichthys stellatus). Developmental stage altered the sensitivity of coho salmon to Bardac 2280, with alevins being approximately twice as sensitive as smolts. Altering salinity up to 30‰ seawater had no significant effect on the toxicity of Bardac 2280 to coho smolts. The 48-h LC50 values for Daphnia magna, Mysidopsis bahia, Hyalella azteca, and Neomysis mercedis were 0.037 ppm, 0.039 ppm, 0.106 ppm, and 0.947 ppm, respectively. Bardac 2280 characteristically produced steep concentration–response curves for fish, i.e., a concentration range considerably less than 10-fold for a complete range of mortality, and caused no major symptoms of sublethal stress in juvenile starry flounder following a 24-h exposure.