Organochlorine Contaminants in Mummichog(fundulus Heteroclitus) Living Downstream From a Bleached-Kraft Pulp Mill in the Miramichi Estuary, New Brunswick, Canada

Abstract

Abstract-Mummichog, a small-sized sentinel fish species, has been proposed for use in environmental effects monitoring programs conducted by pulp mills that release their effluent in marine waters. In order to evaluate the suitability of mummichog as a sentinel species and to support the interpretation of biological effects data, tissue concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans, (PCDD/Fs), chlorophenolic compounds (CPs), polychlorinated biphenyls (PCBs), and chlorinated pesticides were investigated in mummichog sampled in the Miramichi Estuary, which was receiving a bleached-kraft mill (BKM) effluent, and in a reference estuary, the Bouctouche Estuary. Higher concentrations PCDD/Fs (up to 50 times), CPs (up to 60 times), DDT, and PCBs (up to 10 times) were found in mummichog sampled at the upstream site of the Miramichi Estuary. At this site, 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent concentrations were slightly above the threshold for ethoxy resorufin O-deethylase induction. Multivariate analyses on congener profiles revealed that the contamination by PCDD/Fs and CPs originated both from the BKM and from a former wood-preservation plant and that PCDD/Fs and CPs typical of the BKM were transported 40 km downstream from the mill. Patterns and levels of persistent contaminants differed between sites within the Estuary, indicating that the fish did not mix during their growing period. These findings support the use of mummichog in environmental effects monitoring programs, because this species bioaccumulates chlorinated compounds contained in BKM effluent and is sedentary. The causeeffect relationship between exposure to the BKM effluent and the observed biological responses will have to be demonstrated by laboratory studies because of the presence of multiple sources of contamination.

Effects of salinity on sublethal toxicity of atrazine to mummichog (Fundulus heteroclitus) larvae

“…Filtered ambient seawater (salinity $26 PSU) was provided by the Maurice Lamontagne Institute marine laboratory system, located on the south shore of the St. Lawrence Estuary, QC. Previous measurements of PCBs, polychlorinated dibenzodioxins and dibenzofurans in the liver of mummichog captured at Horton's Creek indicated low contamination and supported the selection of this site as a reference (Couillard and Nellis, 1999). To induce gonadal maturation, the water temperature was raised progressively from 10°C to 20°C, and a photoperiod of 14-h light: 10-h dark was maintained (Boyd and Simmonds, 1974;Couillard, 2002).…”

Latitudinal variability in lunar spawning rhythms: absence of a lunar pattern in the northern mummichog Fundulus heteroclitus macrolepidotus

“…Spawning asynchrony with the lunar cycle for the northern subspecies in this study suggests another environmental cue is probably acting as the primary synchronizer as suggested by Wallace & Selman (1981) in Woods Hole, Massachusetts. Because of a positive correlation between water temperature and I G ( P < 0·001; r = 0·62), which is consistent with the findings in other northern studies (Newman, 1907; Wallace & Selman, 1981; Couillard & Nellis, 1999), the spawning processes of the F. h. macrolepidotus appears to be largely temperature dependent. Photoperiod, however, can be considered as well, considering the influence of longer daylight hours on water temperature and the co‐occurrence of peak spawning period with the summer solstice which is the longest period of daylight hours in the northern hemisphere.…”

“…Studies from the New Jersey area have reported varying results compared with more northern studies in terms of reproductive timing (Taylor, 1984). Interestingly, several northern studies have concluded different results than expected in reproductive rhythm when comparison is made with control groups (Leblanc et al , 1997; Couillard & Nellis, 1999; Thériault et al , 2008).…”

Low hepatic ethoxyresorufin‐o‐deethylase activity correlates with high organochlorine concentrations in Atlantic tomcod from the Canadian east coast

“…Tomcods from the SLE have higher percentages of tetrachloro‐substituted PCBs compared with tomcods from the ME and RE. In the SLE, most PCBs likely originate from distant industrial sources located on the shores of the upstream SL River or Lake Ontario, whereas local industrial sources may be the main source of contamination in the ME [25]. Enrichment in lighter PCB congeners is expected to occur as distance from the source increases [11].…”