Sublethal and acute toxicity of the ethylene glycol butyl ether ester formulation of triclopyr to juvenile coho salmon (Oncorhynchus kisutch)

Abstract

The toxicity of Garlon4, the ethylene glycol butyl ether ester formulation of the herbicide tryclopyr, to juvenile coho salmon (Oncorhynchus kisutch) was investigated at several lethal and sublethal concentrations. Fish behavior, random activity and oxygen uptake were monitored. Coho salmon exhibited three distinct responses related to concentration and duration of exposure: (1) at concentrations greater than 0.56 mg/L fish were initially lethargic, then regressed to a highly distressed condition characterized by elevated oxygen uptake and finally death, (2) at 0.32-0.43 mg/L fish were lethargic throughout the exposure period with reduced oxygen uptake, and (3) at concentrations less than or equal to 0.10 mg/L fish were hypersensitive to stimuli, exhibiting elevated activity and oxygen uptake levels during photoperiod transitions. Whole body residue analysis showed that uptake of the ester and subsequent hydrolysis to the acid form in the fish was rapid, with significant accumulation of the acid in the tissues. This suggests that some threshold tissue concentrations were associated with the observed results. For juvenile coho salmon the 96-hr LC50 of Garlon4 was 0.84 mg/L.

Oxygen Consumption of Juvenile Rainbow Trout ( Oncorhynchus mykiss ) Exposed to Sublethal Concentrations of 1,2,4,5-Tetrachlorobenzene and Tetrachloroguaiacol

“…2a & 2b), reflecting the normal daily activity pattern (Brett and Zala 1975) of the fish used in our study. The mean fish oxygen consumption value was similar to values reported by other investigations using similar apparatus (MacKinnon and Farrell 1992;Janz et al 1991;Johansen and Geen 1990) indicating that the system could provide reliable oxygen recordings with the newly installed OxyGuard ® DO probes. The DO detecting system was the major modification of the old respirometer whose oxygen consumption data was generated using the averaged readings of four inflow and outflow electrodes (Johansen and Geen 1990).…”

“…A major modification in this flow-through respirometer compared with that described by Johansen and Geen (1990) was the use of the OxyGuard ® DO probe, which has a built-in temperature compensation, a large anode and electrolyte volume. Probe air calibration was performed according to the manual (Point Four Systems Inc.) prior to each experiment.…”

“…1) originally designed by Duval et al (1981) and modified subsequently by Johansen and Geen (1990). The volume of each glass vessel was around 8 L and was covered with opaque polyethylene during the whole test period to minimize possible disturbance.…”

“…The volume of each glass vessel was around 8 L and was covered with opaque polyethylene during the whole test period to minimize possible disturbance. The oxygen readings were given by the OxyGuard ® dissolved oxygen (DO) probe, mounted through the lid into each glass vessel, instead of the modified YSI Model 53 oxygen monitors used by Johansen and Geen (1990). A transduction 16 bit, 64K DEC LSI 11/02 compatible computer and a custom made A/D-D/A interface were used for system control and data acquisition.…”

Alterations on AChE Activity of the Fish Anguilla anguilla as Response to Herbicide-Contaminated Water

“…Exposed animals exhibited signs of lethargy and a hypoactive state (from 32 to 72 h) accompained by reduced opercular movement. Lethargy has been observed in other "sh species exposed to herbicides (Johansen and Green, 1990).…”