Aqueous Leachate from Western Red Cedar: Effects on Some Aquatic Organisms

Abstract

Water-soluble extractives from western red cedar heartwood, bark, and foliage were investigated for their toxicity to aquatic organisms. The heartwood lignans and bark extractives were found to be moderately toxic, but the foliage terpenes and heartwood tropolones were more toxic, causing 50% mortality to coho salmon (Oncorhynchus kisutch) fry at 0.33 and 2.7 mg/liter, respectively. Tropolones were significantly less toxic to invertebrates than to free-swimming stages of the fish tested. Fry were found to be the stage of development of coho salmon (O. kisutch) most sensitive to the tropolones, and eyed eggs the least sensitive. Sensitivity of the coho fry to tropolones was moderated by previous sublethal exposure or the presence of a chelatable cation. Results from field studies and a leaching study indicate that directly releasing cedar leachate from landfills or allowing logging debris to enter streams should be avoided.

Western redcedar—a literature review.

“…Some of these compounds inhibit bacterial growth (Michel 1976). Those present in the steam volatiles obtained from redcedar foliage are highly toxic to coho salmon fry (Peters 1974, Peters et al 1976). …”

“…The thujaplicins, dolabrin, and thujaplicinol ("tropolones") are toxic to coho salmon fry (Peters 1974, Peters et al 1976) and guppies (Erdtman and Gripenberg 1948b). They are also largely responsible for the high natural durability of western redcedar wood (Barton 1973b).…”

The Possible Importance of Forest Soil Processes in Defining Surface Water pH Depressions

“…58 Neither lethal nor sublethal concentrations of cedar leachate occurred in the study streams, but high acidity of streams was prevalent. 59 With the advent of autumn, rain brought a marked decrease in stream pH. Soils in the study watershed were quite acidic, with pH ranging from 3.8 in the A2 horizon to 5.1 in the IIC horizon.…”

Effect of wood waste dumping on organic matter in seawater and surficial sediments of Alberni Inlet, British Columbia

“…In fact, organic compounds are known to be effectively leached out from woody material in one day (Peters et al, 1976). The origin of the sub-surface maximum of DOC at 30-60 m near the dump site (Fig.…”