The performance of two field probes (YSI 6600 and TriOS), used for the measurement of in vivo phycocyanin fluorescence, was compared and validated in the laboratory in 2008 and 2009 with cultures of Microcystis aeruginosa and field samples. The background noise of the two probes was low and the detection limits were estimated at 1500 cells mL(-1) for the YSI and 0.69 µg PC L(-1) for the TriOS. The linearity and repeatability of both probes have been excellent. Strong relationships were observed between the in vivo fluorescence and the total cyanobacterial biovolume (R(2) = 0.82 YSI; 0.83 TriOS) or the abundance (R(2) = 0.71 YSI; 0.75 TriOS) of cyanobacteria. However, the difference between cell densities determined by microscopy and measured by the YSI can be very large and has been associated to the variability of cell volume among cyanobacteria. This last observation makes the YSI a qualitative tool if a post-calibration is not done. The analysis of filtrated samples showed that dissolved phycocyanin (extracellular) may represent a significant fluorescence signal. No relationship could be established between the abundance, the total cyanobacterial biovolume or the in vivo fluorescence of phycocyanin and the concentrations of cyanotoxins (R(2) ≤ 0.22).

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Municipal biosolids are increasingly used as a low-cost fertilizer in agricultural soil. Biosolids are contaminated by low concentrations (nanograms per gram dry wt range) of a large variety of organic contaminants, such as triclosan. The effect of exposure to low concentrations of organic contaminants on soil biota remains largely undocumented. We evaluated the sublethal effects of triclosan on the earthworm Eisenia andrei using an artificial soil amended with a nominal concentration of triclosan of 50 ng g dry weight soil. Using a 56-d reproduction test, we monitored the effect of triclosan exposure on adult earthworm survival, growth, and reproduction. The bioaccumulation of triclosan in earthworm tissue (adults and juveniles) and degradation of triclosan were monitored. The genotoxicity of triclosan was evaluated using a comet assay (DNA damage) on adult earthworm coelomocytes. Exposure to a low concentration of triclosan had no significant effects on adult earthworm survival and DNA damage but significantly stimulated growth (p < 0.05) by 2-fold compared with controls. It also significantly affected E. andrei reproduction parameters (p < 0.05), as evidenced by an increase in the number of cocoons and juveniles and a decrease in the mean dry weight of juveniles. The bioaccumulation of triclosan in earthworms was moderate (bioaccumulation factor ∼2). In biosolid-borne trials, the bioaccumulation of methyl-triclosan in earthworm tissues was higher than that of the parent compound triclosan. We conclude that exposure to low concentrations of triclosan in artificial soil can significantly affect the growth and reproductive performance of earthworms (i.e., E. andrei). More research is required with natural soils to assess triclosan bioavailability for earthworms. Environ Toxicol Chem 2018;37:1940-1948. © 2018 SETAC.

This study verified the effectiveness and the potential toxic impact of PERACLEAN 1 Ocean ballast water treatment for very cold freshwater (0.1-0.58C) in real ballast tank (750 m 3 ) conditions aboard a ship and in large-volume (4.5 m 3 ) polyethylene tanks. Concentrations of peracetic acid (PAA) and hydrogen peroxide (H 2 O 2 ) gradually dropped by 41-59% over 5 days. The treatment altered the quality of the treated waters by causing a pH drop of 0.9-1.3 units and a fourfold to sevenfold increase in dissolved organic carbon and organophosphates concentrations. More than 90% of the biomass of free-floating micro-organisms and viable phytoplankton were eliminated within 48 h after treatment. The treatment resulted in 100% mortality in caged fish exposed to treated waters but was totally ineffective against adult zebra mussels and some nematods living in tank sediments. Toxic response from ecotoxicological assays indicated that treated waters after 5 days should be diluted by a factor of 1:2 to 1:200 to reduce toxicity below selected endpoints of acute lethality tests. On the basis of PAA degradation rate, fresh waters treated with 100-ppm PERACLEAN 1 Ocean should be kept in ballast tanks for 15-20 days after treatment to reduce toxicity. It is concluded that the treatment can be an effective biocide to rapidly eliminate organisms of the water column inside the ballast tanks over a wide range of environmental conditions, but that the discharge of the toxic treated waters should be properly managed to minimize potential environmental impact. # 2008 Wiley Periodicals, Inc. Environ Toxicol 24: 49-65, 2009.