The relationship between the copper complexing capacity of sea water and copper toxicity in shrimp zoeae

Mortality of larval coon-stripe shrimp, Pandalus danae, was related to labile copper and the copper complexing capacity of sea water, as measured by differential pulse Anodic Stripping Voltammetry (ASV). In nominal treatments of control, 5 and 10μg/litre Cu which contained less than 1·0μg/litre ASV labile Cu, zoeal development was usually complete. In treatments of 20 and 50μg/litre Cu which contained more than 7·0μg/litre ASV labile Cu, most larvae died while in the first zoeal stage. ASV labile Cu was related to the copper complexing capacity of sea water. Copper toxicity at less than 1·0 μg/litre ASV labile Cu is indicated by moulting delay and apparent Cu accumulation in zoea of the 5 and 10μg/litre Cu nominal treatments.     

Reproductive success, xenobiotic contaminants and hepatic mixed-function oxidase (MFO) activity in Platichthys stellatus populations from San Francisco Bay

To identify some specific effects of organic contaminants on fisheries in an urbanized estuary we compared the reproductive success of starry flounder from San Francisco Bay with concentrations of tissue contaminants and hepatic mixed-function oxidase (MFO) activity. We found significantly lower (P < 0·05) sediment concentrations of total identified polynuclear aromatic hydrocarbons (PAHs) in the less urbanized San Pablo Bay (SP) area (Fig. 1) than in the more urbanized central bay (CB) stations (Table 1). For flounder in early gametogenesis (August and September) the SP fish (n = 20) had significantly lower (P < 0·01) liver concentrations of Aroclor 1260 (0·34 ± 0·14 μg/g) than those at the CB stations: Berkeley (BK, n = 20, 1·6 ± 1·6 μg/g); Oakland (OK, n = 16, 2·3 ± 2·8 μg/g); and Alameda (AL, n = 4, 2·2 ± 1 μg/g). A similar pattern existed for DDT concentrations: SP = 0·2 ± 0·16 μg/g; BK = 0·1 ± 0·34 μg/g; OK = 0·4 ± 0·53 μg/g; and AL = 0·4 ± 0·33 μg/g. Total PAHs in livers were as follows: SP = 0·14 μg/g; BK = 2·6 μg/g; OK = 1·4 μg/g; and AL = 14 μg/g. Although gonad index, liver index, and presence of fin rot are inversely related to aryl hydrocarbon hydroxylase (AHH) activity, healthy fish in a similar reproductive state have lower AHH activities in the SP area. For example, in August and September, 1984, mean AHH activities were as follows: SP = 203 ± 89, and CB = 355 ± 200 pmol 3-OH-B[a]P mg microsomal protein min. We found a log-linear relationship for AHH activity and its percent inhibition by 7,8-benzoflavone (10⁻⁴m) and only a few fish from SP showed enhanced AHH activity after addition of 7,8-benzoflavone. This suggests that most of the starry flounder in San Francisco Bay are induced.     

Evidence on the interaction of mercury and selenium in the shrimp Palaemon elegans

The interaction of selenium with mercury was studied in the shrimp Palaemon elegans. The release of ²⁰³HgCl₂ (5·0 μg Hg per gramme body weight) from shrimp pretreated with selenium (SeO₂ doses of 1·97, 3·95 and 7·90 μg Se per gramme fresh weight) was significantly decreased compared with the control group to which only 5·0 μg Hg/g had been administered.In the presence of HgCl₂ (5·0 μg Hg per gramme fresh weight) the release of ⁷⁵Se also diminished significantly at the higher stable Se pretreated dose (7·90 μg Se/g) while, at a lower selenium concentration, the release was not statistically different. Analyses for stable Hg and Se confirmed the decrease in rate of selenium loss in the presence of mercury which had been demonstrated with radiotracers.A dose of 7·9 μg Se per gramme fresh weight injected 12 h before exposure of the shrimp to the various mercuric chloride solutions did not produce a significant difference in the 24 h LC₅₀ compared with the group not pretreated with selenium. However, during exposure to mercury at 3·8 mg/litre, the median lethal time (LT₅₀) for the shrimp pretreated for 4 days with sublethal selenium (6·9 and 10·5 mg Se/litre) was delayed (19·2 and 33·2 h) compared with the group which was not pretreated. The results are discussed in relation to the role of selenium in the acutely toxic effects of inorganic mercury.     

Toxicity of copper to three estuarine bivalves

This paper reports on a study of the toxicity of copper to three species of bivalve of commercial food value, Anadara granosa (Linnaeus), Meretrix casta, Deshayes and Crassostrea madrasensis (Preston) inhibiting the Vellar estuary at Porto Novo (southern India). The LC₅₀ values were estimated as 60 μg Cu/litre for A. granosa, 72 μg Cu/litre for M. casta and 88 μg Cu/litre for C. madrasensis subjected to 96-h static bioassay tests after acclimation for a period of four days in the laboratory. The animals selected for study ranged in length from 29 to 44 mm in A. granosa, from 25 to 42 mm in M. casta and from 31 to 115 mm in C. madrasensis. The experiments were conducted at 25% salinity with pH 8·0 ± 0·1 at a temperature of 27°C ± 0·5°C. The revival rates of bivalves which survived exposure to the LC₅₀ concentrations for the 96-h period (when marked and released in the natural environment) were 67% for A. granosa, and C. madrasensis and 83% for M. casta. The LT₅₀ values for the three bivalves at different concentrations of the metal were also calculated.     

Acute and sublethal toxicity of naphthalene and three methylated derivatives to the estuarine copepod, Eurytemora affinis

The bi-cyclic aromatic hydrocarbon naphthalene (N) and its alkylated derivatives 2-methylnaphthalene (MN), 2,6-dimethylnaphthalene (DMN) and 2,3,5-trimethylnaphthalene (TMN) were used to investigate possible relationships between increased methylation and toxicity during acute high level and chronic low level exposure experiments using the calanoid copepod Eurytemora affinis Poppe. The 24-h LC₅₀ levels determined indicated an approximate twofold increase in toxicity per methyl group addition: N-3798 μg/litre; MN-1499 μg/litre; DMN-852 μg/litre and TMN-316 μg/litre. Low level chronic exposure of E. affinis to the various naphthalenes in sea water concentrations of about 10 μg/litre for the duration of their adult life (maximum twenty-nine days) resulted in significant reductions in length of life, total numbers of nauplii produced and mean brood size. Exposure to all the naphthalenes at this level (10 μg/litre) resulted in reduced rates of egg production which were, on average, about 50% of those of control animals. Results are discussed in relation to previous work on the fate and effect of petroleum hydrocarbons in marine copepods.     

Long-term effects of tributyltin compounds on the baltic amphipod, Gammarus oceanicus

Amphipod larvae, Gammarus oceanicus, were exposed for 8 weeks to bis(tributyltin) oxide (TBTO) or tributyltin fluoride (TBTF), or for 5 weeks to leachates from tributyltin-containing antibiofouling paints. No larvae survived 8 weeks' exposure to 3 μg/litre TBTO or TBTF. Differential larval survival occurred during exposure to 0·3 gmg/litre of these same compounds. Paint leachates were shown to cause similar toxicity responses at comparable aqueous tributyltin concentrations. An examination of sublethal responses showed slight decreases in growth for larvae exposed to TBTO and to paint leachates, although responses at tributyltin levels below 1 μg/litre were not marked. Whole-animal oxygen consumption rates were not affected by low tributyltin exposure levels. While these studies demonstrate low level toxicity of tributyltins, effects on oxygen consumption and growth do not indicate a mode of action for these compounds.     

An experimental marine ecosystem study of the pelagic biogeochemistry of pentachlorophenol

The marine biogeochemistry of pure pentachlorophenol was studied relative to a control treatment at a scale which provided a good model for the pelagic planktonic environment (70 m³ polyethylene bags). Pentachlorophenol that was dispersed at concentrations of 10 and 100 μg/litre showed identical relative rates of decrease over 25 days to concentrations 32·8% and 31·1%, respectively, of the initial concentrations. No bioaccumulation by phytoplankton or zooplankton was observed and pentachlorophenol removal by adsorption (by particulates, zooplankton or the enclosure walls) was insignificant. The log of the pentachlorophenol concentration was significantly correlated to the hours of bright sunshine up to Day 18, after which the photolysis efficiency decreased as the proportion of pentachlorophenol exposed to sunlight decreased. The results imply a long residence time for pentachlorophenol in deeper waters outside the photolysis zone. A persistent reduction in the primary production and production per unit carbon was observed at 100 μg/litre and, when coupled to the reproducible demise of the centric diatom Skeletonema costatum in culture and the spiked enclosures, suggests that pentachlorophenol inhibits phytoplankton growth.     

Sodium hexametaphosphate as an aid in benthic sample sorting

The efficacy of sodium hexametaphosphate, when added to a formalin-Rose Bengal fixative solution, in improving the efficiency of benthic sample sorting by encouraging the disaggregation of silt-clay sediment has been investigated. Samples of estuarine mud (Mdφ = 6·1) from Damhead Creek, River Medway, were used for the analysis. A significant increase (23%; p < 0·01) in sieving efficiency was found in samples treated with concentrations of 1·24g/litre or more of sodium hexametaphosphate; treatments with higher concentrations than 1·24g/litre did not improve on this performance significantly. The use of 1·24g/litre sodium hexametaphosphate in an initial fixative/preservative solution is recommended as an economic and practical means of improving the efficiency of benthic sample sorting, without deleterious effects on the animal specimens in the sample.     

Benthic microalgal biomass in sediments of Onslow Bay, North Carolina

Sediment samples were collected at stations along cross-shelf transects in Onslow Bay, North Carolina, during two cruises in 1984 and 1985. Station depths ranged from 11 to 285 m. Sediment chlorophyll a concentrations ranged from 0·06 to 1·87 μg g⁻¹ sediment (mean, 0·55), or 2·6–62·0 mg m². Areal sediment chlorophyll a exceeded water column chlorophyll a a at 16 of 17 stations, especially at inshore and mid-shelf stations. Sediment ATP concentrations ranged from 0 to 0·67 μg g⁻¹ sediment (mean, 0·28). Values for both biomass indicators were lowest in the depth range including the shelf break (50–99 m). Organic carbon contents of the sediments were uniformly low across the shelf, averaging 0·159% by weight. Photography of the sediments revealed extensive patches of microalgae on the sediment surface.Our data suggest that viable benthic microalgae occur across the North Carolina continental shelf. The distribution of benthic macroflora on the North Carolina shelf indicates that sufficient light and nutrients are available to support primary production out to the shelf break. Frequent storm-induced perturbations do not favour settling of phytoplankton, an alternative explanation for the presence of microalgal pigments in the sediments. Therefore, we propose that a distinct, productive benthic microflora exists across the North Carolina continental shelf.     

Fate of tributyltin in sewage sludge treatment

We have shown that municipal wastewater and sewage sludge are contaminated by organotins. Here, we investigate the behaviour and fate of tributyltin (TBT) in laboratory-scale sewage sludge treatment at various conditions including both aerobic and anaerobic, and mesophilic and thermophilic. Organotins were determined by capillary GC-FPD. Fresh raw sewage sludge was stored in a tank that was connected to five chemostats maintained at different conditions. Raw sludge contained TBT, dibutyltin (DBT) and monobutyltin (MBT) residues in the range of 0·28 to 0·83 mg/kg (dry weight). The volumetric TBT concentration was 10·5 μg/litre in the influent, and ranged from 7·4 to 8·3 μg/litre in the effluent of the different chemostats. In the anaerobic mesophilic treatment, concentrations of TBT did not decrease with increasing sludge residence time, DBT increased and MBT showed no clear trend. The DBT increase is suggested to be due to leaching from the PVC walls of the chemostats, and not to degradation of TBT alone. The TBT reduction did not show significant differences between the mesophilic and thermophilic anaerobic fermentors. These findings indicate that the degradation of TBT during sludge treatment is only low under all conditions tested.     

The influence of dissolved petroleum hydrocarbon residues on natural phytoplankton biomass

The effect of dissolved petroleum hydrocarbons in the environment on phytoplankton biomass measured as chlorophyll a was studied near the oil tanker route in the southern Bay of Bengal. In the transect from 5° N, 77° E to 5° N, 87° E the concentrations of dissolved petroleum hydrocarbons were negatively correlated with phytoplankton biomass, whereas in the 0° N, 87° E to 1° N, 79° E transect they were positively correlated with phytoplankton biomass. The mean petroleum hydrocarbon concentrations in the two transects were 12·12 ± 4·67 μg litre⁻¹ and 11·23 ± 4·5 μg litre⁻¹, respectively.It is surmised that the effect of dissolved petroleum hydrocarbons on phytoplankton biomass varies depending on the nature rather than the quantity of petroleum hydrocarbons present. Culture studies with unialgal Nitzschia sp. in seawater collected from selected stations in the study area as well as in artificial seawater spiked with the water-soluble petroleum hydrocarbon fraction of light Arabian Crude support this.     

Cadmium in Mytilus spp.: Worldwide survey and relationship between seawater and mussel content

A worldwide literature survey of data on cadmium concentration in the soft tissue of the mussel, Mytilus spp., from 591 stations is presented. These stations are from 13 regions. Geometric means for the regions vary from 0·6 to 3·3 μg g⁻¹ (dry weight) for the Barents Sea and the Northeastern Pacific coast, respectively.The averages of seven of these regions, for which reliable cadmium concentrations in seawater were available, were used to calculate a relationship between cadmium concentrations in seawater and mussel soft tissue. The relationship was highly significant: (Cd) mussel (μg g⁻¹, dry weight) = 0·074 (Cd) water (ng litre⁻¹) + 0·39 (P ≤ 0·0005).This model has been successfully applied in the context of the contamination of the Gironde estuary (France). It can also be used to define a water quality criterion for mussel maturing parks consistent with the quality criterion defined for shellfish for human consumption.     

Acute and chronic toxicity of the rice herbicides thiobencarb and molinate to opossum shrimp (Neomysis mercedis)

Neomysis mercedis were exposed to the rice herbicides molinate and thiobencarb, which have been detected in the Sacramento-San Joaquin Delta. Continuous-flow acute and chronic toxicity studies were performed. For thiobencarb, the 4-, 7- and 14-day LC_sos were 304, 214 and 91 μg/liter, respectively. For molinate, these values were 9910, 2530, and 820 μg/liter, respectively. Mortality stabilized after 18 and 28 days exposure, respectively, for thiobencarb and molinate. The incipient lethal concentrations were 53 and 230 μg/liter, respectively. Joint toxicity studies indicated additive toxicity for the two chemicals. Chronic no observable effects concentrations (NOECs) were estimated at 3·2 and 25·6 μg/liter for thiobencarb and molinate, with measurable effects occurring at 6·2 and 45·2 μg/liter, respectively. Environmental monitoring data suggests that concentrations of these chemicals in the Delta prior to 1985 may have exceeded the threshold for chronic toxicity, under conditions of joint exposure. However, due to continued improvements in pesticide management practices, environmental concentrations decreased to approximately 30 percent of the chronic threshold for joint toxicity by 1988. Baseline data on growth and reproduction relevant to toxicity tests are also presented for this species.     

Factors influencing fatty acid and hydrocarbon composition of sedimenting particles in the northeastern Adriatic Sea

Fatty acids and hydrocarbons of sedimenting particles were investigated in the northeastern Adriatic Sea from November 1988 to December 1989. Particles were collected at approximately monthly intervals, using sediment traps deployed at 30 m depth (2 m above bottom). Seasonal changes in sedimentation of particulate matter were very pronounced. Hydrocarbon fluxes and concentrations were found to vary significantly depending on the season. They averaged 2.69 ± 1.44 mg m⁻² day⁻¹ and 232.4 ± 90.93 μg g⁻¹ in winter, respectively. In late spring-early summer the corresponding values amounted to 0.045 ± 0.015 mg m⁻² day⁻¹ and 13.72 ± 5.56 μg g⁻¹, and they increased towards autumn, when mean values of 0.517 ± 0.228 mg m⁻² day⁻¹ and 98.86 ± 48.72 μg g⁻¹ were obtained. In contrast, fatty acid fluxes and concentrations were low during winter (0.26 ± 0.08 mg m⁻² day⁻¹ and 21.95 ± 3.35 μg g⁻¹), increased slightly towards the summer (0.48 ± 0.12 mg m⁻² day⁻¹ and 139.9 ± 44.6 μ g⁻¹) and reached maximum rate and concentration in autumn, when average values were 1.98 ± 1.30 mg m² day⁻¹ and 489.1 ± 186.7 μg g⁻¹, respectively. The differences in composition, concentrations and fluxes of the fatty acids and hydrocarbons were related to the sources of sedimenting material, reflecting the influence of resuspension of bottom sediments during winter and the appearance of mucus aggregates during summer and their subsequent deposition in autumn.     

Carbon and nitrogen primary productivity in three North Carolina estuaries

Uptake of inorganic carbon and ammonium by the plankton community of three North Carolina estuaries was measured using ¹⁴C and ¹⁵N isotope methods. At 0% light, C appeared to be lost via respiration, and at increasing light levels uptake of inorganic carbon increased linearly, saturated (mean I_k = 358±30 μEin m⁻² s⁻¹), and frequently showed inhibition at the highest light intensities. At 0% light NH₄⁺ uptake was significantly greater than zero and was frequently equivalent to uptake in the light (light independent); at increasing light levels NH₄⁺ uptake saturated (mean I_k = 172±44 μEin m⁻² s⁻¹) and frequently indicated strong inhibition. Light-saturated uptake rates of inorganic carbon and NH₄⁺ were a function of chlorophyll a (r² = 0·7−0·9); average assimilation numbers were 625 nmol CO₂ (μg chl. a)⁻¹ h⁻¹ and 12·9 nmol NH₄⁺ (μg chl. a)⁻¹ h⁻¹ and were positively correlated with temperature (r² = 0·3−0·7). The ratio of dark to light-saturated NH₄⁺ uptake tended to be near 1·0 for large algal populations at low NH₄⁺ concentrations, indicating near light independence of uptake; whereas the ratio was lower for the opposite conditions. These data are interpreted as indicative of nitrogen stress, and it is suggested that uptake of NH₄⁺ deep in the euphotic zone and at night are mechanisms for balancing the C:N of cellular pools. A 24-h study using summed short-term incubations confirmed this; the cumulative C:N of CO₂ and NH₄⁺ uptake during the daylight period was 10–20, whereas over the 24-h period the ratio was 6 due to dark NH₄⁺ uptake. Annual carbon and nitrogen primary productivity were respectively estimated as 24 and 4·0 mol m⁻² year⁻¹ for the South River estuary, 42 and 7·3 mol m⁻² year⁻¹ for the Neuse River estuary, and 9·6 and 1·6 mol m⁻² year⁻¹ for the Newport River estuary.     

Effects of long-term exposure to silver or copper on growth, bioaccumulation and histopathology in the blue mussel Mytilus edulis

The purpose of this study was to determine the long-term accumulation of either silver or copper from low concentrations in seawater by blue mussels, Mytilus edulis. Mussels raised from eggs in the laboratory to the age of 2·5 months (approximately 4·5 mm in length) were continuously exposed to 0, 1, 5 and 10μg/liter of either silver (nitrate) or copper (chloride) and sampled at 12, 18 and 21 months for growth studies, measurements of metal accumulation and histopathological examination.Whole-body soft tissues were analyzed for the presence of both silver and copper, as background levels of copper in the incoming seawater averaged 2–4 μg/liter. Mussels exposed to silver had accumulated significant amounts of silver only at the highest test concentration (10 μg/liter Ag) after 12 months, but at 18 and 21 months significant levels were accumulated at all three test concentrations. Mussels exposed to copper accumulated significant amounts of copper at 5 and 10 μg/liter Cu after all three sampling periods, but not at 1μg/liter. Silver-exposed animals also accumulated significantly greater amounts of copper than control animals.In a comparative study, field-collected juvenile mussels (approximately 16·1 mm in shell length) and adult mussels (approximately 53·4 mm in shell length) were exposed for 12 months to 0, 5, 25 and 50 μg/liter silver only and subsequently sampled for metal-accumulation analyses and growth measurements. Juvenile mussels accumulated significant amounts of silver at all test concentrations, with the exception of mussels exposed to 5 μg/liter Ag for 6 months. Copper accumulation in the silver-exposed juveniles was significant only at 50 μg/liter Ag after 6 months, but at all test concentrations after 12 months. Adult mussels exposed to silver accumulated significant levels of both silver and copper, but at somewhat lower levels than juveniles.In the growth study, silver had no effect on laboratory reared mussels at the highest concentration of 10 μg/liter tested, whereas copper at 10 μg/liter did appear to affect growth as early as 4 months after the start of experimental exposure. Field-collected juvenile mussels did show inhibition in growth after 6 months' exposure to 25 and 50 μg/liter Ag, with some growth occurring after 12 months. Adults also showed inhibition in growth after 6 months but not at 12 months.Histopathological examination of mussels exposed to either 5 or 10 μg/liter of copper for 18 months showed changes in the digestive diverticula, gastrointestinal tract, reproductive tract and muscle tissues. These changes were more noticeable in mussels exposed to 5 μg/liter Cu than in those exposed to 10 μg/liter. Mussels exposed to silver for 21 months showed yellowish to black particulate deposition in the basement membrane and connective tissue of the various organs and tissues. Silver deposition increased with increasing test concentration.     

Sublethal effects of hydrogen sulfide in sediments on the Urchin Lytechinus pictus

Laboratory exposures of the urchin Lytechinus pictus to sediment dosed with varying concentrations of hydrogen sulfide (H₂S), but without elevated organic material, were conducted. Changes in mortality, behavior, growth and gonad production were measured during 49 days' flow through exposures. Hydrogen sulfide concentrations of 165·8 μ liter⁻¹ in pore water caused significant changes in all parameters measured. Concentrations as low as 32·9 μ liter⁻¹ caused significant decreases in wet weight and male gonad production. A concentration of 91·8 μ liter⁻¹ caused the mortality rate to increase 100-fold over control exposures (0·63 μ liter⁻¹). Sublethal effects on growth and gonad production could have been caused by either direct biochemical inhibition by H₂S or secondarily through behavioral modifications. Hydrogen sulfide concentrations above 165·8 μ liter⁻¹ are common near sewage outfalls and could contribute to changes in species composition and sediment toxicity that occur there.     

Nutrient flux in the Rhode River: Tidal transport of microorganisms in brackish marshes

Concentrations of bacteria, chlorophyll a, and several dissolved organic compounds were determined during 11 tidal cycles throughout the year in a high and a low elevation marsh of a brackish tidal estuary. Mean bacterial concentrations were slightly higher in flooding (7·1 × 10⁶ cells ml⁻¹) than in ebbing waters (6·5 × 10⁶ cells ml⁻¹), and there were no differences between marshes. Mean chlorophyll a concentrations were 36·7 μg l⁻¹ in the low marsh and 20·4 μg l⁻¹ in the high marsh. Flux calculations, based on tidal records and measured concentrations, suggested a small net import of bacterial and algal biomass into both marshes. Over the course of individual tidal cycles, concentrations of all parameters were variable and not related to tidal stage. Heterotrophic activity measured by the uptake of ³H-thymidine, was found predominantly in the smallest particle size fractions (< 1·0 μm). Thymidine uptake was correlated with temperature (r = 0·48, P < 0·01), and bacterial productivity was estimated to be 7 to 42 μg Cl⁻¹ day⁻¹.     

The sea-surface microlayer of puget sound: Part II. Concentrations of contaminants and relation to toxicity

Many aquatic contaminants, because of low water solubility (hydrophobicity) or association with floatable particles, concentrate at the sea surface. Thirty-six samples of the sea-surface microlayer (SMIC), the upper 50 μm, were collected from sites in Puget Sound, Washington State. Sites included three urban bays, central Puget Sound, and a rural reference site. Exposure of floating fish eggs to approximately half of these samples resulted in sublethal and lethal toxic effects (Hardy et al., 1987c).Chemical analyses revealed high concentrations of contaminants in many of the samples. Major temporal and spatial differences in sea-surface chemistry occurred, but maximum (for all) and mean (for 1985) concentrations were aromatic hydrocarbons, 8030 (mean 132) μg liter⁻¹: saturate hydrocarbons, 2060 μg liter⁻¹: pesticides, 43·8 (mean 0·46) ng liter⁻¹; PCBs, 3890 (mean 631) ng liter⁻¹; and total metals, 4750 (mean 626) μg liter⁻¹. Stepwise multivariate regression indicated that the percentage of fish eggs developing to normal live larvae decreased with increasing concentrations of a complex mixture of contaminants. Principal component analysis demonstrated that the major types of contaminants did not differ greatly in their statistical contribution to the toxicity, i.e. no single chemical was responsible for the observed toxicity.The chemical composition of the SMIC samples suggested that contamination originated from a variety of sources including atmospheric deposition, terrestrial runoff of fossil fuel combustion products, and sewage disposal.     

Glutathione S-transferase from an antarctic fish, Dissostichus mawsoni

Glutathione S-transferase activity was measured in the hepatic cytosol front Dissostichus mawsoni and Pagothenia borchgrevinki. Activity measures with 1-chloro-2,4-dinitrobenzene as substrate were 11·2 and 16·7 μmol/min/g tissue respectively. Little or no activity was detected when p-nitrobenzyl chloride or 3,4-dichloro-1-nitrobenzene were used as substrate. The hepatic glutathione S-transferases from D. mawsoni were partially purified using gel filtration and chromatofocusing. Three peaks of activity were resolved. The major isozyme (158-fold purification) eluting at pH7·1 appeared to be catalytically a homodimer. The isozyme was highly inhibited by triphenyltin chloride (IC₅₀ = 0·1 μ) while inhibition constants for Cibicron Blue 3GA, bromosulphophalein and hematin were 1·1, 20 and 34 μ respectively.