The action of heavy metals on the gametes of the marine mussel, Mytilus edulis (L.)—III. The effect of applied copper and zinc on sperm motilityin relation to ultrastructural damage and intracellular metal localisation

Treatment of Mytilus edulis sperm with external concentrations of copper or zinc (0-1-3-3mM) causes a decrease in motility in which zinc is more inhibitory than copper. Zinc also appeared to cause more extensive mitochondrial damage, as revealed by transmission electron microscopy, than did treatment with copper. The relationship between sperm motility and respiration in the presence of the various heavy metal concentrations used indicates that the depression of sperm motility can be explained largely on the basis of respiratory inhibition. However, zinc produces a less pronounced effect on sperm motility than on r respiration.X-ray microanalysis of thick sections of fixed treated sperm showed that copper accumulation occurs in the acrosomes, mitochondria and nuclei, whereas zinc is found in the acrosomes and in mitochondrial granules in association with calcium and phosphorus. No evidence was obtained for zinc accumulation in the nuclei. Treatment with either copper or zinc resulted in considerable reductions of bound calcium and phosphorus in both the acrosomes and mitochondria. It is suggested that the heavy metal ions cause an increase in the permeability of the organelle membranes to calcium and phosphorus.It is concluded that the less marked effect of zinc on sperm motility as compared to respiration may be due to an increase in the cytosolic free calcium concentration which, in turn, may stimulate the flagellar contractile apparatus.     

Coprecipitation of zinc with silica in seawater and in distilled water

Dissolved silica can coprecipitate with zinc from seawater or distilled water that has been enriched with both elements. More than 2 ppm Si are necessary for the reaction to begin. The coprecipitation shows pH dependence. The addition of pulverized illite or natural sediment as suspended particulate material does not enhance the reaction in seawater. The organic material present in the nearshore seawater samples decreases the rate and extent of reaction, as indicated by comparisons of results of experiments using natural seawater with results obtained using UV-irradiated seawater. In unbuffered distilled water the reaction must compete with hydrolysis of zinc; however, reaction does occur, which indicates that the seawater matrix is not essential for the reaction. The coprecipitation can limit the concentration of zinc in seawater to less than the solubility concentration assumed for ZnCO₃ or Zn(OH)₂. The results suggest that a zinc silicate can precipitate directly from seawater or interstitial water as an authigenic mineral.     

Behavioural responses of the bivalve Scrobicularia plana (da Costa) subjected to short-term copper (Cu II) concentrations

Short-term (6 h) behavioural responses and mortality of Scrobicularia exposed to low concentrations of copper in sea water (31%, S) have been investigated.Scrobicularia can detect copper at a concentration of 0·01 ppm. The initial response is valve closure resulting in a rapid drop in heart rate. In concentrations of 0·05, 0·01 and, to a lesser extent, 0·1 ppm copper added to sea water, the clams begin to interact with the polluted water after 2–3 h. In 0·5 ppm, the valves remain closed and the heart rate is maintained at a low level over the 6-h exposure period.Mortality increases with time in 0·5 ppm copper concentration, reaching 50% in 5–7 days. In 0·05 and 0·01 ppm, no mortality was recorded over this period.There is an increase in mantle cavity water calcium concentration after 6 h in 0·5 ppm, in contrast to 0·1, 0·05 and 0·01 ppm. Aspects of anaerobiosis, accumulation of heavy metals and survival are discussed in relation to the behaviour of Scrobicularia exposed to various copper concentrations.     

Sea urchin sperm bioassay for sewage and chlorinated seawater and its relation to fish bioassays

Bioassays were conducted with sea urchin and sand dollar sperm to determine the toxicity of chlorinated and unchlorinated sewage effluent and chlorinated and brominated seawater. The sperm cells were exposed to seawater dilutions of each toxicant for 5–15 min. The fertilisation of eggs served as the indicators of sperm viability. The effective concentrations which reduced fertilisation success by 50% (EC50) averaged 2·2 and 4·8% chlorinated and unchlorinated sewage in seawater, respectively. The sperm cells were extremely sensitive to chlorinated seawater at concentrations from 0·002 to 0·020 mg/litre total residual oxidant (TRO). Brominated seawater proved toxic to sperm in one test at 0·015 mg/litre TRO. Results of the sperm bioassays are compared with previous acute and chronic bioassays with fish.     

Editorial

A flow-through system for exposure of seagrass to pollutants is described. Sea water with dissolved atrazine or PCP (pentachlorophenol) was pumped through a sealed 2-litre volume glass exposure vessel that contained either whole plants or leaves of Thalassia testudinum. Effects of the compounds on oxygen evolution and uptake by leaves were measured after exposure for 40 and 88 h. Rate of oxygen evolution was depressed strongly after 40 h by 1 ppm of atrazine or PCP. The rate of oxygen uptake was slightly depressed by atrazine but strongly depressed by PCP. Photosynthesis/respiration ratios were depressed to less than one by 1 ppm of atrazine or PCP and by 0·5 ppm atrazine. EC₅₀ values based upon depression of oxygen evolution after 40 hours exposure were: atrazine, 0·32 ppm PCP, 0·74 ppm. The data suggest that leaves may recover from, or adapt to, the presence of either toxicant.     

Trace metals in the common porpoise, Phocoena phocoena

Mercury, cadmium, copper and zinc concentrations in brain, liver, kidney, heart and spleen of twenty-six specimens of the common porpoise (Phocoena phocoena) are presented. Mercury and cadmium levels in liver and kidneys tended to increase with length of animal, but copper and zinc levels show no such trends. The proportion of methylmercury to total mercury (9%–57%) in the liver decreased with increasing total mercury concentrations. Lead, chromium, nickel and cobalt levels were below the analytical detection limits (0·5, 1·0, 1·0 and 2·5 μg^?1, respectively).     

Sensitivity of estuarine phytoplankton to hexavalent chromium

Experiments were conducted in which we tested the effects of hexavalent chromium on both natural assemblages of phytoplankton and cultures of Thalassiosira pseudonana clone 3H. Water was collected from various locations in Yaquina Bay, Oregon, with salinities ranging from 32·5‰ to 0·03‰. A variety of nutrient regimes were tested by adding major nutrients and micro-nutrients, and/or stripping micro-nutrients with activated carbon. In one high salinity experiment, chromium was stimulatory, as were micro-nutrient additions. In other high and medium salinity experiments, chromium was neither stimulatory nor inhibitory, at levels up to 1·9 μ mole l^?1 Cr. There was, however, slight inhibition of growth at 19·0 μ mole l^?1 Cr, due specifically to inhibition of Skeletonema costatum. In our freshwater experiments, chromium was very inhibitory at 1·9 μ mole l^?1 Cr, and slightly inhibitory at 0·19 μ mole l^?1 Cr. Species inhibited by chromium were Surirella ovata, Detonula confervacea, and Cyclotella sp. Experiments were conducted with T. pseudonana grown over a wide range of salinities. Chromium was found to be very inhibitory in freshwater and became progressively less toxic as the salinity increased. Most inhibition was neutralized by a salinity of 2·1‰.     

Effects of dechlorinated seawater on fish behavior

Behavioral responses to chemically dechlorinated seawater were studied using two species of marine fish associated with power plant discharge areas off Southern California. Opaleye (Girella nigricans) neither avoided nor were attracted to chlorinated seawater containing 0·1 mg/liter total residual oxidants (TRO) which had been dechlorinated using equimolar or excess sodium thiosulfate. Blue-banded goby (Lythrypnus dalli) did not avoid dechlorinated seawater initially containing 0·1 or 0·9–1·0 mg/liter TRO. Previously it has been shown that opaleye avoided chlorinated seawater with oxidant concentrations of 0·1 mg/liter and blue-banded gobies avoided 0·9–1·0 mg/liter TRO. Elimination of chlorine-produced oxidants by thiosulphate dechlorination resulted in 100% survival in both species. The toxicological implications of exposure to dechlorinated seawater are discussed.     

An experimental study on the speciation of dissolved zinc,cadmium, lead and copper in river rhine and north sea water,by differential pulsed anodic stripping voltammetry

Dissolved electroactive concentrations of zinc, cadmium, lead and copper in river Rhine and North Sea samples have been measured at natural and lower pH values by differential pulsed anodic stripping voltammetry using a Kemula-type hanging mercury drop electrode. Average concentrations detected in North Sea samples at salinities $\text{? 32‰ S}$ and their range are (in μgl^?1): 3.9 (2.0–7.5) for zinc, 0.23 (0.13–0.31) for cadmium, 0.3 (0.1–0.6) for lead and 0.3 (0.25–0.60) for copper (pH 8.1). The APDC-MIBK extracting/concentrating method, followed by AAS measurement applied to the same samples, resulted in 3.9 (2.0–7.5) for zinc, 0.11 (0.01–0.27) for cadmium, 0.5 (0.2–0.9) for lead and 1.6 (0.7–3.2) for copper. A fraction of the electroactive concentrations at pH 2.7 (6.1 for Zn) is electroactive at pH 8.1. The fractions are 100% for Cd, 20% for Cu, 13% for Pb and 40% for Zn. The remaining fractions are partly composed of organically bound species in solution. The low value for lead may be caused by the presence of particulate lead that is dissolved at low pH.Ionic copper and lead species, added separately to seawater at pH 8.1 are removed from the electroactive form, and taken up in (organic) complexes in the same ratio (at least for copper) as the species already present. Added ionic zinc is not removed within the time scale of the measurements (30 min). North Sea water at the natural pH has a complexing capacity, probably due to the presence of dissolved organic compounds, in a concentration equivalent to 3.10^?7M copper. The complexing capacity is zero at pH 2.7. The usual method of standard addition for the determination of electroactive copper and lead concentrations may lead to erroneous results in samples where complexation of this type occurs.     

Technetium: Uptake,organ distribution and loss in the mussel, Mytilus Californianus (Conrad) and the oyster Crassostrea gigas (Thunberg)

The bivalve molluscs Mytilus californianus and Crassostrea gigas were exposed to filtered seawater containing the isotope ^95mTc added as pertechnetate (TcO₄^?) to study the biokinetic behaviour of this element. Whole body concentration factors for both organisms at equilibrium were small (CF = 1·3–1·5); individual organ concentration factors were highest for the visceral mass in both. Loss rates determined both in the laboratory and under field conditions were biphasic for both molluscs; initial loss of Tc was rapid with slightly more than 50 % of the initial label being lost within 10 days. Thereafter, loss rates decreased and whole body biological half-lives ranged from 80 to 134 days. Neither I^? nor IO₃^? affected the uptake of Tc by M. californianus even when concentrations of these anions exceeded those normally present in seawater by two orders of magnitude.     

条斑紫菜(Porphyra Yezoensis Ueda)和孔石莼(Ulve Pertusa Kjellm)对酸耐受力的研究——Ⅰ.pH对条斑紫菜和孔石莼呼吸强度和致死酸度试验

不同pH海水和不同时间处理紫菜、石莼对呼吸强度和致死酸度试验结果表明,紫菜比石莼耐酸力强。在海水温度为18℃条件下,分别用pH_2、pH_3、pH_4、pH_5、pH_6、pH_7、pH_8处理,处理时间20分钟,紫菜除pH_2处理对呼吸强度有抑制作用和培养5天后有20％死亡外,pH_3、pH_4、pH_5、pH_6、pH_7、pH_8各组处理对呼吸强度都有促进作用,培养5天后没有死亡现象,而石莼经pH_2、pH_3处理,对呼吸强度都有抑制作用,培养5天后,pH_2处理组全部死亡,pH_3处理有50％死亡。pH_3和pH_4在海水温度为18℃条件下,处理时间为40分钟时,对紫菜呼吸强度有促进作用,培养5天报,pH_3处理组仅有20％死亡。而pH_3对石莼呼吸强度有抑制作用,培养5天后,全部灭亡。在生产上是否可以考虑用pH_3的海水处理紫菜网帘以达到消除石莼(杂藻)的目的,将是一项具有生产意义的待试验课题。     

Individual and interactive effects of environmental stress on the embryonic development of the Pacific oyster, Crassostrea gigas. I. The toxicity of copper and silver

Pacific oyster, Crassostrea gigas Thunberg, embryos were exposed to copper and silver salts, alone and in combination, through the completion of embryogenesis and metal effects upon normal embryonic development were monitored. Copper concentrations throughout the test period ranged from 0·0 to 12·0 μg litre^?1 while silver concentrations were between 0·0 and 18·0 μg litre^?1.Administered individually, silver and copper yielded decreasing per cent normal embryonic development with increasing metal concentration. However, both metals exhibited ‘plateaus’ wherein per cent normal embryonic development did not decrease with increasing metal concentration until a particular concentration was attained. A rapid decrease in per cent normal embryonic development occurred with increasing metal concentrations greater than 6·0 μg litre^?1 copper and 11·0 μg litre^?1 silver.The dose-response patterns of copper and silver appear to be similar with copper exhibiting somewhat greater toxicity. At a copper concentration of 10 μg litre^?1 only 50% of the embryos could be considered normally developed, whereas silver concentrations between 16·0 and 18·0 μg litre^?1 yielded 50% normal embryonic development.Response surface methodology indicated that copper and silver interacted additively, with embryonic development affected to a much greater degree by copper than by silver. Optimum development of Crassostrea gigas embryos was greatly influenced by copper concentrations and occurred at all silver concentrations wherein the corresponding copper concentrations were 6·0 μg litre^?1 or less. Above 6·0 μg litre^?1 copper, per cent normal embryonic development was significantly reduced, even at the lowest tested silver concentrations.Abnormal embryos exhibited retarded shell growth, reduced size and extremely erratic swimming behaviour. These sublethal effects probably have a biochemical origin and would limit the organism's capacity to feed properly, escape predation and develop normally, thereby reducing the chances of successful metamorphosis and recruitment into the adult population.     

Changes in the tissue concentrations and contents of calcium, copper and zinc in the shore crab Carcinus maenas (L.) (Crustacea: Decapoda) during the moult cycle and following copper exposure during ecdysis

The tissue concentrations and contents of calcium, copper and zinc were determined at different stages in the moult cycle of the shore crab Carcinus maenas. The crabs were dissected into the following tissues: the midgut gland, the gill, the ‘rest tissue’ (the latter defined as the left over tissue, i.e. muscles and exoskeleton), and the haemolymph, and analysed as such. One group of crabs was maintained in clean seawater. In these crabs, calcium was lost from haemolymph during premoult and apparently stored in the midgut gland. At ecdysis approximately 90% of the whole body calcium content was lost with the exuviae while the haemolymph calcium content doubled. During early postmoult calcium stored in the midgut gland was used in combination with calcium absorbed from the surrounding seawater for a rapid calcification of the new exoskeleton. Both the copper and zinc concentrations declined in the ‘rest tissue’ compartment during premoult. At ecdysis the haemolymph copper and zinc contents increased 35 and 86%, respectively, from premoult to the newly moult stage. At the same time, however, the copper and zinc haemolymph concentrations decreased. During postmoult, copper (25%) and zinc (45%) were lost from haemolymph and mainly excreted but a minor fraction (5–10%) was stored in the midgut gland.A second group of crabs was maintained in copper-contaminated seawater (0.1 mgl⁻¹) during ecdysis and postmoult. Following exposure of the animals to raised ambient levels of copper, the calcium and zinc contents of the midgut gland were reduced while the copper contents of the midgut gland and most other tissues were increased in comparison to crabs held in clean seawater.     

中国对虾受精生物学的研究

于１９８８－１９９１年在青岛对中国对虾进行受精能力和受精生物学的研究。对虾采用加温和不加温培育，然后用人工授精法－－水域法和滴管法授精研究精卵受精能力；应用扫描和透射电以及石蜡切片技术，精卵的形态结构和受精过程的变化。结果表明，水域法授精，精子入水后３ｈ仍具有受精能力；卵子入水后１ｍｉｎ之内受精率最高只达６２．７％。而滴客法授精，受精率最高可达到９８％。平均值也在６０－８０％之间。保持在低温的亲虾     

Disruption of magnesium regulation in the crab Cancer productus exposed to chlorinated seawater

Exposure of the crab Cancer productus to chlorinated seawater resulted in alterations in haemolymph sodium and magnesium concentrations. At the highest chlorination levels, which approached the 96-h LC₅₀, regulation of both ions was essentially abolished. Reciprocal changes in the sodium and magnesium levels suggested an effect on the activity of the bladder wall, which has been implicated in the regulation of haemolymph magnesium in crustaceans.Additionally, exposure to 1·19 μg/ml applied Cl (0·68 μg/ml TRO) for 96 h resulted in a fourfold increase in the ammonia excretion rate. Crabs also contributed considerable chlorine demand to the exposure seawater. Measurements of TRO in the inhalant seawater and water exiting the crabs' branchial chambers indicated a reduction in TRO equivalent to 57% of that initially present in the inhalant water (0·51 μg/ml TRO).Measurements of ammonia concentrations in the exposure water indicated that ammonia in seawater was consumed in reactions with oxidants. This was especially evident at higher levels of chlorination. At 0·58 μg/ml applied Cl and above, chlorination resulted in near disappearance of ammonia from the water.     

Respiratory changes and stability of haemocyanin—O2 binding capacity in the crab cancer irroratus exposed to Kuwait crude oil in sea water

To determine one possible mechanism of hydrocarbon toxicity, studies were carried out to establish: (a) the availability of hydrocarbons from sea water to the crab haemolymph, (b) the effects on respiration and (c) the possible effects on haemocyanin—O₂ binding characteristics in oiled crabs.Crabs incubated in ¹⁴C-naphthalene labelled oiled sea water (Kuwait crude) readily accumulated the isotope into the haemolymph, in concentrations exceeding those in the surrounding sea water medium with one-hour bioconcentration factors from 2·53 to 23·51. Respiration, as measured by uptake of O₂ from the respirometer sea water, was 12·5% lower in crabs held in 11·0 ppm Kuwait crude/sea water than in the same animals when held in unoiled sea water. Respiration levels returned to preoiling levels when the oiled sea water was replaced with fresh non-oiled sea water.Despite the observed effects of oiled sea water on respiration, the haemocyanin—O₂ binding potential, as well as the structural integrity of haemocyanin (as determined by its UV absorption spectrum, sub-unit dissociation and serum-free Cu⁺⁺ levels), remained unaltered. The results suggest that disruption of blood-oxygen transport via disruption of haemocyanin—O₂ binding as one possible mechanism of hydrocarbon toxicity is unlikely and that other alternatives must be considered.     

The uptake and accumulation of Ni by Cerastoderma edule and its effect on mortality,body condition and respiration rate

The concentration of Ni in C. edule ranges from 17·8 μg/g to 53·82 μg/g with the highest concentration in the gills and mantle and the lowest in the foot and adductor muscles. The concentration does not change with either size or season.There is no significant increase in mortality even in the highest Ni concentration (100 μg/litre), nor is body condition correlated with experimental Ni concentrations. The rate of uptake of Ni (y) is described by the equation:

$\text{y=?16·903+11·674x}{}_1\text{+0·437x}{}_2$

where x₁ = Ni concentration (μg/litre) and x₂ = time (h).The respiration rates did not significantly change up to the highest Ni concentration used (1000 μg/litre).It is postulated that the main pathway for Ni uptake is through the gills, possibly through mucus sheet or transmembrane absorption, with a secondary uptake route via the viscera.C. edule may therefore be a suitable indicator species for Ni.     

Concentrations of zinc,manganese, copper,cadmium, magnesium and iron in ten species of algae and sea water from Aqaba,Jordan

Concentrations of zinc, manganese, copper, cadmium, magnesium and iron in three species of red, four species of brown and three species of green macroalgae, and also in sea water have been determined at two localities along the coast of Aqaba. Significant differences in metal concentrations were found between the various species (P<0·01). Similar significant differences were found with regard to different metals (P<0·001). Concentration factors ranged between 10² for Cd and 9·2 × 10⁴ for Fe. The difference in levels of metals between the two localities, however, was not significant (P > 0·05). Of the three groups of algae examined, rhodopytes exhibited the highest concentration power of metals.     

Determination of conditional stability constants of organic copper and zinc complexes dissolved in seawater using ligand exchange method with EDTA

To clarify the nature of organic metal complexes dissolved in seawater, a ligand exchange reaction between ligands of natural origin and an aminopolycarboxylic acid (EDTA) was used to determine the conditional stability constants of organic metal complexes. The results indicate that more than two organic molecules complexed with copper and zinc exist in surface seawater. It is found that the conditional stability constants of these naturally-occurring organic metal complexes are 1–3 orders of magnitude higher than those of EDTA-Cu and EDTA-Zn complexes. These estimates of the conditional stability constants for the dominant species of organic copper and zinc complexes are 10^11.8 and 10^9.3, respectively, at pH 8.1. The results indicate that these naturally-occurring organic metal complexes are stable species and not easily dissociated or displaced with others in the marine environment.     

Cadmium toxicity to three species of estuarine invertebrates

Three species of estuarine invertebrates, Palaemonetes pugio (grass shrimp), Pagurus longicarpus (hermit crab) and Argopecten irradians (bay scallop), were exposed to Cd in flowing seawater at concentrations of 0·06, 0·12, 0·25, 0·5 and 1·0 mg/litre. Incipient LC₅₀ values of 0·53 and 0·07 mg/litre were estimated for bay scallop and hermit crab, respectively. The toxicity curve for grass shrimp had not stabilised, but the incipient LC₅₀ value was estimated to fall within a range of 0·2 to 0·3 mg/litre. Short-term response, as measured by time to 50% mortality at the highest Cd concentration, was 10, 21 and 23 days for the bay scallop, hermit crab and grass shrimp, respectively. Scallop growth was inhibited at all exposure concentrations with a measured 42-day EC₅₀ value of 0·078 mg/litre Cd. Byssal thread detachment precedes death in bay scallops. An EC₅₀ value of 0·54 mg/litre Cd for byssal detachment was measured on day 8 of the bioassay before appreciable mortality. This compared favourably with the incipient LC₅₀ value of 0·53 mg/litre Cd. Cadmium accumulation occurred at all concentrations in bay scallop and grass shrimp.