Trace metals (Cd, Cr, Cu, Fe, Ni, Pb, and Zn) in feathers of Black-browed Albatross Thalassarche melanophrys attending the Patagonian Shelf

We investigated the concentrations of cadmium, chromium, copper, iron, nickel, lead and zinc among feather tissues in sexes of Black-browed Albatross Thalassarche melanophrys killed in longliners off Argentina in 2005. We found no different metal concentration with sex for cadmium, copper, iron, lead and zinc in feathers of adult birds, though there were significant body-size differences between sexes. However, the concentrations of trace metals differed significantly among the type of feather within individual bird. The mean concentrations of copper, iron, and zinc in breast feathers of T.?melanophrys were lower than those reported for the species from Georgias del Sur/South Georgia, the southern Indian Ocean and for other seabirds' worldwide. While cadmium fall within the known range of concentrations for bird feathers lead were not. Our results may be indicating that level of pollution in Patagonia may not be as negligible as previously thought at least for some trace metals.     

Acute toxicity of heavy metals to two species of marine nematodes

The acute toxicity of seawater solutions of copper, zinc, lead, cadmium and mercury to two species of free-living marine nematodes was studied. Enoplus brevis (Bastian) is a euryhaline species inhabitating intertidal estuarinemud. The closely related Enoplus communis (Bastian) is stenohaline and may be found as a commensal in the byssus threads of seed mussels. Specimens of both species were collected from two sites on the Northeast coast of England showing different levels of pollution by heavy metals. Both species were more susceptible to copper, lead and mercury than to zinc and cadmium, but the order of toxicity of the metals changed with exposure concentration. The euryhaline species survived better than the strictly marine species and there is a suggestion that animals from a polluted site were more tolerant of elevated of heavy metals.     

Restoration of oiled mussel beds in Prince William Sound, Alaska

Natural loss of hydrocarbons was often low from mussel (Mytilus trossulus) beds (which were typically not cleaned after the Exxon Valdez oil spill), thus this habitat remained a long-term source of oil. Consequently, experimental restoration of nine contaminated beds was attempted in 1994; mussels were removed, contaminated surface sediment was replaced (33 metric tons), and original mussels were returned. Hydrocarbon concentrations and mussel populations were monitored for 5 years thereafter. Post-restoration mussel population fluctuations were indistinguishable from regional changes. Increased short-term oil loss was apparent, but long-term (5 year) improvement was equivocal and difficult to distinguish from natural losses. By 1999, oil concentrations in mussels were typically at baseline levels in restored and oiled reference beds; concentrations in replaced sediment were elevated in one third of restored beds, indicating recontamination from underlying or surrounding sediment. Our results suggest mussel relocation is feasible but suggest oil might more effectively be removed from sediment mechanically or chemically than manually.     

Vertical concentration gradients of heavy metals in cultured mussels

Cultured mussels, Perna canaliculus (Gmelin), from two widely separated locations in New Zealand have been analysed for variation in heavy metal content with depth. The mussels, which are grown on vertically suspended ropes to a depth of 9 m, have been analysed for cadmium, lead, iron, and zinc at 1‐m intervals. At the first location (Kenepuru Sound), cadmium, lead, and iron increased with depth, while zinc decreased with depth. At the second location (Waiheke Island), concentrations of the four metals all remained essentially constant with depth. The differences in vertical concentration gradients between these two locations must result from differences in mixing of the water column. The differences in mixing may cause variations in the type of food organisms with depth, or variations in the ratio of particulate v. dissolved metal levels with depth. Either or both of these conditions could result in differences in the bioavailability of these metals with depth.     

Heavy metals in some New Zealand commercial sea fishes

To establish a base line against which future pollution may be measured, eight common commercial species of New Zealand sea fish were analysed for cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc. One sample of edible muscle tissue was analysed for each of 70 samples of each species. The internal organs of up to five specimens of each species were also analysed. The fish studied were: kahawai, Arripis trutta, trevally, Caranx lutescens, tarakihi, Cheilodactylis macropterus, snapper, Chrysophrys auratus, moki, Latridopsis ciliaris, hapuku, Polyprion oxygeneios, kingfish, Seriola grandis and gurnard, Trigla kumu.

Although, none of the edible parts of the fish appeared to have trace element levels likely to be a public health problem (cadmium 0.002–0.02 ppm, chromium 0.01–0.04 ppm, copper 0.04–0.95 ppm, iron 0.9–13.5 ppm, lead ‘ 0.14–0.95 ppm, manganese 0.04–2.00 ppm, nickel 0.01–0.08 ppm, zinc 2.0–36.0 ppm), some of the organs (particularly the liver) had relatively high concentrations of elements such as cadmium (up to 54 ppm). Only if some industry were to seek to exploit internal organs of fish for human consumption would such levels become important. There was some evidence for a relationship between trace element concentrations and fish size for copper in kingfish and snapper, iron in hapuku, manganese in gurnard, and for zinc in kingfish and tarakihi. Some element pairs such as copper and zinc, iron and manganese, appeared to have concentrations which were mutually related. It was assumed that the elemental concentrations reported represent natural levels and are not the result of significant man‐made pollution because there are no major industries or large urban centres adjacent to the fishing grounds.     

Effects of acid mine drainage from an abandoned copper mine, Britannia Mines, Howe Sound, British Columbia, Canada, on transplanted blue mussels (Mytilus edulis)

Juvenile mussels (Mytilus edulis) were transplanted to Howe Sound, British Columbia, Canada, along an apparent pollution gradient of acid mine drainage (AMD) from an abandoned copper (Cu) mine. Cages containing 75 mussels each were placed at a total of 15 stations and were exposed to concentrations of dissolved Cu in surface waters ranging from 5 to 1009 micrograms/l for a period of 41 days. Mussels located at stations closer to the source of AMD at the mouth of Britannia Creek bioaccumulated higher concentrations of Cu and zinc (Zn) in their tissues. Mussel growth was adversely affected by Cu tissue concentrations above 20 micrograms/g dry wt., while declines in survival and condition index occurred in mussels that bioaccumulated greater than 40 micrograms/g dry wt. Cu. Tissue Zn concentrations (117-192 micrograms/g dry wt.) were likely not high enough to have a direct impact on mussel health. Reduced survival of transplanted mussels was supported by an absence of natural mussels in contaminated areas. Phytoplankton was also severely reduced in areas contaminated by mine waters. Based on the weight of evidence, AMD from the Britannia mine had a deleterious impact on mussel survival in a zone extending at least 2.1 km to the north and 1.7 km to the south of Britannia Creek on the east shore of Howe Sound.     

Report on the Annual Gametogenesis and Tissue Biochemical Composition in the Gray mussel,Crenomytilus grayanus (Dunker 1853) in the Subtidal Rocky Bottom on the East Coast of Korea

Ocean Science Journal - The Gray mussel Crenomytilus grayanus occurs in high density in the shallow rocky subtidal zone on the east coast of Korea, where the mussel dominates the shallow subtidal...     

Trends in chemical concentrations in mussels and oysters collected along the US coast: update to 2003

With data from the annual analyses of mussels and oysters collected in 1986-1993 from sites located throughout the coastal United States [O'Connor, T.P., 1996. Trends in chemical concentrations in mussels and oysters collected along the US coast from 1986 to 1993. Mar. Environ. Res. 41, 183-200] showed decreasing trends, on a national scale, for chemicals whose use has been banned or has greatly decreased and that concentrations of most other chemicals were neither increasing nor decreasing. With data through 2003 those conclusions still apply. National median concentrations of synthetic organic chemicals and cadmium continue to decrease. The added data show that concentrations of lindane and high molecular weight PAHs are also decreasing on a national scale. For metals other than cadmium and zinc (in mussels), the added data reveal trends at more sites than in 1993 but no additional national trends. However, the longer time series has revealed several local and regional trends.     

Tolerance of five species of tropical marine mussels to continuous chlorination

The paper examines the relative lethal and sublethal response of five important tropical marine mussels (Perna viridis, Perna perna, Brachidontes striatulus, Brachidontes variabilis and Modiolus philippinarum) to different chlorine concentrations varying from 0.25 to 15 mg l(-1). The mussels were observed to co-exist in the cooling water circuits of a coastal power station that adopted intermittent chlorination as a fouling control technique. The five mussel species showed, in response to chlorination, 100% mortality at significantly different exposure times, indicating significant species-specific variability in chlorine tolerance. For example, at 1 mg l(-1) residual chlorine, B. variabilis and P. viridis took 288 and 816 h, respectively, to achieve 100% mortality. The time taken for 100% mortality decreased with increasing chlorine residual concentration. The effect of mussel size (= mussel age) of P. viridis, P. perna, B. striatulus and M. philippinarum on mortality was significant between 1 and 5 mg l(-1) residual chlorine, with larger mussels showing greater resistance than smaller ones. All mussel species showed progressive reduction in physiological activities when chlorine residuals were increased from 0 to 1 mg l(-1). However, species-specific differences in the relative rate of physiological activities were observed. Accordingly, relative reduction in physiological activities in response to chlorination was the lowest in P. viridis and the highest in B. variabilis. The data clearly indicate significant differences in the lethal and sublethal responses of the five mussel species to chlorination. The results, therefore, suggest that for effective fouling control, chlorine treatment against mussels has to be employed judiciously, depending on the mussel species involved.     

Interactions of cadmium with the reproductive cycle of Mytilus edulis L.

Sublethal effects of cadmium on reproduction can have detrimental consequences for the long-term survival, even of species with high LC₅₀ values. The sea mussel, Mytilus edulis, is well-known for its use in biomonitoring work due to its relatively low sensitivity towards many toxicants, including cadmium.¹ Because little is known on sublethal effects of this metal in invertebrates,^2–6 we have studied these effects, with emphasis on reproduction, by exposing mussels to 100 ppb cadmium in sea water. This concentration significantly inhibits follicle development in both male and female gonads, but has subsequently a stimulating effect on the spawning frequency. Due to these opposite effects the consequences of cadmium stress for gamete production are expected to be small, as the average number of gametes released by spawning animals was not significantly changed.     

Survival,growth and shell deformities of copper- and cadmium-exposed mussels (Mytilus edulis L.) in brackish water

Mussels, Mytilus edulis L., were exposed to elevated concentrations of copper or cadmium in the laboratory, then placed in cages in the sea (salinity 7‰). One year later maximum lengths of the mussels were measured and shells screened for deformities. Growth was 0·6 cm year^?1 in the control cages and retarded in cages of exposed mussels. A total of 63% of cadmium-exposed and 46% of copper-exposed mussels had shell deformities. In the control cages 26% were deformed while in a natural population only 3% were deformed. The proportion of deformities to growth was inversely related. Low concentrations showed their injuriousness in this long-term test, probably due to the closing of the valves during exposure to high concentrations.     

Metal pollution assessment of the marine environment by determination of metal-binding proteins in Mytilus sp.

Adult mussels (Mytilus galloprovincialis) (shell length 5–7 cm) exposed to elevated concentrations of Cd (0.1–1.3 mg l⁻¹), in a flowing seawater aquarium under laboratory conditions, responded by elevated synthesis of metal-binding proteins in a digestive gland. Response depended on the Cd concentration level as well as on duration of the exposure time. Results obtained show that inducible proteins (isolated by gel-filtration column chromatography and characterized by electrochemical and spectrophotometric methods) should be considered metallothionein-like proteins.The induced metal-binding proteins of mussels in specific organs or tissues are considered to be a potential biological indicator of metal pollution, taking into account specific qualities of the mussel response to different metals. The advantages of the analytical methods applied (gel-chromatography and polarography) and the relevance of the laboratory data when transferred to environmental conditions are discussed. Previously reported results dealing with metal-binding proteins of Mytilus species are also summarized.     

Trace metals in bivalve molluscs from Thailand

Capture fisheries and aquaculture provide a large quantity of bivalve molluscs for human consumption in Thailand each year. The existing information on trace elements in these bivalves is fragmentary and contradictory. This paper reports data for eight metals (cadmium, chromium, copper, iron, lead, nickel, mercury and zinc) in the four major species marketed. These are the clam Pahia undulata, the cockle Anadara granosa, the green mussel Perna viridis and the rock oyster Crassostrea commercialis. The bivalves analysed were taken at markets or in the field to cover as many of the major sources as possible. The results indicate no major threat to public health from trace elements in these species from Thailand and lend confidence to the expansion of aquaculture operations. In particular, the levels of lead found in the samples analysed are considerably lower than those previously reported by other authors.     

Hydrothermal faunal assemblages and habitat characterisation at the Eiffel Tower edifice (Lucky Strike,Mid‐Atlantic Ridge)

The Eiffel Tower edifice is situated in the Lucky Strike hydrothermal vent field at a mean depth of 1690 m on the Mid‐Atlantic Ridge (MAR). At this 11‐m‐high hydrothermal structure, different faunal assemblages, varying in visibly dominant species (mussels and shrimp), in mussel size and in density of mussel coverage, were sampled biologically and chemically. Temperature and sulphide (∑S) were measured on the different types of mussel‐based assemblages and on a shrimp‐dominated assemblage. Temperature was used as a proxy for calculating total concentrations of CH₄. Based on the physico‐chemical measurements, two microhabitats were identified, corresponding to (i) a more variable habitat featuring the greatest fluctuations in environmental variables and (ii) a second, more stable, habitat. The highest temperature variability and the highest maximum recorded temperatures were found in the assemblages visibly inhabited by alvinocaridid shrimp and dense mussel beds of large Bathymodiolus azoricus, whereas the less variable habitats were inhabited by smaller‐sized mussels with increasing bare surface in between. Larger mussels appeared to consume more ∑S compared with smaller‐sized (<1 cm) individuals and thus had a greater influence on the local chemistry. In addition, the mussel size was shown to be significantly positively correlated to temperature and negatively to the richness of the associated macrofauna. The presence of microbial mats was not linked to specific environmental conditions, but had a negative effect on the presence and abundance of macro‐fauna, notably gastropods. Whereas some taxa or species are found in only one of the two microhabitats, others, such as polychaetes and Mirocaris shrimp, cross the different microhabitats. Temperature was proposed to be a more limiting factor in species distribution than ∑S.     

Teneurs en benzo 3,4 pyrène chez Mytilus edulis L. de l'estuaire et du golfe du Saint-Laurent

Blue mussels (Mytilus edulis L.) taken from 27 stations along the estuary and gulf of St. Lawrence were analyzed for their content in 3,4-benzopyrene. Most of the concentrations are below the detection limit for the analytical method, i.e. 0·15 μg kg^?1 (dry weight) and probably reflect the natural baseline level. However, mussels from two stations located at the mouth of Saguenay Fjord exhibit very high contents: 24 and 28·5μg kg^?1 (dry weight). A mussel transplantation experiment has shown that the entire Fjord is contaminated by anthropogenic 3,4-benzopyrene.     

Mussel colonization of a high flow artificial benthic habitat: byssogenesis holds the key

Water flow is an important characteristic determining the settlement and growth of macro-invertebrates in the marine environment. Intake systems of coastal power stations offer a unique opportunity to study the effect of water flow on benthic organisms under field conditions. The cooling water intake system of a tropical coastal power station is used as an experimental facility to study the effect of flow on the recruitment and growth of three mussel species, viz, Brachidontes variabilis, B. striatulus, and Modiolus philippinarum. The study was prompted by earlier observation that these mussels were numerically abundant in the biofouling community present inside the seawater intake tunnel of the power station, even though their occurrence in the benthic community in the coastal waters outside was only nominal. Recruitment data showed that the three mussel species very successfully colonised surfaces exposed to the intake mouth (characterised by relatively high flow) of the power station. Significant difference was observed in the recruitment recorded at the intake point and the ambient environment outside. Under high flow condition, the growth rates of all the three mussel species were uniformly enhanced. It is argued that recruitment of the different species is related to the number of byssus threads produced by each mussel and the strength of the byssus threads. The results indicate that byssus number and byssus strength of the mussels are important criteria that decide successful colonization and establishment in high flow environments.     

Metal concentrations in the shell of Bathymodiolus azoricus from contrasting hydrothermal vent fields on the Mid-Atlantic Ridge

Specimens of Bathymodiolus azoricus were sampled along the Mid-Atlantic Ridge at the Menez Gwen, Lucky Strike and Rainbow hydrothermal fields. Individual shells (n = 51), through the weight range 0.62 to 15.70 g, were analyzed for their magnesium, strontium, iron, manganese, copper, zinc and cadmium concentrations. Amongst the marine molluscs the shell of B. azoricus is confirmed as being particularly impoverished in strontium (mean 943 microg g(-1)). Trace metal concentrations in the shells decreased in the order Fe> Mn> Zn> Cu> Cd. Despite originating from trace metal rich environments mean concentrations were low (37.9, 13.2, 10.7, 1.1 and 0.7 microg g(-1), respectively). Irrespective of geographical origin magnesium, strontium and copper concentrations were primarily dictated by shell weight. In contrast cadmium concentrations were elevated in shells from the Rainbow field and ambient seawater chemistry imparted site specific chemical fingerprints to the shells with respect to the iron to manganese ratio.     

Upper temperature tolerances of exotic brackish-water mussel, Mytilopsis leucophaeata (Conrad): an experimental study

The dark false mussel, Mytilopsis leucophaeata is an important mussel colonising the brackish-water systems of temperate and subtropical regions. Of late it has earned notoriety as a biofouling species in industrial cooling water systems. However, there are no published data on the temperature tolerance of this species. This paper presents data on the upper temperature tolerance of this mussel from the view point of biofouling control using thermal methods. In addition to mortality, response of physiological activities such as oxygen consumption, filtration rate, foot activity and byssus thread production were also studied at temperatures varying from 5 to 35 degrees C. Experiments were also carried out to understand the effect of mussel size, breeding condition, nutritional status and acclimation conditions (temperature and salinity) on the mortality pattern. The physiological activities were significantly reduced at temperatures beyond 27.5 degrees C and ceased at 35 degrees C. In 20 mm size group mussels exposed to 37 degrees C, 50% mortality was observed after 85 min and 100% mortality after 113 min. The effect of mussel size on mortality at different temperatures was significant, with the larger size group mussels showing greater resistance. M. leucophaeata collected during the non-breeding season (December-April) were more tolerant to temperature than those collected during the breeding season (June-October). Nutritional status of the mussel had no significant influence on the thermal tolerance of the mussel: fed and starved (non-fed) mussels succumbed to temperature at comparable rates. The effect of acclimation temperature and acclimation salinity on M. leucophaeata mortality at different temperatures was significant. Survival time increased with increasing acclimation temperature and decreased with increasing salinity. In comparison with other co-occurring species such as Mytilus edulis and Dreissena polymorpha, M. leucophaeata appears to be more tolerant to high temperature stress.     

Trace metal concentrations in brown seaweeds, Cardigan Bay, Wales

Concentrations of zinc, cadmium, copper, manganese, iron, cobalt, nickel and molybdenum are examined in brown algae, Fucus serratus and F. vesiculosus, from Cardigan Bay, Irish Sea, Great Britain. In both species a seasonal variation in metal content was observed. Zinc, cadmium, copper, iron nickel and cobalt concentrations were highest in the spring and lowest in the autumn, probably reflecting levels of metabolic activity and climatic factors. All the studied elements, except nickel, reached highest concentrations in harbour specimens from Aberystwyth and Aberaeron where rivers draining mineralized areas enter the sea. Outside harbours, marked regional variations were observed in most of the studied elements. Zinc values were highest in the Aberystwyth area while copper and manganese were highest in the northeast part of the bay.Trace-element concentrations varied among different species from the same locality and also varied according to position on the shore.Marine algae may be used to monitor coastal-water trace-metal concentrations, provided a careful sampling procedure is adopted.     

THE EFFECT OF CADMIUM ON THE ACTIVITY OF ALKALINE PHOSPHATASE IN MUSSEL VIRIDIS

The paper preliminarily discusses the effects of cadmium pollution on the alkaline phosphatase of mussel, mytilue viridid. The results show the cadmium pollution has a inhibition on the alkaline phosphatase, and the degree of inhibition rises with the increases of concerntration if cadmium in seawater. When the concentration is within the range of 1-500 ppb, the percentage of inhibited emzyme has a linear relationship with the logarithm of cadmium concentration. The results also prove that the salinity may increase the effects of cadmium on emzyme. The inhibition which may be indirect or secondary effects is reversible.Mussels play a purification role in the waste water containing cadmium, the purification rate of which may as high as 125 mg Cd2 gram (mussel)/day. This is a prospective method in purification and removing of cadmium.The study of effects of cadmium pollution on the alkaline phosphatase of mussel shows that in the study of effects of pollutants on aquatic organisms, biochemical index may