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The potential of periphyton-based aquaculture in South Asia is under investigation in an extensive research program. This paper is a further analysis of data from four experiments carried out in that framework, to explore periphyton, fish and fertilizer dose effects on water quality. Factor analysis and ANOVA models applied to a data matrix of water quality parameters in ponds with and without artificial substrates (bamboo poles and kanchi sticks), with and without fish (filter feeders catla and rohu, with and without bottom feeder kalbaush), and with a standard or 50% increased fertilizer dose, allowed us to identify the underlying ecological processes governing this novel periphyton-based pond system, and construct conceptual graphic models of the periphyton-environment relationships observed. We clearly established that the phosphorus flow is mainly linked to phytoplankton activity in the water column and decomposition on the pond bottom, while nitrogen flow is mainly linked to autotrophic (photosynthesis) and heterotrophic (decomposition and nitrification) processes that take place in the periphyton in addition to the water column and pond bottom. Consequently, disruption of the pond bottom by bottom feeding fish primarily promoted phosphate cycling and phytoplankton, while periphyton development on the supplied substrates and fertilization mainly improved oxygen balance and nitrogen related processes developing in the water column. The use of bamboo poles led to better results than kanchi sticks, related to the greater autotrophic periphyton development on bamboo and to the larger surface of bamboo poles that facilitate fish grazing and periphyton dislodgment that in turn have a renewal effect on periphyton. Stocking bottom feeding fish produces a fertilizing effect through the food web that benefits the filter-feeding fish and that makes it unnecessary to increase the dose of inorganic and organic fertilizers applied to the ponds. Thus, the output of this analysis will help the fish farmers in resource constrained countries to improve their production in periphyton-based ponds just by choosing bamboo substrates, stocking a bottom feeder fish together with the filter feeders, and saving money on fertilizers.

During 2006 and 2008 two bottom trawl surveys were conducted at East Greenland to 72°N covering depths down to 1500 m. In the 149 trawl hauls in total 113 fish species were recorded of which 37 were considered pelagic and excluded from the analyses. As a first step the abundance data for the 76 benthic species were used for analyses of the fish fauna diversity and fish assemblages. Nine assemblages were found by a standard type of cluster analysis. A Bayesian multinomial logit model was then applied to calculate vectors of probabilities defining the likelihood of each haul belonging to each of the nine clusters. By means of a geostatistical tool the spatial distribution of the conditional probabilities for each cluster (assemblage) was mapped. Each of the nine assemblages was further defined by indicator species, depth and temperature. The assemblages were well defined regarding geographical distribution, species composition, temperature and depth. Three of the assemblages were located in the cold Iceland Sea while six were found in the somewhat warmer Irminger Sea

A polyculture experiment with the large carp rohu, catla and either mrigal or common carp (as cash crop fish), and the small indigenous fish punti (as food for the farmer's family) was carried out at Bangladesh Agricultural University, Mymensingh. The main objectives were to compare polycultures of large carp in which the bottom feeder is either the native mrigal or the exotic common carp, and to assess the effects of adding the small indigenous species punti to those polycultures. The results of fish–fish interactions and overall fish production have already been reported. The present paper presents the effects on the water quality, and discusses fish–environment interactions. The main conclusions are: time changes in the pond environment were stronger than fish composition effects. The main practice affecting water quality was liming, that incresed alkalinity, pH and water transparency and decreased ammonia. Rain affected photosynthesis and the match-mismatch of the two steps of nitrification. The more that bottom feeding fish species disrupt the mud bottom, the stronger their effects on pond environment. Common carp produce the strongest disruption of the mud bottom, followed by punti and then by mrigal. Mud disruption produced by common carp leads to a stronger liming effect, nutrient release into the water, and provides more particles that rain-floods wash out, facilitating the mismatch of the two steps of nitrification, and increased phosphorus adsorption into the mud bottom. Mud disruption by punti is only enough to improve the liming effect. Mud disruption by mrigal is the least, hence less particles are resuspended, nitrification is not affected during floods and relatively more phosphate remains in the water available for photosynthesis. The bottom feeder common carp can be seen not only as a target-cultured fish but also as a management tool. Farmers can get double benefit in introducing common carp in the ponds as it enhances the effectiveness of lime application and increases the availability of nutrients to phytoplankton. Through the manipulation of species in the polyculture alone, farmers can maintain the environment better and also reduce input costs.

The aim of this work was to provide information on the role of acid phosphatase (Acp) and alkaline phosphatase (Alp) activities as spoilage indicators of raw fish. Horse mackerel Trachurus japonicus , a red-flesh fish, and gurnard Lepidotriga microptera , a white-flesh bottom fish, were stored at 4 °C. The aerobic bacteria count (APC) of horse mackerel skin increased from 10 3 to 10 7 CFU/cm 2 in seven days, the Alp activity increased about from 10 to 150 nmol p -nitrophenol/min/g tissue with increase of volatile basic nitrogen (VBN), an index of fish spoilage. The APC of gurnard skin also reached 10 7 CFU/cm 2 after 8 days’ storage. The Alp activity was twice that of the Acp activity in the fresh gurnard and the activity decreased slightly during the initial 4 days and increased from four days’ storage.

Studies on the fishways of Nagaragawa Estuary Barrage and migratory fish species that passed the barrage were conducted when the estuary barrage project was planned, before and during the construction of the barrage, and before the barrage went into operation. After the barrage went into operation, its monitoring began, and it is still being carried on. The investigations and studies conducted at the planning stage and before the commencement of barrage construction yielded information on the habitats and helped the development of seed production techniques of ayu (sweetfish) and satsukimasu salmon, which were likely to be affected by barrage operation. Through subsequent studies conducted during the construction of the barrage, knowledge was gained about the habitat of migratory bottom fish species, and the type of fishway structure to be adopted was determined according to the study results. Before the gates went into operation, findings from the studies and deliberations conducted thus far were verified through test operations. In the monitoring of the estuary barrage after it went into service, the migratory habits of fish species likely to be affected by barrage operation were studied, and effectiveness of the fishways was confirmed.

Seasonal dynamics of macrobenthos were studied at five stations located at depths of 10–60 min in the Far East State Marine Reserve (southern Peter the Great Bay) during 1984–1987. Sampling was conducted at stations once per season. Stable seasonal fluctuations of the population density and the biomass in basic taxonomic groups were found. As a rule, the quantitative parameters were augmented in spring and summer, and decreased in fall and winter. This was caused, first of all, by summer fluctuations of the number of small and short-lived species of polychaetes and bivalve molluscs. The amplitude of fluctuations decreased with increasing depth. Variation in the quantitative parameters was significant at the community level only at the most shallow-water stations. It was assumed that this phenomenon might be caused by the seasonal consumption of macrobenthos by bottom fish and by the periodicity of detritus supply to the bottom from the water column with a background of varying environmental temperature parameters and of mass settling of benthic larvae. The seasonal changes in parameters began and ceased earlier in 1986–1987 than 1984–1985, which was related to an appreciable decrease in water temperature in 1986. During the period of study, an increasing trend of parameters, apparently part of a long-term cycle, was recorded both for individual groups and for entire communities, and was the most appreciable at greater depths (47–60 m).

A survey series was started in 1987 to monitor changes in North Sea fish assemblages and to investigate the meso-scale natural variability in catch rates of individual species. The survey began in four areas (boxes) of 10×10 nm, but has been extended to 10 boxes. The boxes are distributed throughout the North Sea.

Fish were sampled with beach seines and small-meshed beam trawls in nearshore (

From bibliographical information on bathymetric and latitudinal distribution of 110 marine fish species of western Patagonia (42º-57ºS), the ichthyogeographic zonation of the area is discussed. The bathymetric distribution of the fish species shows a species association distributed at depths less than 100 m, a second association between 50 and 500 m, and a third association below 500 m depth. This third one is interpreted as a transitional situation of the second one, because of the scarcity of endemic species. These associations present similar latitudinal zonation patterns, including separation into a northern sector, characterized by species of lower latitudes, a southern sector with characteristic and endemic elements of that zone, and an intermediate transition sector considered as an independent association by its large extension and species composition. The Straits of Magellan represent an important faunistic exchange zone between the bottom fish communities of the Southwestern Atlantic and the Southeastern Pacific. A partir de la información, principalmente bibliográfica, sobre distribución batimétrica y latitudinal de 110 especies de peces marinos de la Patagonia occidental (42º-57ºS), se presenta un esquema de zonación ictiogeográfica para el área. La distribución batimétrica de las especies muestra la existencia de una asociación de peces distribuida entre 0 y 50 m de profundidad, una segunda asociación entre 50 y 500 m de profundidad y una tercera asociación a más de 500 m de profundidad. Esta tercera asociación es interpretada como situación de transición de la segunda asociación, a causa de la escasez de especies endémicas. Estas asociaciones presentan un patrón similar de distribución latitudinal, que incluye un sector norte, caracterizado por elementos de latitudes menores, un sector sur, con elementos característicos del área y un sector intermedio de transición considerado como una unidad independiente por su extensión y composición íctica, confirmando los resultados de revisiones biogeográficas anteriores. El Estrecho de Magallanes destaca como sector de intercambio faunístico entre el Atlántico suroccidental y el Pacífico suroriental.

Neoplasm epizootics in fish from a wide variety of freshwater, marine, and estuarine locations have been associated with genotoxins in sediment or water. The majority of cases have involved benthic or bottom feeding fish living in habitats with sediment contaminated by PAHs. The most common lesions involved in such epizootics include liver neoplasms, both biliary and hepatic, and skin neoplasms. Laboratory research has demonstrated the ability of fish to metabolize carcinogenic PAHs such as B(a)P into the ultimate carcinogen with the resulting formation of DNA adducts. Fish dosed with B(a)P or sediment extracts containing carcinogenic PAHs have developed skin and liver neoplasms. In the Black River, OH, neoplasm prevalence in wild brown bullhead has reflected PAH exposure as the latter has changed due to coke plant closures and remedial dredging activity. The weight of evidence supports a cause-and-effect relationship between exposure to genotoxins in sediment and water and neoplasm epizootics in wild fish populations.

The mean trophic level of the species groups reported in Food and Agricultural Organization global fisheries statistics declined from 1950 to 1994. This reflects a gradual transition in landings from long-lived, high trophic level, piscivorous bottom fish toward short-lived, low trophic level invertebrates and planktivorous pelagic fish. This effect, also found to be occurring in inland fisheries, is most pronounced in the Northern Hemisphere. Fishing down food webs (that is, at lower trophic levels) leads at first to increasing catches, then to a phase transition associated with stagnating or declining catches. These results indicate that present exploitation patterns are unsustainable.

A quantitative echo sounder (QES) was used to measure the bottom surface backscattering strength (SS) extensively off Southern Jawa Island, Indonesia. The average SS by the bottom echo integration method were plotted as a map with the depth contour to give a synoptic view of the topography. On the other hand, the results from the ring surface scattering (RSS) model gave us more detailed SS values in ping base. A simultaneous display of the fish volume backscattering strength and the bottom SS was useful to observe bottom fish habitats remotely. The bottom material estimated by the measured SS showed that the fish schools were abundant in the sand bottom in this area.

Studies have shown that some cyclic methyl siloxanes were identified as characterized of persistent, bioaccumulated, toxic, and potential to ecological harm. In this study, we determined methyl siloxanes in seawater, sediment and bottom fish samples collected from marine environment in Northeast China. The mean concentrations of total methyl siloxanes were 46.1 ± 27.2 ng/L, 12.4 ± 5.39 ng/g dry weight (dw) and 5.10 ± 1.34 wet weight (ww) in seawater, sediment and fish, respectively. Very strong and significant correlations (r = 0.94, p

Experiments were conducted to examine the dynamics of the sediment-associated polychlorinated biphenyl (PCB) using a benthic-based trophic transfer model (sediments to benthic copepods to juvenile fish). Field-collected benthic copepods were exposed to sublethal levels of PCB in sediments for 96 h. Accumulation of PCB was measured in the copepods, and these contaminated copepods were fed to the juvenile fish predator Leiostomus xanthurus in uncontaminated sediments. After gut clearance, whole fish were homogenized and examined for PCB accumulation. Similar experiments with L. xanthurus in which meals of uncontaminated copepods were fed in PCB-contaminated sediments were conducted to determine the relative roles of contaminated sediments and contaminated copepod prey ingestion to PCB transfer. Total PCB transfer as well as PCB congener group contributions were examined. A total of 30 congeners were grouped according to log K{sub ow} increments and according to chlorine homologue groups. Copepods exposed to PCB-contaminated sediments to 90 {micro}g/g accumulated PCBs to 326 {micro}g/g dry weight. Accumulation of PCB in fish feeding in contaminated sediments was five times higher than that in fish feeding on contaminated prey in uncontaminated sediments (p = 0.0498). In terms of congener patterns, log K{sub ow} grouping provided clearer discrimination between groups. Congener patternsmore » were similar in PCB stock solution, sediments, and copepods and were different in the two fish treatments. K{sub ow} group relative accumulation patterns in fish were mixed. The chlorine homologue groups revealed that the fish preferentially accumulated the tetrachlorinated congeners relative to copepods and sediments.« less

Periphytic bacteria found on the carapace and gills of crabs collected from near a tannery effluent outlet were shown to be able to concentrate chromium. By concentrating Cr, the bacteria contributed to the total Cr concentration of the crabs. Since crabs and other crustaceans are eaten by bottom feeding fish, bacteria may be contributing to the passage of Cr up the food chain.

Submersible data from two areas along the Carolina-Virginia continental slope reveal a Hatteras upper middle slope (HMS) (35.30’N, 74.50’W) demersal fish fauna remarkable for diminutive size of individuals within and across species, a fauna which is accordingly termed ‘Lilliputian’. Contrast of HMS submersible data with Virginia trawl and submersible data support this finding. The four top-ranking HMS fishes, Lycenchelys verrillii, Glyptocephalus cynoglossus, Myxine glutinosa and Nezumia bairdii, are all significantly smaller than on the Virginia upper middle slope. Also peculiar to the HMS is the dominance of sedentary benthic species, rarity of active benthopelagic foragers, and markedly elevated fish population density. Species composition of the HMS fauna differs from that of the general Middle Atlantic Bight fauna; notably absent are species of otherwise continuous distribution along the U.S. East Coast (e.g. Synaphobranchus affinis, Nezumia aequalis). Since HMS megafaunal and macrofaunal invertebrate communities are also anomalous, the Lilliputian phenomenon among HMS bottom fishes provides a characteristic biotic signature of a pervasively re-structured benthic boundary layer community. The authors hypothesize that the HMS faunal anomaly reflects a limiting factor, episodic sediment surface hypoxia, peculiar to this region of high particulate organic carbon flux from surface waters. Results indicate that substantial changes in fish faunal composition and structure can occur on a small geographic scale on the open soft-Substrate continental slope.

There were many studies that reported the concentrations of trace elements in fish and assessed the human health risk through consumption of contaminated fish. However, fish species with different feeding habits may accumulate toxic elements differentially in their muscle. In this study, we conducted a field survey to analyze concentrations of ten trace elements in water, sediment, artificial feed, and different part of muscles either with or without skin of two species of fish, tilapia and milkfish. The results of this study showed that the ventral and dorsal muscles with skin contained higher concentrations of metals than those without skin for both species of fish. Tilapia lives in the bottom layer, the ventral part therefore contacts closely with sediment. A higher metal concentration in ventral muscle was obtained in this study when compared to dorsal muscle for tilapia. The estimated Metal Pollution Index (MPI) of tilapia is higher than that of milkfish. Our results indicated that metal concentrations in muscle of tilapia are mainly originated from sediment. However, sources of metal concentrations in muscle of milkfish can be from sediment and artificial feed.

In September, 1973 the expedition of the Odessa Branch of Institute of Biology of the Southern Seas (OdO INBYUM) has found for the first time mass kill of benthic organisms between mouths of the Kiliya arm of the Danube and Dniester estuary on the area of 3,500 km2 with depths from 10 to 20 m (Salsky 1977). The number of dead hydrobionts during this period reached 500 thousand tons. Thus, in the Zhebriyansk bay adjoining the Danube, near the coast there was a large concentration of half dead passive bottom fish. Since then the similar events which were named “suffocation”, during the summer—autumn period (from June to September) after offshore storms (under northerlies) are repeated from 4 to 10 times, being accompanied with “outbursts” of waters with unusual claybank color and hydrogen sulfide smell to the surface in the coastal zone (Fashchuk 1981). Near-bottom water, fishing gears, devices and ground lifted in the same time from the sea bottom on the open shelf sites at large distance from the coast have the similar smell

Interactive effects of three alternating normoxia-hypoxia cycles on benthic prey exploitation by mobile fish (spot, Leiostomus xanthurus; and hogchoker, Trinectes maculatus) and a burrowing crustacean (Squilla empusa) were investigated in the York River, Chesapeake Bay, Virginia, USA, in 1989. Predators collected in four depth strata (A: 5 to 10 m; B: 10 to 14 m; C: 14 to 20 m; D:>20 m) variously affected by hypoxia were separated into size classes (three for spot and two each for hogchoker and mantis shrimp) to examine potential ontogenetic influences in prey selection. The most severe effects of hypoxia on the benthos occurred in the two deepest strata (C and D) and decreased in shallower strata (B>A), with Stratum A never affected by low oxygen. Predators investigated exhibited dietary evidence of optimal prey exploitation during or immediately after hypoxic events. In most instances gut contents contained significantly larger, deeper-burrowing prey during periods of low oxygen than during alternating peroids of normal oxygen levels. Spot consumed a greater biomass (45 to 73%) of polychaetes than other prey, with crustaceans initially also constituting a main dietary component but decreasing in importance later in the study period. The deep-burrowing anemone, Edwardsia elegans, was an important prey species for spot, particularly in the lower depth strata affected by hypoxia. Prey consumed by 10-to 15-cm-long spot increased significantly in size during some hypoxic events, suggesting a sublethal effect of hypoxia on large benthic species. Polychaetes (primarily Glycera americana, Notomastis latericeus and Loimia medusa) were dominant dietary components in hogchoker, making up between 85 and 98% of the diet. Bivalve siphons became important prey for hogchoker in the three deepest strata and were only consumed after the August hypoxia. Stomach contents of mantis shrimp were difficult to identify in most instances due to the near complete mastication of consumed prey. Crustaceans were important prey initially but became less conspicuous in the diet subsequent to the July hypoxia event, when hydroids became more dominant. Overall, predator species exhibited optimal exploitation of moribund or slowly recovering benthos affected by hypoxia. The sublethal effects of hypoxia through increased availability of benthos to resident predators can have important consequences for energy flow in areas such as the York River which experience periodic low-oxygen cycles.

This paper describes the pollution status of North Sea sediments, and is based on results of sediment testing conducted during the Bremerhaven Workshop designed to test various methods (chemical and biological) for assessing the status of North Sea waters, sediments and biota. Testing comprised 2 transects, one down current from an abandoned drilling site, and the other across the German Bight from the mouth of the Elbe northwest. Sediment methods focused on tox~clty testing, chemical analyses, and measures of in sltu benthic community structure Together these 3 methods comprise the Sediment Quality Triad. Using the Triad In a burden-of-evidence approach, ~t was determined that sediments nearest the Elbe are moderately polluted (pollution is defined as contamination. toxicity and benthic community alteration), and that sediments offshore and at Dogger Bank are unpolluted. Sediments nearest the drilllng site show evidence of relatively low level toxicity and benthic community alteration. Limited chemical measurements did not indicate contamination. Observed laboratory toxicity and alterations in benthic infauna community structure may be due to unmeasured toxic chemicals. Anticipated effects due to drilling were not observed and appear to have been amellorated by natural deposition of clean sediment. North Sea sediments away from point sources of pollution (e.g. coastal areas, drilling platforms) are expected to be unpolluted. Lesions in bottom fish in such offshore areas (e.g, the Dogger Bank) cannot be attributed to sediment pollution in these areas, but if they are truly indicative of anthropogenic pollution, could be due to other factorjs) such as exposure of plankton~c larvae to sea surface microlayer chemical contamination and toxicity. Integrative assessments such as the Triad are essential for adequately assessing the status of European marine ecosystems. Although relatively expensive, such complete studies determine and prioritise problem areas such that managers, regulators and the public have access to the best possible information for decisionmaking and resource allocation.

Underwater acoustic instrument was used to quantify the fish backscattering strength (SV) and bottom scattering (SS). The measured SS by the bottom echo integration method are compared with the result from the ring surface scattering (RSS) model to confirm the reliability of the measurements and theory. The bottom material estimated by the quantified SS show that the fish schools are abundant in the sand bottom. It is found the acoustic instrument can identify fish, plankton and bottom fish habitats remotely.

Publisher Summary Shepherd's beaked whale is the only beaked whale to have a full set of functional teeth. It has between 17 and 21 upper teeth on each side and between 18 and 28 lower teeth. It was initially thought to be a primitive member of the beaked whale family (Ziphiidae) on the basis of retention of teeth. There has not been a good study of the evolutionary relationships of the beaked whales, but Tasmacetus seems in ways other than the teeth to be just as specialized as the remainder of the family. There are six published sightings attributed to this species, one from New Zealand, one from the Seychelles Islands, one from the South Sandwich Islands, two from Tristan da Cunha, and one from south of Tasmania. It is limited to temperate waters and may not ordinarily come as far north as the tip of Africa. This species presumably feeds primarily on squid and fish. One adult female that stranded in Argentina had traces of bottom fish, squid, and one small crab. Shepherd's beaked whale has not been known to be involved in any fisheries and certainly has not been kept in captivity. It was first known to science by a publication on a stranded adult female, which Shepherd found and collected in 1933.

An ecological system dynamics model is developed for the prediction of the seabed change after the placement of a sand layer over the contaminated seabed. The model simulates the cycling of materials among seawater, seabed sediments, and marine natures such as benthos, bottom fish and oyster in the coastal seas. Special attention is paid to the modelling of the interaction between the aquatic system and the sedimentary one, such as settling and the release of nutrient salts. The computation domain is divided into ten boxes with eleven layers in the water zone and seven layers in the sediment zone. The degree of seabed improvement is evaluated with the decrease of benthonic mortality and the decrease of dissolved oxygen consumption in the bottom layer. A field experiment of seabed capping was carried out in Kure Bay, Japan. The model predicted quite well the seasonal variations of the dissolved oxygen, zooplankton, and benthos, which were observed in the field. The model developed here enables to evaluate ...

The Bahia Paraiso spilled an estimated 600,000 liters of refined product (diesel fuel arctic, DFA) into Arthur Harbor, Antarctica, in January 1989. Water, organisms, and sediments within a two-mile radius of the wreck were contaminated to various degrees for at least one year after the spill. The DFA contained about one percent toxic aromatic hydrocarbons, including naphthalenes, fluorenes, and phenanthrenes. Intertidal areas were most directly affected, but all components of the harbor ecosystem were contaminated during the first few weeks of the spill. DFA was detected in tissues from birds, limpets, macroalgae, clams, and bottom feeding fish as well as water and sediments collected over a six-week period. During the most intense phase of the spill, total polynuclear aromatic hydrocarbons reached levels as high as 125,147 and 1,723 ppb (dry weight) in limpet tissues and sediments, respectively. The high-energy environment, the relatively small volume of material released, and the volatility of the refined product helped to limit toxic effects over time and space. Most of the spilled material evaporated, and the rest was diluted and swept from the area by winds and currents. Sedimentation, biological uptake, microbial oxidation, and photo-oxidation accounted for removal of only a minor portion of the spill.

Over the past 25 years, there have been an increasing number of fish tumor epizootics recognized in discrete geographical areas in North America. This is consistent with an association between tumor development in fish and exposure to waterborne contaminants as a result of increased industrialization. Reports of fish tumor epizootics from the literature, plus acquisitions at the Registry of Tumors in Lower Animals, Smithsonian Institution originate from 41 geographical regions in North America. Epizootics of hemic, neural, connective tissue, and gonial neoplasms seem unrelated to environmental pollution, but epizootics of hepatic and epidermal neoplasms appear to be caused or strongly influenced by environmental pollution. The 14 species with epizootic liver tumors are all bottom feeding fish, and tumor-bearing fish are generally located in areas where chemical contaminants are concentrated. Epidermal neoplasms are also found in fish near polluted areas, but a direct cause-and-effect link with chemical carcinogens is not clear.

Concern has existed for years that the Los Alamos National Laboratory (LANL), a complex of nuclear weapons research and support facilities, has released polychlorinated biphenyls (PCBs) to the environment that may have reached adjacent bodies of water through canyons that connect them. In 1997, we began measuring PCBs in fish in the Rio Grande upstream and downstream of ephemeral streams that cross LANL and later began sampling fish in Abiquiu and Cochiti reservoirs, which are situated on the Rio Chama and Rio Grande upstream and downstream of LANL, respectively. In 2005, six species of fish from Abiquiu and Cochiti reservoirs were collected and the edible portion (fillets) was analyzed for 209 possible PCB congeners. Fish from the reservoirs were last sampled in 2001. Mean total PCB concentrations in fish from Abiquiu Reservoir ({mu} = 2.4 ng/g) were statistically similar ({alpha} = 0.01; P (T{le}t) [range = 0.23-0.71]) to mean total PCB concentrations in fish from Cochiti Reservoir ({mu} = 2.7 ng/g), implying that LANL is not the source of PCBs in fish in Cochiti Reservoir. The levels of PCBs in fish from Cochiti Reservoir generally appear to be declining, at least since 2001, which is when PCB levels might havemore » peaked resulting from storm water runoff after the Cerro Grande Fire. Although a PCB ''fingerprinting'' method can be used to relate PCB ''signatures'' in one area to signatures in another area, this method of implicating the source of PCBs cannot be effectively used for biota because they alter the PCB signature through metabolic processes. Regardless of the source of the PCBs, certain species of fish (catfish and carpsuckers) at both Abiquiu and Cochiti reservoirs continue to harbor levels of PCBs that could be harmful to human health if they are consistently eaten over a long period of time. Bottom-feeding fish (carpsucker and catfish) from Cochiti Reservoir contained statistically higher levels of total PCBs ({mu} = 4.25 ng/g-fillet-wet) than predator fish (walleye, northern pike, bass) ({mu} = 1.67 ng/g) and the bottom-feeding fish had levels of PCBs that fall into a restricted consumption category in U.S. Environmental Protection Agency (EPA) charts. Similarly, bottom-feeding fish from Abiquiu Reservoir also contained statistically higher levels of total PCBs ({mu} = 4.25 ng/g-wet) than predator fish (walleye, bass) ({mu} = 0.68 ng/g-wet) and only the bottom-feeding fish had levels of PCBs that fall into a restricted consumption category in the EPA charts.« less

Publisher Summary This chapter discusses the scallops in Venezuela. The Venezuelan coast, in the southwestern Caribbean Sea, is a tropical region that supports a high diversity of bivalve molluscs. Most of these scallops are small and only Nodipecten nodosus and Euvola ziczac are exploited by coastal populations for local consumption, and a drag fishery exploits Amusium papiraceum, Amusium Laurenti, and Argopecten nucleus. Euvola ziczac forms small beds on sandy bottoms in areas of upwelling. It is a functional hermaphrodite and is unusual among tropical bivalves because of its markedly seasonal reproduction. Populations of N. nodosus along the northeast coast of Venezuela show even lower generic variability than E. ziczac, as the frequency of polymorphic loci is 1.92% and mean heterozygosity is 0.0016. A. papyraceum forms the major scallop beds in Venezuela and is fished commercially. It is part of a multi-species bottom trawl fishery, which targets shrimps, bottom fish, and molluscs. The large size of the adductor muscle of Euvola ziczac and Nodipecten nodosus suggests that they should be good species for aquaculture and a number of studies have evaluated their growth and survival in suspended and bottom culture.

The ecosystem of the benthos, which is situated on the continental shelf, slope and abyssal plains, consists of bottom sediments, zoobenthos, bottom fish fauna, bot­tom waters and porewater in sediments. The process of accumulation of sus­pended and dissolved radionuclides on the shelf, continental slope and further on the Ocean bottom is determined by a number of natural factors. The dependence of radioactive pollution of the sea bottom ecosystem on the flux of pollutants from the coastal and pelagic zones is quite evident. The northern seas with shelf depths to 300–600 m are a large reservoir to which radioactive material of different origin is delivered by numerous pathways.

Experiments were conducted to examine the dynamics of a sediment-associated pesticide azinphosmethyl (APM) using a sublethal benthic based trophic transfer model (meiobenthic copepods to juvenile fish). Two predominant pathways for contaminant transfer during feeding, prey ingestion and sediment ingestion, were examined to determine their relative contributions to APM transfer and subsequent effects on fish brain AChE inhibition. Experiments were conducted in 1993 and in 1994. Field collected benthic copepods were exposed to 14-C labeled APM, a potent acetylcholinesterase (AChE) inhibitor, in sediments for 96 h. APM burdens were measured in the copepods, and these contaminated copepods were fed to the juvenile fish predator Leiostomus xanthurus in uncomtaminated sediments. After gut clearance, fish were examined for brain AChE activity and APM residues in the liver, heart, gut, muscle, gill, and remains. Similar experiments were conducted in which meals of uncontaminated copepods were fed to spot in APM contaminated sediments, to determine the relative contribution of contaminated sediments to APM transfer. Copepods exposed to APM at a mean sediment concentration of 1223 ng/g dry weight accumulated APM at the level of 2.5mgr;g/g dry tissue. Brain AChE activity was significantly depressed (23%) in the 1993 fish fed one meal of contaminated copepods, however there was no significant decline in AChE activity in the fish tested during 1994. APM accumulation in fish feeding in contaminated sediments was generally greater than in fish feeding on contaminated prey. Significant accumulation was found in bodily remains, gills, gut, and muscle in fish that fed in contaminated sediments. No significant APM accumulation was found in fish fed the contaminated copepods.

Nektons refer to the aquatic organisms that have fully developed mobile organs and a strong ability to swim. They can overcome water current resistance and migrate a long distance and are virtually not affected by water current movement. They are gregarious and constitute an ecological group. Marine nektons include most species of marine fishes (Chondrichthyes and Osteichthyes, etc.) and of marine mammals, some species of Cephalopoda and Crustacea, and a few species of Reptilia and Aves.

ABSTRACT Spillage of -600,000 liters of refined product (diesel fuel arctic, DFA) into Arthur Harbor in January 1989 by the Bahia Paraiso marked the beginning of one of the first major spill clean-up and monitoring efforts in Antarctica. The impacted area contains numerous islands, breeding sites for sea birds and penguins, seal habitats, as well as abundant assemblages of macroalgae and invertebrates. Intertidal areas were most directly impacted and all components of the harbor ecosystem were contaminated during the first few weeks of the spill. DFA was detected in tissues from birds, limpets, macroalgae, clams, bottom feeding fish as well as in water and sediments. While the most intense contamination was during the first few weeks, some areas continued to be contaminated one year after the incident. The high energy environment, the relatively small volume of material released, and the volatility of the refined product combined to limit the spill's impact both areally and temporally. Even in this polar climate most of the spilled material evaporated. The remaining material was diluted with seawater and swept from the area by winds and currents. INTROPUCTION Man's activities in the southern oceans have raised concerns about human impacts on what is seen as one of the last pristine areas on earth. Potential mineral exploration and increasing tourism subjects even the remotest areas to possible petroleum contamination. While the impact studied in temperate climates these findings may not be directly applicable to high latitude, cold environments. The grounding of the Bahia Paraiso in Arthur Harbor, Antarctica provided one of our first experiences in responding to, and monitoring of, an oil spill in Antarctica. Enroute to resupply an Argentine Antarctic base the Bahia Paraiso ran aground on 28 January 19891,2. The vessel contained a cargo of diesel fuel arctic (DFA), jet fuel (JP-1), gasoline and compressed gas cylinders totaling more than one million liters. An estimated 600,000 liters of DFA were released during the main phase of the spill. A comprehensive sampling effort implemented within one day of the spill included collection of water, intertidal organisms, sediment from beaches, and oil slicks. The analysis of these samples provides information on the location, fate, and effects of the spill. The hydrocarbon chemistry portion of the program, which focused on documenting the distribution and fate of the petroleum release, is reported here. METHODS A variety of samples were collected for use in this study (Figure 1). Samples from the intertidal and subtidal (sediments, macroalgae and limpets) were collected by divers or from the shore. Sediments were collected in syringes and stoppered by the diver or scooped up with clean spatulas into sample containers. Sediment samples in deeper portions of the bays were sampled using a Smith-MacIntyre grab sampler from the R/V Polar Duke. Water column samples were diver collected by opening combusted glass stoppered bottles immersed to the appropriate depth in the water column or by 30 L Go-Flo Niskin bottles from the R/V Polar Duke. Slicks were collected by skimming the water surface into a glass bottle or by a screen mesh. Refined products were collected from the Bahia Paraiso, R/V Polar Duke, Palmer Station and Old Palmer Station including JP-1, DFA, lube oil, heating fuel and hydraulic fluid.

This report summarizes results of recent analyses of heavy metals in fish from Savannah River Site (SRS) streams near the F-Area and H-Area seepage basins. Fish were collected from headwater areas of Four Mile Creek and Pen Branch, from just below the H-Area seepage basin, and from three sites downstream in Four Mile Creek. These fish were analyzed for RCRA trace metals using standard EPA methods. Silver, arsenic, beryllium, cadmium, copper, nickel, lead, antimony, and thallium were all either undetectable or had only a few detectable values. Mercury values were all well below the regulatory limit of 1 {mu}g/g. For the total group of fish analyzed, there were no differences among sampling site for aluminum, chromium, or zinc. Selenium concentrations differed among sites, with fish collected near the H-Area and two control sites having the highest concentrations. When selenium concentrations were compared across sunfishes only, the seepage basin site was shown to be slightly elevated. Among species, yellowfin shiners had higher aluminum and zinc concentrations than sunfishes and bottom fish. 24 refs.

In Texas coastal bays and in many other low energy environments a high degree off shell,fragmentation (generally,from 75 to 95 weight percent) is characteristic of shell material in sediment samples. The feeding activity of predators such as the euryhaline sciaenid Pogonias cromis (Black drum), which is a common inhabitant off Atlantic and Gulf of Mexico shallow marine waters, is responsible ,for,fragmenting large quantities of live molluscan shell material in environments in which the natural energy gradient precludes extensive mechanical,fragmentation. P. cromis locates potential,food items with sensory barbels located on its lower jaw. Prey are ingested and crushed with pharyngeal teeth. Shell material may be rejected orally or may pass through the digestive system

Studies with several bottom fish species from urban waterways show that of the identified xenobiotic chemicals in bottom sediments, polycylic aromatic hydrocarbons (PAHs) are the most strongly asso...

Broad-scale comparative data for sediment chemistry, sediment bioassays and bottom fish histopathology are used to derive quantitative site-specific sediment criteria for three representative chemical contaminants in Puget Sound, Washington. The criteria, in terms of concentrations at or below which biological effects have been shown to be minimal, are (dry weight sediment): lead, 50 μg/g (ppm); combustion polyaromatic hydrocarbons, 3.8 μg/g; total polychlorinated biphenyls, 0.1 μg/g.

Concentrations of 14 elements (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, Sn, Tl, V, and Zn) were measured in the dorsal muscle of omnivorous white suckers and brown bullheads, fish likely to ingest sediment while feeding. The fish were collected in two acidic Adirondack lakes known to have elevated concentrations of several of these elements in their surface sediment. Trace element concentrations in the muscle of the white suckers and brown bullheads were compared with government guidelines for edible fish and survey data for concentrations present in commercial species. Only the largest white sucker exceeded the U.S. Food and Drug Administration's guidelines for Hg in food of 1 ppm (wet wt). Concentrations of all the other elements measured were at low or innocuous levels in the edible muscle. A significant positive correlation was found between body weight and Hg concentrations in both species. Zinc was negatively correlated for the same parameters in white suckers. With the possible exception of Hg, our results indicate that elevated levels of potentially toxic elements in the surface sediment of the two acidic Adirondack lakes are not reflected in the edible muscle of the omnivorous bottom feeding fish present in these systems.

Sarcoplasmic proteins were extracted from the ordinary muscle of twelve species of marine and four species of freshwater fish. Disc-gel electrophoresis in the absence of SDS resulted in species-specific patterns. Patterns of marine fishes widely differed from those of freshwater fishes. Polyacrylamide slab gel electrophoresis in the presence of SDS made it possible to categorize those fishes into three groups by patterns: marine white-fleshed, bottom fish (rich in 43K and 35K components), marine red-fleshed, pelagic fish (rich in 43K, 40K and 35K components), and freshwater fish (rich in 43K component). Red sea bream, Pacific mackerel and carp, as repre-sentatives of the three groups, were analyzed for relative amounts of 43K, 40K and 35K com-ponents in the total sarcoplasmic proteins: 12.6, 13.7 and 13.5% in red sea bream, 13.7, 18.7 and 11.6% in Pacific mackerel, and 19.5, 12.3 and 10.7% in carp, respectively.

Field studies were conducted over a 5-year period in Puget Sound to investigate etiological relationships between prevalences of hepatic neoplasms in bottom-dwelling marine fish, with emphasis on English sole (Parophrys vetulus), and concentrations of toxic chemicals in sediments and bottom fish. Statistically significant correlations were found between prevalences of hepatic neoplasms and (1) sediment concentrations of aromatic hydrocarbons, and (2) concentrations of metabolites of aromatic compounds in the bile. A significant difference was also found between the concentrations of N-oxyl derivatives of nitrogen heterocycles (free radicals) in liver microsomes of English sole with liver lesions compared to sole without liver lesions. These N-oxyl free radicals were apparently metabolically derived from complex suites of nitrogen heterocycles present in Puget Sound environments. Recent evidence suggests that aromatic free radicals (possibly derivatives of aromatic hydrocarbons) may also be bound to hepatic DNA isolated from English sole with liver neoplasms collected in several polluted areas of Puget Sound. Such evidence for xenobiotic-DNA interactions has thus far not been obtained for fish from reference areas and for lesion-free fish from polluted areas. Various laboratory studies designed to evaluate the etiology of the liver neoplasms have also yielded evidence that is consistent with the view that high molecular weight aromatic hydrocarbons play a significant role in the etiology of hepatic tumors in the bottom-dwelling fish. Associations between chemical exposures and diseases in other marine species from southern California and Boston Harbor are also discussed. Similar relationships between liver and skin neoplasms in selected bottom feeding fresh water species and sediment-associated chemicals are also presented.

Residues of DDE, DDD, DDT and PCB were measured in different tissues of fourteen sperm whales caught in the waters off Spain's north-western coasts. Unlike what seems common in other marine mammal species, females appear to be more contaminated by organochlorine compounds than males. Pollutant levels in this species were found to be intermediate to other cetaceans, probably due to their feeding habits mainly based on squid and bottom fish. Concentrations of total DDT and PCB in blubber were similar to most of those determined in sperm whales from other areas of the northern hemisphere.

Among environmental pollutants, polynuclear aromatic hydrocarbons (PAH) are of interest because of their widespread occurrence and the human carcinogenicity of their metabolic products. Most PAH are relatively water insoluble and ultimately are deposited in sediments. In localized areas of eastern Lake Erie, sediments have been shown to have high concentrations of PAH. As a part of an ongoing research on environmental carcinogenesis, the authors have been examining possible routes of exposure to carcinogens in feral fish. They report here data indicating that the diet of bottom-feeding fish can contain substantial concentrations of PAH. Some of these PAH can be metabolically activated to carcinogens and may be involved in neoplasia in these fish.

A difference between compositions of the fatty acids has been discussed in another paper in this issue dealing with the meat of two kinds of shellfish, gastropoda and pelecypoda. It is inferable that non-depot lipids of fish flesh might have their own specific composition pat-terns of fatty acids according to their living environments or food habits. Thirty-six kinds of materials including shark, bony fish, and their processed products, were purchased from the market to study the patterns. Lipids were extracted from dorsal muscle which usually contains depot lipids less in amount than the flesh of other parts. Total cholesterol and fatty acid composition were examined in the same manner as described for shellfish. The following are the results from the data shown in Tables 1 and 2. 1) In the dorsal flesh cholesterol content varied from 9.5mg of flying fish to 72mg of pond smelt; though the majority of sea fish had it in the range of 40±10mg, rainbow trout, loach, and pond smelt showed it with slightly higher value of 70-72mg. 2) Lipids of dorsal flesh showed less contents of such fatty acids as C14 saturated, C16:1, C18:1, and C20:1, and more quantity of C22:6, than the lipids of ventral flesh. 3) A pattern of fatty acid composition shown in Table 3 was obtained by averaging the results from seventeen marine bony fish and three cured products which had less than 1% of oil contents in the dorsal flesh and more than 15% of C22:6 fatty acid in the lipids. 4) In case of inshore bottom fish, C22:6 acid was found around one tenth of total acids. Two species of shark had a resemblance in fatty acid composition between them (Fig. 4), but those were different from the pattern of Table 3. 5) Fresh water fish, such as loach and sweet smelt, contained 1.3-2.5% of C22:6 acid with a distinct amount of C18:3 acid which was scarcely present in sea fish (Figs. 1 and 2). In the meat of rainbow trout and pond smelt, however, C22:6 acid reached to 14.9-28.9%, almost similar in amount to the acid found in marine fish (Fig. 3).

Observations show that during the winter period of strong southeast winds, light surface waters accumulate along the coast, displacing the deeper waters offshore. During the summer period of weak southeast winds the accumulated surface waters move offshore allowing the return of the deep waters.The winter accumulation is accompanied by a northwestward-flowing coastal current which appears to be continuous from California to the Gulf of Alaska. During the summer this current is small or absent.It is noted that this seasonal change of water masses accounts for a major part of the observed sea level oscillation.It is suggested that the winter displacement of deep waters and their return affect the movement of bottom fish of the region.

The author studied on the morphological property of the fish-blood mainly from a biological point of view; namely red-corpuscle, white-corpuscle, platelet, hematocrit, hemoglobin, cytochrome (Nadi-reaction) and Fe content of several fish-blood were determined. The results were summarized in Table 1-3 and by these studies following phenomena were observed. The blood of migratory fish such as tunny, bonito and mackerel contained more red-corpuscle and its size was smaller than that of bottom fish and consequently the surface of red corpuscle in the former was magnified. The hematcrit value, hemoglobin and Fe content of blood were greater in the active fish than that of blood in inactive one. It was thought that these property showed the nature of fish connected with their activity and the degree of evolution. The blood of shark contained very large red-corpuscle and its number, hematocrit value, hemoglobin content were very few. The platelet and white-corpuscle of fish-blood was very unstable. The polimorphy was most numerous in the white-corpuscle, basiphils wanting in many fishes. The morphological property of fish-blood was more primitive than that of human, and the shark-blood had peculiarity in many respects.

This investigation utilizes the techniques of functional anatomy to determine adaptive differences between two closely-related species, the Common Murre (Uria aalge) and the Thick-billed Murre (Uria lomvia). While the Thick-billed Murre predominates in the far north (many breeding localities within the Arctic Circle), and the Common Murre is more successful to the south (the only breeding murre in the British Isles, the Faeroes, and along the Pacific coast of the US and British Columbia), the two species overlap broadly in their breeding and wintering ranges. And although they have been the objects of numerous ecological investigations, no consensus has developed concerning their niche differentiation. For Novaya Zemlya and Seven Islands (USSR), where both species occur, Uspenski (1956) emphasizes shortage of nesting sites rather than food as a limiting factor, thus implying that food differences are unimportant or nonexistent. Belopol'skii (1957) classifies Uria aalge as a "stenophage" (i.e., narrowly restricted in its food preferences) that feeds almost exclusively on pelagic fish. Conversely, he regards Uria lomvia as a "polyphage," capable of switching to zooplankton and bottom fish. However, Tuck (1960) on the basis of existing information concluded that there is no distinct food spectrum for either species, and felt that their diets consist of whatever small fish are available.

Red mud is an industrial waste originating from the production of aluminium from bauxite. Since the difficulties connected with the removal of red mud are increasing and the possibilities for land deposition are restricted, German aluminium-producers wanted to dump their wastes in the southern North Sea. Several experiments were carried out to assess the effects on marine organisms. Red mud proved to be harmful to a variety of organisms; the most predominant effect was agglutination of gill tissues. Regarding the very severe effects of suspended red mud on different marine organisms the authors refuse the proposed dumping project. Taking into account the special hydrographic situation of the German Bight, which cnanot be compared with that of other dumping areas and further knowing that the North Sea is one of the most important fishery areas of the world, it is concluded that dumping of red mud would endanger the stocks of bottom fish and fauna and should therefore take place in regions without any fishing activities with depth greater than 3000 m.

The Hyuga Nada (Hyuga High Sea) when taken in wide sense extends off the eastern and east-southern coasts of Kyushu Island, viz., from up north the Bungo Strait down to south the Osumi Penninsula, and abounds, amoungst others, in red gurnards, of which economically important are the following five species; Chelidonichthys kumu, Pachytrigla alata, Lepido-trigla japonicus, L, guntheri and L, microptera. Examination of their stomach contents reveal that they devour by far Crustaceans and those small fishes as hidden in sand-mud or crawling on sea bottom (Table 2). Voracious as they are, their stomach was often found stuffed with food, which weighed 3-4% of the body at maximum. Table 3 and Fig. 1, A-F give the results of the statistical observation of their egg. Ova measuring over 1.0mm in diameter are characterized by having one or three oil globules and almost complete transparency and were taken as mature eggs. The degree of maturity was defined by ratio of mature ova to the whole ovary in weight and is given in Table 6. Single mature ovum weighs about 0.0011gr in Chelidonichthys kumu and about 0.00095gr in Pachytigla alata. Number of ova to be liberated at first spawning is estimated 10, 000-25, 000 in C, kumu, and 2, 000-3, 500 in P, alata.

The pantothenic acid (PA) content in the tissues of various kinds of fish and shellfish has been determined by microbiological assay (SKEGGS, H. R. and WRIGHT, L. D., 1944) using Lactobacillus arabinosus as the test microbe. 1. Among the tissues of fish so far examined, the gonad is most potent in the PA content, and both the dark colored meat and the liver rank next. Whereas, the PA level in the ordinary meat is poor except the case of flounders, whose ordinary meat contains more PA than the liver (Table 1). 2. In the common mackerel, Scomber japonicus, the quantitative ratios of PA in the meat (both ordinary and dark), gonad and liver to the total PA contents are about 70, 10, and 5% respectively (Table 2). 3. The individual differences of the PA content in the ordinary meat and the liver are little among the same species. It seems that the ordinary meat of fish with a greater locomotion contains PA more abundantly than that of bottom fish or less locomotive ones (Table 3). 4. The level of PA in soft parts of bivalves is generally between those in the liver and the ordinary meat of usual fish. It is worth noting that the muscle of abalone is found with very rich PA content (Table 4).

The volatile basic-and amine-N of the fish sold at the store in Sendai, August 1957, were determined by Conway's microdiffusion method and the results obtained were summarized in Table 1. Comparing the values with those in fish of May and June 1957, the quality of marketing fish was better in summer (26-35°C) than in spring (18-25°C) (Table 1-3). This fact will be caused by the rapid transportation from the fishing ground to the fish store and the proper treatment of fish with ice in August. It was found that the percentage of fish of the poor quality was small in the well equipped store (Table 5) and that comparing the bottom fish with the surface fish, the former always had the high value of the volatile amine-N in comparing with the volatile basic-N (Table 1, 6).

SUMMARY The proximate composition and sodium and potassium contents of four species of bottom fish from Pacific Coast waters were investigated. Pacific Ocean perch, Pacific cod, and lingcod were quite uniform in composition regardless of species, size, season and area of capture, and method of preservation on board the fishing vessel. The averages were 79-81% moisture, 18-19% protein, 0.5-1.5% oil, 1.1-1.3% ash, 60-70 mg% sodium, and 390-440 mg% potassium. Sablefish varied greatly in oil content, with a range of 3-23% and an average of 15%. Variations in the other constituents were rather large; averages were 71% moisture, 13% protein, 1% ash, 56 mg% sodium, and 348 mg% potassium.