calcareous benthic foraminifera: Topics by WorldWideScience.org

Facies variation, diagenesis, and exploration potential of the Cretaceous rudist-bearing carbonates of the Arabian Gulf

Benthic biological samples were taken in 1977 from the vicinity of the Farallon Islands radioactive waste disposal sites for characterization of the infaunal macroinvertebrates and foraminifera. A total of 120 invertebrate species were collected, of which 75 species (63 percent) were polychaetes. Forty-three of these polychaete species have not previously been reported from depths greater than 1000m. A total of 1044 macroinvertebrate specimens were collected of which 54 percent were polychates. Only the nematods were present at all six benthic stations, but the community structure was dominated by the polychaetes Tauberia gracilis, Allia pulchra, Chaetozone setosa, and Cossura candida. Living and dead foraminifera were reported. The possible role of polychaetes in bioturbation and in the marine food chain is briefly discussed with respect to the various polychaete feeding mechanisms.

Modern carbonate sediments and environments of the LaPaz region, Baja California Sur, Mexico

The Cretaceous rudist-bearing carbonates of the Arabian Gulf region are proven exploration targets for hydrocarbons and form the reservoirs of a number of giant fields, including Bu Hasa, Fateh, Fahud, Idd El Shargi, Rumaila, Shaybah, and Shah. Rudist buildups occur in three principal formations: (1) Aptian Shuaiba, (2) Cenomanian Mishrif, and (3) Maastrichtian Simsima. A regional subaerial unconformity marks the upper boundary of each of these formations. Associated with the rudists that dominate the Shuaiba Formation are calcareous algal crusts, foraminifera, and echinoid plates, which accumulated in mudstone, packstone, and carbonate sands. The Mishrif Formation contains mollusk fragments, bioclasitc packstones to grainstones, miliolid and nonrudist bivalves in muddy limestones, and rudist (mainly radiolitids and caprinids) conglomeratic floatstones, with fragmented rudists mixed with wackestone lithoclasts. The Mishrif sediments accumulated ...

1995-04-01

SOFIA - Metadata - Historical Changes in Salinity, Water Quality...

The Gulf of California represents one of the most productive and unique marginal seas in the world. The mouth of the Gulf captures warm equatorial water while annual wind patterns assure major upwelling of nutrient-rich water leading to a rich marine biota. These conditions have created a wide array of tropical through warm temperate carbonate environments. The most unusual of these environments is located in the La Paz region of Baja California Sur where tropical-subtropical water temperatures and low rainfall have allowed growth of corals, calcareous red algae, and other shelled invertebrates to form a carbonate bank environment. Sampling and mapping transacts in shallow bays north of La Paz and on the adjacent Espiritu Santo island have revealed a full spectrum of subenvironments including mangrove bordered, terrigenous mud dominated coastal zones, which grade into carbonate tidal flats. In addition, single coral heads as well as incipient reef structures ...

1996-12-31

A comparison of benthic biodiversity in the North Sea, English ...

will be derived from biochemical analyses of molluscs, ostracodes, foraminifera and corals. The corals will allow us to compare marine and estuarine trends, examine the linkage...

2011-08-27

Benthic Habitats of the Asuncion Island Northern Mariana Archipelago 2001-2003, Derived From IKONOS Imagery

A comparison of benthic biodiversity in the North Sea, English Channel, and Celtic Seas. ICES J. Mar. Sci./J. Cons. int. Explor. Mer 56: 228-246. ...

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Wastenet

...Benthic Marine Bioregionalisation of Australia's Exclusive Economic Zone The benthic (sea floor) component of the National Marine Bioregionalisation covers the 80% of Australia's ... Exclusive Economic Zone that lies beyond the continental shelf break. It provides a description of patterns of biological distributions and physical habitats on the seafloor....sea floor) component of the National Marine Bioregionalisation covers the 80% of Australia's Exclusive Economic Zone that lies beyond the continental shelf break. It provides a ... Benthic Marine Bioregionalisation of Australia's Exclusive Economic Zone Change text size Skip to content Marine Bioregional Planning resources Search: About us Contact us You ...

Benthic Habitats of Swains Island 2001-2003, Derived from IKONOS Imagery

... Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. ... ...

Benthic Habitat of Oahu Derived From IKONOS and Quick Bird Satellite Imagery, 2004-2006

... Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. ... ...

Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 3. Calcareous ooze

... Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. ... ...

On the quantitative distribution and community structure of the meio and macrofaunal communities in the coastal area of the Central Adriatic Sea (Italy)

The physicochemical forms and partitioning of corrosion products released from stainless steel upon exposure to selected environmental conditions is the subject of this investigation. This report describes the influence of calcareous sediment on the rate of release and fate of corrosion products produced when neutron-activated stainless steel specimens were exposed to a Globigerina ooze taken from the Northeast Pacific Ocean. The calcareous ooze used in this study consists largely of planktonic formanifera tests and was found to be about 90% CaCO_3. The trace metal content of this sediment was typical of average deep-sea carbonate sediments, and the ratios of trace elements to Ti were not remarkably different from a coastal clayey silt or a Northeast Pacific pelagic red clay. Most (>80%) of the trace metals extracted by sequential chemical treatment were associated with reductant-soluble materials, i.e., amorphous Mn and Fe oxides, or were ...

British Library Electronic Table of Contents (United Kingdom)

Many coastal areas have served as repositories of different anthropogenic and naturally induced organic material and nutrients. The major sources thereof are riverine inputs which strongly influence the spatial and temporal distribution of benthic communities. In this study, the benthic foraminiferal, meiofaunal, and macrofaunal colonies in front of three rivers in a poorly known, but environmentally valuable, area of the Central Adriatic Sea have been examined concurrently. The physico-chemical parameters of bottom water and sediment characteristics were determined in order to characterize both the sediment?water interface and the benthic environments. Although changes in the biota are neither univocal nor unidirectional, a moderate influence of riverine input on the different communities...

2011-01-01

Sediment trap fluxes and benthic recycling of organic carbon, polycyclic aromatic hydrocarbons, and polychlorobiphenyl congeners in Lake Superior

Contaminated Site Clean-Up Information (CLU-IN): Providing information...

Sediment trap fluxes of solids, organic carbon, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) were measured in Lake Superior in 1984 and 1985. Mass fluxes from surface waters ranged from 0.14 to 1.1 g/m{sup 2}{center dot}day and increased near the lake floor due to resuspension of surficial sediment and horizontal transport in the benthic nepheloid layer. Organic matter fluxes from surface water ranged from 60 to 90 mg of C/m{sup 2}{center dot}day, with {approximately}5% of organic carbon settling from surface waters accumulating in bottom sediments. Concentrations of PCBs and PAHs are enriched 10-100 times on settling particles relative to those on suspended particles. Resultant settling fluxes are 10-100 times greater for several PCB and PAH compounds than net accumulation rates in bottom sediments, indicating the effective and rapid recycling in the benthic region. Biological packaging of organic pollutants ...

1991-03-01

CO-DEVELOPMENT OF WETLANDS SOILS AND BENTHIC INVERTEBRATE COMMUNITIES FOLLOWING SALT MARSH CREATION. (R826111)

/Stabilization Nov 16: NARPM Presents...In Situ Sediment Remediation Using Benthic Waterjet Amendment Placement Nov 17: Use of Risk Assessment in Management of Contaminated...

2011-10-08

Abrupt climate change and collapse of deep-sea ecosystems

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

UK PubMed Central (United Kingdom)

We investigated the deep-sea fossil record of benthic ostracodes during periods of rapid climate and oceanographic change over the past 20,000 years in a core from intermediate depth in the northwestern...Full Text Available

2008-02-05

The effects of soil type and chemical treatment on nickel speciation in refinery enriched soils: A multi-technique investigation

British Library Electronic Table of Contents (United Kingdom)

Aerial deposition of Ni from a refinery in Port Colborne, Ontario, Canada has resulted in the enrichment of 29km2 of land with Ni concentrations exceeding the Canadian Ministry of the Environment's remedial action level of 200mgkg-1. Several studies on these soils have shown that making the soils calcareous was effective at reducing chemically extractable Ni, as well as alleviating Ni phytotoxicity symptoms in vegetable crops grown in the vicinity of the refinery. Conversely, dolomitic limestone additions resulted in increased uptake of Ni in the Ni hyperaccumulator Alyssum murale `Kotodesh', a plant whose use was proposed as a remediation strategy for this area. In this paper we use multiple techniques to directly assess the role soil type and lime treatments play in altering the speciati...

2007-01-01

Allelochemicals produced by Caribbean macroalgae and cyanobacteria have species-specific effects on reef coral microorganisms

British Library Electronic Table of Contents (United Kingdom)

Coral populations have precipitously declined on Caribbean reefs while algal abundance has increased, leading to enhanced competitive damage to corals, which likely is mediated by the potent allelochemicals produced by both macroalgae and benthic cyanobacteria. Allelochemicals may affect the composition and abundance of coral-associated microorganisms that control host responses and adaptations to environmental change, including susceptibility to bacterial diseases. Here, we demonstrate that extracts of six Caribbean macroalgae and two benthic cyanobacteria have both inhibitory and stimulatory effects on bacterial taxa cultured from the surfaces of Caribbean corals, macroalgae, and corals exposed to macroalgal extracts. The growth of 54 bacterial isolates was monitored in the presence of l...

2011-01-01

Carbonate shoreline sedimentation in San Andres Formation, Lincoln County, New Mexico

Geologic setting of the New Production Reactor within the Savannah River Site

The Permian San Andres Formation of late Leonardian-early Guadalupian age is a significant hydrocarbon producer and crops out over a large area in south-central New Mexico. However, since its definition in 1909, the age and depositional environment of this unit have been questioned. In 1971 in Pecos County, Vincent Kelly divided the unit into three members: Rio Bonito, Bonney Canyon, and Fourmile Draw. The lowest member, although named for the Rio Bonito, has a type section designated at Sunset along U.S. Highway 70/380. Two miles east of Sunset, near Riverside, on the Rio Bonito, the Rio Bonito Member is exposed in a long series of roadcuts. Petrographic investigation of these rocks reveals an alternating sequence of high to low-energy intertidal to subtidal facies marked by oolitic and fossiliferous dolocalcarenite interbedded with dolomitic mudstone. The unit has been recrystallized and stylolites are abundant, as is dolomite and nodular mosaic anhydrite. These alternating units ...

1986-03-01

Vulnerability of soil resources to heavy metals contamination in Central Bekaa-Lebanon

The geology and hydrology of the reference New Production Reactor (NPR) site at Savannah River Site (SRS) have been summarized using the available information from the NPR site and areas adjacent to the site, particularly the away from reactor spent fuel storage site (AFR site). Lithologic and geophysical logs from wells drilled near the NPR site do not indicate any faults in the upper several hundred feet of the Coastal Plain sediments. However, the Pen Branch Fault is located about 1 mile south of the site and extends into the upper 100 ft of the Coastal Plain sequence. Subsurface voids, resulting from the dissolution of calcareous portions of the sediments, may be present within 200 ft of the surface at the NPR site. The water table is located within 30 to 70 ft of the surface. The NPR site is located on a groundwater divide, and groundwater flow for the shallowest hydraulic zones is predominantly toward local streams. Groundwater flow in deeper Tertiary ...

1991-12-31

Structural and functional responses of benthic invertebrates to imidacloprid in outdoor stream mesocosms

Full text.Changes in land use and urbanization yield more pressure put on limited soil and water resources, including the risk of pollution with toxic heavy metals. The study area lies in the Bekaa valley totaling about 12753 ha. The valley receives from the west torrential fan deposits and a mixture of colluvial and alluvial material. The principal soil classes are Fluvisols, Cambisols, Regosols, Vertisols and Luvisols. The area is populated and also the most important agricultural part of the plain. Agriculture in the plain is being practiced mainly with cash, field crops and vegetables. The western surrounding area is being used mainly for terraced fruit trees. This Arab-German Technical Cooperation Project (ACSAD-BGR) aimed, following the ISO standards and Eikman-Klocke recommendations, at investigating the nature of the extends of soil pollution by heavy metals in two pilot areas: The central Bekaa-Lebanon and Ghouta-Damascus. Different institutions cooperate in the implementation ...

2000-11-23

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In situ studies with Asian clams (Carbacula fluminea) detect acid mine drainage and nutrient inputs in low-order streams

Structural and functional responses of a benthic macroinvertebrate assemblage to pulses of the insecticide imidacloprid were assessed in outdoor stream mesocosms. Imidacloprid pulses reduced invertebrate abundance and community diversity in imidacloprid-dosed streams compared to control streams. These results correlated well with effects of imidacloprid on leaf litter decomposition and feeding rates of Pteronarcys comstocki, a stonefly, in artificial streams. Reductions in oxygen consumption of stoneflies exposed to imidacloprid were also observed in laboratory experiments. Our findings suggest that leaf litter degradation and single species responses can be sensitive ecotoxicological endpoints that can be used as early warning indicators and biomonitoring tools for pesticide contamination. The data generated illustrates the value of mesocosm experiments in environmental assessment and how the consideration of functional and structural endpoints of natural ...

The use of the isotope "3"2P in the study of some ecological aspects of a laboratory stream ecosystem

This study evaluates the correlation between transplanted Asiatic clam and indigenous community responses to acid mine drainage and nutrient loading in first-to-third-order streams, by comparing the toxicological endpoints of clam survival and growth with benthic macro-invertebrate community indices as community responses to both acid mine drainage and nutrient loading. Clam survival was found to be positively correlated with water column pH and negatively correlated with conductivity and metal concentrations. There was also a positive correlation with the relative abundance of the macro-invertebrate Ephemeroptera, the most sensitive taxonomic group, to acid mine drainage in this watershed. No correlation was found between clam growth and acid mine drainage inputs, but there was evidence of positive correlation with nitrate concentrations and the relative abundance of collector-filterer functional feeding groups. These results suggest that clam growth is related to ...

2001-03-01

Biotoxicity characterization of a produced-water discharge in Wyoming

A laboratory stream consisting of two stream sections interrupted by two pools was filled with a mixture of tap water and organically enriched water from rivers nearby. Bottom sediment material, Potamogeton pectinatus, macro-invertebrate organisms, as well as the mosquito fish, Aplocheilichthys johnstonii were collected from rivers around Johannesburg and introduced into the laboratory stream. After initial acclimatization, the distribution of the isotope "3"2P through this laboratory stream was followed. Absorption of this isotope by benthic algae, Potamogeton pectinatus, several macro-invertebrate organisms as well as Aplocheilichthys johnstonii was recorded.

2001 evaluation of juvenile fall chinook stranding on the Hanford Reach of the Columbia River.; TOPICAL

The objectives of this paper are to document the physicochemical and aquatic toxicological quality of a beneficial-use produced-water discharge and its effect on a receiving stream in Wyoming. Fish and water-flea survival, growth, and reproduction tests indicated that the discharge and all other sampling stations passed the state effluent biomonitoring acute toxicity testing endpoints. while benthic macroinvertebrates were absent at the discharge point designated by the Natl. Pollutant Discharge Elimination System (NPDES), productive and reproducing populations were present at all other downstream and mixing-zone stations. This investigation confirmed the validity of the beneficial-use subcategory for this oilfield discharge.

2000 evaluation of juvenile fall chinook stranding on the Hanford Reach of the Columbia River.; TOPICAL

The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach of the Columbia River. The evaluation, in the fifth year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fishes, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 2001 field season.

1999 evaluation of juvenile fall chinook stranding on the Hanford Reach of the Columbia River, annual report 1999.; ANNUAL

The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the fourth year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fishes, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 2000 field season.

1998 evaluation of juvenile fall chinook salmon stranding on the Hanford Reach of the Columbia River.; TOPICAL

The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the third year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fishes, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 1999 field season.

The influence of Cu contamination on Nereis diversicolor bioturbation

The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the second year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fish species, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 1998 field season.

British Library Electronic Table of Contents (United Kingdom)

Aquatic sediments feature a two-way interaction between contaminants and benthic macrofauna. The effect of the macrofauna community on the transport of contaminants in sediment has received considerable attention. Yet, few studies have investigated the reverse effect, i.e., the influence of contaminants on bioturbation activity. To this end, we performed laboratory experiments to investigate the effect of copper contamination on sediment reworking activity of the ragworm Nereis diversicolor. A density of 570 ind m2 was introduced in mesocosms containing natural and copper spiked (2.99 nmol Cu g?1) cohesive intertidal sediments from Ponta da Erva (Tejo estuary, Portugal). Luminophore tracers were used to quantify sediment reworking activity over time (2, 7, 14 and 21 days). Bioturbation was...

2006-01-01

Simple calculation of daily photosynthesis by means of five photosynthesis-light equations

Relationship between the lability of sediment-bound metals (Cd, Cu, Zn) and their bioaccumulation in benthic invertebrates

The performance of five well-known photosynthesis-light equations is compared by presenting a wide range of solutions in the form of dimensionless nomographs for the case where photosynthetically available radiation (PAR) reduces exponentially down the water column and is distributed sinusoidally through the photoperiod. These provide a simple means of calculating daily photosynthesis at any depth (e.g. at a benthic layer), or through a water column, avoiding the need to perform complex integrations. An examination is made of the accuracy of common approximate methods for calculating daily photosynthesis, assuming constant PAR. For optically deep water a modification is proposed to Talling's planimetric solution, to enable daily photosynthesis to be calculated more accurately, yet simply, over the whole range of possible PAR values. The errors induced by approximating the daily PAR distribution as a half-sinusoid are also reported. 13 refs., 9 figs., 5 ...

1992-12-01

British Library Electronic Table of Contents (United Kingdom)

The present study has investigated metal contamination at nine sites (10 sampling stations) from the English Channel to the Mediterranean Sea, including low level and highly contaminated sediments. Both total and labile concentrations of metals were determined in superficial sediments. The influence of different pHs was tested and metal lability at pHs encountered in the gut of invertebrates (the ragworm Nereis diversicolor, the blue mussel Mytilus edulis, the Japanese oyster Crassostrea gigas) was compared with the distribution of metals in various operationally defined geochemical fractions. Cd showed the highest lability and Cu the lowest, whereas Zn lability was intermediate. Metal concentrations were determined in bivalves at six sites and in worms at three sites. Cd in living organis...

2007-01-01

Measurement of Lake Roosevelt biota in relation to reservoir operations. Appendices 1991

Feeding ecology of Xenoturbella bocki (phylum Xenoturbellida) revealed by genetic barcoding

This report consists of appendices A-F containing the biological data which were collected from Lake Roosevelt, Washington. The data are to be used in the design of a computer model that would predict biological responses of reservoir operations as part of the System Operation Review program. Major components of the model included: Quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times.

1995-11-05

British Library Electronic Table of Contents (United Kingdom)

Abstract The benthic marine worm Xenoturbella is frequently contaminated with molluscan DNA, which had earlier caused confusion resulting in a suggested bivalve relationship. In order to find the source of the contaminant, we have used molluscan sequences derived from Xenoturbella and compared them to barcodes obtained from several individuals of the nonmicroscopic molluscs sharing the same environment as Xenoturbella. Using cytochrome oxidase 1, we found the contaminating sequences to be 98% similar to the bivalve Ennucula tenuis. Using the highly variable D1-D2 region of the large ribosomal subunit in Xenoturbella, we found three distinct species of contaminating molluscs, one of which is 99% similar to the bivalve Abra nitida, one of the most abundant bivalves in the Gullmarsfjord where...

2008-01-01

Development of a waterjet system for direct delivery of granular iron and activated carbon to remediate contaminated aqueous sediments

British Library Electronic Table of Contents (United Kingdom)

Abstract While the techniques and technologies associated with contaminated sediment remediation are relatively mature, there are several issues associated with these practices that make them unattractive. The inability of currently used mechanical mixing implements to place amendments in aqueous environments and their intrusive behavior toward benthic communities are just two examples of a necessity for an improved delivery method. Waterjets may be a viable option for placement of particulate remediation amendments, such as activated carbon and granular iron, at depth. A custom waterjet nozzle and injection system has been fabricated by the authors to examine this delivery concept. The developed injection system's performance was tested by characterizing the waterjet-delivered amendment (...

2011-01-01

The economic geology of clays/shales raw materials for the ceramics industry in Lebanon

New oil exploration play in Florida: The upper Fredericksberg Dollar Bay Formation

Author.Field, laboratory and market studies are a must for proper evaluation of natural resources for the mineral industry of lebanon. Sites selectively convenient to the existing major Lebanese ceramics industry centered in the Beqa'a region, were investigated as to their geology, geography and economic character. The raw materials are shales, mud stones, siltstones and other argillaceous rocks of Jurassic to Cretaceous age coming from selective sites in south and central Lebanon. The finished products include wall, floor, roofing tiles, pipes, sanitary ware, pottery and brick specimens. Differential thermal analysis, scanning electron microscopy, firing and physico-chemical tests and analyses characterized the raw materials into two major groups: the suitable are siliceous argillaceous rocks and unsuitable calcareous argillaceous rocks. The suitable group is divided into two varieties. The first is dominantly a disordered Kaolinite with low drying and firing ...

Patterns of lineage diversification in the genus Naso (Acanthuridae).

The Fredericksberg of South Florida may have a great oil potential that has been overlooked as a primary target in past decades. Previous exploration in the area has targeted the Lower Cretaceous oil-producing Sunniland Formation lower in the stratigraphic section. The Fredericksberg Dollar Bay Formation has hydrocarbon shows in many wells occurring in limestone biohermal deposits as well as in an upper dolomitic section. The Dollar Bay Formation is part of the Big Cypress Group of the Comanchean Series of the Lower Cretaceous. The Lower Cretaceous lithology is composed of evaporitic-carbonate cycles consisting of anhydrites, dolomites, and limestones. There are also present some calcareous shales, mudstones, salt, lignitic material, and carbonaceous material, especially in the anhydrite and limestone intervals. The limestones are usually micritic, chalky, calcarenitic, sometimes argillaceous, containing skeletal particles of gastropods, pelecypods, ostracods, ...

1990-09-01

Natural resource injury assessment of a crude oil spill

The evolutionary history of the reef fish genus Naso (F. Acanthuridae) was examined using a complete species-level molecular phylogeny of all recognized (19) species based on three loci (one nuclear ETS2 and two mitochondrial 16S, cyt b). This study demonstrates that distinct foraging modes and specialized body shapes arose independently at different times in the evolutionary history of the genus. Members of the subgenus Axinurus, characterized by a scombriform morphology, caudal fin structure and pelagic foraging mode, were consistently placed basal to the remaining Naso species, suggesting that pelagic foraging is plesiomorphic and benthic foraging derived in this genus. We used a genus-level phylogeny (nuclear marker, ETS2), which included several taxa from all other acanthurid genera, to obtain a range of age estimates for the most recent common ancestor of the genus Naso. These age estimates (range of 52-43.3 MY) were then used to estimate divergence times (by ...

2004-07-01

Sampling method, storage and pretreatment of sediment affect AVS concentrations with consequences for bioassay responses

In January 1994, a 6.7 magnitude earthquake in southern California ruptured a pipeline releasing approximately 4,200 barrels of blended San Joaquin Valley crude oil. A smaller volume entered the Santa Clara River and flowed 25 km downstream to an emergency containment dam. Ruptured water mains and chlorinated discharges from a damaged sewage treatment plant also affected water quality in the river. Quantitative injury assessment studies were initiated within days of the spill and included water/sediment chemistry, benthic macroinvertebrate community analyses and aquatic toxicity tests. Water quality values for TPH, BTEX, and chlorine ranged from nondetectable to 78 mg/l (TPH), nondetectable to 5.4 microg/l (total BTEX constituents) and nondetectable to 600 microg/l (residual chlorine) within 72 hours of the spill. Ammonia concentrations ranged from nondetectable to 12.1 mg/l within 10 days of the spill. Hydrocarbon concentrations in sediments ranged from ...

1996-11-17

Primary productivity C-14 and algal assay in the study of water pollution effects in the Citarum River and Jatiluhur Reservoir

Sediment treatment and sediment storage may alter sediment toxicity, and consequently biotic response. Purpose of our study was to combine these three aspects (treatment-toxicity-biotic response) in one integrated approach. We used Acid Volatile Sulfide (AVS) concentrations as a proxy of the disturbance of the sediment. AVS and Simultaneously Extracted Metal (SEM) concentrations were compared to bioassay responses with the freshwater benthic macroinvertebrate Asellus aquaticus. Storage conditions and sediment treatment affected AVS but not SEM levels. AVS can be used as a proxy for sediment disturbance. The best way to pretreat the sediment for use in a bioassay in order to maintain initial AVS conditions was to sample the sediment with an Ekman grab, immediately store it in a jar without headspace, and freeze it as soon as possible. In a survey using seven different sediments, bioassay responses of A. aquaticus were correlated with SEM and AVS characteristics. - ...

2008-01-01

Morphological and ultrastructural analysis of Turritopsis nutricula during life cycle reversal.

Water quality of the Citarum River and the Jatiluhur Reservoir in Indonesia was evaluated using C-14 radioisotope. A close relationship between the abiotic (physical and chemical) and the biotic (algal growth potential, primary productivity, chlorophylla and diversity index of planktonic and benthic macroinvertebrate) parameters was obtained. Algal growth potential to abiotic parameters relationship has the highest correlation coefficient and can be used as a pollution indicator. The other biotic parameters do not show clear relationship with the abiotic parameters. The Citarum water quality is the lowest in those locations which receive human and industrial waste from Bandung and its environment. This water cannot be used for drinking purposes and fishery. The water quality in other locations of the river, however, meets the criteria for agriculture. Agricultural waste does not show any drastic effect on the water quality profile due to non-polluted ...

1983-03-01

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Methods and results of an evaluation of aquatic receptor risk at the Rocky Flats Environmental Technology Site, Golden, Colorado

The hydrozoa life cycle is characterized, in normal conditions, by the alternation of a post-larval benthic polyp and an adult pelagic medusa; however, some species of Hydrozoa react to environmental stress by reverting their life cycle: i.e. an adult medusa goes back to the juvenile stage of polyp. This very uncommon life cycle could be considered as some sort of inverted metamorphosis. A morphological study of different stages during the reverted life cycle of Turritopsis nutricula led to the characterization of four different stages: healthy medusa, unhealthy medusa, four-leaf clover and cyst. The ultrastructural study of the cellular modifications (during the life cycle reversion of T. nutricula) showed the presence of both degenerative and apoptotic processes. Degeneration was prevalent during the unhealthy medusa and four-leaf clover stages, while the apoptotic rate was higher during the healthy medusa and cyst stages. The significant presence of degenerative ...

2003-06-01

Geographic analysis of thermal equilibria: A bioenergetic model for predicting thermal response of aquatic insect communities

The Rocky Flats Environmental Technology Site (RFETS) has historically released radionuclide chemicals of potential concern into the surrounding environment. The off-site environment was evaluated for Pu"2"3"9"/"2"4"0 and Am"2"4"1 occurrence. An evaluation of exposure and effects to the aquatic ecology within off-site areas including: Standley Lake, Great Western Reservoir, Mower Reservoir and portions of Big Dry Creek, Walnut Creek, and Woman Creek was performed for the completion of an Ecological Risk Assessment. Collocated sampling activities were performed for surface water, sediment, benthic macroinvertebrates and fish. Results of the analytical data were used to assess ongoing exposure and effects. Data collected to determine effects (chemical content of fish tissue, diversity and density of macroinvertebrate populations) provided some of the necessary information needed to evaluate risk. However, due to conditions of interfering stressor effects, a ...

1995-11-05

Effects of a chelating resin on metal bioavailability and toxicity to estuarine invertebrates: Divergent results of field and laboratory tests

The thermal regime immediately downstream from bottom release reservoirs is often characterized by reduced diel and seasonal (winter warm/summer cool) conditions. These unusual thermal patterns have often been implicated as a primary factor underlying observed downstream changes in the species composition of aquatic macroinvertebrate communities. The potential mechanisms for selective elimination of benthic species by unusual thermal regimes has been reviewed. Although the effects of temperature on the rate and magnitude of larval growth and development has been included in the list of potential mechanisms, only recently have field studies below dams focused on this interrelationship. This study investigates the overall community structure as well as the seasonal pattern of larval growth and development for several univoltine species of insects in the Delaware River below or near the hypolimnetic discharge of the Cannonsville and Pepeacton dams. These dams, which ...

Use of man-made impoundment in mitigating acid mine drainage in the North Branch Potomac River

Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300TM in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight ...

2010-05-01

Transfer of 137Cs and 60Co in a waste retention pond with emphasis on aquatic insects

The US Department of the Army, Baltimore District Corps of Engineers, oversees a long-term monitoring study to assess and evaluate effects of the Jennings-Randolph reservoir on biota in the North Branch Potomac River. The reservoir was intended, in part, to mitigate effects of acid mine drainage originating in upstream and headwater area. The present study assessed recovery of benthos and fish in this system, six years after completion of the reservoir. Higher pH and lower iron and sulfate concentrations were observed upstream of the reservoir compared to preimpoundment conditions, suggesting better overall water quality in the upper North Branch. Water quality improved slightly directly downstream of the reservoir. However, the reservoir itself was poorly colonized by macrophytes and benthic organisms, and plankton composition suggested either metal toxicity and/or nutrient limitation. One large tributary to the North Branch and the reservoir (Stony River) was ...

Terra Nova Environmental effects monitoring program

The objectives of this research were (1) to analyze the transfers of 137Cs and 60Co in a retention pond, with emphasis on aquatic insects and (2) to determine if detectable concentrations of these radionuclides are exported by emerging aquatic insects. We analyzed the radionuclide concentrations in the following components: water solution, bottom sediments, suspended particulate matter, plankton, floating mats of filamentous algae, benthic macroinvertebrates, and emerging aquatic insects. Samples were collected quarterly from June 1981 to April 1982. The lowest concentrations (in picocuries per milliliter) occurred in solution (range: 1.4 X 10(2) to 3.2 X 10(2) for 137Cs and 8.1 X 10(-1) to 2.2 X 10(0) for 60Co). The highest concentrations (in picocuries per gram dry weight) occurred in the sediments (range: 1.5 X 10(4) to 1.1 X 10(8) for 137Cs and 1.0 X 10(2) to 4.3 X 10(6) for 60Co). The primary producers and aquatic insect consumers had concentrations of both ...

Recovery and reconnaissance of the Leading Creek watershed, Meigs County, Ohio, following a dewatering of Meigs number-sign 31 coal mine

Elements of the environmental effects monitoring program in the Terra Nova oil field, about 350 km east-southeast of St. John's, Newfoundland, are described. This oilfield is being developed using a floating production storage and offloading (FPSO) facility. A total of 24 wells are expected to be drilled through seven subsea templates located in four glory holes to protect them from icebergs. Subsea installations will be linked to the FPSO by trenched flowlines connected to flexible risers. The FPSO will offload to shuttle tankers. First oil is expected in 2001. The environmental effects monitoring program will be conducted annually for the first two years beginning in 2000. Subsequent scheduling will be determined after a review of monitoring data collected during the first three years. Input to the design of the monitoring program was provided by all stakeholders, i. e. owners, local public, government agencies and regional and international experts. A model was developed ...

2000-07-01

Radioactivity in sediments of the Great Lakes: post-depositional redistribution by deposit-feeding organisms

A database has been developed before and after the dewatering of the Meigs number-sign 31 deep coal mine in Meigs County, Ohio, three years ago. This strategy was to compare potential recovery of the watershed in the mainstem of Leading Creek as well as to reconnaissance the tributaries for point-source input into the creek. After the dewatering process, #approx# half of the 31-mile Leading Creek mainstem received a discharge of conductivity, low pH, high metals (iron, manganese, copper, aluminum), and total suspended solids (TSS). Most forms of aquatic life in the creek were depleted in the impacted areas, but recovery has been encouraging. Relative fish abundance has returned to pre-event levels, while benthic macroinvertebrates show recovery in two key stream segments. Reconnaissance of the watershed indicated that the system is uniquely segregated with high sedimentation from agricultural input in the upper half and abandoned mined land (AML) discharges in the ...

1996-11-17

Influence of Hexagenia on the fate and bioavailability of contaminants in sediment

At two locations in southern Lake Huron (U.S.A.), twelve 35.5-cm diameter cores of fine-grained sediments were taken for comparison of the vertical distribution of "2"1"0Pb and fallout "1"3"7Cs with the distribution of benthic macroinvertebrates, mainly oligochaete worms (Tubificidae) and the amphipod, Pontoporeia affinis. Locations were selected on the basis of "2"1"0Pb distributions measured a year earlier which indicated contrasting depths of mixing of surface sediments. At one location the activity of "2"1"0Pb is uniform down to about 6 cm and 95% of total invertebrates occur within this zone; at the other location the zone of constant activity is only 3 cm deep but 90% of the invertebrates occur within it. Comparison of published tubificid defecation rates with sediment accumulation rates based on "2"1"0Pb shows that oligochaetes alone can account for mixing in one case while the effects of amphipods may be required in the case of shallower mixing. If mixing ...

Increased Mercury Bioaccumulation Follows Water Quality Improvement

The influence of sediment dwelling macroinvertebrates on fate and bioavailability of contaminants in freshwater systems was determined using the burrowing mayfly, Hexagenia limbata, as a representative benthic organism. Two series of experiments were conducted: the first to determine the effect of mayflies on movement of contaminants into sediment and organisms, and the second to examine the effect of mayflies on release of contaminants from sediments to the water column and their subsequent accumulation in fish. Concentrations of "1"4C labelled DDT, hexachlorobenzene (HCB), and dihexylphthalate (DHP) in water were 0.11 +/- 0.01, 0.062 +/- 0.005 and 0.006 +/- 0.007 ppb, respectively. Total mass of DHP in the burrow wall was about equal to mass on the surface, indicating that mayflies were capable of doubling the amount of DHP sorbed per unit surface area of sediment. Adsorption of contaminants from water pumped through mayfly burrows increased depth of penetration ...

Ecological risk assessments for protected migratory birds and marine species at Midway Atoll

Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics ...

Dual radiotracer measurement of zoobenthos-mediated solute and particle transport in freshwater sediments

In June 1997, the US Navy plans to close its Naval Air Facility on Sand Island and transfer the atoll to the US Fish and Wildlife Service for use as a National Wildlife Refuge. Midway provides breeding and feeding habitat for migratory seabirds, terrestrial and marine mammals, sea turtles and other reptiles, and a variety of reef fishes and invertebrates. As part of the base closure and transfer process, 36 sites of potential environmental concern were identified on Sand and Eastern islands. These sites include landfills and uncontrolled disposal areas, hazardous materials storage areas, abandoned transformers, sewer outfalls, and other potential hazardous waste sites. Potential contaminants include pesticides, PAHs, PCBs, and heavy metals. A screening ecological risk assessment was performed at each site with a goal of determining whether contaminants could pose any current or future risks to protected migratory bird or marine mammal wildlife species. Specific exposure pathways ...

1995-12-31

Deep-ocean record of major late Cenozoic rhyolitic eruptions from New Zealand

#gamma# spectroscopy methods have been applied to determine the effects of two freshwater benthic macroinvertebrates, on reworking of sediments and the transfer of solutes across the sediment-water interface. Natural lake sediments and overlying water were contained in temperature-regulated rectangular plastic cells. After addition of Stylodrilus (oligochaete worms) and Pontoporeia (crustacean amphipods) to these microcosms, the vertical distribution of Cs-137 (a tracer of particle transport) and Na-22 (a tracer of solute transport) were determined. In cells with Stylodrilus, the Cs-137 layer moved downward at a rate that decreased exponentially with time. In cells with Pontoporeia, Cs-137 activity was smeared downward in time owing to eddy diffusive mixing of sediments over a small range (1-2 cm). In cells without worms, the veneer of Cs active material remained at the interface while the penetration of Na-22 into sediments was consistent with diffusion in free ...