Bay Off Research Articles

P,p′-DDE bioaccumulation in female sea lions of the California Channel Islands

An area of sediment on the Palos Verdes shelf and in Santa Monica Bay off Los Angeles, CA is contaminated with DDE and other breakdown products of DDT as a result of discharges of DDT through the Whites Point outfall. Elevated concentrations of DDE have been found in the water column of the Palos Verdes Shelf and in various fish species inhabiting the shelf and Santa Monica Bay. High concentrations have also been found in California sea lions from San Miguel Island and sea lion carcasses on Santa Catalina Island. These islands are located some distance from the Palos Verdes shelf and Santa Monica Bay. It was the purpose of this study to determine if it is likely that the Palos Verdes Shelf/Santa Monica Bay sediments were the principal source of the DDE in the Channel Island sea lions via a pathway from sediments to water and fish preyed on by sea lions. A time variable, age dependent, physiologically based toxicokinetic model of female California sea lions was developed. Mass and energy balance equations describe the uptake and loss of contaminants. The contaminants are partitioned among multiple body compartments, including lipid and non-lipid body tissue and milk. Contaminants are distributed into a fetus of females. Physiological and toxicokinetic data were used to establish rates of growth, respiration, reproduction and lactation, internal partitioning of DDE, efficiency of DDE uptake and rates of DDE excretion. The model was used to estimate the likely DDE exposure history of the sea lions in view of their DDE body burdens. Field-measured dietary composition and prey contaminant levels were then used to establish potential exposure to DDE from various regions within the Southern California Bight. Comparison of the estimated exposure history with that attainable from the various regions indicated that the more highly contaminated lactating females were exposed to prey at levels found only on the Palos Verdes Shelf and in Santa Monica Bay. Thus, it is likely that the sediments impacted by the Whites Point outfall were the source of much of the DDE and PCBs in these animals.

GIS-assisted site selection for artificial reefs

: Five geographic information system (GIS) grid themes, water depth, bottom type, topographic slope, distance to coast and distance to fishing ports, were adapted to evaluate and select a site for artificial reef deployment in I-Lan Bay off north-eastern Taiwan. From AHP (analytic hierarchy process) analysis, the weights of suitability of the five GIS grid themes were 0.416, 0.141, 0.331, 0.074, and 0.038, respectively. The results show that water depth is the most important factor in selecting a site for an artificial reef. Using ArcView, a GIS software package, a suitability map was made based on the selected grid themes. The suitable sites for artificial reef deployment identified by the GIS method corresponded to the sites selected using the traditional non-GIS approach. Based on the individual GIS grid themes, the GIS software and AHP method can be integrated to select objectively the optimal sites for artificial reef deployment.

Vertical Changes of Holocene Ostracodes in Bore Hole Cores from off Kobe, Related to the Opening of Straits and Relative Sea-Level Change in Western Japan.

Fossil ostracodes were studied in two bore hole cores (OB-1 and OB-2) from Osaka Bay off Kobe in western Japan to examine vertical changes in ostracode faunas. Fifty-two species were identified in 56 sediment samples. Based on numerical analyses of these ostracodes, the samples examined are grouped into five biofacies: BM (brackish mud), SM (shallow mud), SS (shallow sandy mud), DS (deep sandy mud) and DM (deep mud). These biofacies are distributed in upward sequence in both cores. From ca. 11, 000-10, 000cal yrs BP, the predominant species living were those dominant in enclosed inner brackish bays at water depths of 2-7m. Inner to middle, enclosed shallow muddy bay species increased at the study sites after the opening of the Akashi Strait (ca. 9, 700cal yrs BP). Ostracode assemblages changed ca. 8, 000cal yrs BP, when Osaka and Harima-nada Bays were connected with Mizushima-nada Bay. Tidal currents from the Akashi Strait have since been strong. As a result, specimens of intertidal to shoreface species were transported with sandy sediments into deeper Osaka Bay off Kobe. Thus, their individual numbers increased rapidly. A peak in the number of intertidal to shoreface species and deep mud-dwellers occurred around 5, 500cal yrs BP, suggesting that tidal currents from the Akashi Strait and paleo-water depth reached their maxima at this time (ca. 33m). These species then decreased with time, with the start of a regression. After ca. 2, 000-1, 600cal yrs BP, mud-dwellers inhabiting enclosed, organic matter-rich bays were abundant. Their numbers increased further as coarse materials from the Akashi Strait decreased and the Yodo River began to bring flood clays into the study sites. Both “form A” and “form M” of Bicornucythere bisanensis are present in both core samples. “Form M” first invaded the study sites through the Kitan Strait to the south. “Form A” came to Osaka Bay off Kobe, ca. 8, 350-8, 000cal yrs BP, and has since become the dominant of the two forms.

Synoptic weather conditions during the pilot study of Bay of Bengal and Monsoon Experiment (BOBMEX)

BOBMEX-Pilot was organised from 23rd October–11th November, 1998 when the seasonal trough had already shifted to south Bay of Bengal. The activity during this period was marked by the development of a monsoon depression from 26th–29th October that weakened over the sea; onset of northeast monsoon along the east coast of India on 29th October; a low pressure area that formed on 2nd November over southwest Bay off Sri Lanka — southTamilnadu coast; and another cyclonic circulation that formed towards the end of the BOBMEX-Pilot period. This paper describes the development of these synoptic systems through synoptic charts and satellite data.

Discovery of crab fossils from the bottom of Tosa Bay off Shikoku, Japan(Photo)

Discovery of crab fossils from the bottom of Tosa Bay off Shikoku, Japan(Photo)

Determination of the freshwater mark in otoliths of Japanese eel elvers using microstructure and Sr/Ca ratios

The microstructure, in particular checks within the otolith edge, of Anguilla japonica glass-eels and elvers and changes in otolith Sr/Ca ratios were examined to ascertain the environmental history of the eels, especially with regard to the time when glass-eels entered the river, and as a benchmark for count daily increments. The percentage of glass eels and elvers with checks and the mean number of checks within the otoliths of glass-eels caught at four localities, Tosa Bay off Tosa City, the mouth of the Gokase River, the mouth of the Saigo River and the dam of the Tsuri River were 0% (0), 15.0% (0.2), 51.6% (1.0) and 100.0% (4.2), respectively. The Sr/Ca ratios and Sr content peaked in the region where checks were formed and the values decreased rapidly towards the edge of the checks; on the other hand, these decreased gradually in the otolith when checks were not formed. These checks were estimated to be formed by stress when the glass-eels were affected by ambient fresh water within the river. The innermost check was called the ‘freshwater mark’ in the present study and this mark may be useful as a benchmark in studying the growth history of the eel before and after entering freshwater.

The Influence of Winds and Tides in the Formation of Circulation Layers in a Bay, a Case Study: Concepción Bay, Chile

Horizontal water velocities were measured using three current meters moored at the levels of 5, 18, and 30m depth in the oriental side of Concepción Bay (36°40′S; 73°02′W), an almost rectangular, shallow bay off central Chile, connected with the open sea through two mouths.The large momentum transfer from the wind to the water causes variations of the internal volume of the bay generating circulation layers having almost anti-parallel directions. Northerly winds carry superficial water into the bay, causing a compensating flow leaving the bay near its bottom. Winds from the SW, on the other hand, cause an outgoing circulation layer in the surface and a circulation layer entering into the bay near the bottom. During wind calm periods, longer than 12h, the two layers disappear, leaving a current system comprising only one circulation layer. The response time necessary for the generation or dissipation of these layers, which fluctuates between 1 and 7h, depends on the initial conditions of the bay and on the intensity, direction and persistence of the wind.

Genetic relationships among subpopulations of the American lobster (Homarus americanus) as revealed by random amplified polymorphic DNA

Random amplified polymorphic DNA (RAPD) profiles were used in a preliminary investigation of the genetic relationships among American lobsters (Homarus americanus) from the ecologically disparate and geographically separate regions of the southern Gulf of St. Lawrence, a bay off southwestern Nova Scotia, and a deep-sea canyon off Georges Bank. Phenotypic analyses of the RAPD bands showed no significant difference between samples caught at these three geographic locations. Lobsters from the Gulf of Maine, collected inshore from Lobster Bay, Nova Scotia, and offshore from Georges Bank, were genetically the most similar (D = 0.002), whereas Gulf of St. Lawrence lobsters were about three times as genetically distant from these two subpopulations (D = 0.005-0.006). However, FSTvalues at each RAPD band ranged from <0.000 to 0.073, indicating that lobsters at these three locations are not genetically isolated. The number of migrants needed to account for this observed level of genetic differentiation could be as few as five animals in each generation. The present findings should not have been surprising given the enormous potential for larval dispersal, the wide ranging movements of adult lobsters within each region, and the level of anthropogenic interference through both displacement of larvae and adults over the past century in the name of conservation, particularly adults released into the Gulf of Maine.

Source Apportionment of Pb Pollution in the Coastal Waters of Elefsis Bay, Greece

206Pb/207Pb isotope ratios were measured by ICP−MS in both seawater and sediments sampled in the severely polluted Elefsis Bay off Athens, Greece. The Pb isotope ratios found were significantly lower than those of local background or industrial sources and are influenced by the isotopic composition of gasoline lead (206Pb/207Pb = 1.06). Pb pollution of the sediments is dominated by industrial activities (70−80%) leading to enrichment factors of up to 18. However, up to 70% of dissolved Pb in Elefsis Bay is derived from gasoline lead. 206Pb/207Pb ratios in seawater were used to trace the direction of surface flow of the contaminant plume, which was from southeast to northwest during the December 1989 cruise, but with winds blown opposite to the normal trend. The lateral Pb isotope pattern points toward the Athens sewage outfall at Keratsini Channel with surface runoff from the greater Athens area as the primary source rather than direct atmospheric impact. The isotope pattern in sequential extractions of sediments suggest that the gasoline-derived Pb fraction accumulates by precipitation with sulfide phases at rates of 2 ± 0.5 mg m2 yr-1 during summer anoxia. Vertical Pb isotope profiles in seawater measured at all seasons indicate that this fraction is probably not remobilized upon breakdown of the pycnocline in winter and reoxidation of the sediment−water interface.

A review of the hydrogeological studies for the Cardiff Bay Barrage

Abstract Plans to construct a barrage across the entrance to Cardiff Bay on the South Wales coast were evolved by the Welsh Office in 1986 in parallel with proposals to establish an Urban Development Corporation to redevelop 1080 hectares of derelict land in South Cardiff. The proposed barrage which is 1.4 kilometres in length will cut the bay off from the adjacent Severn Estuary. The project was first promoted in 1987 necessitating a Parliamentary Bill to permit its construction in tidal waters. Since the first private Bill was introduced in November 1987 there has been concerted opposition to the proposals, in the main due to the inundation of a winter feeding ground for wading birds (protected SSSI), concerns over water quality and flooding, and fears of a catastrophic rise in groundwater level as a result of the impoundment and the impact of such a rise on the infrastructure of the city. This paper reviews the work undertaken to assess the impact of the impoundment on the existing groundwater regime as presented to the various Parliamentary Committees and to the public.

Short term variations of the anticyclonic circulation in Bahía Sebastián Vizcaíno, BC

Hydrographic observations of currents and satellite images obtained from 7 to 19 September 1992 were used to analyze variability, on a time scale of days, of a anticyclonic eddy located in Bahía Sebastián Vizcaíno. The results indicate that during September 1992 there was a close relationship between the superficial manifestation of a warm-water eddy in the interior of Bahía Sebastián Vizcaíno and the intensification or relaxing of the upwelling to the north of the bay off Punta Baja. During episodes of intense wind from the northwest, the eddy was delimited by marked gradients of surface temperature, generated by the advection of low-temperature water that rose to the surface in Punta Baja and was transported towards the interior of the bay. During periods on the order of days, the diameter of the eddy fluctuated between 55 and 75 km and its depth between 40 and 55 m; these fluctuations were associated with variations in the wind intensity. A noteworthy characteristic of the wind field in the interior of the bay was the generation of a calm zone to the southwest of Isla de Cedros when winds from the northwest were present. The wind stress curl resulting from that distribution produces a convergence in the Ekman transport, which, according to the recent results of a barotropic model applied to Bahía Sebastián Vizcaíno (Palacios et al., in preparation), is the mechanism responsible for generating the anticyclonic eddy. The observations made indicate that there also exists an important baroclinic response to this convergence of the Ekman transport.

An input/output flux for lead in a coastal bay off Alexandria region

During 1987, seawater, rain, dust and drainage water samples were collected from Abu-kir bay (360 km2) east of Alexandria city to set up and evaluate the relative importance of different sources to the biogeochemical cycle of Pb in the bay. The mean total concentration of Pb in the bay water was 455 ± 180 and 785 ± 287 ng kg−1 during low and high flow periods, respectively. About 75 ±12% are in the particulate form. The bay receives annually about 8.12 ± 2.18 and 6.13 ± 1.06 ± of Pb through agricultural and industrial discharge. In addition, 0.48 ± 0.11 ± yr−1 and 0.23 ± 0.04 t yr−1 of Pb reaches the bay through wet and dry depositions, respectively. The outflowing surface water from the bay carries 15.4 ± 3.6 t Pb yr−1 to the southeastern Mediterranean waters. Data from sedimentation traps indicated that the bulk sedimentation rate in the bay was 95 ± 18 kg yr−1 elevating the concentrations of Pb in sediments to more than 64 μg g−1. The imbalance in the Pb flux (excess + 0.6 ± 0.08 t) indicates Pb accumulation in the water column. The apparent residence time of Pb in the bay is 62 ± 15 d. The assimilative capacity of Pb in the bay expressed in terms of Pb loading / in bay concentration amounted to 25 ± yr−1/ μg L−1. A 10% reduction in the present day load to the bay will yield a Pb concentration of less than 0.1 μg kg−1 after 11 to 12 yr.

Venerable Presidio Houses Varied Medical, Research Programs for Army

GOLDEN GATE BRIDGE spanning the sparkling bay off to one side, picture-pretty houses on the hills of the beckoning city on another, and buildings stretched out for acres all across the historic manicured grounds of the oldest established military base in the United States—that's the Presidio of San Francisco, Calif. In this idyllic setting is the Letterman Army Institute of Research. On September 14, 1966, the Department of the Army established the US Medical Research Unit at the Presidio. Its mission was to conduct general research in medicine and dentistry. Then, between 1969 and 1973, four other activities were combined to form the Letterman Army Institute of Research. Letterman Army Medical Center, also at the Presidio, is under the Army's Health Services Command and trains military interns and residents, while Letterman Army Institute of Research is under the Army Research and Development Command. The medical center, an approximately 400-bed facility

Prymnesium calathiferum sp. nov. (Prymnesiophyceae), a new species isolated from Northland, New Zealand

Abstract Prymnesium calathiferum sp. nov. is described from samples taken during a summer phytoplankton bloom dominated by Cerataulina pelegica (Cleve) Hendey, which occurred in Bream Bay off Northland, New Zealand. This new species, which is closely related to P. parvum Carter, was implicated in fish and shellfish mortalities in the area. Isolates of P. calathiferum were examined using both light and electron microscopy. Prymnesium calathiferum may be separated from the other six species of Prymnesium by several features. Firstly, P. calathiferum has elaborate wicker-basket-like external scales which are unique to this species, and secondly, it has the greatest ratio of flagella to cell length and the lowest ratio of haptonema to flagella length of all known Prymnesium species.

えびひき網のえい網時間が漁獲効率に与える影響

A shrimp Metapenaeopsis acclivis (RATHBUN) is caught commercially as a bait for long-line fishing in the western part of Wakasa Bay off Kyoto Prefecture. The shallow parts of the area of less than 40m depth are optimal area of distribution of this species. Beam trawlings were conducted experimentally in this area in May and October 1982. The fishing boats employed had a displacementof 3 gross tons with a 35 H. P. engine. The times of trawling operations were 15, 30, 45, 60, 75, 90 and 120 minutes per haul at a speed of 1-2 knots and three kinds of nets with different cod-end in stretched mesh size, 13.0mm, 14.3mm, 15.8mm, together with a cod-end cover of 4mm mesh size, were alternately used.Catches of shrimp in number increased linearly with the protraction of towing duration. The difference in catches between May and October depended upon the shrimp density, which in October seemed to be about 1.8 times as much as in May.Shrimps ranged from 15mm to 95mm in total length. There appeared to be a prominent group in the size distribution of shrimp in May and two prominent groups in October regardless of the towing duration. The mesh selectivity in May was sharper than that in October as a whole, because of a large number of small sized shrimps in October. In the case of rather longer towing duration than 45 minutes, the marked differences of sharpness of mesh selectivity were not discerned. As the mesh size of cod-end used became smaller, the selectivity was sharpened when towing duration were shorter than 30 minutes.

Landsat classification of the coastal water areas of the Bothnian bay off Oulu [Finland]: a pilot study : Arkimaa, Hilkka and Jouko Raitala, 1984. Finn. mar. Res., 250:45–51. Geol. Surv. of Finland, Kivimiehentie 1, SF-02150 Espoo 15, Finland

Landsat classification of the coastal water areas of the Bothnian bay off Oulu [Finland]: a pilot study : Arkimaa, Hilkka and Jouko Raitala, 1984. Finn. mar. Res., 250:45–51. Geol. Surv. of Finland, Kivimiehentie 1, SF-02150 Espoo 15, Finland

Water masses and circulation in the region of Prydz Bay, Antarctica

Hydrographic and expendable bathythermograph (XBT) measurements are used to describe the characteristics and circulation of the water within and to the north of Prydz Bay, Antarctica. The surface waters in Prydz Bay are highly variable and are linked to the local ice conditions. The isolation of a warm surface feature corroborates previous suggestions of a permanent high surface temperature anomaly. Water mass analysis reveals both high- and low-salinity varieties of continental shelf water and a significant Ice Shelf Water mode. Low-salinity shelf water is confined to the West Ice Shelf region and high-salinity shelf water to the central and western areas of Prydz Bay. The Ice Shelf Water mass is related to freezing beneath the Amery Ice Shelf and to prolonged isolation due to topographic restraints. There is evidence of strong vertical convection in Prydz Bay and on the continental shelf. The present analysis indicates no evidence of Antarctic Bottom Water formation in Prydz Bay but recognizes the possibility of contributions from the region west of the bay off Enderby Land. Geostrophic calculations show predominantly westward flow adjacent to the continental rise and a large cyclonic gyre in Prydz Bay. The off-shelf pattern is consistent with previous calculations from hydrographic data and with iceberg and buoy observations. The water masses and circulation within Prydz Bay resemble those of similar sites within the Weddell and Ross seas but there are significant differences in the large-scale circulations and in the geostrophic and topographic constraints imposed on the flows.

Steroid transformations in Recent marine sediments

The surface sediments and overlying water column from 3 Recent sedimentary environments—Walvis Bay off southwestern Africa, the Black Sea and the western North Atlantic—have been analyzed for stenols and their transformation products, stanols, sterenes, and steroid ketones. The steroid distributions in surface sediments are controlled by inputs from source organisms and from microbial or chemically mediated reactions occurring at the sediment-water interface or in the overlying water column. A general correlation was found to exist for various steroidal compounds in sediments from each area, suggesting related reaction sequences. Also, the steroid transformation products correlated with photoproduction in the overlying waters as well as with the oxic and anoxic conditions of the sedimentary environment.

Pb 210 -Determined Sedimentation Rate, and Accumulation of Metals in Sediments at a Station in Chesapeake Bay

This paper contains the first published radiometrically determined contemporary sedimentation rate, a rate characteristic of the past few decades, for any part of the Chesapeake Bay estuarine system. Cores collected from a station in the main body of the Chesapeake Bay off Tilghman Island (38°41′30″N, 76°24′00″W) were analyzed for Pb210, organic carbon, nitrogen, and selected metals. A mean sedimentation rate of between 0.09–0.12 cm/y was inferred from the Pb210 data. The distributions of C and N are typical of many areas of the Bay. The distributions of extractable Ni, Cr, Cu, and Pb increased in the upper 10–15 cm of the core. The increases in metal concentrations over the past century or so may be a result of man’s activities.

Survey of metals in sediments near Quonset Point, Rhode Island

Elevated levels of silver, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc were observed in sediments collected from Narragansett Bay off Quonset Point during autumn of 1973. The probable source of the metals contamination was an electroplating facility on Quonset Point, in continuous operation from 1943 until it was closed in spring of 1973. Data on elemental composition of surficial sediments collected from various geographical locations reported by other investigators are presented and compared to those reported herein.