138 resultados para Bank lending channel
em Aquatic Commons
Resumo:
This is the River habitat survey and geomorphological evaluation of the Glaze Brook Catchment report produced by the Environmental Research and Consultancy of the University of Liverpool in 2002. The major aims of the project were to provide baseline information on river habitats in the Glaze catchment using standard River Habitat Survey (RHS) methods (sampling 25% of the catchment length) and, through the geomorphological audit, to assess the distribution and intensity of geomorphological processes, notably sediment transfer, sources and sinks. This information was then used to develop informed management recommendations. The Glaze catchment is a heavily modified watercourse of generally poor habitat quality. The most important factors contributing to the low quality of the sites are poor bank and channel features; low diversity/absence of channel vegetation; paucity of bankside trees and, to a lesser extent, a lack of channel substrate diversity. The high degree of modification relates principally to extensively resectioned banks and channels plus extensive culverting in the urban parts of the catchment.
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In this report we describe the temporal and spatial distributions of inorganic nutrients over Georges Bank and in adjacent waters and discuss major features with respect to tbe nutrient environments of pbytoplankton. Nitrate and orthophosphorus were rapidly depleted from the surface layer of much of the study area in spring, but major differences were found between the shallow areas on Georges Bank and the surrounding stratified waters. In the "well-mixed" area of Georges Bank, the depletion encompassed the entire water column and ammonium became the dominant form of inorganic nitrogen throughout. Dissolved silicon was depleted slowly over central Georges Bank, reaching a minimum concentration in September while orthophosphorus gradually increased during the summer. The nutrient environment of phytoplankton over central Georges Bank may be described as vertically uniform but temporally changing in the relative availability of the various nutrients. In areas that undergo stratification (e.g., the central Gulf of Maine), a quasi-steady state was established as the surface water layer formed, consisting of declining nutrient gradients from below the euphotic layer to the top of the water column. These intergrading nutrient environments are relatively stable through time. Destratification reintroduced nutrients to depleted areas beginning in October; however, dissolved silicon was again depleted over shallow Georges Bank in late autumn though nitrate remained abundant. Slope water has been found to enter the bottom layer of the Gulf of Maine via the Northeast Channel. High nutrient concentrations observed in the bottom water of the Northeast Channel are consistent with this mechanism being the nutrient source for the Gulf of Maine. (PDF file contains 40 pages.)
Resumo:
This study was conducted to assess the impact of Nigerian Agricultural, Co-operative and Rural Development Bank Loan on beneficiaries and non-beneficiaries fishermen in Lake Kainji. A total of fifty fishermen (25 beneficiaries and 25 non-beneficiaries) were randomly selected from five fishing villages along the lake basin. Data collected were scored and the percentages of the parameters were calculated appropriately. The types of loans disbursed to beneficiaries revealed that 52% was cash and 48% was in kind. The credit package ranged between N5, 000 to N150, 000 only. Only 48% of the loans granted were paid while the rest remained unpaid. The results obtained from the membership of fishermen Cooperative showed that 64% of beneficiaries were members while 36% were non-members. Also 36% of non-beneficiaries were members while 64% were not. The Common fishing gears used by the two categories of fishermen include gillnets longline, castnet and driftnets. Sixty percent of beneficiaries and 8% of non-beneficiaries fishermen were using canoe with outboard engines while the rest used canoes with paddles. Beneficiaries earned a higher income (N1, 000 to N9, 000) daily than non-beneficiaries (N1, 000 to N6, 000) daily from sales of fish caught. Major contrainsts to increased catch and income identified include inadequate capital, non- availability of fishing inputs, stealing of fishing gears, lack of access to credit facilities and menace of stump and water hyacinth in the lake. Lastly, recommendation were made for the bank management, government and other lending institutions on how to improve the livelihood of the Artisanal fishermen by increasing the loan usually granted
Resumo:
NMFS bottom trawl survey data were used to describe changes in distribution, abundance, and rates of population change occurring in the Gulf of Maine–Georges Bank herring (Clupea harengus) complex during 1963–98. Herring in the region have fully recovered following severe overfishing during the 1960s and 1970s. Three distinct, but seasonally intermingling components from the Gulf of Maine, Nantucket Shoals (Great South Channel area), and Georges Bank appear to compose the herring resource in the region. Distribution ranges contracted as herring biomass declined in the late 1970s and then the range expanded in the 1990s as herring increased. Analysis of research survey data suggest that herring are currently at high levels of abundance and biomass. All three components of the stock complex, including the Georges Bank component, have recovered to pre-1960s abundance. Survey data support the theory that herring recolonized the Georges Bank region in stages from adjacent components during the late 1980s, most likely from herring spawning in the Gulf of Maine.
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The Channel Islands—sometimes called the Galapagos of North America—are known for their great beauty, rich biodiversity, cultural heritage, and recreational opportunities. In 1980, in recognition of the islands’ importance, the United States Congress established a national park encompassing 5 of California’s Channel Islands (Santa Barbara, Anacapa, Santa Cruz, Santa Rosa, and San Miguel Islands) and waters within 1 nautical mile of the islands. In the same year, Congress declared a national marine sanctuary around each of these islands, including waters up to 6 nautical miles offshore. Approximately 60,000 people visit the Channel Islands each year for aquatic recreation such as fishing, sailing, kayaking, wildlife watching, surfing, and diving. Another 30,000 people visit the islands for hiking, camping, and sightseeing. Dozens of commercial fishing boats based in Santa Barbara, Ventura, Oxnard, and other ports go to the Channel Islands to catch squid, spiny lobster, sea urchin, rockfish, crab, sheephead, flatfish, and sea cucumber, among other species. In the past few decades, advances in fishing technology and the rising number of fishermen, in conjunction with changing ocean conditions and diseases, have contributed to declines in some marine fishes and invertebrates at the Channel Islands. In 1998, citizens from Santa Barbara and Ventura proposed establishment of no-take marine reserves at the Channel Islands, beginning a 4-year process of public meetings, discussions, and scientific analyses. In 2003, the California Fish and Game Commission designated a network of marine protected areas (MPAs) in state waters around the northern Channel Islands. In 2006 and 2007, the National Oceanic and Atmospheric Administration (NOAA) extended the MPAs into the national marine sanctuary’s deeper, federal waters. To determine if the MPAs are protecting marine species and habitats, scientists are monitoring ecological changes. They are studying changes in habitats; abundance and size of species of interest; the ocean food web and ecosystem; and movement of fish and invertebrates from MPAs to surrounding waters. Additionally, scientists are monitoring human activities such as commercial and recreational fisheries, and compliance with MPA regulations. This booklet describes some results from the first 5 years of monitoring the Channel Islands MPAs. Although 5 years is not long enough to determine if the MPAs will accomplish all of their goals, this booklet offers a glimpse of the changes that are beginning to take place and illustrates the types of information that will eventually be used to assess the MPAs’ effectiveness. (PDF contains 24 pages.)
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Research cruises were conducted in August-October 2007 to complete the third annual remotely operated vehicle (ROV)-based assessments of nearshore rocky bottom finfish at ten sites in the northern Channel Islands. Annual surveys at the Channel Islands have been conducted since 2004 at four sites and were expanded to ten sites in 2005 to monitor potential marine protected area (MPA)effects on baseline fish density. Six of the ten sites are in MPAs and four in nearby fished reference areas. In 2007 the amount of soft-only substrate on the 141 track lines surveyed was again estimated in real-time in order to target rocky bottom habitat. These real-time estimates of hard and mixed substrate for all ten sites averaged 57%, 1% more than the post-processed average of 56%. Surveys generated 69.9 km of usable video for use in finfish density calculations, with target rocky bottom habitat accounting for 56% (39.1 km) for all sites combined. The amount of rocky habitat sampled by site averaged 3.8 km and ranged from 3.3 km sampled at South Point, a State Marine Reserve (SMR) off Santa Rosa Island, to 4.7 km at Anacapa Island SMR. A sampling goal of 75 transects at all 10 sites was met using real-time habitat estimates combined with precautionary over-sampling by 10%. A total of seventy kilometers of sampling is projected to produce at least seventy-five 100 m2 transects per site. Thirteen of 26 finfish taxa observed were selected for quantitative evaluation over the time series based on a minimum criterion of abundance (0.05/100 m2). Ten of these 13 finfish appear to be more abundant at the state marine reserves relative to fished areas when densities were averaged across the 2005 to 2007 period. One of the species that appears to be more abundant in fished areas was señorita, a relatively small prey species that is not a commercial or recreational target. (PDF contains 83 pages.)
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Executive Summary: The western National Coastal Assessment (NCA-West) program of EPA, in conjunction with the NOAA National Ocean Service (NOS), conducted an assessment of the status of ecological condition of soft sediment habitats and overlying waters along the western U.S. continental shelf, between the target depths of 30 and 120 m, during June 2003. NCA-West and NOAA/NOS partnered with the West Coast states (Washington (WA), Oregon (OR), and California (CA)), and the Southern California Coastal Water Research Project (SCCWRP) Bight ’03 program to conduct the survey. A total of 257 stations were sampled from Cape Flattery, WA to the Mexican border using standard methods and indicators applied in previous coastal NCA projects. A key study feature was the incorporation of a stratified-random sampling design with stations stratified by state and National Marine Sanctuary (NMS) status. Each of the three states was represented by at least 50 random stations. There also were a total of 84 random stations located within NOAA’s five NMSs along the West Coast including the Olympic Coast NMS (OCNMS), Cordell Bank NMS (CBNMS), Gulf of Farallones NMS (GFNMS), Monterey Bay NMS (MBNMS), and Channel Islands NMS (CINMS). Collection of flatfish via hook-and-line for fish-tissue contaminant analysis was successful at 50 EMAP/NCA-West stations. Through a collaboration developed with the FRAM Division of the Northwest Fisheries Science Center, fish from an additional 63 stations in the same region and depth range were also analyzed for fish-tissue contaminants. Bottom depth throughout the region ranged from 28 m to 125 m for most stations. Two slightly deeper stations from the Southern California Bight (SCB) (131, 134 m) were included in the data set. About 44% of the survey area had sediments composed of sands (< 20% silt-clay), about 47% was composed of intermediate muddy sands (20-80% silt-clay), and about 9% was composed of muds (> 80% silt-clay). The majority of the survey area (97%) had relatively low percent total organic carbon (TOC) levels of < 2%, while a small portion (< 1%) had high TOC levels (> 5%), in a range potentially harmful to benthic fauna. Salinity of surface waters for 92% of the survey area were > 31 psu, with most stations < 31 psu associated with the Columbia River plume. Bottom salinities ranged only between 31.6 and 34.4 psu. There was virtually no difference in mean bottom salinities among states or between NMS and non-NMS stations. Temperatures of surface water (range 8.5 -19.9 °C) and bottom water (range 5.8 -14.7 °C) averaged several degrees higher in CA in comparison to WA and OR. The Δσt index of watercolumn stratification indicated that about 31% of the survey area had strong vertical stratification of the water column. The index was greatest for waters off WA and lowest for CA waters. Only about 2.6 % of the survey area had surface dissolved oxygen (DO) concentrations ≤ 4.8 mg/L, and there were no values below the lower threshold (2.3 mg/L) considered harmful to the survival and growth of marine animals. Surface DO concentrations were higher in WA and OR waters than in CA, and higher in the OC NMS than in the CA sanctuaries. An estimated 94.3% of the area had bottom-water DO concentrations ≤ 4.8 mg/L and 6.6% had concentrations ≤ 2.3 mg/L. The high prevalence of DO from 2.3 to 4.8 mg/L (85% of survey area) is believed to be associated with the upwelling of naturally low DO water across the West Coast shelf. Mean TSS and transmissivity in surface waters (excluding OR due to sample problems) were slightly higher and lower, respectively, for stations in WA than for those in CA. There was little difference in mean TSS or transmissivity between NMS and non-NMS locations. Mean transmissivity in bottom waters, though higher in comparison to surface waters, showed little difference among geographic regions or between NMS and non-NMS locations. Concentrations of nitrate + nitrite, ammonium, total dissolved inorganic nitrogen (DIN) and orthophosphate (P) in surface waters tended to be highest in CA compared to WA and OR, and higher in the CA NMS stations compared to CA non-sanctuary stations. Measurements of silicate in surface waters were limited to WA and CA (exclusive of the SCB) and showed that concentrations were similar between the two states and approximately twice as high in CA sanctuaries compared to OCNMS or nonsanctuary locations in either state. The elevated nutrient concentrations observed at CA NMS stations are consistent with the presence of strong upwelling at these sites at the time of sampling. Approximately 93% of the area had DIN/P values ≤ 16, indicative of nitrogen limitation. Mean DIN/P ratios were similar among the three states, although the mean for the OCNMS was less than half that of the CA sanctuaries or nonsanctuary locations. Concentrations of chlorophyll a in surface waters ranged from 0 to 28 μg L-1, with 50% of the area having values < 3.9 μg L-1 and 10% having values > 14.5 μg L-1. The mean concentration of chlorophyll a for CA was less than half that of WA and OR locations, and concentrations were lowest in non-sanctuary sites in CA and highest at the OCNMS. Shelf sediments throughout the survey area were relatively uncontaminated with the exception of a group of stations within the SCB. Overall, about 99% of the total survey area was rated in good condition (<5 chemicals measured above corresponding effect range low (ERL) concentrations). Only the pesticides 4,4′-DDE and total DDT exceeded corresponding effect range-median (ERM) values, all at stations in CA near Los Angeles. Ten other contaminants including seven metals (As, Cd, Cr, Cu, Hg, Ag, Zn), 2-methylnaphthalene, low molecular weight PAHs, and total PCBs exceeded corresponding ERLs. The most prevalent in terms of area were chromium (31%), arsenic (8%), 2-methylnaphthalene (6%), cadmium (5%), and mercury (4%). The chromium contamination may be related to natural background sources common to the region. The 2-methylnaphthalene exceedances were conspicuously grouped around the CINMS. The mercury exceedances were all at non-sanctuary sites in CA, particularly in the Los Angeles area. Concentrations of cadmium in fish tissues exceeded the lower end of EPA’s non-cancer, human-health-risk range at nine of 50 EMAP/NCA-West and nine of 60 FRAM groundfish-survey stations, including a total of seven NMS stations in CA and two in the OCNMS. The human-health guidelines for all other contaminants were only exceeded for total PCBs at one station located in WA near the mouth of the Columbia River. Benthic species richness was relatively high in these offshore assemblages, ranging from 19 to 190 taxa per 0.1-m2 grab and averaging 79 taxa/grab. The high species richness was reflected over large areas of the shelf and was nearly three times greater than levels observed in estuarine samples along the West Coast (e.g NCA-West estuarine mean of 26 taxa/grab). Mean species richness was highest off CA (94 taxa/grab) and lower in OR and WA (55 and 56 taxa/grab, respectively). Mean species richness was very similar between sanctuary vs. non-sanctuary stations for both the CA and OR/WA regions. Mean diversity index H′ was highest in CA (5.36) and lowest in WA (4.27). There were no major differences in mean H′ between sanctuary vs. nonsanctuary stations for both the CA and OR/WA regions. A total of 1,482 taxa (1,108 to species) and 99,135 individuals were identified region-wide. Polychaetes, crustaceans and molluscs were the dominant taxa, both by percent abundance (59%, 17%, 12% respectively) and percent species (44%, 25%, 17%, respectively). There were no major differences in the percent composition of benthic communities among states or between NMSs and corresponding non-sanctuary sites. Densities averaged 3,788 m-2, about 30% of the average density for West Coast estuaries. Mean density of benthic fauna in the present offshore survey, averaged by state, was highest in CA (4,351 m-2) and lowest in OR (2,310 m-2). Mean densities were slightly higher at NMS stations vs. non-sanctuary stations for both the CA and OR/WA regions. The 10 most abundant taxa were the polychaetes Mediomastus spp., Magelona longicornis, Spiophanes berkeleyorum, Spiophanes bombyx, Spiophanes duplex, and Prionospio jubata; the bivalve Axinopsida serricata, the ophiuroid Amphiodia urtica, the decapod Pinnixa occidentalis, and the ostracod Euphilomedes carcharodonta. Mediomastus spp. and A. serricata were the two most abundant taxa overall. Although many of these taxa have broad geographic distributions throughout the region, the same species were not ranked among the 10 most abundant taxa consistently across states. The closest similarities among states were between OR and WA. At least half of the 10 most abundant taxa in NMSs were also dominant in corresponding nonsanctuary waters. Many of the abundant benthic species have wide latitudinal distributions along the West Coast shelf, with some species ranging from southern CA into the Gulf of Alaska or even the Aleutians. Of the 39 taxa on the list of 50 most abundant taxa that could be identified to species level, 85% have been reported at least once from estuaries of CA, OR, or WA exclusive of Puget Sound. Such broad latitudinal and estuarine distributions are suggestive of wide habitat tolerances. Thirteen (1.2%) of the 1,108 identified species are nonindigenous, with another 121 species classified as cryptogenic (of uncertain origin), and 208 species unclassified with respect to potential invasiveness. Despite uncertainties of classification, the number and densities of nonindigenous species appear to be much lower on the shelf than in the estuarine ecosystems of the Pacific Coast. Spionid polychaetes and the ampharetid polychaete Anobothrus gracilis were a major component of the nonindigenous species collected on the shelf. NOAA’s five NMSs along the West Coast of the U.S. appeared to be in good ecological condition, based on the measured indicators, with no evidence of major anthropogenic impacts or unusual environmental qualities compared to nearby nonsanctuary waters. Benthic communities in sanctuaries resembled those in corresponding non-sanctuary waters, with similarly high levels of species richness and diversity and low incidence of nonindigenous species. Most oceanographic features were also similar between sanctuary and non-sanctuary locations. Exceptions (e.g., higher concentrations of some nutrients in sanctuaries along the CA coast) appeared to be attributable to natural upwelling events in the area at the time of sampling. In addition, sediments within the sanctuaries were relatively uncontaminated, with none of the samples having any measured chemical in excess of ERM values. The ERL value for chromium was exceeded in sediments at the OCNMS, but at a much lower percentage of stations (four of 30) compared to WA and OR non-sanctuary areas (31 of 70 stations). ERL values were exceeded for arsenic, cadmium, chromium, 2- methylnaphthalene, low molecular weight PAHs, total DDT, and 4,4′-DDE at multiple sites within the CINMS. However, cases where total DDT, 4,4′-DDE, and chromium exceeded the ERL values were notably less prevalent at CINMS than in non-sanctuary waters of CA. In contrast, 2-methylnaphthalene above the ERL was much more prevalent in sediments at the CINMS compared to non-sanctuary waters off the coast of CA. While there are natural background sources of PAHs from oil seeps throughout the SCB, this does not explain the higher incidence of 2-methylnaphthalene contamination around CINMS. Two stations in CINMS also had levels of TOC (> 5%) potentially harmful to benthic fauna, though none of these sites exhibited symptoms of impaired benthic condition. This study showed no major evidence of extensive biological impacts linked to measured stressors. There were only two stations, both in CA, where low numbers of benthic species, diversity, or total faunal abundance co-occurred with high sediment contamination or low DO in bottom water. Such general lack of concordance suggests that these offshore waters are currently in good condition, with the lower-end values of the various biological attributes representing parts of a normal reference range controlled by natural factors. Results of multiple linear regression, performed using full model procedures to test for effects of combined abiotic environmental factors, suggested that latitude and depth had significant influences on benthic variables regionwide. Latitude had a significant inverse influence on all three of the above benthic variables, i.e. with values increasing as latitude decreased (p< 0.01), while depth had a significant direct influence on diversity (p < 0.001) and inverse effect on density (p <0.01). None of these variables varied significantly in relation to sediment % fines (at p< 0.1), although in general there was a tendency for muddier sediments (higher % fines) to have lower species richness and diversity and higher densities than coarser sediments. Alternatively, it is possible that for some of these sites the lower values of benthic variables reflect symptoms of disturbance induced by other unmeasured stressors. The indicators in this study included measures of stressors (e.g., chemical contaminants, eutrophication) that are often associated with adverse biological impacts in shallower estuarine and inland ecosystems. However, there may be other sources of humaninduced stress in these offshore systems (e.g., bottom trawling) that pose greater risks to ambient living resources and which have not been captured. Future monitoring efforts in these offshore areas should include indicators of such alternative sources of disturbance. (137pp.) (PDF contains 167 pages)
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Summary: This cruise report is a summary of a field survey conducted within the Stellwagen Bank National Marine Sanctuary (SBNMS), located between Cape Cod and Cape Ann at the mouth of Massachusetts Bay. The survey was conducted June 14 – June 21, 2008 on NOAA Ship NANCY FOSTER Cruise NF-08-09-CCEHBR. Multiple indicators of ecological condition and human dimensions were sampled synoptically at each of 30 stations throughout SBNMS using a random probabilistic sampling design. Samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants (metals, pesticides, PAHs, PCBs, PBDEs) in sediments and target demersal biota; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as depth, salinity, temperature, dissolved oxygen, turbidity, pH, sediment grain size, and organic carbon content. In addition to the fish samples that were collected for analysis of chemical contaminants relative to human-health consumption limits, other human-dimension indicators were sampled as well including presence or absence of fishing gear, vessels, surface trash, marine mammals, and noxious sediment odors. The overall purpose of the survey was to collect data to assess the status of ecosystem condition and potential stressor impacts throughout SBNMS, based on these various indicators and corresponding management thresholds, and to provide this information as a baseline for determining how such conditions may be changing with time. While sample analysis is still ongoing a few preliminary results and observations are reported here. A final report will be completed once all data have been processed. The results are anticipated to be of value in supporting goals of the SBNMS and National Marine Sanctuary Program aimed at the characterization, protection, and management of sanctuary resources (pursuant to the National Marine Sanctuary Reauthorization Act) as well as a new priority of NCCOS and NOAA to apply Ecosystem Based approaches to the Management of coastal resources (EBM) through Integrated Ecosystem Assessments (IEAs) conducted in various coastal regions of the U.S. including the Northeast Atlantic continental shelf. This was a multi-disciplinary partnership effort made possible by scientists from the following organizations: NOAA, National Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Environmental Health and Biomolecular Research (CCEHBR), Charleston, SC. U.S. Environmental Protection Agency (EPA), National Health and Environmental Effects Research Laboratory (NHEERL), Atlantic Ecology Division (GED), Narragansett, RI. U.S. Environmental Protection Agency (EPA), National Health and Environmental Effects Research Laboratory (NHEERL), Gulf Ecology Division (GED), Gulf Breeze, FL. U.S. Geological Survey (USGS), National Wetlands Research Center, Gulf Breeze Project Office, Gulf Breeze, FL. NOAA, Office of Marine and Aviation Operations (OMAO), NOAA ship Nancy Foster. (31pp) (PDF contains 58 pages)
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In the spring of 2001, NOAA’s National Marine Sanctuary Program (NMSP) and National Centers for Coastal Ocean Science (NCCOS), in consultation with the National Marine Fisheries Service (NMFS), launched a 24-month effort to define and assess biogeographic patterns of selected marine species found within and adjacent to the boundaries of three west coast National Marine Sanctuaries. These sanctuaries, Monterey Bay, Gulf of the Farallones, and Cordell Bank are conducting a joint review process to update sanctuary management plans. The management plans for these sanctuaries have not been updated for over ten years and the status of the natural resources and their management issues in and around the sanctuaries may have changed. In addition, significant accomplishments in research and resource assessments have been made within the region. Thus, it is important to incorporate new and expanding knowledge into the revised management plans for these Sanctuaries.
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Dr. Charles M. Breder participated on the 1934 expedition of the Atlantis from Woods Hole, Massachusetts to Panama and back and kept a field diary of daily activities. The Atlantis expedition of 1934, led by Prof. A. E. Parr, was a milestone in the history of scientific discovery in the Sargasso Sea and the West Indies. Although naturalists had visited the Sargasso Sea for many years, the Atlantis voyage was the first attempt to investigate in detailed quantitative manner biological problems about this varying, intermittent ‘false’ bottom of living, floating plants and associated fauna. In addition to Dr. Breder, the party also consisted of Dr. Alexander Forbes, Harvard University and Trustee of the Woods Hole Oceanographic Institution (WHOI); T. S. Greenwood, WHOI hydrographer; M. D. Burkenroad, Yale University’s Bingham Laboratory, carcinology and Sargasso epizoa; M. Bishop, Peabody Museum of Natural History, Zoology Dept., collections and preparations and H. Sears, WHOI ichthyologist. The itinerary included the following waypoints: Woods Hole, the Bermudas, Turks Islands, Kingston, Colon, along the Mosquito Bank off of Nicaragua, off the north coast of Jamaica, along the south coast of Cuba, Bartlett Deep, to off the Isle of Pines, through the Yucatan Channel, off Havana, off Key West, to Miami, to New York City, and then the return to Woods Hole. During the expedition, Breder collected rare and little-known flying fish species and developed a method for hatching and growing flying fish larvae. (PDF contains 48 pages)
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The implementation of various types of marine protected areas is one of several management tools available for conserving representative examples of the biological diversity within marine ecosystems in general and National Marine Sanctuaries in particular. However, deciding where and how many sites to establish within a given area is frequently hampered by incomplete knowledge of the distribution of organisms and an understanding of the potential tradeoffs that would allow planners to address frequently competing interests in an objective manner. Fortunately, this is beginning to change. Recent studies on the continental shelf of the northeastern United States suggest that substrate and water mass characteristics are highly correlated with the composition of benthic communities and may therefore, serve as proxies for the distribution of biological biodiversity. A detailed geo-referenced interpretative map of major sediment types within Stellwagen Bank National Marine Sanctuary (SBNMS) has recently been developed, and computer-aided decision support tools have reached new levels of sophistication. We demonstrate the use of simulated annealing, a type of mathematical optimization, to identify suites of potential conservation sites within SBNMS that equally represent 1) all major sediment types and 2) derived habitat types based on both sediment and depth in the smallest amount of space. The Sanctuary was divided into 3610 0.5 min2 sampling units. Simulations incorporated constraints on the physical dispersion of sampling units to varying degrees such that solutions included between one and four site clusters. Target representation goals were set at 5, 10, 15, 20, and 25 percent of each sediment type, and 10 and 20 percent of each habitat type. Simulations consisted of 100 runs, from which we identified the best solution (i.e., smallest total area) and four nearoptimal alternates. We also plotted total instances in which each sampling unit occurred in solution sets of the 100 runs as a means of gauging the variety of spatial configurations available under each scenario. Results suggested that the total combined area needed to represent each of the sediment types in equal proportions was equal to the percent representation level sought. Slightly larger areas were required to represent all habitat types at the same representation levels. Total boundary length increased in direct proportion to the number of sites at all levels of representation for simulations involving sediment and habitat classes, but increased more rapidly with number of sites at higher representation levels. There were a large number of alternate spatial configurations at all representation levels, although generally fewer among one and two versus three- and four-site solutions. These differences were less pronounced among simulations targeting habitat representation, suggesting that a similar degree of flexibility is inherent in the spatial arrangement of potential protected area systems containing one versus several sites for similar levels of habitat representation. We attribute these results to the distribution of sediment and depth zones within the Sanctuary, and to the fact that even levels of representation were sought in each scenario. (PDF contains 33 pages.)
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In 2003, twelve marine protected areas were established in state waters (0-3 nmi) surrounding the Channel Islands. NOAA is considering extending this network (3-6 nmi) into deeper waters of the Channel Islands National Marine Sanctuary (CINMS). In order for effective long-term management of the deep water reserves to occur, a well-structured monitoring program is required to assess effectiveness. The CINMS and the National Marine Sanctuary Program (NMSP) hosted a 2-day workshop in April 2005 to develop a monitoring plan for the proposed federal marine reserves in that sanctuary. Conducted at the University of California at Santa Barbara, participants included scientists from academic, state, federal, and private research institutions. Workshop participants developed project ideas that could answer priority questions posed by the NMSP. This workshop report will be used to develop a monitoring plan for the reserves. (PDF contains 47 pages.)
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Although ambient (background) noise in the ocean is a topic that has been widely studied since pre-World War II, the effects of noise on marine organisms has only been a focus of concern for the last 25 years. The main point of concern has been the potential of noise to affect the health and behavior of marine mammals. The Stellwagen Bank National Marine Sanctuary (SBNMS) is a site where the degradation of habitat due to increasing noise levels is a concern because it is a feeding ground and summer haven for numerous species of marine mammals. Ambient noise in the ocean is defined as “the part of the total noise background observed with an omnidirectional hydrophone.” It is an inherent characteristic of the medium having no specific point source. Ambient noise is comprised of a number of components that contribute to the “noise level” in varying degrees depending on where the noise is being measured. This report describes the current understanding of ambient noise and existing levels in the Stellwagen Bank National Marine Sanctuary. (PDF contains 32 pages.)
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Daytime feeding behavior of humpback whales (Megaptera novaeangliae) in Gulf of the Farallones, California, and adjacent waters was observed during autumn of 1988 to 1990. Bodega Canyon, Cordell Bank, and the Farallon Islands were the primary sites of feeding activity. Fecal samples of whales and zooplankton tows contained euphausiids exclusively, dominated by Thysanoessa spinifera (79%), with lesser amounts of Euphausia pacifica (14%), Nyctiphanes simplex (4%), and Nematoscelis difficilis (3%). In 1988 and 1990, whales also were infrequently observed feeding on small schooling fish, presumably Pacific herring (Clupea pallasii), northern anchovy (Engraulis mordax), and juvenile rockfish (Sebastes spp.). Feeding was the most common behavior observed (52%), and less frequently traveling (23%), milling (21 %), and resting (4%). Whales used different methods to consume euphausiid prey at the surface (0-10 m), in shallow water (11-60 m), and deep water (61-140 m). Humpback whales fed at the surface 56% of time in 1988 and 32% of time in 1990, using primarily lateral lunges to capture swarms of euphausiids. In 1989, no surface feeding was observed; however, deep, long-duration dives were followed by extended surface intervals with many respirations. These 1989 observations coincided with increased prey depth as indicated by depth sounder records of diving whales and prey scattering layers. In 1989, increased prey depth and associated feeding behaviors were strongly associated with unusually high surface temperatures, calm seas, and changes in water circulation. Environmental conditions in 1989 triggered the most intense and wide-spread occurrence of red tide in this region since 1980. Red tide samples collected throughout this period contained Alexandrium (=Gonyaulax) catenella and Noctiluca scintillans. Surface feeding was observed only in 1988 and 1990, when surface prey were available and red tides were very limited in extent, duration, and intensity. Annual variations in humpback whale feeding behavior were related to prey availability which is affected by corresponding environmental conditions. (PDF contains 94 pages)
Resumo:
This study examines zooplankton periodicity and some physicochemical parameters of the intake channel of Lake Chad (Nigeria). Nine different zooplankton species were identified at the sampling station 1, while seven different zooplankton species were identified at the sampling station 2 (the intake channel of Lake Chad). Each identified zooplankton species was grouped according to its major group of copepods, Cladocera or Rotifera. The copepods dominated the zooplankton community with the highest numbers of occurrence as Cyclopedia species throughout the course of the study at both station l and 2. There was a clear evidence of the influence of organic manure nutrients on total zooplankton population at station 1 when compared to that of station 2. The water quality variables measured in the course of this study show that the surface water temperature in station 1 ranges from 27.5 degree C to 30.5 degree C. The pH ranges from 6.8 to 8.5, while D.O. contents ranges from 2.9mg/L to 6.1mg/L and alkalinity recorded was 172.00 to 208.00. At the station 2 the water quality parameters obtained show that surface water temperature ranges from 27.3 degree C to 30.2 degree C, pH ranges between 6.9 to 8.5, while the D.O contents ranges from 3.0 mg/L to 6.2 mg/L.Alkalinity ranges from 172mg/L to 212 mg/L