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Full-Text Articles in Marine Biology

Spatial And Temporal Patterns In Macrofaunal Diversity Components Relative To Sea Floor Landscape, Roman Zajac, Brittney R. Gibbons, Joseph M. Vozarik Jun 2013

Spatial And Temporal Patterns In Macrofaunal Diversity Components Relative To Sea Floor Landscape, Roman Zajac, Brittney R. Gibbons, Joseph M. Vozarik

Biology and Environmental Science Faculty Publications

We examined temporal changes in macrofaunal α- and β-diversity over several spatial scales (within patches, among patches, across landscapes and across regions) in Long Island Sound on the northeast USA coast. Regional ε-diversity was estimated at 144 taxa, however γ-diversity fluctuated over time as did α- and β-diversity components. Based on additive partitioning, patch- and region-scale β-diversity components generally had the highest contributions to γ-diversity; lower percentages were found at within-patch and landscape scales. Multiplicative diversity partitioning indicated highest species turnover at within- and among patch scales. For all partition results, within-patch and patch-scale β-diversity increased sharply when hypoxia impacted …


Applying Marine Protected Area Design Models In Large Estuarine Systems, Roman Zajac, Amanda E. Neely Dec 2008

Applying Marine Protected Area Design Models In Large Estuarine Systems, Roman Zajac, Amanda E. Neely

Biology and Environmental Science Faculty Publications

Several types of design models are currently being used to develop marine protected areas (MPAs) for conservation of coastal and pelagic ecosystems. However, few studies have applied these models in large estuaries which have unique characteristics that need to be considered in MPA design, including strong physical, chemical and biological gradients and significant human impacts. We explored how one design model, MARXAN, can be applied to estuarine systems by developing MPA design scenarios for Long Island Sound, an estuary in the northeastern USA. Using sedimentary texture as a proxy for habitats, we modeled and tested several scenarios where conservation goals …


Sidescan Sonar Image, Surficial Geological Interpretation, And Bathymetry Of The Long Island Sound Sea Floor Off Milford, Connecticut, Roman Zajac, David C. Twichell, Larry J. Poppe, Ralph S. Lewis, Veeann Cross Jan 1998

Sidescan Sonar Image, Surficial Geological Interpretation, And Bathymetry Of The Long Island Sound Sea Floor Off Milford, Connecticut, Roman Zajac, David C. Twichell, Larry J. Poppe, Ralph S. Lewis, Veeann Cross

Biology and Environmental Science Faculty Publications

The surficial geology of a 6-km X 8-km section of the western part of Long Island Sound has been mapped. The map area is 4 to 12 km south of the mouth of the Housatonic River in 14 to 40 m water depth (see location map). This study is part of an interdisciplinary program to define the surficial geology and benthic habitats in Long Island Sound and to see how they are changing with time, and includes, in addition to this map area, the other survey areas shown on the location map. The U.S. Geological Survey, in cooperation with the …


Sidescan Sonar Image, Surficial Geologic Interpretation, And Bathymetry Of The Long Island Sound Sea Floor Off Hammonasset Beach State Park, Connecticut, Roman Zajac, Larry J. Poppe, Ralph S. Lewis, David C. Twichell, Mary L. Digiacomo-Cohen, Eric A. Schmuck, Kenneth F. Parolski Jan 1997

Sidescan Sonar Image, Surficial Geologic Interpretation, And Bathymetry Of The Long Island Sound Sea Floor Off Hammonasset Beach State Park, Connecticut, Roman Zajac, Larry J. Poppe, Ralph S. Lewis, David C. Twichell, Mary L. Digiacomo-Cohen, Eric A. Schmuck, Kenneth F. Parolski

Biology and Environmental Science Faculty Publications

Ongoing research by the U.S. Geological Survey (USGS) in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States, is building upon cooperative research with the State of Connecticut that was initiated in 1982. During the initial phase of this cooperative program, geologic framework studies in Long Island Sound were completed and results published (Lewis and Needell, 1987; Needell and others, 1987; Lewis and Stone, 1991). Emphasis of the present program in Long Island Sound is shifting from framework studies toward studies of the sediment distribution, processes that control this sediment …


The Texture Of Surficial Sediments In Central Long Island Sound Off Milford, Connecticut., Roman Zajac, Larry J. Poppe, B B. Taylor, Dann Blackwood, Ralph S. Lewis, Mary L. Digiacomo-Cohen Jan 1996

The Texture Of Surficial Sediments In Central Long Island Sound Off Milford, Connecticut., Roman Zajac, Larry J. Poppe, B B. Taylor, Dann Blackwood, Ralph S. Lewis, Mary L. Digiacomo-Cohen

Biology and Environmental Science Faculty Publications

The purpose of this study was to determine the grain-size distributions and associated statistical parameters of the surficial sediment samples from central Long Island Sound off Milford, Connecticut. These grain-size data, which help to ground-truth a pre-existent sidescan sonar survey (Poppe and others, 1995a; Twichell and others, in press), will eventually be used to describe the sedimentary processes active in this portion of central Long Island Sound. Other potential uses for these textural data include benthic biologic studies that evaluate faunal distributions and relate them to habitats (Zajac and others, 1995), and geochemical studies involving the distribution, transport and deposition …


Organic Carbon, Hydrogen, And Nitrogen Concentrations In Surficial Sediments From Western Long Island Sound, Connecticut And New York, Roman Zajac, Larry J. Poppe, Ralph S. Lewis, S E. Pratt, Zofia J. Mlodzinska, B. B. Taylor, Mary L. Digiacomo-Cohen Jan 1996

Organic Carbon, Hydrogen, And Nitrogen Concentrations In Surficial Sediments From Western Long Island Sound, Connecticut And New York, Roman Zajac, Larry J. Poppe, Ralph S. Lewis, S E. Pratt, Zofia J. Mlodzinska, B. B. Taylor, Mary L. Digiacomo-Cohen

Biology and Environmental Science Faculty Publications

Total organic carbon, hydrogen, and nitrogen (CHN) analyses were performed on 147 surficial sediment samples from study areas off the Norwalk Islands and Milford, Connecticut, in western Long Island Sound. The CHN data and gross lithologic descriptions of the sediments are reported herein. The concentrations of total organic carbon (TOC), hydrogen, and nitrogen in these samples average 1.54, 1.40, and 0.17 weight percent, respectively. The individual CHN concentrations vary inversely with grain size, with CHN values increasing with the percent fines. Increasing nutrient inputs and decreasing circulation cause TOC and nitrogen values to generally increase westward within the Sound. C/N …


The Texture Of Surficial Sediments In Western Long Island Sound Off The Norwalk Islands, Connecticut, Roman Zajac, Larry J. Poppe, B. B. Taylor, Dann Blackwood, A. E. Harmon Jan 1996

The Texture Of Surficial Sediments In Western Long Island Sound Off The Norwalk Islands, Connecticut, Roman Zajac, Larry J. Poppe, B. B. Taylor, Dann Blackwood, A. E. Harmon

Biology and Environmental Science Faculty Publications

Grain-size analyses were performed on 69 samples from western Long Island Sound. The relative grain-size frequency distributions and related statistics are reported herein. Descriptions of the benthic character from video tapes and still camera photographs of the bottom at these stations, and 33 others, are also presented. The southern and eastern parts of the study area are dominated by poorly sorted clayey silts that have nearly symmetrical distributions. Gravelly sediments are prevalent in the shallow northwestern part of the study area, but are also present in central part of the study area. Bands of sand, silty sand, and sand-silt-clay occur …


Map Showing The Distribution Of Surficial Sediments In Fishers Island Sound, New York, Connecticut, And Rhode Island, Larry J. Poppe, Ralph S. Lewis, Sidney Quarrier, A. M. Moffet Jan 1994

Map Showing The Distribution Of Surficial Sediments In Fishers Island Sound, New York, Connecticut, And Rhode Island, Larry J. Poppe, Ralph S. Lewis, Sidney Quarrier, A. M. Moffet

Biology and Environmental Science Faculty Publications

The data presented on this map were collected as part of a State of Connecticut and U.S. Geological Survey (USGS) cooperative program intended to further understand the marine geology of Connecticut and Long Island Sound. The purpose of this cooperative program is (1) to resolve sedimentologic and oceanographic problems and data gaps in Long Island Sound, (2) to integrate these findings with terrestrial data and the Pleistocene histories of Long Island and Connecticut, and (3) to initiate investigations of offshore resources that are keyed to the better management of Long Island Sound. With this in mind, the fundamental objectives of …


Population Ecology Of Polydora Ligni (Polychaeta: Spionidae). I. Seasonal Variation In Population Characteristics And Reproductive Activity, Roman Zajac Nov 1991

Population Ecology Of Polydora Ligni (Polychaeta: Spionidae). I. Seasonal Variation In Population Characteristics And Reproductive Activity, Roman Zajac

Biology and Environmental Science Faculty Publications

A population of the polychaete Polydora ligni Webster was studied during 1982 and 1983 in Alewife Cove, Connecticut, USA, to determine seasonal changes in population characteristics. During early spring (March and April), the population was comprised of primarily large adults that had over-wintered. Females in this group exhibited the highest mean individual fecundity over the year (> 2000 larvae per brood). However, total larval production at this time was low (5200 to 208 000 larvae m-2 per 14 d) due to low densities of adults. Population density increased slowly during spring as juveniles produced by overwintering adults recruited into …


Population Ecology Of Polydora Ligni (Polychaeta: Spionidae). Ii. Seasonal Demographic Variation And Its Potential Impact On Life History Evolution, Roman Zajac Nov 1991

Population Ecology Of Polydora Ligni (Polychaeta: Spionidae). Ii. Seasonal Demographic Variation And Its Potential Impact On Life History Evolution, Roman Zajac

Biology and Environmental Science Faculty Publications

Seasonal demographic variation was studied in an estuarine population of the opportunistic polychaete Polydora ligni between May 1982 and November 1983 in Alewife Cove, Connecticut, USA. The demography of 15 cohorts settling during this period was analyzed using life cycle graph models. Cohorts settling in spring and early summer had the shortest life spans (≈ 10 wk); highest survivorship over all life cycle stages and adult females produced an estimated maximum of 6 larval broods. Early adult stages contributed most to population growth during this period, and the potential for population growth, λ, was the highest during the study. Late …


Natural And Disturbance-Induced Demographic Variation In An Infaunal Polychaete, Nephtys Incisa, Roman Zajac, Robert B. Whitlatch Sep 1989

Natural And Disturbance-Induced Demographic Variation In An Infaunal Polychaete, Nephtys Incisa, Roman Zajac, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Demography of the infaunal polychaete Nephtys incisa was investigated for periods of 1 yr prior to and following disturbance (dredge material disposal) at a site in central Long Island Sound, USA. Infaunal grab samples were taken at 5 stations 200 m to 3 km apart. The demography of populations at each station was based on age-classes spanning juveniles to adults 4 + yr of age. Age-specific survivorship and fecundity were based on changes in mean density of each cohort and a positive correlation between female size and egg production, respectively. Analyses of population matrix models indicated pre-disposal populations had positive …


Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman Aug 1989

Effects Of Inter-Specific Density And Food Supply On Survivorship And Growth Of Newly Settled Benthos, Roman Zajac, Robert B. Whitlatch, Richard W. Osman

Biology and Environmental Science Faculty Publications

Using a laboratory model system comprised of newly settled oysters Crassostrea virginica and established fouling species (Botrylloides sp. initially, and others including Styela clava and Ciona intestinalis as the experiment progressed), we tested how differences in food supply and competitor density may affect post-settlement surivorship and growth of sessile marine invertebrates over a 44 d period. After 15 d, results were mixed but indicated that both food and density conditions affected growth and survivorship significantly, with some suggestion of high food levels ameliorating high density effects However, 44 d after settlement, oysters had reduced survivorship and growth when competitors …


Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch Jun 1989

Effects Of Resident Species On Recruitment Into A Community: Larval Settlement Versus Post-Settlement Mortality In The Oyster Crassostrea Virginica, Roman Zajac, Richard W. Osman, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Laboratory and field experiments revealed that a variety of species of common, sessile invertebrates, including barnacles, ascidians, and bryozoans, affected the settlement and post-settlement abundance of the oyster Crassostrea virginica (Gmelin). While the nature of the effects varied, most species both reduced oyster settlement by covering and removing substrate available for attachment, and increased settlement on adjacent surfaces. The solitary ascidians Ciona intestinalis (L.) and Styela clava (Herdman), were found to be predators of oyster larvae. Post-settlement survivorship and growth were also strongly affected by the presence of sessile species. In most cases the effects were negative and correlated with …


Responses Of Estuarine Infauna To Disturbance. I. Spatial And Temporal Variation Of Initial Recolonization, Roman N. Zajac, Robert B. Whitlatch Nov 1982

Responses Of Estuarine Infauna To Disturbance. I. Spatial And Temporal Variation Of Initial Recolonization, Roman N. Zajac, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Responses to disturbance of estuarine infauna were studied to test the hypothesis that seasonality, the estuarine environmental gradient and sediment composition would significantly affect recolonization. The study was conducted in a small estuary located in southeastern Connecticut, USA, using controlled disturbance experiments and sampling of the ambient infauna. Species composition in experimental plots and ambient sediments usually did not differ, either on a seasonal or areal basis. Numerically dominant species usually included the polychaetes Streblospio benedicti, Capitella spp. and Polydora ligni, and the oligochaete Peloscolex gabriellae. Other species included the polychaetes Scoloplos fragilis, Hobsonia florida and Nereis …


Responses Of Estuarine Infauna To Disturbance. Ii. Spatial And Temporal Variation Of Succession, Roman N. Zajac, Robert B. Whitlatch Nov 1982

Responses Of Estuarine Infauna To Disturbance. Ii. Spatial And Temporal Variation Of Succession, Roman N. Zajac, Robert B. Whitlatch

Biology and Environmental Science Faculty Publications

Infaunal successional patterns in Alewife Cove, a small estuary in southeastern Connecticut, USA, varied significantly seasonally and along the estuarine environmental gradient. Each study site exhibited different patterns of change in species composition and abundance. However, suites of species found during succession did not differ greatly from those found in ambient sediments. Species which exhibited the most variable population changes during succession were numerically dominant tubiculous polychaetes (Streblospio benedicti, Capitella spp., Polydora ligni], and an oligochaete (Peloscolex gabriellae). Other species which exhibited significant activity were the polychaetes Scoloplos fragilis, Hobsonia florida and Nereis virens, the hemichordate Saccoglossus kowaleski, and the …