American East Coast Research Articles

An initial assessment of native and invasive tunicates in shellfish aquaculture of the North American east coast

Summary The objective of the study was to assess the distribution of native and invasive tunicates in the fouling community of shellfish aquaculture gear along the U.S. east coast of the Atlantic. Since the 1980s, several species of invasive tunicates have spread throughout the coastal waters of the North American east coast and have become dominant fouling organisms on docks, boat hulls, mooring lines, and in shellfish aquaculture. Invasive and native tunicates negatively impact shellfish aquaculture through increased maintenance costs and reduced shellfish growth. While the presence of alien tunicates has been well documented at piers, harbors, and marinas, there are few published reports of invasive tunicate impacts to aquaculture. We surveyed shellfish aquaculture operations at Martha’s Vineyard, Massachusetts and shellfish aquaculturists in other areas along the North American east coast and report high levels of fouling caused by seven invasive, three native, and two cryptogenic species of tunicates. All study sites were fouled by one or more tunicate species. Biofouling control treatments varied among aquaculture sites and were effective in removing tunicates. Invasive and native tunicates should be considered when assessing the economic impacts of fouling organisms to the aquaculture industry.

Geospatial analysis of vulnerable beach-foredune systems from decadal time series of lidar data

Time series of lidar data, acquired over the past decade along the North American East Coast, provide opportunities to gain new insights into 3D evolution of barrier islands and their beach and dune systems. GIS-based per grid cell statistics and map algebra was applied to time series of Digital Surface Models representing two sections of North Carolina barrier islands to quantify elevation change trends, map dynamic and stable locations, identify new and lost buildings, measure relative volume evolution in the beach and foredune systems and analyze shoreline dynamics. Results show a relatively small stable core in both study areas, with beaches and the ocean side of the dunes exhibiting systematic high rates of elevation loss while areas landward from the dunes increase slightly in elevation. Significant number of new homes have been built at locations with very small core surface elevation, and homes built within the shoreline dynamics band have already been lost. The raster-based methodology used in this study can be applied to perform similar analyses in other coastal areas where time series of lidar data are available.

High regional differentiation in a North American crab species throughout its native range and invaded European waters: a phylogeographic analysis

Rhithropanopeus harrisii (Gould 1841) has a native distribution from New Brunswick (Canada) to Veracruz (Mexico) and is considered an invasive species in northwestern North American (Oregon and California), South American (Brazil) and European estuaries and rivers. In Europe, it was observed for the first time in 1874, in The Netherlands. We sequenced and analyzed part of the cytochrome oxidase subunit I gene (mitochondrial DNA) of eight populations, three from the east coast of the United States of America (USA) and five from Europe, in order to assess their genetic diversity and to determine a potential founder population. European populations are characterized by a lower number of haplotypes than the whole native region of the eastern USA, suggesting that genetic bottlenecks occurred during the European colonisation. Along the North American East Coast, there is evidence of clearcut genetic heterogeneity, New Jersey being the most similar population in its genetic structure to the postulated Europe-founding population. Also the different European populations are heterogeneous and there is a tendency of higher genetic diversity in the populations founded earlier. R. harrisii is still in the process of expansion in Europe and may have been introduced once or repeatedly by different invasion mechanisms. The pronounced lack of gene flow among populations is of great ecological significance, since it may facilitate rapid adaptation and specialization to local conditions within single estuarine systems.

A chronology of hurricane landfalls at Little Sippewissett Marsh, Massachusetts, USA, using optical dating

Optical dating has been applied to sediments preserved in Little Sippewissett Marsh, Massachusetts, USA, which are associated with overwashing of the beach barrier during hurricane strikes on the coast. The aims were to determine the hurricane landfall frequency, and make comparisons with independent age control and the historical record. Written sources of hurricane activity along the American east coast are only considered reliable back to the mid 19th century, but the sedimentary record is potentially much longer. Optical dating was applied to quartz grains extracted from thirteen samples within a sediment core from the salt-marsh. Variability in the luminescence characteristics between aliquots was observed and ~ 33% of the measured aliquots were discarded based upon the ratio of the fast component to the medium component. The majority of the samples gave normal dose distributions implying homogeneous resetting of the luminescence signal at the time of deposition, but three of the samples required application of the minimum age model (MAM). Ages ranging between 20 ± 2 and 594 ± 38 years were obtained and are broadly in agreement with independent chronologies, thus demonstrating the potential of optical dating in this setting. The hurricane record based upon optical dating extends approximately 300 years further back in time than the official National Oceanic Atmospheric Administration (NOAA) record. The localised nature of hurricane landfalls means that it will be necessary to collect multiple cores from a number of different sites in order to build up a complete hurricane record for this part of the coast.

Signature of the Atlantic meridional overturning circulation in sea level along the east coast of North America

In this letter we examine the relationship between the North Atlantic Meridional Overturning Circulation (MOC) and sea level (SL) along the east coast of North America. In the eddy permitting ocean model OCCAM we find a distinctive, topography‐following pattern of SL variability in the western North Atlantic that is closely linked with the changing strength of the MOC, with a 2 cm drop in SL along the US east coast corresponding to a 1Sv increase in the MOC. We find a similar pattern of SL variability in the altimetry record and show that this meridionally coherent SL mode dominates interannual SL variability at tide gauges along the North American east coast between 40–50°N. Hence we conclude that North American coastal sea‐level may indeed be a useful indicator of MOC variability on interannual timescales, allowing an observationally‐based estimate of the likely range of interannual MOC fluctuations to be determined.

Lagrangian analysis of low altitude anthropogenic plume processing across the North Atlantic

Abstract. The photochemical evolution of an anthropogenic plume from the New-York/Boston region during its transport at low altitudes over the North Atlantic to the European west coast has been studied using a Lagrangian framework. This plume, originally strongly polluted, was sampled by research aircraft just off the North American east coast on 3 successive days, and then 3 days downwind off the west coast of Ireland where another aircraft re-sampled a weakly polluted plume. Changes in trace gas concentrations during transport are reproduced using a photochemical trajectory model including deposition and mixing effects. Chemical and wet deposition processing dominated the evolution of all pollutants in the plume. The mean net photochemical O3 production is estimated to be −5 ppbv/day leading to low O3 by the time the plume reached Europe. Model runs with no wet deposition of HNO3 predicted much lower average net destruction of −1 ppbv/day O3, arising from increased levels of NOx via photolysis of HNO3. This indicates that wet deposition of HNO3 is indirectly responsible for 80% of the net destruction of ozone during plume transport. If the plume had not encountered precipitation, it would have reached Europe with O3 concentrations of up to 80 to 90 ppbv and CO between 120 and 140 ppbv. Photochemical destruction also played a more important role than mixing in the evolution of plume CO due to high levels of O3 and water vapour showing that CO cannot always be used as a tracer for polluted air masses, especially in plumes transported at low altitudes. The results also show that, in this case, an increase in O3/CO slopes can be attributed to photochemical destruction of CO and not to photochemical O3 production as is often assumed.

Denitrification effects on air‐sea CO2 flux in the coastal ocean: Simulations for the northwest North Atlantic

The contribution of coastal oceans to the global air‐sea CO2 flux is poorly quantified due to insufficient availability of observations and inherent variability of physical, biological and chemical processes. We present simulated air‐sea CO2 fluxes from a high‐resolution biogeochemical model for the North American east coast continental shelves, a region characterized by significant sediment denitrification. Decreased availability of fixed nitrogen due to denitrification reduces primary production and incorporation of inorganic carbon into organic matter, which leads to an increase in seawater pCO2, but also increases alkalinity, which leads to an opposing decrease in seawater pCO2. Comparison of simulations with different numerical treatments of denitrification and alkalinity allow us to separate and quantify the contributions of sediment denitrification to air‐sea CO2 flux. The effective alkalinity flux resulting from denitrification is large compared to estimates of anthropogenically driven coastal acidification.

Fight global warming now: the handbook for taking action in your community

Hurricane Katrina. A rapidly disappearing Arctic. warmest winter on the American East Coast in recorded history. leading scientist at NASA warns that we have only ten years to reverse climate change; the British government's report on global warming estimates that the financial impact will be greater than the Great Depression and both world wars - combined. Bill McKibben, the author of the first major book on global warming, The End of Nature, warns that it's no longer time to debate global warming, it's time to fight it.Drawing on the experience of Step It Up, a national day of rallies held on April 14, McKibben and the Step It Up team of organizers provide the facts of what must change to save the climate and show how to build the fight in your community, church, or college. They describe how to launch online grassroots campaigns, generate persuasive political pressure, plan high-profile events that will draw media attention, and other effective actions. This essential book offers the blueprint for a mighty new movement against the most urgent challenge facing us today.

Sea lampreyPetromyzon marinus: an exception to the rule of homing in anadromous fishes

Anadromous fishes are believed to make regular circuits of migration in the sea before homing to their natal rivers. Sea lamprey Petromyzon marinus is an anadromous fish that is an exception to this life-history pattern. It also differs from other anadromous fishes in that its adult phase is parasitic, a feeding strategy that should make homing problematic for lamprey cohorts that become widely dispersed through transport by the diverse hosts they parasitize. We sequenced a portion of the mitochondrial DNA control region from sea lampreys collected from 11 North American east coast rivers to test for genetic evidence of homing. There were no significant differences (chi2=235.1, p=0.401) in haplotype frequencies among them, with almost 99 per cent of haplotypic diversity occurring within populations. These findings, together with concordant genetic results from other geographical regions and ancillary information on pheromonal communication, suggest that sea lamprey does not home but rather exhibits regional panmixia while using a novel 'suitable river' strategy to complete its life cycle.

Molecular identification key based on PCR/RFLP for three polychaete sibling species of the genus Marenzelleria, and the species’ current distribution in the Baltic Sea

Studies of Marenzelleria species were often hampered by identification uncertainties when using morphological characters only. A newly developed PCR/RFLP protocol allows a more efficient discrimination of the three species Marenzelleria viridis, Marenzelleria neglecta and Marenzelleria arctia currently known for the Baltic Sea. The protocol is based on PCR amplification of two mitochondrial DNA gene segments (16S, COI) followed by digestion with restriction enzymes. As it is faster and cheaper than PCR/sequencing protocols used so far, the protocol is recommended for large-scale analyses. The markers allow an undoubted determination of species irrespective of life stage or condition of the worms in the samples. The protocol was validated on about 950 specimens sampled at more than 30 sites of the Baltic and the North Sea, and on specimens from populations of the North American east coast. Besides this test we used mitochondrial DNA sequences (16S, COI, Cytb) and starch gel electrophoresis to further investigate the distribution of the three Marenzelleria species in the Baltic Sea. The results show that M. viridis (formerly genetic type I or M. cf. wireni) occurred in the Oresund area, in the south western as well as in the eastern Baltic Sea, where it is found sympatric with M. neglecta. Allozyme electrophoresis indicated an introduction by range expansion from the North Sea. The second species, M. arctia, was only found in the northern Baltic Sea, where it sometimes occurred sympatric with M. neglecta or M. viridis. For Baltic M. arctia, the most probable way of introduction is by ship ballast water from the European Arctic. There is an urgent need for a new genetic analysis of all Marenzelleria populations of the Baltic Sea to unravel the current distribution of the three species.

DISTRIBUTION OF TESTATE AMOEBAE IN SALT MARSHES ALONG THE NORTH AMERICAN EAST COAST

This study describes the distribution of testate amoebae in three North American East Coast salt marshes (Leipsic River marsh, Delaware, USA; Little River marsh, Maine, USA; and Little Dipper Harbour marsh, New Brunswick, Canada). Five zones are recognized in the high salt marsh. With increasing marine influence, these zones are characterized by the following succession of dominant taxa: Valkanovia elegans, Tracheleuglypha dentata , Centropyxis cassis type, C. platystoma type and Difflugia pristis type. Most species occur in all three marshes, and their general vertical distribution is comparable. The results are also comparable with those obtained from British salt marshes, suggesting that salt-marsh testate amoebae have similar distributions on both sides of the Atlantic Ocean. The precision of the sea-level indicative value of testate amoebae in fossil salt-marsh sediments is a function of the local mean tidal range (MTR). Results of this study show that testate amoebae can indicate former sea levels with a precision of ±0.04 m in the Leipsic River marsh (MTR = 1.75 m), ±0.09 m in the Little River marsh (MTR = 2.6 m), and ±0.18 m in the Little Dipper marsh (MTR = 5.8 m).

Community assembly and seasonal succession of marine dinoflagellates in a temperate estuary: The importance of life cycle events

Dinoflagellate successional strategies and community structure were investigated in Perch Pond, a temperate estuary on the North American east coast by field surveys as well as laboratory investigations on growth rates, cyst maturation period, and cyst germination temperature thresholds. The dominant species were those predicted by the Smayda and Reynolds Rules of Assembly life form model. Three successional strategies were characterized: (1) holoplanktonic, (2) meroplanktonic (i.e., germinated from cysts), and (3) introduced by advection. The seasonal succession of the meroplanktonic dinoflagellates that were studied reflects the differential lengths of their mandatory dormancy periods as well as differences in their temperature thresholds or ‘’windowsÂ’Âȉ for germination. The holoplanktonic species present at low densities year-round in Perch Pond had a wide temperature tolerance for growth and thus did not need a cyst stage to survive seasonal extremes. Another non-cyst-forming species relied solely on advection to inoculate the salt pond; thus, blooms in successive years would be expected to be more stochastic in nature than for the other two strategies. The timing of cyst formation and population decline for meroplanktonic species corresponded on several occasions to an increase in grazers, suggesting that grazing might have contributed to bloom decline from cyst formation. This timing also suggests the possibility of encystment as a predator avoidance strategy. We suggest that seasonal succession of cyst-forming dinoflagellates is not stochastic. Instead, the appearance of these species in the plankton is predictable on the basis of measurable physiological responses to both endogenous and exogenous factors that they experience during dormancy and quiescence.

North American East Coast Conference International Society of Protistologists

Journal of Eukaryotic MicrobiologyVolume 53, Issue 1 p. 6S-15S North American East Coast Conference International Society of Protistologists First published: 24 January 2006 https://doi.org/10.1111/j.1550-7408.2005.00076_2.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume53, Issue1January 2006Pages 6S-15S RelatedInformation

A study of extratropical transition in the Western North Atlantic Ocean, 1963–1996

A synoptic‐ dynamic climatology of the forty‐five extratropical‐transitioning tropical cyclones, (as compiled by the United States National Hurricane Center) travelling through offshore regions of the North American east coast during the 1963–96 hurricane seasons, is presented. The National Centers for Environmental Prediction global reanalyses of geopotential height are used to construct large‐scale circulation features associated with the passage of these systems. Soundings of six near‐track stations are used to study the stratification of temperature and moisture during the cyclones ‘ passage. Sea‐surface temperature (SST) structures are also studied with respect to these events. Primary results of the study include: a) a statistically‐significant 1000–500 hPa warm anomaly (with respect to a 1963–96 climatology) persists over central and eastern North America during the two‐day period prior to the passage of the tropical systems into the Canadian Maritime provinces; b) a northwestward extension of the surface subtropical anticyclone exists over the Canadian Atlantic Provinces during the two‐day period prior to the arrival of the cyclone; c) the tropical cyclone's convectively‐unstable tropical air mass is maintained for at least eighteen hours after transition; and d) the presence of quasi‐geostrophic forcing for ascent, typically seen in extratropical cyclones, is observed during periods in which the systems are still classified as tropical cyclones. This forcing for ascent continues during the extratropical transformation, and typically occurs ahead and to the left of the storm track. Additionally, these transforming systems travel through a region of SST gradients that are anomalously strong compared with the climatology for that region. Storms are also classified according to whether they were deepening or filling. These classifications were composited to distinguish circulation structures unique to each classification. Considering that several of the systems passing through the maritime‐coastal regions are filling and several are intensifying, we distinguish the circulation structures between the deepening and filling systems. The primary distinction of the deepening extratropical transition is the statistically‐significant colder tropospheric air mass to the north of the storm track. Such a finding is similar to that found in other studies for cold‐season deepening extratropical cyclones.

Reconstructing a century of Spartina alterniflora invasion with historical records and contemporary remote sensing

:Remote sensing is becoming a vital tool for understanding the changing vegetation patterns that are associated with broad-scale plant invasions. The establishment of North American east coast native Spartina alterniflora (smooth cordgrass) in Willapa Bay, Washington is a specific example of broad-scale invasion following local introduction. In this study, we examined a 120-y historical record of aerial photographs, oral histories, museum records, and publications to reconstruct the spatial, temporal, and historical elements of this invasion. We conclude that the most likely means for S. alterniflora to have reached Willapa Bay was the transport and translocation of oysters from New York harbour. Our data and analysis suggest that multiple areas were colonized between 1894 and 1920 coincident with sustained import of oysters from the Atlantic seaboard. We have evidence that S. alterniflora had been long established and growing in multiple widely spread locations by 1945, which is in contrast to a widely reported single introduction. Multiple foci would not only explain the colonization patterns we have observed, but could also increase the heterogeneity of the founding populations, helping to overcome barriers to reproduction that may have initially slowed the colonization in isolated populations during the first 50–70 y.

Comment on “Anomalous cold water detected along Mid‐Atlantic Coast”

The recent Eos article by Sun et al. [2004] described unusually chilly ocean conditions along the U.S. mid‐Atlantic coast in summer 2003 that the authors attributed to stronger than usual upwelling. The stress of alongshore (northward on the North American east coast) wind on the ocean's surface, in concert with Earth's rotation, causes surface water to move offshore and be replaced by water that upwells along the coast from depths of 50–100 m and more. Upwelled water is cooler and more saline than the original surface water, and typically has much greater concentrations of nutrients that are key to sustaining biological production [Smith, 1968].Coastal upwelling is principally considered a west coast process, but it can play an important role in the physics, chemistry, and ecology of the broad continental shelves of east coasts.

Low-frequency Atlantic sea level variability

The control run of the Hadley Centre-coupled climate model (HadCM3) is used to establish the sources of multidecadal/centennial sea level (SL) variations in the northwest Atlantic. It is shown that variations in the sea level for the largest part of this area are related to variations in the thermohaline structure of the upper (≈500 m) part of the ocean. Temperature variations dominate steric sea level variations, while salinity variations are dominant only in the margins of the Labrador Sea and near the Mediterranean outflow. In the Labrador Sea, lower layers in the ocean also contribute to the variability in expansion/contraction of the water column. It is shown that along the North American East Coast, variations in the thermohaline structure of the water column are predominantly related to variations in the wind-driven circulation rather than the thermohaline circulation, which dominates the thermohaline structure in the central parts of the North Atlantic. In the Gulf Stream area and near the Labrador Current, sea level has on the multidecadal/centennial time scale a strong barotropic signal superposed on steric sea level variations.

Histories of Protected Areas: Internationalisation of Conservationist Values and their Adoption in the Netherlands Indies (Indonesia).

Abstract National parks and wildlife sanctuaries are under threat both physically and as a social ideal in Indonesia following the collapse of the Suharto New Order regime (1967-1998). Opinion-makers perceive parks as representing elite special interest, constraining economic development and/or indigenous rights. We asked what was the original intention and who were the players behind the Netherlands Indies colonial government policy of establishing nature 'monuments' and wildlife sanctuaries. Based on a review of international conservation literature, three inter-related themes are explored: a) the emergence in the 1860-1910 period of new worldviews on the human-nature relationship in western culture; b) the emergence of new conservation values and the translation of these into public policy goals, namely designation of protected areas and enforcement of wildlife legislation, by international lobbying networks of prominent men; and 3) the adoption of these policies by the Netherlands Indies government. This paper provides evidence that the root motivations of protected area policy are noble, namely: 1) a desire to preserve sites with special meaning for intellectual and aesthetic contemplation of nature; and 2) acceptance that the human conquest of nature carries with it a moral responsibility to ensure the survival of threatened life forms. Although these perspectives derive from elite society of the American East Coast and Western Europe at the end of the nineteenth century, they are international values to which civilised nations and societies aspire. It would be a tragedy if Indonesia rejects these social values and protected areas because subsequent management polices have associated protected areas with aspects of the colonial and New Order regime that contemporary society seeks to reform.

Development of a multiplex PCR for the detection of Haplosporidium nelsoni, Haplosporidium costale andPerkinsus marinus in the eastern oyster (Crassostrea virginica, Gmelin, 1971)

Haplosporidium costale (SSO), Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo) have caused oyster mortality on the North American east coast since the 1950s. Currently, the monitoring of oyster populations for these pathogens depends on histopathology for H. nelsoni, H. costale and the Ray/Mackin assay for P. marinus. In this study we describe the development and optimization of a multiplex polymerase chain reaction (MPCR) for the detection of H. nelsoni, H. costale and P. marinus. In addition, we determine its specificity and sensitivity. The MPCR clearly detects and differentiates the protozoan pathogens. There was no cross-reactivity between these species. The MPCR was able to detect DNA from H. nelsoni as low as 10 fg and P. marinus and H. costale as low as 1 pg. The MPCR allows for the detection of H. nelsoni, H. costale and P. marinus in a single PCR reaction.

Determination of the origin of the cold-adapted populations of barnyard grass (Echinochloa crus-galli) in eastern North America: a total-evidence approach using RAPD DNA and DNA sequences

This survey attempts to establish the origin of cold-adapted populations of barnyard grass (Echinochloa crus-galli (L.) Beauv.) in North America using molecular techniques, including random amplified polymorphic DNA (RAPD) and two types of sequences: chloroplast intron (trnL (UAA)) and rDNA nuclear spacer (ITS 1). There exists many possible scenarios to explain the origin of E. crus-galli in eastern Canada (Quebec), but we dwelled on two particular hypotheses, which are not mutually exclusive. The first hypothesis stipulates that the populations originated only from Europe, whereas the second implies that native subtropical and warm-temperate populations migrated from the south towards northern regions. To assess the likelihood of these hypotheses, the genetic distance matrices obtained from RAPD markers, nuclear, and chloroplastic sequences were combined and tested against the competing models. A principal coordinate analysis was used to discriminate among populations sampled from three different regions (i.e., Quebec, American east coast, and western Europe) and an analysis of molecular variance (AMOVA) detected a significant genetic structure among these populations (FST= 0.110, p < 0.05). Pairwise comparisons further indicated that European populations were significantly different from all other populations, whereas North American populations were not different from one another. The combined sequences revealed eight different haplotypes. Six populations were characterized by unique haplotypes, while one haplotype was shared by 3 of the 12 North American populations. The last and most common haplotype was observed in 9 of the 18 populations from all three regions. The tests computed thus supported the second hypothesis suggesting that the cold-adapted populations of eastern Canada are probably derived from other North American populations rather than European populations.Key words: AMOVA, RAPD, rDNA, cpDNA, genetic variation, population structure.