59 research outputs found

    Ascidians of South Padre Island, Texas, with a Key to Species

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    The ascidians of South Padre Island, Texas were surveyed in August 2004. Because the subtidal area is limited to soft sediments, the survey was restricted to marina floats and pilings, harbor buoys, boat hulls and other artificial substrates which offer suitable attachment surfaces for ascidians. Fifteen species were documented, with multiple species representing each of the three orders of ascidians. None of the species found in this survey are native, suggesting they were all introduced through boat traffic. About half the species were found in a reproductive state, however, indicating that they have established local breeding populations

    Report on the 2013 Rapid Assessment Survey of Marine Species at New England Bays and Harbors

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    Introduced species (i.e., non-native species that have become established in a new location) have increasingly been recognized as a concern as they have become more prevalent in marine and terrestrial environments (Mooney and Cleland 2001; Simberloff et al. 2005). The ability of introduced species to alter population, community, and ecosystem structure and function, as well as cause significant economic damage is well documented (Carlton 1989, 1996b, 2000; Cohen and Carlton 1995; Cohen et al. 1995; Elton 1958; Meinesz et al. 1993; Occhipinti-Ambrogi and Sheppard 2007; Pimentel et al. 2005; Thresher 2000). The annual economic costs incurred from managing the approximately 50,000 introduced species in the United States alone are estimated to be over $120 billion (Pimentel et al. 2005). Having a monitoring network in place to track new introductions and distributional changes of introduced species is critical for effective management, as these efforts may be more successful when species are detected before they have the chance to become established. A rapid assessment survey is one such method for early detection of introduced species. With rapid assessment surveys, a team of taxonomic experts record and monitor marine species–providing a baseline inventory of native, introduced, and cryptogenic (i.e., unknown origin) species (as defined by Carlton 1996a)–and document range expansions of previously identified species. Since 2000, five rapid assessment surveys have been conducted in New England. These surveys focus on recording species at marinas, which often are in close proximity to transportation vectors (i.e., recreational boats). Species are collected from floating docks and piers because these structures are accessible regardless of the tidal cycle. Another reason for sampling floating docks and other floating structures is that marine introduced species are often found to be more prevalent on artificial surfaces than natural surfaces (Glasby and Connell 2001; Paulay et al. 2002). The primary objectives of these surveys are to: (1) identify native, introduced, and cryptogenic marine species, (2) expand on data collected in past surveys, (3) assess the introduction status and range extensions of documented introduced species, and (4) detect new introductions. This report presents the introduced, cryptogenic, and native species recorded during the 2013 survey

    Ascidians at the Pacific and Atlantic entrances to the Panama Canal

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    © The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Aquatic Invasions 6 (2011): 371-380, doi:10.3391/ai.2011.6.4.02.The Panama Canal region is susceptible to non-native species introductions due to the heavy international shipping traffic through the area. Ascidian introductions are occurring worldwide but little is known about introductions at the Panama Canal. Surveys were conducted in 2002, 2008, and 2009 within the Pacific and Atlantic entrances to the canal. We found a high diversity of ascidians on both sides of the canal, dominated by non-native species; six species occurred at both Pacific and Atlantic Panama sites. This is the first report of Polyandrocarpa anguinea and P. sagamiensis in Atlantic Panama waters and Ascidia incrassata, Ascidia sydneiensis, Botrylloides nigrum, Botryllus planus, Didemnum perlucidum, Diplosoma listerianum, Microcosmus exasperatus, Polyandrocarpa zorritensis, Polyclinum constellatum, Symplegma brakenhielmi, Symplegma rubra, and Trididemnum orbiculatum in Pacific Panama waters. The canal may serve as a major invasion corridor for ascidians and should be monitored over time.Funding for this project came from WHOI Ocean Life Institute-Tropical Research Initiative to Carman and CNPq to Rocha

    Marine Invaders in the Northeast: Rapid Assessment Survey of Non-native and Native Marine Species of Floating Dock Communities, August 2003

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    In his seminal book on The Ecology of Invasions by Animals and Plants, Elton (1958) laid the foundation for the science of biological invasions. He identified the importance of human-mediated vectors as means of transporting organisms to new locations and discussed invasions in the context of ecological impacts and evolutionary consequences. Elton even identified what needed to be done to prevent practical and ecological damages from invaders--keep them out, eradicate them, and if all else fails, manage them at acceptable levels. We have not been vigilant in applying this knowledge to marine ecosystems, although this is changing. Our ability to detect changes in numbers and rate of marine introductions depends on well-documented lists of species in time and space, appropriate identification of non-native species, and careful records that follow changes in nomenclature, distribution, potential vectors, and ecosystem alterations caused by non-native species.United States. Environmental Protection Agency (Grant X83055701

    The colonial ascidian Didemnum sp. A: Current distribution, basic biology and potential threat to marine communities of the northeast and west coasts of North America

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    Author Posting. © The Author(s), 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Experimental Marine Biology and Ecology 342 (2007): 99-108, doi:10.1016/j.jembe.2006.10.020.Didemnum sp. A is a colonial ascidian with rapidly expanding populations on the east and west coasts of North America. The origin of Didemum sp. A is unknown. Populations were first observed on the northeast coast of the U.S. in the late 1980s and on the west coast during the 1990s. It is currently undergoing a massive population explosion and is now a dominant member of many subtidal communities on both coasts. To determine Didemnum sp. A’s current distribution, we conducted surveys from Maine to Virginia on the east coast and from British Columbia to southern California on the west coast of the U.S. between 1998 and 2005. In nearshore locations Didemnum sp. A currently ranges from Eastport, Maine to Shinnecock Bay, New York on the east coast. On the west coast it has been recorded from Humboldt Bay to Port San Luis in California, several sites in Puget Sound, Washington, including a heavily fouled mussel culture facility, and several sites in southwestern British Columbia on and adjacent to oyster and mussel farms. The species also occurs at deeper subtidal sites (up to 81 m) off New England, including Georges, Stellwagen and Tillies Banks. On Georges Bank numerous sites within a 147 km2 area are 50-90% covered by Didemnum sp. A; large colonies cement the pebble gravel into nearly solid mats that may smother infaunal organisms. These observations suggest that Didemnum sp. A has the potential to alter marine communities and affect economically important activities such as fishing and aquaculture.Funding for this project was provided by EPA (STAR) grant GZ1910464 to R.B. Whitlatch, NSF-DGE 0114432 to J. Byrnes, NSF-OCE 0117839 to R. Etter and R.J. Miller, MIT Sea Grant NA86RG0074 and USEPA Grant GX83055701-0 to J. Pederson. RI Sea Grant NA07R90363 to J.S. Collie. Funding for A.N. Cohen and G. Lambert was provided by Mass. Sea Grant, U.S. EPA, Smithsonian Envl. Research Center Invasions Lab, Natl. Geographic Soc., San Francisco Bay-Delta Science Consortium and CALFED Science Program, Calif. Coastal Conservancy and the Rose Foundation. Additional funding and support was provided by the Stellwagen Bank National Marine Sanctuary

    Report on the 2013: Rapid assessment survey of marine species at New England Bays and Harbors

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    Introduced species (i.e., non-native species that have become established in\ud a new location) have increasingly been recognized as a concern as they have\ud become more prevalent in marine and terrestrial environments (Mooney and\ud Cleland 2001; Simberloff et al. 2005). The ability of introduced species to alter\ud population, community, and ecosystem structure and function, as well as\ud cause significant economic damage is well documented (Carlton 1989, 1996b,\ud 2000; Cohen and Carlton 1995; Cohen et al. 1995; Elton 1958; Meinesz et al.\ud 1993; Occhipinti-Ambrogi and Sheppard 2007; Pimentel et al. 2005; Thresher\ud 2000). The annual economic costs incurred from managing the approximately\ud 50,000 introduced species in the United States alone are estimated to be over\ud $120 billion (Pimentel et al. 2005).\ud Having a monitoring network in place to track new introductions and\ud distributional changes of introduced species is critical for effective\ud management, as these efforts may be more successful when species are\ud detected before they have the chance to become established. A rapid\ud assessment survey is one such method for early detection of introduced\ud species. With rapid assessment surveys, a team of taxonomic experts\ud record and monitor marine species–providing a baseline inventory of\ud native, introduced, and cryptogenic (i.e., unknown origin) species (as\ud defined by Carlton 1996a)–and document range expansions of previously\ud identified species.\ud Since 2000, five rapid assessment surveys have been conducted in New\ud England. These surveys focus on recording species at marinas, which often\ud are in close proximity to transportation vectors (i.e., recreational boats).\ud Species are collected from floating docks and piers because these structures\ud are accessible regardless of the tidal cycle. Another reason for sampling floating\ud docks and other floating structures is that marine introduced species are often\ud found to be more prevalent on artificial surfaces than natural surfaces (Glasby\ud and Connell 2001; Paulay et al. 2002). The primary objectives of these surveys\ud are to: (1) identify native, introduced, and cryptogenic marine species,\ud (2) expand on data collected in past surveys, (3) assess the introduction status\ud and range extensions of documented introduced species, and (4) detect new\ud introductions. This report presents the introduced, cryptogenic, and native\ud species recorded during the 2013 survey.CZM through NOAA NA13NOS4190040MIT Sea Grant through NOAA NA10OAR4170086

    Parasite fate and involvement of infected cells in the induction of CD4+ and CD8+ T cell responses to Toxoplasma gondii

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    During infection with the intracellular parasite Toxoplasma gondii, the presentation of parasite-derived antigens to CD4+ and CD8+ T cells is essential for long-term resistance to this pathogen. Fundamental questions remain regarding the roles of phagocytosis and active invasion in the events that lead to the processing and presentation of parasite antigens. To understand the most proximal events in this process, an attenuated non-replicating strain of T. gondii (the cpsII strain) was combined with a cytometry-based approach to distinguish active invasion from phagocytic uptake. In vivo studies revealed that T. gondii disproportionately infected dendritic cells and macrophages, and that infected dendritic cells and macrophages displayed an activated phenotype characterized by enhanced levels of CD86 compared to cells that had phagocytosed the parasite, thus suggesting a role for these cells in priming naïve T cells. Indeed, dendritic cells were required for optimal CD4+ and CD8+ T cell responses, and the phagocytosis of heat-killed or invasion-blocked parasites was not sufficient to induce T cell responses. Rather, the selective transfer of cpsII-infected dendritic cells or macrophages (but not those that had phagocytosed the parasite) to naïve mice potently induced CD4+ and CD8+ T cell responses, and conferred protection against challenge with virulent T. gondii. Collectively, these results point toward a critical role for actively infected host cells in initiating T. gondii-specific CD4+ and CD8+ T cell responses

    The Magnitude of Global Marine Species Diversity

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    Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century
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