Search

Search Results

• 1. [Article] Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA

  Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch ...

  Citation × Citation Citation Abstract Copy Title: Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA Author: Christy, John A. Year: 2013 Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch associations are being infilled by a combination of plant succession and invasive species. Repeat photography using aerial and ground-based imagery is recommended as a way to gauge the rate of change in dune communities. Prescribed fire is recommended to monitor rejuvenation effects on two shore pine woodland associations that are most at risk of infilling. Vegetation mapping based on remote sensing will enable more accurate assessment of vegetation features, and facilitate modeling of management scenarios and effects of seal level rise, earthquakes, and tsunamis. Title: Rare Plant Associations, Oregon Dunes National Recreation Area, Sutton Recreation Area, and Heceta Sand Dunes ACEC/ONA Author: Christy, John A. Year: 2013 Nine of the ten rare plant associations identified in the dunes in 1993 are recommended for continued inclusion in conservation planning. Large-patch associations are currently in good condition, but small-patch associations are being infilled by a combination of plant succession and invasive species. Repeat photography using aerial and ground-based imagery is recommended as a way to gauge the rate of change in dune communities. Prescribed fire is recommended to monitor rejuvenation effects on two shore pine woodland associations that are most at risk of infilling. Vegetation mapping based on remote sensing will enable more accurate assessment of vegetation features, and facilitate modeling of management scenarios and effects of seal level rise, earthquakes, and tsunamis. Close

• 2. [Article] Recreational Boats as Potential Vectors of Marine Organisms at an Invasion Hotspot

  With more than 200 aquatic nonindigenous species (NIS), San Francisco Bay (California, USA) is among the world’s most invaded harbors. Hard-substratum benthic (biofouling) organisms, which dominate NIS ...

  Citation × Citation Citation Abstract Copy Title: Recreational Boats as Potential Vectors of Marine Organisms at an Invasion Hotspot Author: Davidson, Ian C., Zabin, Chela J., Chang, Andrew L., Brown, Christopher W., Sytsma, Mark, Ruiz, Gregory M. Year: 2010 With more than 200 aquatic nonindigenous species (NIS), San Francisco Bay (California, USA) is among the world’s most invaded harbors. Hard-substratum benthic (biofouling) organisms, which dominate NIS richness, have arrived primarily as a result of shipping and aquaculture activity over past centuries. To date there has been no assessment of the leisure craft vector in the Bay. We aimed to characterize (1) biofouling on boats’ submerged surfaces and (2) boater behavior likely to affect the risk of NIS transfers. We used an underwater pole-cam, specimen collections, and a boater questionnaire to quantify the extent and composition of biofouling on recreational boats and to evaluate boater behavior at a subset of the Bay’s marinas. Several NIS, already established within the Bay, were recorded from vessel hulls, including the bryozoans Bugula neritina, Membranipora chesapeakensis and Watersipora sp., the ascidians Botrylloides violaceus, Styela clava and Ciona intestinalis, the polychaete Ficopomatus enigmaticus, and the sponge Clathria prolifera. Only 16% of questionnaire respondents had traveled to sites outside the Bay in the previous 12 mo. Frequency of hull painting and cleaning varied substantially, but we did not find strong patterns of biofouling extent associated with hull husbandry or boat usage. The potential for within-Bay and coastwise regional spread of NIS is high, and recreational boats probably interact in close proximity to other vectors (e.g. commercial ships), causing a ratchet effect of vector events; however, there remains a gap in understanding the levels and condition of biofouling on transient boats. Transient vessels from San Francisco Bay and other West Coast sites should be the focus of future studies to evaluate the extent to which organisms are being transferred among bays and how vector management could be applied to prevent NIS transfers and impacts. Title: Recreational Boats as Potential Vectors of Marine Organisms at an Invasion Hotspot Author: Davidson, Ian C., Zabin, Chela J., Chang, Andrew L., Brown, Christopher W., Sytsma, Mark, Ruiz, Gregory M. Year: 2010 With more than 200 aquatic nonindigenous species (NIS), San Francisco Bay (California, USA) is among the world’s most invaded harbors. Hard-substratum benthic (biofouling) organisms, which dominate NIS richness, have arrived primarily as a result of shipping and aquaculture activity over past centuries. To date there has been no assessment of the leisure craft vector in the Bay. We aimed to characterize (1) biofouling on boats’ submerged surfaces and (2) boater behavior likely to affect the risk of NIS transfers. We used an underwater pole-cam, specimen collections, and a boater questionnaire to quantify the extent and composition of biofouling on recreational boats and to evaluate boater behavior at a subset of the Bay’s marinas. Several NIS, already established within the Bay, were recorded from vessel hulls, including the bryozoans Bugula neritina, Membranipora chesapeakensis and Watersipora sp., the ascidians Botrylloides violaceus, Styela clava and Ciona intestinalis, the polychaete Ficopomatus enigmaticus, and the sponge Clathria prolifera. Only 16% of questionnaire respondents had traveled to sites outside the Bay in the previous 12 mo. Frequency of hull painting and cleaning varied substantially, but we did not find strong patterns of biofouling extent associated with hull husbandry or boat usage. The potential for within-Bay and coastwise regional spread of NIS is high, and recreational boats probably interact in close proximity to other vectors (e.g. commercial ships), causing a ratchet effect of vector events; however, there remains a gap in understanding the levels and condition of biofouling on transient boats. Transient vessels from San Francisco Bay and other West Coast sites should be the focus of future studies to evaluate the extent to which organisms are being transferred among bays and how vector management could be applied to prevent NIS transfers and impacts. Close