Download or read book Physiological Factors Affecting the Distribution of the Non indigenous Seagrass Zostera Japonica Along the Pacific Coast of North America written by Deborah Joyce Shafer and published by . This book was released on 2007 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Utilization of the Non Native Seagrass Zostera Japonica by Crab and Fish in Pacific Northwest Estuaries written by Daniel M. Sund and published by . This book was released on 2015 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction of non-native species often results in fundamental changes in the structure and function of disturbed environments. In the Pacific Northwest (PNW), the introduced seagrass Zostera japonica is rapidly expanding in distribution, impacting stakeholders and public use of the intertidal. Z. japonica's expansion has prompted a number of different management strategies and many research studies that examine its ecology in the PNW. A number of studies have compared the benthic and epifaunal communities in Z. japonica to those of the native Z. marina, but to date, none have contrasted the nekton communities using the two seagrasses. The goals of this project were to 1) examine the community composition of a variety of available estuarine habitats in Willapa Bay, Washington, and Yaquina Bay, Oregon, via paired deployment of cameras and small fish traps; and 2) to explore the different management strategies used in the PNW and identify strengths and weaknesses associated with invasive species management, as indicated by short interviews with professionals working on Z. japonica. In Willapa Bay, Z. japonica, Z. marina, clam aquaculture, and on-ground oyster aquaculture were examined. In Yaquina Bay, Z. japonica, Z. marina, and bare substrate were examined. A total of 11 species, with 10 occurring in Willapa Bay and 9 in Yaquina Bay, were observed in video footage. Habitat was a significant predictor of catch per unit effort (CPUE) for the most abundant species in Yaquina Bay but not those in Willapa Bay. Community composition was significantly different between habitats in each bay but not between the bays. Explicit comparisons of seagrass habitat in each bay indicate some evidence that community composition of the two seagrasses differs in Yaquina Bay, but not in Willapa Bay. We conclude that community composition varies little between seagrass structure in Yaquina Bay and Willapa Bay and that local variation is highly dependent on the availability of structured habitats. Additionally, the distribution of Z. japonica relative to Z. marina may drive these differences in community composition between seagrass habitats in these estuaries. In short, unstructured interviews with professionals working on Z. japonica in the PNW, ecological characteristics that prompted management consideration; historical and potential management approaches; and suggestions to improve invasive species management at the local, regional, and national levels were discussed. Interview participants highlighted Z. japonica's expansion into historically unstructured regions of the intertidal, its role as an ecosystem engineer, and the intrinsic value of the local, native ecology as reasons for management. The need for collaboration across all levels (local, state, regional, and federal) of invasive species management, public outreach and education, professional development, and explicit statement of management position were all stressed as potential improvements to invasive species management.

Download or read book The Potential Role of Climate in the Distribution and Zonation of the Introduced Seagrass Zostera Japonica in North America written by Deborah J. Shafer and published by . This book was released on 2008 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Ecological Framework for the Management of the Non indigenous Seagrass Zostera Japonica in Washington State written by Glenn Grant Merrill and published by . This book was released on 1995 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Distribution and Potential Effects of a Non native Seagrass in Washington State written by Megan E. Mach and published by . This book was released on 2010 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Effects and Tradeoffs Affect Vegetative Growth and Sexual Reproduction in an Invasive Seagrass Experiencing Different Disturbance Regimes written by Jeremy Scott Henderson and published by . This book was released on 2013 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disturbance has both direct and indirect ramifications that can influence species abundance, distribution, and ultimately the diversity found within a community. As a result, we might expect disturbance to play a particularly important role in the ability of non-native species to proliferate outside of their native range. In practice, disturbance has been shown to facilitate invasions indirectly by reducing competition with established species, but less is known about the direct effects of disturbance on potential invaders. It is generally assumed that the direct effects of disturbance will be negative, but an exemption to this exists if disturbance results in tradeoffs that favor the allocation of resources to sexual reproduction. To examine this possibility, I considered the direct effects of disturbance and the relative importance of tradeoffs on the invasion dynamics of the dwarf eelgrass, Zostera japonica Aschers. & Graebn., across different sediment disturbance regimes in Yaquina Bay, a North American Pacific coast estuary near Newport, Oregon. The basis of my thesis work is a conceptual model in which tradeoffs in resource allocation between reproduction and vegetative growth in plants results in increased sexual reproduction at intermediate levels of disturbance. My hypothesis is that as disturbance severity increases, vegetative biomass declines until there is complete mortality of the population. Moreover, I suggest that flowering biomass will increase with disturbance to some intermediate level but then decline as disturbance severity increases. This increase in flowering biomass is the result of a tradeoff in which individuals reallocate resources from asexual to sexual reproduction as disturbance increases the mortality risk and reduces the fitness of clonal progeny. To test this model, I conducted two years of monthly monitoring at six sites representing the potential for different sediment disturbance regimes, and also conducted a field experiment at three sites representative of low, moderate, and high sediment disturbance. The observational study showed sediment disturbance was strongly site dependent, with three sites having high sedimentation, one site having moderate sedimentation, and two sites having low sedimentation. In the observational and experimental study, there was a negative linear relationship between the abundance (percent cover and biomass) of Z. japonica and sedimentation among the sites. Vegetative growth showed a negative linear response to increased sedimentation, with approximately 50% mortality seen at sediment deposition rates of 1 cm per month, and nearly 100% mortality seen at rates above 3.5 cm per month. The experiment also showed that flowering and seed production responded unimodally to increased sedimentation, and they were greatest at sediment deposition rates of roughly 0.75 cm per month, and effectively inhibited at rates above 1.5 cm per month. My results suggest that the unimodal response of this non-native eelgrass to disturbance is the result of tradeoffs in resource allocation favoring sexual reproduction and the production of seeds, which is potentially an escape from increasing disturbance severity. This type of tradeoff might result in an increased likelihood that Z. japonica could reach new sites, and, as has been shown in other invasive grasses, could possibly result in an increase in genetic diversity that would allow this species to successfully proliferate across a wider range of environmental conditions. As disturbance regimes change due to anthropogenic causes, it is important to document these tradeoffs and determine whether they could contribute to making communities more susceptible to invasion and thus of greater management concern.

Download or read book Using a Temperature based GIS Model to Identify Potential Habitat for Zostera Japonica in Humboldt Bay CA written by Andrew Edward Weltz and published by . This book was released on 2012 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Science and Management of the Introduced Seagrass Zostera Japonica in North America written by Deborah J. Shafer and published by . This book was released on 2014 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book World Atlas of Seagrasses written by Frederick T. Short and published by Univ of California Press. This book was released on 2003 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seagrasses are a vital and widespread but often overlooked coastal marine habitat. This volume provides a global survey of their distribution and conservation status.

Download or read book Physical Factors Associated with the Limits to Zostera Marina Distribution in Rosario Bay WA written by Erica Haley Franklin and published by . This book was released on 2017 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: From Abstract: Eelgrasses and other seagrasses are important habitats along the Pacific Northwest coast for a variety of marine life. They are also widely known to be indicators of coastal ecological health. There are many parameters that affect eelgrass growth, and several of those parameters were investigated in order to determine whether or not those factors were associated with the limits to Z. marina growth in Rosario Bay, Washington ...

Download or read book A Manual of Chemical Biological Methods for Seawater Analysis written by Timothy R. Parsons and published by Elsevier. This book was released on 2013-10-22 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the quantitative analysis of seawater, describing in detail biological and chemical techniques, which are considered to be amongst those most often used by biological oceanographers. The manual provides complete instructions for the addition of reagents and calculation of results with reference material for each method so that the original texts can be consulted if necessary. In general, the techniques require a minimum of prior professional training and methods needing very expensive equipment have been avoided.

Download or read book Ecological and Evolutionary Dynamics of Zostera Japonica and Spartina Alterniflora Invasions in the Eastern Pacific written by Kathy Jun Bando and published by . This book was released on 2005 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecology Abstracts written by and published by . This book was released on 1983 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Salinity on Photosynthesis and Respiration of the Seagrass Zostera Japonica written by Deborah J. Shafer and published by . This book was released on 2011 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Influence of Multiple Scales of Environmental Context on the Distribution and Interaction of an Invasive Seagrass and Its Native Congener written by Michael P. Hannam and published by . This book was released on 2013 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Predicting invasive species impacts is complicated by the variable context in which they occur. Furthermore, species invasion is an inherently multi-scale process, warranting examination at multiple spatial scales. In its introduced range, the invasive seagrass Zostera japonica often grows at higher elevations than its native congener, Zostera marina, but at some sites the congeners overlap. At overlapping sites, the two seagrasses often grow in a patch mosaic associated with intertidal microtopography. I examine the role of multiple scales of environmental context in the vertical zonation of Z. japonica and Z. marina, and the relationship of meter to decameter scale microtopography to the local distribution and biotic interactions of Z. marina and Z. japonica. Nearshore intertidal topography, hydrodynamic exposure, and tidal range were examined as abiotic predictors of the deep extents of Z. japonica and Z. marina, the shallow extent of Z. marina and the elevation overlap of the two species, both at within site and among site spatial scales. Bottom profile complexity was the most consistently important predictor studied, confirming the importance of the geomorphic template on the zonation of these species. Z. japonica's deep extent was well-predicted by Z. marina's shallow extent, but Z. marina's shallow extent was best predicted by physical factors. Using a terrestrial laser scanner, I mapped and monitored a one hectare study site for three years. The location and shape of microtopographic features were generally stable from year to year, but the magnitude of local relief was variable. Z. marina was more likely to occur in water-filled depressions than on well-drained mounds, but the presence of Z. japonica, was better predicted by low shoot densities of Z. marina. Transplant experiments revealed that Z. marina suppressed Z. japonica shoot densities, more so in pools than on mounds. Topographic context remained the most influential predictor of Z. marina responses, even when I transplanted Z. marina into higher densities of Z. japonica. I show that decameter to kilometer-scale environmental context influences the vertical zonation of Z. marina and Z. japonica, and that meter to decimeter-scale microtopographic relief influences their local spatial distribution. Furthermore, centimeter-scale topographic relief can modify competitive outcomes and promote decameter-scale coexistence of these two species.

Download or read book Global Seagrass Research Methods written by F.T. Short and published by Elsevier. This book was released on 2001-11-06 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thorough and informative volume presents a set of detailed, globally applicable techniques for seagrass research.The book provides methods for all aspects of seagrass science from basic plant collection to statistical approaches and investigations of plant-animal interaction. The emphasis is on methods that are applicable in both developing and developed countries. The importance of seagrasses in coastal and near shore environments, and ultimately their contribution to the productivity of the world's oceans, has become increasingly recognised over the last 40 years.Seagrasses provide food for sea turtles, nearly 100 fish species, waterfowl and for the marine mammals the manatee and dugong. Seagrasses also support complex food webs by virtue of their physical structure and primary production and are well known for their role as breeding grounds and nurseries for important crustacean, finfish and shell fish populations. Seagrasses are the basis of an important detrital food chain. The plants filter nutrients and contaminants from the water, stabilise sediments and act as dampeners to wave action. Seagrasses rank with coral reefs and mangroves as some of the world's most productive coastal habitat and strong linkages among these habitats make the loss of seagrasses a contributing factor in the degradation of the world's oceans.Contributors from around the world provide up-to-date methods for comparable collection of ecological information from both temperate and tropical seagrass ecosystems.