Download or read book A Spatial Model of Eelgrass Zostera Marina Habitat in Humboldt Bay California written by Whelan Gilkerson and published by . This book was released on 2008 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was conducted to model the extent of eelgrass habitat in Humboldt Bay, California through physical surveys of the maximum depths and upper limits of growth in conjunction with recently acquired high-resolution bathymetry data and supplemental imagery. A combination of chronic turbidity, frequent coastal stratus, and wind-waves, make Humboldt Bay a challenging environment to assess subtidal eelgrass (Zostera marina) habitat from remotely-sensed imagery. Additionally, eelgrass and green algae overlap extensively in shallow intertidal areas, confounding efforts to distinguish between habitat types from imagery alone. A relative exposure index (REI) was developed to identify areas of eelgrass habitat that may be prone to disturbance from wind-waves. Approximately 2200 hectares of eelgrass habitat were identified. Accuracy was assessed at 91% for modeled eelgrass habitat in South Humboldt Bay based on a comparison with hyperspectral imagery captured in October, 2004. Modeling the extent of eelgrass habitat represents an important step towards understanding the extent to which future restoration or mitigation may be possible in Humboldt Bay.
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 Inventory of Eelgrass Zostera Marina L in San Francisco San Pablo Bay written by Sandy Wyllie-Echeverria and published by . This book was released on 1989 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Spatial and Temporal Variation of Eelgrass Zostera Marina Its Epiphytes and the Grazer Phyllaplysia Taylori in Arcata Bay California USA written by Aimee Louise Keiser and published by . This book was released on 2004 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Structure of Eelgrass Zostera Marina Within Humboldt Bay California written by Bethany Baibak and published by . This book was released on 2014 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global FST and overall RST values were close to zero implying that the subpopulations in both datasets share many alleles in similar frequency. Pairwise FST comparisons of MRS:ELK and MRS:HBS were slightly significant indicating that there are alleles that are not shared in equal frequency between these subpopulations. Although not statistically significant, some distinctive structure of ELK and MRS was observed in scatterplots in DAPC: this is consistent with their physical isolation within the bay and ecological attributes of each system. In contrast to the lack of structural variability among subpopulations, a large proportion of variability was identified among samples as demonstrated by high levels of clonal richness (R > 0.97), overall heterozygosity (HO = 0.51, HE = 0.53) and allelic richness (5.6 - 7.4). These findings could be due to a combination of plant (e.g., outcrossing) and environmental attributes (e.g., too few generations) that minimize genetic differentiation in the bay. Alternatively, HBN may have lost genetic structure due to disturbances accumulated since 1850 and HBN may be relying on seed dispersal from other areas of the bay, thereby minimizing horizontal genetic structure.
Download or read book The Ecology of Humboldt Bay California written by Roger A. Barnhart and published by . This book was released on 1992 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluating Eelgrass Zostera Marina Site Quality by the Settlement Performance and Survival of a Marine Fish written by and published by . This book was released on 2011 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quantity of suitable habitat can be simply defined by the distribution and abundance of organisms, but it is the quality of the habitat that may have more direct demographic consequences. Habitat quality is best assessed by determining demographic rates and the performance of the focal species residing within a habitat. Using this framework, I used two demographic rates (settlement and survival) and two performance measures (growth and condition) of the giant kelpfish (Heterostichus rostratus) to evaluate whether eelgrass (Zostera marina) habitat quality varies spatially (i.e., site quality) within San Diego Bay, CA. Seven sites were selected that encompass the northern and central areas of the bay. Settlement was estimated bi-weekly from May-July 2009 with artificial seagrass units (ASUs) and standard monitoring units for the recruitment of fishes (SMURFs). Eelgrass habitat complexity (shoot height and density) was measured at each site, and three complexity treatments were replicated with ASUs in large mesocosms to estimate survival of giant kelpfish after exposure to kelp bass (Paralabrax clathratus) as predators. Growth and condition were derived from juvenile giant kelpfish collected from sites two months after the settlement period. Growth and condition were estimated from otolith daily growth increments and total lipid content, respectively. Settlement, growth, and condition were evaluated using a multivariate approach to provide an assessment of habitat quality among sites. Combined with habitat-dependent survival from predators in laboratory trials that reflected site-specific habitat attributes, sites were ranked along a gradient of habitat quality. The multivariate analysis of site quality based on demographic and performance variables was then overlaid with a similar analysis of environmental variables. Environmental variables that would serve as proxies for habitat quality were not concordant with the suite of demographic and performance variables used to differentiate site quality. Consequently, a multivariate approach using demographic rates and individual performance is the most appropriate method to evaluate habitat quality, whether among different habitats or among sites with the same habitat.
Download or read book Effects of Eelgrass Zostera Marina Habitat Fragmentation on the Epifaunal Community in San Diego Bay USA written by Danielle Healey and published by . This book was released on 2005 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seafloor Mapping along Continental Shelves written by Charles W. Finkl and published by Springer. This book was released on 2016-03-24 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This university-level reference work covers a range of remote sensing techniques that are useful for mapping and visualizing benthic environments on continental shelves. Chapters focus on overviews of the history and future of seafloor mapping techniques, cartographical visualisation and communication of seafloor mapping, and practical applications of new technologies. Seabed mapping is referenced by high-resolution seismic methods, sidescan sonar, multibeam bathymetry, satellite imagery, LiDAR, acoustic backscatter techniques, and soundscape ecology monitoring, use of autonomous underwater vehicles, among other methods. The wide breadth of subjects in this volume provides diversified coverage of seafloor imaging. This collection of modern seafloor mapping techniques summarizes the state of the art methods for mapping continental shelves.
Download or read book Remote Sensing and Modeling written by Charles W. Finkl and published by Springer. This book was released on 2014-09-01 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is geared for advanced level research in the general subject area of remote sensing and modeling as they apply to the coastal marine environment. The various chapters focus on the latest scientific and technical advances in the service of better understanding coastal marine environments for their care, conservation and management. Chapters specifically deal with advances in remote sensing coastal classifications, environmental monitoring, digital ocean technological advances, geophysical methods, geoacoustics, X-band radar, risk assessment models, GIS applications, real-time modeling systems, and spatial modeling. Readers will find this book useful because it summarizes applications of new research methods in one of the world’s most dynamic and complicated environments. Chapters in this book will be of interest to specialists in the coastal marine environment who deals with aspects of environmental monitoring and assessment via remote sensing techniques and numerical modeling.
Download or read book Long term Spatial temporal Eelgrass Zostera Marina Habitat Change 1932 2016 in the Salish Sea Using Historic Aerial Photography and Unmanned Aerial Vehicle written by Natasha K. Nahirnick and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Eelgrass (Zostera marina) is a critical nearshore marine habitat for juvenile Pacific salmon (Oncorhynchus spp.) as they depart from their natal streams. Given the poor marine survival of Coho (O. kisutch) and Chinook (O. tshawytscha) salmon juveniles in recent decades, it is hypothesized that deteriorating eelgrass habitats could contribute to their low survival. The primary goal of this research was to investigate the possible long-term spatial-temporal trends in eelgrass habitat in the Salish Sea and was addressed by two main objectives: (1) Define a methodology for mapping eelgrass habitats using UAV imagery to create a baseline for long-term mapping; and (2) Assess changes in eelgrass area coverage and fragmentation over the period of 1932-2016 using historic aerial photographs and Unmanned Aerial Vehicle (UAV) imagery, and assess the relationship between eelgrass and residential housing density and shoreline activities. Three study sites in the Southern Gulf Islands of the Salish Sea were chosen for analysis. The overall accuracies of eelgrass delineation from UAV imagery were 95.3%, 88.9%, and 90.1% for Village Bay, Horton Bay, and Lyall Harbour, respectively. The UAV method was found to be highly effective for this size of study site, however results were impacted by the environmental conditions at the time of acquisition, namely: sun angle, tidal height, cloud cover, water clarity, and wind speed. The results from the first objective were incorporated into a long-term dataset of historic aerial photography and used to evaluate changes in eelgrass area and fragmentation. All three eelgrass meadows showed a deteriorating trend in eelgrass condition. On average, eelgrass area coverage decreases by 41% while meadow complexity as indicated by the shape index increases by 76%. Shoreline activities (boats, docks, log booms, and shoreline armouring) and residential housing density increased markedly at all sites over the study period. By using a linear correlation model, it was revealed that eelgrass areal coverage and fragmentation (Shape Index) were, in general, very strongly correlated to these landscape-level coastal environmental indicators. While this correlation model is not meant to show a direct causative impact on eelgrass at these sites, these results suggest an overall deterioration of coastal environmental health in the Salish Sea due to a dramatic increase in the use of the coastal zone, as well as likely declines in water quality due to urbanization.
Download or read book The Growth and Distribution of Eelgrass Z o s t e r a M a r i n a L in Humboldt Bay California written by Mathew Keller and published by . This book was released on 1963 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Epifaunal Community Structure and Trophic Interactions in Eelgrass Zostera Marina Habitats of San Francisco Bay written by Lindsey Anne Carr and published by . This book was released on 2008 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Eelgrass Zostera Marina Habitat Loss on Epifaunal Abundance and Diversity written by Brendan J. Reed and published by . This book was released on 2005 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Buhne Point Shoreline Erosion Demonstration Project written by and published by . This book was released on 1987 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Observational and Experimental Analysis of Eelgrass and Its Epifaunal Community in Bodega Harbor California written by Grace Ha and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Seagrass - marine flowering plants that create underwater meadows through-out temperate and tropical coastal waters - are important foundation species, acting as key nursery grounds for many commercial and recreational fisheries, performing ecosystem functions including flow modification and sediment stabilization, and providing habitat to diverse and productive communities of marine life. Given the decline of seagrass globally, there is particular need for documenting and understanding the dynamics of seagrass ecosystems. Focusing on the eelgrass (Zostera marina L.) beds of Bodega Harbor, California, USA, I approached this task through methods that incorporated natural history, field research, statistical analysis, and taxonomy. In Chapter 1, I conducted a 16-month survey of eelgrass and its epifauna and analyzed species abundances in the context of the extreme warm-water event known as "The Blob" that occurred along the Californian coastline in 2014. My research found a diverse invertebrate assemblage comprising mostly native detritivore-grazers, which contrasted sharply with nearby San Francisco Bay, which has been dominated by invasive species. Invertebrate population dynamics correlated closely to that of the eelgrass they inhabited, and in general, both habitat and epifauna declines coincided with increasing seawater temperatures. In Chapter 2, I used eelgrass as a model system to test the role of camouflage in predator-prey interactions. I conducted field experiments, testing whether prey survival was affected by color-matching between prey and habitat, using the green amphipod, Ampithoe lacertosa and artificial habitats made of eelgrass, and clear, red, and green plastic ribbon. With seine nets and underwater video recordings, I also collected data on fish predator abundance and diversity. Although generalized linear regressions in-dicated habitat color significantly affected prey survival, greater color-matching did not predict greater prey survival. Further analysis using structural equation modeling indicated that the effect of habitat on prey survival was significantly mediated by fish density and, to a lesser degree, fish diversity. Even after taking these effects into account, I did not find survival to clearly correspond to increasing color-match between prey and habitat. These results were consistent with the equivocal conclusions of previous studies on the anti-predator hypothesis of camouflage, altogether suggesting further theory development and experimentation is needed to explain the frequency of apparent camouflage in nature. In Chapter 3, I described a new species of porcellidiid copepod - found during the epifaunal surveys I conducted in 2013-2014. This was the first porcellidiid copepod species to be described from North America, although porcellidiid copepods have been previously recorded in Northeast Pacific coastal surveys. Porcellidium species nova n. sp., can be distinguished by a deep cleft in the female genital double somite, a lack of plumulose setae and three coupling denticles (two bulbous denticulate pads and one smooth protrusion) on the male antennule, and clear coloration with purple/maroon bands across the first and last metasomes. I have provided a partial revision to a key to Porcellidium species, along with a discussion of the natural history and distribution of porcellidiid copepods along the Northeastern Pacific coastline.
Download or read book The Ecological Consequences of Genetic Diversity in Eelgrass Zostera Marina written by Anne Randall Hughes and published by . This book was released on 2006 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
