Download or read book Interactions and Dynamics of Eelgrass Zostera Marina L Epiphytes and Grazers in Subtidal Meadows of Puget Sound written by Timothy Alan Nelson and published by . This book was released on 1995 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Ecology written by Melany P. Puglisi and published by CRC Press. This book was released on 2018-08-30 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past 20 years, marine chemical ecology has emerged as a respected field of study providing a better understanding of the role natural products play in organisms and their environments. Ample data in this book advocates the conservation of marine environments for future drug discovery efforts while sustaining their overall health. Marine chemical ecology has expanded to include research in the areas of predator–prey interactions, marine microbial chemical ecology, and seasonal and geographical distribution of marine natural products.

Download or read book Context dependent Species Interactions in Seagrass Ecosystems written by and published by . This book was released on 2014 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unifying observation in ecology is that environmental context can play a key role in regulating the sign, strength, and mechanisms of species interactions. Estuaries and coastal seas are ideal ecosystems for exploring the impacts of environmental variability on ecological interactions because they are characterized by strong, dynamic gradients of abiotic conditions, such as physical disturbance and biogeochemical stress. Estuaries also are heavily impacted by biotic disruptions, including overexploitation of top predators and invasion by non-native species. For my dissertation, I explored the effects of abiotic and biotic environmental context on species interactions in subtidal and intertidal meadows of eelgrass Zostera marina, a marine angiosperm and key habitat-forming species in temperate estuaries worldwide, in three unique chapters. First, I tested how disturbance mediates competition between eelgrass and the burrowing ghost shrimp Neotrypaea californiensis in several California estuaries by conducting a series of transplantation and disturbance experiments. I found that both live eelgrass and structural mimics of belowground eelgrass tissues cause rapid declines in local ghost shrimp abundances, indicating that plant structure is an important mechanism in determining ghost shrimp distributions. However, ghost shrimp quickly colonize disturbances to eelgrass patch edges, which are common in shallow estuaries. Thus, coexistence is maintained by disturbance and a competition-colonization trade-off: eelgrass is competitively superior, but physical disturbances permit ghost shrimp coexistence at the landscape scale by modulating the availability of space. Second, I explored how light availability influences the sign, strength, and mechanisms of interactions between eelgrass and blue mussels, Mytilus edulis. I hypothesized that light availability regulates bivalve habitat modification and subsequent impacts on seagrasses by shifting net effects between alleviation of nutrient stress and intensification of sulfide stress. I manipulated light availability and blue mussel abundance in eelgrass mesocosms and measured biogeochemical and plant responses. I found that light modifies the effect of mussels on porewater ammonium, but eelgrass was not nutrient limited and, therefore, mussels did not enhance growth. Mussels increase sediment sulfides irrespective of light availability and, by reducing net oxygen flux (production and respiration), mussels and low light availability exacerbate sulfide intrusion of eelgrass tissues. Surprisingly, I found that sulfide stress did not affect plant growth, survival, or energy stores. Thus, habitat modification by mussels represents a risk to eelgrass, especially during low productivity conditions, but eelgrass can resist harm from short-term stress, even during light limitation. These findings suggest that while bivalve impacts on seagrasses may be variable in oligotrophic estuaries, they are likely negative in eutrophic systems, which are increasing globally. Third, I examined how invasive mussels impact their native bivalve competitors through both direct effects and indirect, predator-mediated interactions. Competition is a major process by which introduced species impact native populations, communities, and ecosystems, but ecological theory predicts that invading prey can also interact with their native competitors indirectly through shared native predators. Nevertheless, indirect effects are largely overlooked in invasive species science and management. In southern California estuaries, introduction of the Asian mussel Arcuatula senhousia has been linked to profound changes in native bivalve assemblages. I performed three field experiments to assess the mechanisms of competition between Arcuatula and native bivalves, and evaluate the potential for Arcuatula to indirectly mediate native predator-prey dynamics. I found that Arcuatula reduces the diversity, abundance, and size of native bivalve recruits by preemptively exploiting sediment surface space. When paired with native shallow-dwelling clams, Arcuatula reduces adult survival through overgrowth competition. However, Arcuatula also attracts native predators, indirectly increasing predation of native clams, especially poorly-defended species. Therefore, the vulnerability of invasive prey to predation can greatly exacerbate impacts on their native competitors. Overall, my dissertation improves our basic understanding of the causes and consequences of variation in species interactions in shallow estuaries and coastal lagoons. Furthermore, this research enhances our ability to predict the impacts on species interactions caused by human-induced ecosystem disruptions, such as habitat destruction, eutrophication, and non-native species introductions, which are widespread concerns for estuaries and coastal seas.

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 Temporal Diel and Vertical Distribution Variation of Epiphyte Grazers in a Temperate Eelgrass Zostera Marina L System written by Travis Shaw and published by . This book was released on 1994 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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:

Download or read book Ecological Life History of Zostera Marina L eelgrass in Puget Sound Washington written by Ronald C. Phillips and published by . This book was released on 1972 with total page 306 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 Status of Eelgrass Zostera Marina on the North Atlantic Coast February 1938 written by Clarence Cottam and published by . This book was released on 1938 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Eelgrass Zostera Marina Ecosystems in Eastern Canada and Their Importance to Migratory Waterfowl written by Mélanie-Louise Leblanc and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Seagrasses are marine flowering plants that create some of the most productive coastal habitats globally and play a key role in the functioning of nearshore ecosystems. The most common seagrass genus in Canada is Zostera and the species Zostera marina (eelgrass) is the predominant seagrass in intertidal and subtidal shoreline zones along the Atlantic, Pacific, and eastern James Bay coasts. Eelgrass has specific habitat requirements, with growth and productivity optimized within particular ranges of salinity, temperature, light availability, and nutrient concentrations. Large eelgrass meadows can impact nearshore environments by filtering the water column, stabilizing sediment, buffering shorelines, and providing habitat for various marine and coastal species, including commercially important species like Atlantic cod (Gadus morhua) and lobster (Homarus americanus). Eelgrass is also a vital food resource for migratory waterfowl, notably Canada Geese (Branta canadensis), Pacific Black Brant (Branta bernicla nigricans), and Atlantic Brant (Branta bernicla hrota). Despite their ecological importance, seagrasses are among the most vulnerable coastal ecosystems on the planet. The global loss of seagrass has been linked to a variety of human activities, including pollution, invasive species, and catchment modifications. There is an urgent need to improve monitoring of seagrass responses to environmental change, better document the importance of seagrass meadows to species reliant on them for food and habitat, and advance effective management and conservation of seagrass ecosystems. In this thesis, I investigated the spatiotemporal dynamics of eelgrass meadows in eastern Canada and the importance of eelgrass as a food source for migratory waterfowl, using remote sensing data, long-term monitoring data (biomass, density, and cover), and field observations. In Chapter 3, I used a novel cost-efficient approach for satellite imaging time-series to examine changes in eelgrass distribution and abundance from 1984 to 2017 in a wetland of international importance in northeastern New Brunswick. With minimal ground truth data, the novel time-series approach revealed a slow and steady decline in eelgrass abundance in some areas of the estuary. In contrast, other areas were characterized by highly dynamic shifts in eelgrass cover over time. I demonstrated how time-series analysis can be used to identify potential drivers of seagrass change and the benefits of including time-series analysis in seagrass monitoring programs. In Chapter 4, I contributed to advancing knowledge of migratory waterfowl stopover behaviour by examining the influence of eelgrass and human activities on Canada Geese habitat selection. Combining field observations of Canada Geese and the eelgrass distribution maps produced in Chapter 3, I found that Canada Geese selected areas with high eelgrass availability during periods of low human disturbance, which emphasized the importance of eelgrass as a food source during the fall migration. However, higher levels of human disturbance led to a redistribution of geese away from dense eelgrass meadows. In Chapter 5, I presented new insights into the recent and current state of eelgrass along the eastern coast of James Bay after a drastic and large-scale decline in the late 1990s. By aggregating, synthesizing, and analyzing long-term monitoring data and current surveys, spanning 1982 - 2020, I provided the first quantitative evidence that changes in eelgrass biomass in northeastern James Bay may reflect synergistic impacts of climate change and altered freshwater discharge regimes. Overall, this thesis advances understanding of how temperate and subarctic Zostera marina ecosystems and associated fauna respond to coastal development and climate change"--

Download or read book Production Ecology of Eelgrass Zostera Marina L and Its Epiphytes in Little Egg Harbor New Jersey written by David Elwyn Vaughan and published by . This book was released on 1982 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Eelgrass macroalgae Interactions written by Margot Hessing-Lewis and published by . This book was released on 2011 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation investigates the context-dependency of species interactions between seagrass and macroalgae in upwelling-influenced estuaries. In all coastal systems, nutrient loading is multidirectional, resulting from mostly freshwater and marine inputs. The directionality of nutrient inputs may affect the rate of supply of organic matter to the system. In systems where freshwater nutrient loading dominates, and has increased through time, research shows that blooms of fast-growing macroalgae often result in loss of critical seagrass habitats. In upwelling-influenced systems, marine- based nutrient inputs dominate during the summer, also resulting in blooms of ulvoid macroalgae during these productive months. The dominance of marine nutrients in these estuaries, coupled with additional variation in the physicochemical characteristics of seagrass beds, present novel contexts to study the outcomes of species interactions between the seagrass (Zostera marina L. (eelgrass) and ulvoid macroalgae. I studied these interactions at two different spatial scales that both address the relative importance of marine versus terrestrial nutrient sources on interaction outcome. Regionally, I studied between-estuary, latitudinal patterns in species interactions relative to differences in marine and terrestrial drivers of nutrient loading. Within an estuary, I also compared interactions among zones along an estuarine gradient, where nutrient patterns were reflective of the relative contribution of marine- based nutrients. At both scales of inquiry I employed both observational and experimental approaches to quantify species interaction dynamics. At the regional scale, I used a 5- year observational dataset from four estuaries along the Oregon and Washington coasts to study the relationship between eelgrass and ulvoid macroalgae (Chapter 2). Across latitudes that span ~220 km, macroalgal production was highest in the southern estuaries, and associated with decreased eelgrass production compared to the northern estuaries. However, through time, no estuarine site, regardless of its macroalgal biomass, was associated with declining eelgrass biomass. Contrary to systems where macroalgal production is driven by terrestrial inputs, I found that blooms in upwelling- influenced systems were associated with both marine and terrestrial drivers of nutrient inputs and production. In Coos Bay (South Slough), at the within-estuary scale, I also found differences in macroalgal and eelgrass biomass among sites along an estuarine gradient. Here too, based on a 2-year seasonal dataset of producer dynamics, I found no temporal relationship between eelgrass and macroalgae producer dynamics (Chapter 3). I used a comparative-experimental framework to understand the impact of macroalgal manipulations (additions and removals) on interactions with eelgrass along this gradient. In intertidal seagrass beds in the marine and polyhaline zones of the estuary I found that interaction strength was neutral and sometimes positive. However, in the riverine zone, interaction strength was negative, caused by decreased eelgrass density following macroalgal manipulation. To further examine the mechanisms informing interaction outcomes in the marine zone, a large-scale macroalgal manipulation was conducted, coupled with a mesocosm experiment (Chapter 4). For the mesocosm experiment I manipulated macroalgae and nutrients as in the field, but found dissimilar results. In the mesocosms, where water movement was limited and no tidal action occurred, negative effects of macroalgal addition were found. These were associated with increased light attenuation and decreased sediment oxygen levels. Contrary to these results, I found no macroalgal, or covariate effects in the field experiment. I also manipulated water column nutrients in both experiments, and found limited effects of nutrient enrichment on eelgrass, but not macroalgae, in the mesocosm experiment. Throughout these studies I demonstrated that the mechanisms determining context-dependency in upwelling-influenced estuaries are informed by physical and biogeochemical conditions, coupled with high ambient marine-derived nutrient concentrations. These findings are important to coastal management because they suggest that the strength, direction and mechanisms of interactions are shaped by local abiotic conditions and long-term nutrient regimes, rather than high nutrient concentrations per se. Given the shifting nature of nutrient concentrations in coastal waters associated with both coastal development and climate change, knowledge of context dependency can also be used to assess and forecast future changes in species interactions.

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 Phenotypic Expressions of Zostera Marina L Ectotypes in Puget Sound Washington written by Thomas William Hightower Backman and published by . This book was released on 1984 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Eelgrass Zostera Marina written by and published by . This book was released on 2004* with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigating Perennial Annual Eelgrass Zostera Marina L in Padilla Bay as Potential Donor Sources for Seed based Restoration written by Yuki Wilmerding and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper explores recovery of eelgrass (Zostera marina L.) meadows through seed-based restoration to address declines from natural and anthropogenic disturbances. The study focuses on the Joe Leary meadow site in Padilla Bay, Washington, aiming to (1) determine the spatial distribution of perennial and annual Z. marina, (2) understand variation in flowering shoot density and potential seed production, and (3) compare the phenology of flowering shoots. These objectives were investigated using field-based methods to collect presence/absence transect data for delineation, quadrat-based count data, and monitor seed development. Data collection occurred in the summer throughout the flowering life stage of eelgrass in the site. The study found spatial and temporal variation in the distribution, density, and phenology of flowering perennial and annual populations. Delineation methods revealed that annuals have a similar range in the intertidal as perennials, with differences highlighted in response to potential stress indicators such as proximity to the slough, algal mats, or elevation. Quadrat-based monitoring found annual shoots in the transect higher in the intertidal, above the perennial population. Phenology data indicated that perennial shoots flower about a month prior to annual shoots. While the study advises against using perennial flowering shoots for restoration due to low densities, it emphasizes Joe Leary's potential as a donor site for flowering annuals for seed-based restoration. Careful considerations are crucial to avoid unintended introductions of non-native species. The research concludes with recommendations for refining delineation methods, enhancing understanding of eelgrass population dynamics, and optimizing seed collection strategies for genetically diverse and resilient restoration in the face of climate change.

Download or read book Interacting Effects of Light and Sediment Sulfide on Eelgrass Zostera Marina L Growth written by William Ahlering Kuhn and published by . This book was released on 1992 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: