Download or read book The Effect of Water Currents on the Movement of the Green Sea Urchin Strongylocentrotus Droebachiensis written by Bryan Lee Morse and published by . This book was released on 2007 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Trans life Cycle Impacts of Ocean Acidification on the Green Sea Urchin Strongylocentrotus Droebachiensis written by and published by . This book was released on 2013 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental and Biological Drivers of Feeding and Spatial Dynamics in the Green Sea Urchin Strongylocentrotus Droebachiensis written by Desta Lynne Braden Frey and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In eastern Canada, the destruction of foundational kelp beds by dense aggregations (fronts) of the omnivorous green sea urchin, Strongylocentrotus droebachiensis, is a key determinant of the structure and dynamics of shallow reef communities. Current knowledge about factors affecting the ability of S. droebachiensis to exert top-down community control is based largely on observational studies of patterns in natural habitats, yielding fragmentary, and sometimes contradictory, results. The present research incorporated laboratory microcosm experiments and surveys of urchins in natural habitats to test the effects of abiotic (wave action, water temperature) and biotic (body size, population density) factors on: (1) individual and aggregative feeding on the winged kelp, Alaria esculenta; and (2) displacement, microhabitat use, distribution, and aggregation in food-depleted habitats. Wave action, water temperature, and body size strongly affected the ability of urchins to consume kelp: individual feeding increased with increasing body size and temperature, while aggregative feeding decreased with increasing wave action. Yet, feeding in large urchins dropped by two orders of magnitude between 12 and 18°C. Increasing wave action triggered shifts in urchin displacement, microhabitat use, distribution, and aggregation: urchins reduced displacement and abandoned flat surfaces in favour of crevices. They increasingly formed two-dimensional aggregations at densities ≥110 individuals m−2. Collectively, results provide a foundational understanding of some of the drivers of feeding and spatial dynamics of S. droebachiensis and potential impacts on the formation of grazing fronts.
Download or read book Individual and Population Level Responses to the Environment written by Kathleen Anne MacGregor and published by . This book was released on 2020 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Feeding and the search for food are one of the most important activities of all mobile animals, providing individuals with the energy and resources to grow and reproduce. Foraging is fundamentally concerned with movement through an explicit landscape. Marine environments present a set of unique opportunities and challenges for mobile foragers because water is much denser than air and exerts significant drag and lift forces on benthic organisms moving across the bottom. Substratum type, therefore, functions as a key determinant of movement in subtidal marine environments. Urchins (Phylum Echinodermata, Class Echinoidea) are one of the most important marine grazers worldwide. When urchin populations are large, they can overgraze brown macroalgal (kelp) beds and form urchin barren grounds, characterized by a complete lack of kelp and high densities of urchins. Under such conditions, the foraging of adult urchins largely determines the state of subtidal benthic habitats by limiting the recolonization of macroalgae. Urchins in barren grounds thus exist in a resource-limited state, and the rapid detection and consumption of resource patches, particularly pieces of macroalgae from adjacent algal beds, is therefore key in determining individual growth and reproduction. However, there are very few detailed examinations of urchin movement and none which explicitly take both seascape and the presence of food into account, making predictions about community responses to environmental changes difficult. My objective in this thesis was to evaluate the environmental factors modifying the movement behaviour of urchins in barren grounds, including the role of environment in determining the response of these communities to perturbations such as a fishery or disease outbreak which entail a reduction in urchin numbers and biomass. First, I combined a global literature review of previous experimental manipulations of urchin abundances with my own replicated urchin removal experiment in order to examine the causal link between grazing pressure exerted by urchins and macroalgal colonization and growth. In the published literature, urchin removals result in kelp colonization in only two thirds of cases worldwide. In my own manipulations in the Gulf of St. Lawrence, site was the most important determinant of successful reduction of urchin densities. Spatial variability, possibly related to the strength of indirect interactions such as competition between large and small urchins, was essential in determining the outcomes of perturbation experiments. In order to examine the movement behaviour that could explain the spatial variability in community response in detail, I then experimentally manipulated substrata composition in the field to examine the interacting effects of substrata and the presence of drift kelp on urchin movement behaviour. Unstable substrata (sand) did not function as absolute barriers to urchin movement in barren grounds, but urchin densities were lower on sand relative to adjacent rocky substrata, and sand barriers slowed cumulative consumption of drift kelp. Once again, however, there were clear and consistent site-to-site differences in movement behaviour, possibly related to the size-structure of urchin populations. Sand patches v appear to reduce movement of very large urchins (test diameter > 50 mm) but not of medium-sized urchins (test diameter of 20-50 mm). Finally, I used time-lapse photography to describe the movements of individual urchins in relation to the presence of kelp and differences in seascape substratum composition. Green sea urchins were able to detect the presence of drift kelp in barren ground habitats and alter their movement behaviour in response but did not move directly towards the kelp. Seascapes with increased proportions of rocky substrata facilitated increased urchin movement in response to the presence of drift, but only in the summer and not in spring. The intriguing relationships between movement behaviour and urchin size at specific sites combined with the observed seasonal variability indicate that the role of seascape in determining the movement behaviour of urchins is complex and modified by important intrinsic and extrinsic factors. My results are the first detailed observations of urchin movement in a spatially explicit context and clearly demonstrate that a mechanistic understanding of the responses of barren ground systems to future perturbations must include detailed information on environmental modification of behaviour.
Download or read book The Effect of Ocean Acidification on Phototaxis Within the Green Sea Urchin strongylocentrotus droebachiensis written by Jefferson Norwood and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pathogenic Impacts on the Green Sea Urchin Strongylocentrotus Droebachiensis in the Gulf of Maine written by Scott Raymond Randolph Haskell and published by . This book was released on 2008 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Various Conditions on the Growth Development and Survival of Green Sea Urchin Strongylocentrotus Droebachiensis Larvae written by Brock O. A. Thomson and published by . This book was released on 1999 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Urchin Injury written by William E. Donaldson and published by . This book was released on 1989 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Urchin Injury written by William E. Donaldson and published by . This book was released on 1998 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions in the Marine Benthos written by Stephen J. Hawkins and published by Cambridge University Press. This book was released on 2019-08-29 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive account of how abiotic and biotic interactions shape patterns of coastal marine biodiversity and ecosystem processes globally.
Download or read book Effects of Ocean Acidification on Key Physiological Parameters in the Green Urchin Strongylocentrotus Droebachiensis written by Katja Trübenbach and published by . This book was released on 2009 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Size and Feeding Pattern on the Respiration Rate of the Green Sea Urchin Strongylocentrotus Droebachiensis written by Paul Barter and published by . This book was released on 1999 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Short term Temperature Changes on Grazing and Physical Condition in the Green Sea Urchin Strongylocentrotus Droebachiensis written by Alana Kavanagh and published by . This book was released on 2015 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Outlook for Establishing a Fishery for the Green Sea Urchin Strongylocentrotus Droebachiensis in the St Lawrence River written by D. E. Kramer and published by . This book was released on 1980 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book S U R F written by Jessica C. Kraft and published by . This book was released on 2001 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Impact of Light Quality and Quantity on Gonadic and Somatic Growth of the Green Sea Urchin Strongylocentrotus Droebachiensis written by Maria Kathryn Stapleton and published by . This book was released on 2010 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spawning Inducers of the Green Sea Urchin Strongylocentrotus Droebachiensis written by Nicole Caron and published by . This book was released on 1999 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
