Influences of Structural Complexity, Predation Risk and Food Availability on Habitat Selection of Southern California Seagrass Fauna PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Influences of Structural Complexity, Predation Risk and Food Availability on Habitat Selection of Southern California Seagrass Fauna PDF full book. Access full book title Influences of Structural Complexity, Predation Risk and Food Availability on Habitat Selection of Southern California Seagrass Fauna by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages : 35
Book Description
Habitat structure is a chief determinant of the distribution of organisms in many systems, but is not often known whether organism-habitat associations are driven primarily by interactions with other species (e.g., higher predator-induced mortality rates in poor quality habitat) or by active habitat selection. Moreover, active habitat selection may be modified by factors such as perceived predation risk or food availability. In seagrass habitat, positive associations between faunal abundance and habitat structure are common and may be due both to high survival in structurally complex microhabitats or to active selection. We tested whether two species that are abundant in eelgrass (Zostera marina) habitat, the epifaunal grass shrimp Hippolyte californiensis and the mesopredatory juvenile giant kelpfish Heterostichus rostratus select habitat based on structural complexity, and if patch selectivity is modified by predation risk and food levels. Experiments to determine habitat preferences consisted of comparing the distribution of grass shrimp and kelpfish within mesocosms in which they had a choice of high or low complexity eelgrass vs. mesocosms in which they had no choice, as well as a field experiment testing how the propensity of grass shrimp to remain within eelgrass patches varied with structural complexity and predator presence. Generally, grass shrimp and kelpfish preferred high complexity seagrass over low complexity seagrass, but trends differed between species and between experiments with and without predators. Grass shrimp exhibited relatively modest preference for high complexity habitat in mesocosms as well a tendency to change preference to low complexity seagrass when a predatory threat was present in high complexity seagrass. In contrast, in naturally occurring seagrass beds shrimp exhibited a clear preference for high complexity seagrass during the day, but not at night when they may move among patches. Juvenile giant kelpfish exhibited a strong preference for high complexity seagrass even when a predatory threat was present in high complexity seagrass and food was made available in low complexity seagrass, though kelpfish displayed antipredator behaviors only when predators were present. Our research highlights the importance of considering the covariation of several factors when trying to predict habitat selection and species distributions in seagrass beds.
Author: Publisher: ISBN: Category : Languages : en Pages : 35
Book Description
Habitat structure is a chief determinant of the distribution of organisms in many systems, but is not often known whether organism-habitat associations are driven primarily by interactions with other species (e.g., higher predator-induced mortality rates in poor quality habitat) or by active habitat selection. Moreover, active habitat selection may be modified by factors such as perceived predation risk or food availability. In seagrass habitat, positive associations between faunal abundance and habitat structure are common and may be due both to high survival in structurally complex microhabitats or to active selection. We tested whether two species that are abundant in eelgrass (Zostera marina) habitat, the epifaunal grass shrimp Hippolyte californiensis and the mesopredatory juvenile giant kelpfish Heterostichus rostratus select habitat based on structural complexity, and if patch selectivity is modified by predation risk and food levels. Experiments to determine habitat preferences consisted of comparing the distribution of grass shrimp and kelpfish within mesocosms in which they had a choice of high or low complexity eelgrass vs. mesocosms in which they had no choice, as well as a field experiment testing how the propensity of grass shrimp to remain within eelgrass patches varied with structural complexity and predator presence. Generally, grass shrimp and kelpfish preferred high complexity seagrass over low complexity seagrass, but trends differed between species and between experiments with and without predators. Grass shrimp exhibited relatively modest preference for high complexity habitat in mesocosms as well a tendency to change preference to low complexity seagrass when a predatory threat was present in high complexity seagrass. In contrast, in naturally occurring seagrass beds shrimp exhibited a clear preference for high complexity seagrass during the day, but not at night when they may move among patches. Juvenile giant kelpfish exhibited a strong preference for high complexity seagrass even when a predatory threat was present in high complexity seagrass and food was made available in low complexity seagrass, though kelpfish displayed antipredator behaviors only when predators were present. Our research highlights the importance of considering the covariation of several factors when trying to predict habitat selection and species distributions in seagrass beds.
Author: S.S. Bell Publisher: Springer Science & Business Media ISBN: 9401130760 Category : Science Languages : en Pages : 451
Book Description
We conceived the idea for this book after teaching a graduate seminar on 'Habitat Complexity' at The University of South Florida. Discussions during the seminar led us to conclude that similar goals were to be found in studies of the topic that spanned the breadth of ecological research. Yet, the exact meaning of 'habitat structure', and the way in which it was measured, seemed to differ widely among subdisciplines. Our own research, which involves several sorts of ecology, convinced us that the differences among subdisciplines were indeed real ones, and that they did inhibit communica tion. We decided that interchange of ideas among researchers working in marine ecology, plant-animal interactions, physiological ecology, and other more-or-less independent fields would be worthwhile, in that it might lead to useful generalizations about 'habitat structure'. To foster this interchange of ideas. we organized a symposium to attract researchers working with a wide variety of organisms living in many habitats, but united in their interest in the topic of 'habitat structure'. The symposium was held at The University of South Florida's Chinsegut Hill Conference Center, in May. 1988. We asked participants to think about 'habitat structure' in new ways; to synthesize important, but fragmented, information; and. perhaps. to consider ways of translating ideas across systems. The chapters contained in this book reflect the participants' attempts to do so. The book is divided into four parts, by major themes that we have found useful categorizations.
Author: Publisher: ISBN: Category : Electronic books Languages : en Pages : 52
Book Description
Seagrasses form important coastal habitats that promote the foraging and survival of mesopredators. Variation in seagrass habitat structure at local and seascape scales mediates foraging success and survival, but the interactive effects of structure at these scales rarely is quantified when evaluating nursery habitat function. For my thesis, I tested how the interactions of multiscale habitat structural variation on juvenile fish body size mediates the value of seagrass habitat through survival and foraging success. In Chapter 1, I tested the hypothesis that in eelgrass (Zostera marina) optimal structural complexity (SC) for juvenile giant kelpfish (Heterostichus rostratus) changes through ontogeny. I found that habitat selection differed with kelpfish size: small and large fish selected high and low SC respectively. Smaller kelpfish experienced lower predation risk and higher foraging in high SC, suggesting high SC is selected by these fish because it minimizes risk and maximizes growth potential. Larger kelpfish experienced lower predation risk and higher foraging in high and low SC respectively, suggesting they select low SC to maximize foraging efficiency. My study highlights that trade-offs between predation risk and foraging can occur within a single habitat type, that studies should consider how habitat value changes through ontogeny, and that seagrass nursery habitat value may be maximal when within-patch variability in SC is high. In Chapter 2, I used a spatially explicit individual-based model to examine how seagrass fragmentation influences foraging and survival of a mesopredator, and how these relationships are influenced by SC, body size, and mesopredator and prey densities. I found that mesopredator survival and foraging dropped beyond threshold levels of habitat area (60 and 30% respectively) and depended on level of SC in the seascape. The relationship between habitat area and foraging did not depend on SC or body size, but did depend on organismal densities: when mesopredators and prey densities increased with decreasing habitat area, foraging was highest in highly fragmented seascapes. My results suggest that small- and large-scale habitat structure jointly dictate the value of a nursery habitat, and the effects of survival and foraging should consider interactions with habitat structure at multiple scales.
Author: Stacy Nicole Trackenberg Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Biogenic coastal habitats such as salt marshes, seagrasses, and oyster reefs, support diverse faunal communities and can serve as nursery areas by enhancing the abundance, growth, and survival of juvenile fish and crustaceans. The structure and complexity of these biogenic habitats can strongly influence the composition of marine faunal communities and contribute to their roles as nursery areas. It is imperative to understand how nursery areas are defined in the ecological literature as these definitions are applied to nursery area management across the United States. Further, the relative importance of how habitat structural attributes, which are influenced by abiotic and biotic factors, shape faunal communities within these nursery areas is critical to understand these important coastal ecosystems. My dissertation focuses on (1) how nursery frameworks in the ecological literature have evolved and how these frameworks are applied to state management of nursery areas; (2) how abiotic and biotic factors influence the restoration success and complexity of seagrass meadows; and (3) how, in turn, this habitat complexity influences faunal community composition and structure. For my first chapter, I found six overarching frameworks to define and delineate nursery areas in the ecological literature: measures of juvenile abundance and vital rates, habitat characteristics, seascape connectivity, populations fitness and contribution to adult biomass, and persistence. Of the 23 coastal states, only seven explicitly protect nursery areas and of these seven states, the aforementioned frameworks are not equally applied. Gathering and analyzing data necessary to integrate higher-order metrics (e.g., connectivity and biomass contribution) to designate nurseries will require significant research investment and greater collaboration between ecologists and fisheries scientists. My second chapter combines two years of observational seagrass and faunal surveys with a habitat preference experiment to investigate to which degree multiple seagrass complexity metrics influence the composition and abundance of faunal communities in North Carolina seagrass beds. Trawl surveys revealed that taller canopied seagrass beds support higher faunal abundances and species richness than shorter canopied beds, however this was not true across all species. There were species-specific relationships between complexity metrics and abundances, with these relationships shifting between the two years of our study, potentially due to the range of sampling months each year. Pinfish (Lagodon rhomboides), the most common fish found in North Carolina seagrass meadows demonstrated a preference for deep seagrass beds, but only preferred taller canopies when these areas also offered increased blade surface area. In Chapter 3, I conducted field surveys of natural seagrass beds to understand the spatio-temporal distribution and morphology of seagrasses in North Carolina coastal sounds and used these observations to inform a field transplantation experiment of the subtropical seagrass species, Halodule wrightii. Seagrass morphology differed across sampling months but only canopy height differed across depth. Depth was also influential in transplantation success with higher survival of intertidal seagrass transplants compared to subtidal. Considerations of both structural complexity and physical setting of the habitat are therefore imperative for a comprehensive approach in understanding how habitats as well as their faunal communities are responding to future changes across ecosystem settings.
Author: Publisher: ISBN: Category : Electronic books Languages : en Pages : 31
Book Description
Structural complexity plays an important role in mediating predator-prey interactions. Structural elements can limit predator mobility and reduce predator efficiency, increasing prey survival. Seagrasses are marine plants that provide refuge for many fishes and invertebrates by adding structural complexity to the seafloor. Though many studies have found positive correlations between prey survival and seagrass biomass or shoot density, seagrass is frequently colonized by epibiotic organisms, including algae and colonial invertebrates like bryozoans. Epibionts may fundamentally alter the structural complexity in seagrass habitat, but their effects on predator-prey interactions rarely have been investigated. The goal of this study was to determine whether epibionts of eelgrass (Zostera marina) alter predator-prey interactions by mediating predator and prey behaviors and prey survival probability. In San Diego Bay, Thalamoporella californica is a common rigid branching bryozoan that creates a unique 3-dimensional structure. I conducted (i) a laboratory experiment to determine whether predator (juvenile giant kelpfish Heterostichus rostratus) foraging behaviors and prey (grass shrimp Hippolyte californiensis) escape behavior in eelgrass are altered by colonization by T. californica, (ii) a field experiment to determine whether prey survival is correlated with the degree of bryozoan encrustation of eelgrass habitat, and (iii) a habitat selection experiment to determine if the presence of epibionts deter fish from foraging in eelgrass habitat. I found that increasing eelgrass structural complexity altered kelpfish foraging behaviors, reducing their foraging efficiency but the presence of bryozoans did not. In contrast, intermediate levels of structural complexity optimized the ability of shrimp to evade oncoming predators. Despite clear effects of structural complexity on fish foraging in the lab experiment, my field experiment in San Diego Bay eelgrass suggested that eelgrass habitat structure did not influence prey survival. Finally, I found that kelpfish strongly avoided foraging in bryozoan-encrusted eelgrass compared to uncolonized eelgrass. Overall, bryozoan structure influenced prey behavior in the lab but did not affect prey survival or prey density in the field, indicating that bryozoan structure in the field does not increased prey refuge. Understanding how fish interact with their habitat is crucial when determining how to effectively conserve and restore critical habitats like eelgrass beds.
Author: Anthony W. D. Larkum Publisher: Springer ISBN: 331971354X Category : Science Languages : en Pages : 791
Book Description
This book takes the place of “Biology of Seagrasses: A Treatise on the Biology of Seagrasses with Special Reference to the Australian Region”, co-edited by A.W.D. Larkum, A.J. MaCComb and S.A. Shepherd and published by Elsevier in 1989. The first book has been influential, but it is now 25 years since it was published and seagrass studies have progressed and developed considerably since then. The design of the current book follows in the steps of the first book. There are chapters on taxonomy, floral biology, biogeography and regional studies. The regional studies emphasize the importance of Australia having over half of the world’s 62 species, including some ten species published for Australia since the previous book. There are a number of chapters on ecology and biogeography; fish biology and fisheries and dugong biology are prominent chapters. Physiological aspects again play an important part, including new knowledge on the role of hydrogen sulphide in sediments and on photosynthetic processes. Climate change, pollution and environmental degradation this time gain an even more important part of the book. Decline of seagrasses around Australia are also discussed in detail in several chapters. Since the first book was published two new areas have received special attention: blue carbon and genomic studies. Seagrasses are now known to be a very important player in the formation of blue carbon, i.e. carbon that has a long turnover time in soils and sediments. Alongside salt marshes and mangroves, seagrasses are now recognized as playing a very important role in the formation of blue carbon. And because Australia has such an abundance and variety of seagrasses, their role in blue carbon production and turnover is of great importance. The first whole genomes of seagrasses are now available and Australia has played an important role here. It appears that seagrasses have several different suites of genes as compared with other (land) plants and even in comparison with freshwater hydrophytes. This difference is leading to important molecular biological studies where the new knowledge will be important to the understanding and conservation of seagrass ecosystems in Australia. Thus by reason of its natural abundance of diverse seagrasses and a sophisticated seagrass research community in Australia it is possible to produce a book which will be attractive to marine biologists, coastal scientists and conservationists from many countries around the world.
Author: Publisher: ISBN: Category : Ecology Languages : en Pages : 738
Book Description
Coverage: 1982- current; updated: monthly. This database covers current ecology research across a wide range of disciplines, reflecting recent advances in light of growing evidence regarding global environmental change and destruction. Major ares of subject coverage include: Algae/lichens, Animals, Annelids, Aquatic ecosystems, Arachnids, Arid zones, Birds, Brackish water, Bryophytes/pteridophytes, Coastal ecosystems, Conifers, Conservation, Control, Crustaceans, Ecosyst em studies, Fungi, Grasses, Grasslands, High altitude environments, Human ecology, Insects, Legumes, Mammals, Management, Microorganisms, Molluscs, Nematodes, Paleo-ecology, Plants, Pollution studies, Reptiles, River basins, Soil, TAiga/tundra, Terrestrial ecosystems, Vertebrates, Wetlands, Woodlands.
Author: 
Author: 
Author: S.S. Bell
Author: 
Author: Stacy Nicole Trackenberg
Author: 
Author: Anthony W. D. Larkum
Author: 
Author: Dr. Silvia Opitz
Author: 
Author: