Download or read book Juvenile Blue Crab Survival in Nursery Habitats written by Amanda Marie Bromilow and published by . This book was released on 2017 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Predator populations can have significant impacts on prey recruitment success and prey population dynamics through consumption. Young, inexperienced prey are often most vulnerable to predation due to their small size and limited evasion capabilities. To reduce the risk of predation, new recruits and young juveniles typically settle in structured nursery habitats, such as seagrass beds, which promote higher survival by acting as refuges from predators. Thus, successful recruitment to the adult portion of the population is often dependent on the availability of suitable nursery habitat. In this thesis, I used field tethering experiments and gut content analyses to assess the role of habitat, body size, finfish predation, and cannibalism on the survival of one of the most ecologically and economically important species in Chesapeake Bay: the blue crab Callinectes sapidus. In field tethering experiments, survival probability of juvenile blue crabs in York River nursery habitats (i.e. seagrass beds, sand flats) increased significantly and additively with crab size and SAV cover. Images of predation events during tethering experiments revealed cannibalism by adult blue crabs to be a major source of juvenile mortality. Gut content analyses from three field studies identified seven predators of juvenile blue crabs in lower Chesapeake Bay nursery habitats: adult blue crabs, striped bass Morone saxatilis, red drum Sciaenops ocellatus, silver perch Bairdiella chrysoura, weakfish Cynoscion regalis, Atlantic croaker Micropogonias undulatus, and oyster toadfish Opsanus tau. Using frequency of consumption and diet proportion metrics, I determined striped bass, red drum, and silver perch to be the most impactful finfish predators on juvenile mortality, in addition to cannibalism. Atlantic croaker and oyster toadfish play minor roles in juvenile mortality in Chesapeake Bay nursery habitats. The probability of juvenile crabs being present in a predator’s gut was also significantly higher in seagrass beds than in unvegetated sand flats. Food web dynamics are an important aspect of ecosystem-based fisheries management. Understanding the ecological interactions between populations, and their environment, can provide insight into natural population fluctuations of valuable fishery species such as the blue crab. This thesis demonstrated the positive effects of body size and SAV cover on juvenile crab survival, indicating the importance of seagrass nursery habitat for blue crab population dynamics in Chesapeake Bay. However, despite the predator refuge offered by SAV, high densities of predators and prey in seagrass beds resulted in greater consumption of juveniles in those habitats. Key predators of juvenile blue crabs were also identified and their relative impacts were estimated. The predator-prey relationships revealed in this thesis were integrated into a revised food web for blue crabs in Chesapeake Bay, in the hopes of informing future ecosystem-based management efforts.
Download or read book Juvenile Blue Crab Callinectes Sapidus Habitat Utilization and Survival written by Kenneth W. Able and published by . This book was released on 1990 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Juvenile Blue Crab Callinectes Sapidus Response to Altered Nursery Habitat written by Megan Wood and published by . This book was released on 2017 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Habitats of Chesapeake Bay have been altered due to anthropogenic impacts and climate change. Due to these human disturbances, seagrasses have been extirpated from many areas in lower Chesapeake Bay and persisting beds face future losses as water temperatures continue to rise. Further loss of seagrass habitat will negatively impact juvenile blue crabs (Callinectes sapidus) that use seagrass beds as nursery grounds. Habitat degradation allows for more successful introductions of exotic species, and the communities formed from the mixing of native and exotic species are known as emerging ecosystems. Gracilaria vermiculophylla, an exotic macroalga, may be an emerging nursery habitat for juvenile blue crabs in Chesapeake Bay; however the extent to which the alga is present and used as a nursery by juvenile blue crabs are largely unknown. I investigated algal distribution in the shallow littoral areas of the York River, a subestuary of Chesapeake Bay, over two years (2013 – 2014) and found that G. vermiculophylla presence correlated with salinity and that algal presence and biomass increased with seagrass presence, although biomass was generally low. The alga was present in areas where seagrasses have been lost, and is therefore likely providing nursery habitat in these areas of high megalopal recruitment. Benthic epifaunal communities had lower species richness and were less abundant in G. vermiculophylla relative to seagrass, while benthic infaunal communities had lower species richness but similar abundance in the alga relative to seagrass. Juvenile blue crab densities were similar in the alga and seagrass, although seagrass supported about 3 times as many first and second instar crabs than G. vermiculophylla. Young juvenile blue crabs preferred seagrass, which may be due to epifaunal prey preference, and G. vermiculophylla likely represents a secondary nursery habitat. Juvenile blue crab growth rates of crabs 15 – 50 mm carapace width were similar in the alga, native seagrass, and unvegetated habitat, indicating that growth does not drive ontogenetic shifts in habitat use by larger (20 – 30 mm carapace width) juveniles. Similar growth rates also suggest that G. vermiculophylla performs similarly to seagrass as a nursery habitat in terms of providing resources for growth. Simulations of density-dependent migration of young juvenile blue crabs between habitat types suggest that G. vermiculophylla may mediate continued seagrass loss, at least in part. Together, these results increase our understanding of an emerging Chesapeake Bay ecosystem and the impacts that changes to nursery habitats have on the juvenile component of the blue crab population.
Download or read book Human Impacts on Salt Marshes written by Brian R. Silliman and published by Univ of California Press. This book was released on 2009-06-03 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Human Impacts on Salt Marshes provides an excellent global synthesis of an important, underappreciated environmental problem and suggests solutions to the diverse threats affecting salt marshes."—Peter B. Moyle, University of California, Davis
Download or read book Habitat Complexity as a Determinant of Juvenile Blue Crab Survival written by Jessica L. Schulman and published by . This book was released on 1996 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Blue Crab written by Victor S. Kennedy and published by Maryland Sea Grant College University of Maryland. This book was released on 2007 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Survival Benefit of Benthic Macroalgae Gracilaria Vermiculophylla as an Alternative Nursery Habitat for Juvenile Blue Crabs written by Justin A. Falls and published by . This book was released on 2008 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Macroalgae as Alternative Nursery Habitat for Juvenile Blue Crab written by Cora Ann Johnston and published by . This book was released on 2008 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Living Shorelines written by Donna Marie Bilkovic and published by CRC Press. This book was released on 2017-03-03 with total page 956 pages. Available in PDF, EPUB and Kindle. Book excerpt: Living Shorelines: The Science and Management of Nature-based Coastal Protection compiles, synthesizes and interprets the current state of the knowledge on the science and practice of nature-based shoreline protection. This book will serve as a valuable reference to guide scientists, students, managers, planners, regulators, environmental and engineering consultants, and others engaged in the design and implementation of living shorelines. This volume provides a background and history of living shorelines, understandings on management, policy, and project designs, technical synthesis of the science related to living shorelines including insights from new studies, and the identification of research needs, lessons learned, and perspectives on future guidance. Makes recommendations on the correct usage of the term living shorelines Offers guidance for shoreline management in the future Includes lessons learned from the practice of shoreline restoration/conservation Synthesizes regional perspectives to identify strategies for the successful design and implementation of living shorelines Reviews specific design criteria for successful implementation of living shorelines Provides detailed discussions of social, regulatory, scientific and technical considerations to justify and design living shoreline projects International perspectives are presented from leading researchers and managers in the East, West and Gulf coasts of the United States, Europe, Canada, and Australia that are working on natural approaches to shoreline management. The broad geographic scope and interdisciplinary nature of contributing authors will help to facilitate dialogue and transfer knowledge among different disciplines and across different regions. This book provides coastal communities with the scientific foundation and practical guidance necessary to implement effective shoreline management that enhances ecosystem services and coastal resilience now and into the future.
Download or read book The Effect of Seagrass Habitat Fragmentation on Juvenile Blue Crab Survival written by Kevin Alexander Hovel and published by . This book was released on 1999 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synopsis of Biological Data on the Blue Crab Callinectes Sapidus Rathbun written by Mark R. Millikin and published by . This book was released on 1984 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Life History of the Blue Crab written by Edward Perry Churchill and published by . This book was released on 1919 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seascape Ecology written by Simon J. Pittman and published by John Wiley & Sons. This book was released on 2017-12-18 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seascape Ecology provides a comprehensive look at the state-of-the-science in the application of landscape ecology to the seas and provides guidance for future research priorities. The first book devoted exclusively to this rapidly emerging and increasingly important discipline, it is comprised of contributions from researchers at the forefront of seascape ecology working around the world. It presents the principles, concepts, methodology, and techniques informing seascape ecology and reports on the latest developments in the application of the approach to marine ecology and management. A growing number of marine scientists, geographers, and marine managers are asking questions about the marine environment that are best addressed with a landscape ecology perspective. Seascape Ecology represents the first serious effort to fill the gap in the literature on the subject. Key topics and features of interest include: The origins and history of seascape ecology and various approaches to spatial patterning in the sea The links between seascape patterns and ecological processes, with special attention paid to the roles played by seagrasses and salt marshes and animal movements through seascapes Human influences on seascape ecology—includes models for assessing human-seascape interactions A special epilogue in which three eminent scientists who have been instrumental in shaping the course of landscape ecology offer their insights and perspectives Seascape Ecology is a must-read for researchers and professionals in an array of disciplines, including marine biology, environmental science, geosciences, marine and coastal management, and environmental protection. It is also an excellent supplementary text for university courses in those fields.
Download or read book Quantification of Nursery Habitats for Blue Crabs in Chesapeake Bay written by Gina M. Ralph and published by . This book was released on 2013 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seagrasses Biology Ecology and Conservation written by Anthony W. D. Larkum and published by Springer Science & Business Media. This book was released on 2007-05-16 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seagrasses are unique plants; the only group of flowering plants to recolonise the sea. They occur on every continental margin, except Antarctica, and form ecosystems which have important roles in fisheries, fish nursery grounds, prawn fisheries, habitat diversity and sediment stabilisation. Over the last two decades there has been an explosion of research and information on all aspects of seagrass biology. However the compilation of all this work into one book has not been attempted previously. In this book experts in 26 areas of seagrass biology present their work in chapters which are state-of–the-art and designed to be useful to students and researchers alike. The book not only focuses on what has been discovered but what exciting areas are left to discover. The book is divided into sections on taxonomy, anatomy, reproduction, ecology, physiology, fisheries, management, conservation and landscape ecology. It is destined to become the chosen text on seagrasses for any marine biology course.
Download or read book Large scale Recruitment of Early Juvenile Blue Crabs written by Lisa Lowe Etherington and published by . This book was released on 1998 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biology and Conservation of Horseshoe Crabs written by John T. Tanacredi and published by Springer Science & Business Media. This book was released on 2009-06-04 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: Horseshoe crabs, those mysterious ancient mariners, lured me into the sea as a child along the beaches of New Jersey. Drawn to their shiny domed shells and spiked tails, I could not resist picking them up, turning them over and watching the wondrous mechanical movement of their glistening legs, articulating with one another as smoothly as the inner working of a clock. What was it like to be a horseshoe crab, I wondered? What did they eat? Did they always move around together? Why were some so large and others much smaller? How old were they, anyway? What must it feel like to live underwater? What else was out there, down there, in the cool, green depths that gave rise to such intriguing creatures? The only way to find out, I reasoned, would be to go into the ocean and see for myself, and so I did, and more than 60 years later, I still do.
