Author: Michelle D. Carlson
Publisher:
ISBN:
Category :
Languages : en
Pages : 57
Get Book Here
Book Description
Author's abstract: Purpose: Coastal wetlands offer refuge for juveniles of many species, with protection often coming in the form of dense vegetation. Human impacts have led to a 67% loss of coastal wetlands worldwide in the past 300 years, thus decreasing available refuges. There are no studies that show what affect this has on fiddler crabs (Uca spp.), a key species in salt marsh habitats. The present study looks at how human impacts are affecting juvenile fiddler crab densities, shell use, and species compositions. This study was conducted at 3 low and 3 high impact sites on Tybee and Skidaway Island, Georgia. Six collection trips were completed from June to August 2010 to each of the 6 sites. During each trip ten quadrats (1m 2) were placed at each site, and juvenile fiddler crab densities, Littoraria irrorata shell availability, and percent shell use were recorded. In the lab, juvenile fiddler crab carapace width and sex were determined and multiplex PCR was used to identify juvenile fiddler crab species. Juvenile fiddler crab densities were lower at high impact sites, while shell availability and shell use were similar at both low and high impact sites. Juvenile fiddler crab sizes and sex ratios did not differ between low and high impact sites on the substrate, nor did the sex ratios in shells. However low impact sites had significantly larger juvenile fiddler crabs found in shells as compared to high impact sites. Species compositions differed between low and high impact sites on the substrate and in shells, with an increase in Uca pugilator and U. minax at high impact sites. Impacts to salt marshes can cause a decrease in available refuge for juvenile fiddler crabs which could lead to higher mortality rates and an overall decrease in juvenile fiddler crab densities. Fiddler crabs are important in aerating the soil, soil drainage, and decomposition rates. A change in fiddler crab densities and behavior can have an adverse affect to the salt marsh and could lead to the loss of an important ecosystem.
Author: Charles Robert Hubbard
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 58
Get Book Here
Book Description
Author's abstract: Quantifying the density of burrowing crabs is challenging, and several techniques have been developed to accomplish it, including burrow counting, visual surveys of surface-active crabs, and substrate excavation. These techniques have been compared in mangrove forests but not in a salt marsh, nor has anyone attempted to excavate traps repeatedly for multiple days. Previous comparisons have not examined these techniques over the course of several months, nor considered the cost and precision associated with each technique. Therefore, from May of 2007 to April 2008, I conducted burrow, visual, single excavation, and repeated excavation surveys to estimate Uca pugnax density in a salt marsh on Tybee Island, Georgia and estimated the cost and precision associated with each technique. Only single and repeated excavation accurately measured juvenile density, but these methods were more costly and caused temporary habitat damage. Burrow surveys yielded reliable adult density but visual surveys underestimated adult and juvenile density, likely due to the difficulty of spotting small crabs in thick vegetation. This information may be useful to management officials monitoring fiddler crab populations and their predators in salt marsh ecosystems.
Author: Gwendolyn A. Murphy
Publisher:
ISBN:
Category : Animal burrowing
Languages : en
Pages : 198
Get Book Here
Book Description
Positive rather than negative species interactions dominate in stressful environments like tidal marshes. Fiddler crabs have been shown to ameliorate environmental stress and increase primary productivity through their burrowing behavior. Most notably, bioturbation may facilitate growth of tidal marsh plants by altering soil oxygen concentration, decomposition rates, and soil drainage. In turn, plants provide protection from the elements, refuge from predators and roots provide structural support for burrows in soft substrate. However, dense vegetation may limit the fiddler crab's ability to maneuver on the surface and burrow. Similarly, there may be a threshold where fiddler crab activity becomes destructive to plant growth instead of facilitative. Relatively few fiddler crab and plant interaction studies have been conducted on the Gulf Coast compared to Atlantic Coast. Gulf Coast tidal marshes have distinct climate, dominant vegetation zones and dominant fiddler crab species, and consequently it is likely that community dynamics will differ from Atlantic Coast tidal marshes. To explore interactions between Gulf Coast fiddler crabs and tidal marsh plants, I conducted a seasonal fiddler crab habitat survey and a fiddler crab enclosure study. Both studies were conducted at Grand Bay National Estuarine Research Reserve in Mississippi, across four dominant tidal marsh vegetation zones (salt marsh, brackish marsh, fresh marsh and salt panne). Fiddler crab burrows and associated vegetation were randomly surveyed across the vegetation zones to determine fiddler crab burrow density and habitat preferences. Fiddler crab enclosures were established across the four vegetation zones. Enclosures provided a method to test impacts of fiddler crab burrowing on soil and plant parameters as well as to survey fiddler crab populations. Results of the habitat survey indicated that fiddler crabs utilized all four vegetation zones, but burrow density was statistically higher in the fresh marsh during winter compared to other zones. These results suggest that the fresh marsh may be important habitat for overwintering Gulf Coast fiddler crabs. Additionally, the fresh marsh was found to host higher fiddler crab species diversity and a more balanced sex ratio compared to other zones. The enclosure study established that fiddler crab activity had negligible impacts on plant growth in the salt and fresh marsh yet influenced plant growth in the brackish marsh (positively) and salt panne (negatively). The brackish marsh and salt panne are habitats of intermediate environmental stress for plants and fiddler crabs. Brackish marsh is more frequently inundated than the salt panne and hence bioturbation is likely to be more beneficial in the brackish marsh. Furthermore, brackish marsh below-ground structure is substantial and fiddler crab burrow density was low relative to the salt panne. My work indicates that vegetation abundance and fiddler crab burrow density may balance environmental stresses in tidal marshes and influence nature of fiddler crab and plant interactions.
Author: Victor H. Rivera-Monroy
Publisher: Springer
ISBN: 3319622064
Category : Science
Languages : en
Pages : 407
Get Book Here
Book Description
This book presents a comprehensive overview and analysis of mangrove ecological processes, structure, and function at the local, biogeographic, and global scales and how these properties interact to provide key ecosystem services to society. The analysis is based on an international collaborative effort that focuses on regions and countries holding the largest mangrove resources and encompasses the major biogeographic and socio-economic settings of mangrove distribution. Given the economic and ecological importance of mangrove wetlands at the global scale, the chapters aim to integrate ecological and socio-economic perspectives on mangrove function and management using a system-level hierarchical analysis framework. The book explores the nexus between mangrove ecology and the capacity for ecosystem services, with an emphasis on thresholds, multiple stressors, and local conditions that determine this capacity. The interdisciplinary approach and illustrative study cases included in the book will provide valuable resources in data, information, and knowledge about the current status of one of the most productive coastal ecosystem in the world.
Author: M. Schwartz
Publisher: Springer Science & Business Media
ISBN: 1402038801
Category : Science
Languages : en
Pages : 1243
Get Book Here
Book Description
This new Encyclopedia of Coastal Science stands as the latest authoritative source in the field of coastal studies, making it the standard reference work for specialists and the interested lay person. Unique in its interdisciplinary approach. This Encyclopedia features contributions by 245 well-known international specialists in their respective fields and is abundantly illustrated with line-drawings and photographs. Not only does this volume offer an extensive number of entries, it also includes various appendices, an illustrated glossary of coastal morphology and extensive bibliographic listings.
Author: C. Herb Ward
Publisher: Springer
ISBN: 1493934473
Category : Technology & Engineering
Languages : en
Pages : 917
Get Book Here
Book Description
This book is open access under a CC BY-NC 2.5 license. The Gulf of Mexico is an open and dynamic marine ecosystem rich in natural resources but heavily impacted by human activities, including agricultural, industrial, commercial and coastal development. The Gulf of Mexico has been continuously exposed to petroleum hydrocarbons for millions of years from natural oil and gas seeps on the sea floor, and more recently from oil drilling and production activities located in the water near and far from shore. Major accidental oil spills in the Gulf are infrequent; two of the most significant include the Ixtoc I blowout in the Bay of Campeche in 1979 and the Deepwater Horizon Oil Spill in 2010. Unfortunately, baseline assessments of the status of habitats and biota in the Gulf of Mexico before these spills either were not available, or the data had not been systematically compiled in a way that would help scientists assess the potential short-term and long-term effects of such events. This 2-volume series compiles and summarizes thousands of data sets showing the status of habitats and biota in the Gulf of Mexico before the Deepwater Horizon Oil Spill. Volume 1 covers: water and sediment quality and contaminants in the Gulf; natural oil and gas seeps in the Gulf of Mexico; coastal habitats, including flora and fauna and coastal geology; offshore benthos and plankton, with an analysis of current knowledge on energy capture and energy flows in the Gulf; and shellfish and finfish resources that provide the basis for commercial and recreational fisheries.
Author: D. Raffaelli
Publisher: Springer Science & Business Media
ISBN: 940091489X
Category : Science
Languages : en
Pages : 367
Get Book Here
Book Description
The seashore has long been the subject of fascination and study - the Ancient Greek scholar Aristotle made observations and wrote about Mediterranean sea urchins. The considerable knowledge of what to eat and where it could be found has been passed down since prehistoric times by oral tradition in many societies - in Britain it is still unwise to eat shellfish in months without an 'r' in them. Over the last three hundred years or so we have seen the formalization of science and this of course has touched intertidal ecology. Linnaeus classified specimens collected from the seashore and many common species (Patella vulgata L. , Mytilus edulis L. , Littorina littorea (L. )) bear his imprint because he formally described, named and catalogued them. Early natural historians described zonation patterns in the first part of the 19th century (Audouin and Milne-Edwards, 1832), and the Victorians became avid admirers and collectors of shore animals and plants with the advent of the new fashion of seaside holidays (Gosse, 1856; Kingsley, 1856). As science became professionalized towards the end of the century, marine biologists took advantage of low tides to gain easy access to marine life for taxonomic work and classical studies of functional morphology. The first serious studies of the ecology of the shore were made at this time (e. g.
Author: U.S. Fish and Wildlife Service
Publisher:
ISBN:
Category : Aquatic ecology
Languages : en
Pages : 110
Get Book Here
Book Description
Author:
Publisher: Academic Press
ISBN: 0080548474
Category : Science
Languages : en
Pages : 437
Get Book Here
Book Description
The first book entirely devoted to this topic, Ecosystem Engineers begins with the history of the concept, presenting opposing definitions of ecosystem engineeing. These varied definitions advance the debate and move past trivial difficulties to crystallize key issues such as the value of process-based vs. outcome-based. Authors include case studies spanning a wide spectrum of species and habitats, including above and below-ground, aquatic and terrestrial, and extant and paleontological examples. These studies enable readers to understand how the categorization of species as ecosystem engineers allows scientists to forge new explanatory generalizations. Key for all ecologists and environmentalists, this book ultimately illustrates how to inform and manage natural resources. The only consolidated treatment available Provides definitions, case studies, and examples of ecological models Discusses how ecosystem engineering can inform and improve the management of natural resources Includes contributions from Clive Jones, the leading figure in the development of the ecosystem engineer concept, and many other eminent ecologists, such as Alan Hastings
Author: Duncan M. FitzGerald
Publisher: Cambridge University Press
ISBN: 1107186285
Category : Nature
Languages : en
Pages : 499
Get Book Here
Book Description
A multidisciplinary review of salt marshes, describing how they function and respond to external pressures such as sea-level rise.
