Dispersal, Fishing, and the Conservation of Marine Species

Dispersal, Fishing, and the Conservation of Marine Species
Author :
Publisher : Stanford University
Total Pages : 186
Release :
ISBN-10 : STANFORD:fk096nf3828
ISBN-13 :
Rating : 4/5 (28 Downloads)

Synopsis Dispersal, Fishing, and the Conservation of Marine Species by : Malin La Farge Pinsky

A central goal of ecology is to understand the forces driving the distribution and abundance of organisms. However, understanding the population dynamics of high-dispersal species, their conservation, and the connections between population dynamics and evolution remains difficult. It is in this context that marine organisms provide a particularly intriguing and challenging study system. Their population dynamics are often highly stochastic, most species have a great ability to disperse, and as the last group of wild species exploited commercially, their ecology and evolution can be strongly influenced by human behavior. By using population genetics, modeling, and meta-analysis, this thesis investigates the spatial ecology of reef fish and the causes and evolutionary consequences of global fisheries collapse. One of the first challenges in understanding spatial population dynamics is obtaining accurate measurements of dispersal abilities. This has been especially difficult for marine species with pelagic larvae. In Chapter 1, I apply a new approach to measuring single-generation dispersal kernels in Clark's anemonefish (Amphiprion clarkii) in the central Philippines. After developing two methods for measuring the strength of local genetic drift, my results suggest that larval dispersal kernels in A. clarkii had a spread near 11 km (4-27 km). This study shows that ecologically relevant larval dispersal can be estimated with widely available genetic methods when effective density is measured carefully through cohort sampling and ecological censuses. In Chapter 2, I use dispersal kernels to develop a model for population openness. Openness refers to the degree to which populations are replenished by immigrants or by local production, a factor that has strong implications for population dynamics, species interactions, and response to exploitation. It is also a population trait that has been increasingly measured empirically, though we have until now lacked theory for predicting population openness. I show that considering habitat isolation elegantly explains the existence of surprisingly closed populations in high dispersal species, and that relatively closed populations are expected when patch spacing is more than twice the standard deviation of a species' dispersal kernel. In addition, empirical scales of habitat patchiness on coral reefs are sufficient to create both largely open and largely closed populations. We predict that habitat patchiness has strong control over population replenishment pathways for a wide range of marine and terrestrial species with a highly dispersive life stage. While the first tow chapters have strong implications for the design of regional marine protected areas, I turn to global conservation questions in Chapters 3 and 4. I first ask which marine fishes are most vulnerable to human impacts. Surveys of terrestrial species have suggested that large-bodied species and top predators are the most at risk, but there has been no global test of this hypothesis in the sea. Contrary to expectations, two datasets compiled from around the world suggest that up to twice as many fisheries for small, low trophic level species have collapsed as compared to those for large predators. I then show that collapsed and overfished species have lower genetic diversity than their close relatives. While the ecological and ecosystem impacts of harvesting wild populations have long been recognized, it has been controversial how widespread evolutionary impacts are. Using a meta-analytical approach across 37 taxonomically paired comparisons, I find on average 19% fewer alleles per locus in overfished species, but little difference in heterozygosity. I confirm with simulations that these results are consistent with a recent population bottleneck. These results suggest that the genetic impacts of overharvest are widespread, even among abundant species. A loss of allelic richness has implications for the long-term evolutionary potential of species.

Age Determination Manual of the Alaska Fisheries Science Center Age and Growth Program

Age Determination Manual of the Alaska Fisheries Science Center Age and Growth Program
Author :
Publisher :
Total Pages : 114
Release :
ISBN-10 : UCSD:31822039197074
ISBN-13 :
Rating : 4/5 (74 Downloads)

Synopsis Age Determination Manual of the Alaska Fisheries Science Center Age and Growth Program by : Mary Elizabeth Matta

The Age and Growth Program at the Alaska Fisheries Science Center is tasked with providing age data in order to improve the basic understanding of the ecology and fisheries dynamics of Alaskan fish species. The primary focus of the Age and Growth Program is to estimate ages from otoliths and other calcified structures for age-structured modeling of commercially exploited stocks; however, the program has recently expanded its interests to include numerous studies on topics ranging from age estimate validation to the growth and life-history of non-target species. Because so many applications rely upon age data and particularly upon assurances as to their accuracy and precision, the Age and Growth Program has developed this practical guide to document the age determination of key groundfish species from Alaskan waters. The main objective of this manual is to describe techniques specific to the age determination of commercially and ecologically important species studied by the Age and Growth Program. The manual also provides general background information on otolith morphology, dissection, and preparation, as well as descriptions of methods used to measure precision and accuracy of age estimates. This manual is intended not only as a reference for age readers at the AFSC and other laboratories, but also to give insight into the quality of age estimates to scientists who routinely use such data.

Fish Population Dynamics, Monitoring, and Management

Fish Population Dynamics, Monitoring, and Management
Author :
Publisher : Springer
Total Pages : 248
Release :
ISBN-10 : 9784431566212
ISBN-13 : 443156621X
Rating : 4/5 (12 Downloads)

Synopsis Fish Population Dynamics, Monitoring, and Management by : Ichiro Aoki

This book explores how we can solve the urgent problem of optimizing the use of variable, uncertain but finite fisheries resources while maintaining sustainability from a marine-ecosystem conservation perspective. It offers readers a broad understanding of the current methods and theory for sustainable exploitation of fisheries resources, and introduces recent findings and technological developments. The book is divided into three parts: Part I discusses fish stock dynamics, and illustrates how ecological processes affecting life cycles and biological interactions in marine environments lead to fish stock variability in space and time in major fish groups; small pelagic fish, demersal fish and large predatory fish. These insights shed light on the mechanisms underlying the variability in fish stocks and form the essential biological basis for fisheries management. Part II addresses the technologies and systems that monitor changes in fisheries resources and marine ecosystems using two approaches: fishery-dependent and fishery-independent data. It also describes acoustic surveys and biological sampling, as well as stock assessment methods. Part III examines management models for effectively assessing the natural variability in fisheries resources. The authors explore ways of determining the allowable catch in response to changes in stock abundance and how to incorporate ecological processes and monitoring procedures into management models. This book offers readers a broad understanding of sustainable exploitation as well as insights into fisheries management for the next generation.

Fishes of the Salish Sea

Fishes of the Salish Sea
Author :
Publisher :
Total Pages : 0
Release :
ISBN-10 : 0295743743
ISBN-13 : 9780295743745
Rating : 4/5 (43 Downloads)

Synopsis Fishes of the Salish Sea by : Theodore W. Pietsch

Fishes of the Salish Sea is the definitive guide to the identification and history of the marine and anadromous fishes of Puget Sound and the Straits of Georgia and Juan de Fuca. This comprehensive three-volume set, featuring striking illustrations of the Salish Sea's 260 fish species by noted illustrator Joseph Tomelleri, details the ecology and life history of each species and recounts the region's rich heritage of marine research and exploration. Beginning with jawless hagfishes and lampreys and ending with the distinctive Ocean Sunfish, leading scientists Theodore Wells Pietsch and James Orr present the taxa in phylogenetic order, based on classifications that reflect the most current scientific knowledge. Illustrated taxonomic keys facilitate fast and accurate species identification. These in-depth, thoroughly documented, and yet accessible volumes will prove invaluable to marine biologists and ecologists, natural resource managers, anglers, divers, students, and all who want to learn about, marvel over, and preserve the vibrant diversity of Salish Sea marine life. Comprehensive accounts of 260 fish species Brilliant color plates of all treated species Illustrated taxonomic keys for easy species identification In-depth history of Salish Sea research and exploration

Multispecies Approaches to Fisheries Management Advice

Multispecies Approaches to Fisheries Management Advice
Author :
Publisher :
Total Pages : 188
Release :
ISBN-10 : UCSD:31822002394658
ISBN-13 :
Rating : 4/5 (58 Downloads)

Synopsis Multispecies Approaches to Fisheries Management Advice by : M. C. Mercer

This publication comprises the proceedings of an international workshop convened in St. John's, Nfld, Nov. 26-29, 1979. The purpose of the workshop was to discuss the results of recent multispecies research, its applications to management, and to consider future directions for research in this field. A total of 26 papers were presented, including a combination of experience papers, state-of-the-art review, and new scientific findings. Sequential sessions were held on fisheries systems research by the Department of Fisheries and Oceans, multispecies considerations in fisheries research and management advice in the ICES area, species interactions in the Northeast Pacific and Northwest Atlantic, fisheries interactions, and applications to fisheries management. The workshop concluded with a substantial discussion of implications of present knowledge for advice to fisheries managers and implications for research program planning. The Workshop Report comprises the Chairman's opening remarks, a report on main elements of discussion in the sessions, and a summarization of workshop conclusions.

Climate Change Implications for Fisheries and Aquaculture

Climate Change Implications for Fisheries and Aquaculture
Author :
Publisher : Food & Agriculture Organization of the UN (FAO)
Total Pages : 0
Release :
ISBN-10 : 9251063478
ISBN-13 : 9789251063477
Rating : 4/5 (78 Downloads)

Synopsis Climate Change Implications for Fisheries and Aquaculture by : K. L. Cochrane

An overview of the current scientific knowledge available on climate change implications for fisheries and aquaculture is provided through three technical papers that were presented and discussed during the Expert Workshop on Climate Change Implications for Fisheries and Aquaculture (Rome, 7-9 April 2008). A summary of the workshop outcomes as well as key messages on impacts of climate change on aquatic ecosystems and on fisheries- and aquaculture-based livelihoods are provided in the introduction of this Technical Paper. The first paper reviews the physical and ecological impacts of climate change relevant to marine and inland capture fisheries and aquaculture. The paper begins with a review of the physical impacts of climate change on marine and freshwater systems and then connects these changes with observed effects on fish production processes. It also outlines a series of scenarios of climate change impacts on fish production and ecosystems through case studies in different regions and ecosystems. The second paper tackles the consequences of climate change impacts on fisheries and their dependent communities. It analyses the exposure, sensitivity and vulnerability of fisheries to climate change and presents examples of adaptive mechanisms currently used in the sector. The contribution of fisheries to greenhouse gas emissions is addressed and examples of mitigation strategies are given. The role of public policy and institutions in promoting climate change adaptation and mitigation is also explored. Finally, the third paper addresses the impacts of climate change on aquaculture. It provides an overview of the current food fish and aquaculture production and a synthesis of existing studies on climate change effects on aquaculture and fisheries. The paper focuses on the direct and indirect impacts of climate change on aquaculture, in terms of biodiversity, fish disease and fishmeal. Contribution of aquaculture to climate change is addressed (carbon emission and carbon sequestration), as well as possible adaptation and mitigation measures that could be implemented.

Marine Priority Conservation Areas

Marine Priority Conservation Areas
Author :
Publisher :
Total Pages : 136
Release :
ISBN-10 : UCSD:31822034224485
ISBN-13 :
Rating : 4/5 (85 Downloads)

Synopsis Marine Priority Conservation Areas by : Lance Edward Morgan

Describes the process of identifying priority conservation areas--areas of trinational importance due to their ecological significance and threatened nature--which are in need of international cooperation for successful conservation.

Salmon Without Rivers

Salmon Without Rivers
Author :
Publisher :
Total Pages : 346
Release :
ISBN-10 : UVA:35007003673518
ISBN-13 :
Rating : 4/5 (18 Downloads)

Synopsis Salmon Without Rivers by : Jim Lichatowich

"Fundamentally, the salmon's decline has been the consequence of a vision based on flawed assumptions and unchallenged myths.... We assumed we could control the biological productivity of salmon and 'improve' upon natural processes that we didn't even try to understand. We assumed we could have salmon without rivers." --from the introduction From a mountain top where an eagle carries a salmon carcass to feed its young to the distant oceanic waters of the California current and the Alaskan Gyre, salmon have penetrated the Northwest to an extent unmatched by any other animal. Since the turn of the twentieth century, the natural productivity of salmon in Oregon, Washington, California, and Idaho has declined by eighty percent. The decline of Pacific salmon to the brink of extinction is a clear sign of serious problems in the region. In Salmon Without Rivers, fisheries biologist Jim Lichatowich offers an eye-opening look at the roots and evolution of the salmon crisis in the Pacific Northwest. He describes the multitude of factors over the past century and a half that have led to the salmon's decline, and examines in depth the abject failure of restoration efforts that have focused almost exclusively on hatcheries to return salmon stocks to healthy levels without addressing the underlying causes of the decline. The book: describes the evolutionary history of the salmon along with the geologic history of the Pacific Northwest over the past 40 million years considers the indigenous cultures of the region, and the emergence of salmon-based economies that survived for thousands of years examines the rapid transformation of the region following the arrival of Europeans presents the history of efforts to protect and restore the salmon offers a critical assessment of why restoration efforts have failed Throughout, Lichatowich argues that the dominant worldview of our society -- a worldview that denies connections between humans and the natural world -- has created the conflict and controversy that characterize the recent history of salmon; unless that worldview is challenged and changed, there is little hope for recovery. Salmon Without Rivers exposes the myths that have guided recent human-salmon interactions. It clearly explains the difficult choices facing the citizens of the region, and provides unique insight into one of the most tragic chapters in our nation's environmental history.