Connectivity of Marine Bivalve Species in the Northern Gulf of California: Implications for Fisheries Management and Conservation

Persistent Link:
http://hdl.handle.net/10150/194808
Title:
Connectivity of Marine Bivalve Species in the Northern Gulf of California: Implications for Fisheries Management and Conservation
Author:
Soria, Rodrigo Gaspar
Issue Date:
2010
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Understanding the level of biological connectivity among populations of harvested species is an important step towards establishing fisheries management and conservation guidelines. Many marine benthic resources present a complex metapopulation structure in which separate subpopulations of sessile post-larval individuals are connected through larval dispersal. The extent to which these subpopulations are linked is termed connectivity and can have different patterns and implications. Therefore, good management practices require tools that explicitly acknowledge this complexity across scales.I investigated the level of connectivity in a commercially important benthic species, the rock scallop (Spondylus calcifer), in an ecologically sensitive region in the NE margin of the Gulf of California, Mexico. My approach involved the development of a predictive coupled biological-oceanographic model (CBOM), which simultaneously incorporated key oceanographic and biological features. I validated CBOM outputs by means of two different techniques: population genetics analysis and measurements of spat abundance on artificial collectors.In order to infer the planktonic period of S. calcifer larvae to be used as an input for the model, I studied the early life history of the species under laboratory conditions. I estimated that the minimum period for larvae of S. calcifer to reach the settlement is approximately 15 days after fertilization. In addition to providing information useful for the model, this study produced information about the experimental conditions under which spawning induction and rearing of the species can be successful.I found strong connectivity along the study region (covering approximately 300 km of coastline). Sampled localities showed low levels of genetic structure, suggesting the existence of two subtly differentiated genetic populations. Both genetic and CBOM spatial scales of connectivity are in agreement suggesting that, on average, connectivity between subpopulation decreases when the geographic distance between them is >100 km.This study provides a multidisciplinary approach to evaluate the direction, magnitude and spatial scale of larval dispersal and connectivity, with implications for fisheries management and conservation in the study region. More broadly, it provides a baseline for future studies on coastal connectivity at various spatial scales of interest in the Gulf of California and beyond.
Type:
text; Electronic Dissertation
Keywords:
Conservation; Fisheries; Gulf of California; Marine Reserves; Scallop; Spondylus calcifer
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Natural Resources; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Shaw, William W
Committee Chair:
Shaw, William W

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleConnectivity of Marine Bivalve Species in the Northern Gulf of California: Implications for Fisheries Management and Conservationen_US
dc.creatorSoria, Rodrigo Gasparen_US
dc.contributor.authorSoria, Rodrigo Gasparen_US
dc.date.issued2010en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractUnderstanding the level of biological connectivity among populations of harvested species is an important step towards establishing fisheries management and conservation guidelines. Many marine benthic resources present a complex metapopulation structure in which separate subpopulations of sessile post-larval individuals are connected through larval dispersal. The extent to which these subpopulations are linked is termed connectivity and can have different patterns and implications. Therefore, good management practices require tools that explicitly acknowledge this complexity across scales.I investigated the level of connectivity in a commercially important benthic species, the rock scallop (Spondylus calcifer), in an ecologically sensitive region in the NE margin of the Gulf of California, Mexico. My approach involved the development of a predictive coupled biological-oceanographic model (CBOM), which simultaneously incorporated key oceanographic and biological features. I validated CBOM outputs by means of two different techniques: population genetics analysis and measurements of spat abundance on artificial collectors.In order to infer the planktonic period of S. calcifer larvae to be used as an input for the model, I studied the early life history of the species under laboratory conditions. I estimated that the minimum period for larvae of S. calcifer to reach the settlement is approximately 15 days after fertilization. In addition to providing information useful for the model, this study produced information about the experimental conditions under which spawning induction and rearing of the species can be successful.I found strong connectivity along the study region (covering approximately 300 km of coastline). Sampled localities showed low levels of genetic structure, suggesting the existence of two subtly differentiated genetic populations. Both genetic and CBOM spatial scales of connectivity are in agreement suggesting that, on average, connectivity between subpopulation decreases when the geographic distance between them is >100 km.This study provides a multidisciplinary approach to evaluate the direction, magnitude and spatial scale of larval dispersal and connectivity, with implications for fisheries management and conservation in the study region. More broadly, it provides a baseline for future studies on coastal connectivity at various spatial scales of interest in the Gulf of California and beyond.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectConservationen_US
dc.subjectFisheriesen_US
dc.subjectGulf of Californiaen_US
dc.subjectMarine Reservesen_US
dc.subjectScallopen_US
dc.subjectSpondylus calciferen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineNatural Resourcesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorShaw, William Wen_US
dc.contributor.chairShaw, William Wen_US
dc.contributor.committeememberGuertin, Phillipen_US
dc.contributor.committeememberRaimondi, Peteren_US
dc.contributor.committeememberCudney-Bueno, J. Richarden_US
dc.identifier.proquest11343en_US
dc.identifier.oclc752261202en_US
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