Thesis (M.S.) in Resource Economics and Policy--University of Maine, 2001. / Includes vita. Advisory Committee: Hsiang-Tai Cheng, Assoc. Prof. of Resource Economics and Policy, Advisor; George K. Criner, Prof. of Resource Economics and Policy; Alan S. Kezis, Prof. of Resource Economics and Policy and Assoc. Dean of College of Natural Sciences, Forestry and Agriculture. Bibliography: leaves 72-76.

Thesis (M. Sc.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 116-122.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2001. / Bibliography: leaves 188-206.

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.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2003. / Restricted until October 2004. Bibliography: leaves 185-203.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 73-80.

Recently, biogenic carbonates have received much attention as potential proxies of environmental change; however, a major pathway of elemental incorporation is often overlooked when making interpretations or designing experiments. This research experimentally examines the influence of diet on elemental composition in juvenile shells of the bay scallop, Argopecten irradians concentricus, and the northern quahog, Mercenaria mercenaria. Exploratory trials were conducted using Argopecten irradians concentricus juveniles fed different algal diets: Isochrysis, Chaetoceros, Pavlova, Tetraselmis, or a mix of all four in a 2:1:2:2 ratio. No differences between the left and right valves were revealed, thus, subsequent analysis of the dietary influence on shell chemistry utilized both valves. Only Mg/Ca and K/Ca were significantly different between the diet groups, though different influences were determined. Experiments with juvenile Mercenaria mercenaria compared shell chemistries among clams fed unicellular diets of Isochrysis sp. (CCMP1324), Pavlova pinguis (CCMP609), Chaetoceros mulleri (CCMP1316), Isochrysis sp. (CCMP1611) culture, Pavlova sp. (CCMP1209), or Chaetoceros galvestonensis (CCMP186), a mixed diet of all species in equal ratios (Mixed), or no food (starvation control). The results indicate that diet can influence shell chemistry either directly or indirectly, with degree of influence varying by diet and mollusc species. Additional information concerning the use of alternative element ratios and changes in the shell chemistry due to starvation-induced stress are also presented. Altogether, the present research provides valuable information concerning shell dynamics and potential diet-associated fluxes, thus demonstrating the need to consider the composition of dietary inputs when assessing environmental associations with elemental shell chemistries.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2000. / Bibliography: leaves 88-98.

North Atlantic short-finned squid (Illex illececbrosus) is an underutilized species and calico scallops (Argopecten gibbys) do not achieved the same market value as Sea scallops due to their small size. North Atlantic short-finned squid have limited consumer acceptability due to their smaller, thinner, and more leathery texture than Atlantic long-finned squid (Loligo pealei). The market limitation of calico scallops is derived from their small size compared to other species of scallops available in the marketplace. Thus, restructuring or engineering food technology applied to these species to produce new products will result in more profit to the industry. Restructured squids were fabricated with heat-set binders according to the following combinations: starch, egg white albumin, fish sarcoplasmic protein, starch and egg white albumin, and starch and fish sarcoplasmic protein at various levels. Increasing the level of starch from 2 to 10% decrease the hardness, cohesiveness, and springiness of restructured squid. Two percent egg white albumin improved the hardness and cohesiveness, while 2% fish sarcoplasmic protein improved cohesiveness and springiness of the squid gel. The hardness, cohesiveness, and springiness of starch-based combinations decreased as a function of starch. Restructured scallops were prepared from cold-set binders: alginate and microbial transglutaminase at the 1% level with different setting times to yield the highest binding strength. At the setting temperature of 5° C, restructured scallops bound with alginate presented the greatest binding strength at 2 hr setting, while those bound with microbial transglutaminase required 24 hr to reach the maximum binding strength. Although alginate benefits the manufacturer with respect to the shorter setting time, the lower binding strength values may result in a decrease in consumer acceptability. / Master of Science

This paper examines scallop (Argopecten purpuratus) booms experienced in the Pisco-Paracas Region of southern Peru, triggered by the 1982-1983 and the 1997-1998 mega-El Niño Southern Oscillation (ENSO) events.The quiet fishing ports have been transformed by these booms, which have attracted outside stakeholders transforming the local society. Government institutions in their role as resource managers and environmental stewards have attempted to control access to a region that until recently contained the only marine protected area of Peru.This situation has led to rapid growth in the scallop industry, the overexploitation and depletion of the shellfish, creating a sustainability crisis. Furthermore, this paper examines contradictions and relationships across local, regional, national, and international scales. / Este trabajo examina los ciclos de expansión (boom) de la explotación de la concha de abanico (Argopecten purpuratus) observados en la región Pisco-Paracas del sur del Perú, resultantes de los fenómenos El Niño de 1982-1983 y 1997-1998.Los apacibles puertos de pesca han sido transformados por estos booms productivos que han atraído actores externos y han generado un impacto en la sociedad local. Las instituciones gubernamentales, en su papel de administradores de recursos y protectores del medio ambiente, han tratado de controlar el acceso a una región que hasta hace poco contenía la única área marina protegida del Perú.Esta situación ha producido un rápido crecimiento de la industria de la concha de abanico, su sobreexplotación y el agotamiento de dicho recurso, y ha producido una crisis de sostenibilidad. Asimismo, este trabajo examina las contradicciones y las relaciones entre las escalas local, regional, nacional e internacional.