Identification of optimal broodstock for Pacific Northwest oysters

• Main Author: Stick, David A.
• Other Authors: Camara, Mark D., Langdon, Christopher J., Banks, Michael, Meyer, Howard, Fisheries and Wildlife, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Olympia oyster > Conservation > Pacific Coast (North America); Pacific oyster > Breeding > Pacific Coast (North America); Pacific oyster > Genome mapping > Pacific Coast (North America); Brood stock assessment > Pacific Coast (North America); Pacific oyster > Pacific Coast (North America) > Molecular genetics; Olympia oyster > Pacific Coast (North America) > Molecular genetics; Oyster culture > Pacific Coast (North America); Crassostrea gigas; Pacific oyster
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/g732dc75z

The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat degradation, and competition and predation by non-native species has drastically depleted their densities and extirpated many local populations. As a result, shellfish aquaculture production has shifted to the introduced Pacific oyster, Crassostrea gigas. An underlying objective of this dissertation is the use of molecular genetics to improve our ability to accurately identifying optimal oyster broodstock for either restoration of Olympia oysters or farming of Pacific oysters. The ecological benefits provided by oysters as well as the Olympia oyster's historical significance, has motivated numerous restoration/supplementation efforts but these efforts are proceeding without a clear understanding of the genetic structure among extant populations, which could be substantial as a consequence of limited dispersal, local adaptation and/or anthropogenic impacts. To facilitate this understanding, we isolated and characterized 19 polymorphic microsatellites and used 8 of these to study the genetic structure of 2,712 individuals collected from 25 remnant Olympia oyster populations between the northern tip of Vancouver Island BC and Elkhorn Slough CA. Gene flow among geographically separated extant Olympia oyster populations is surprisingly limited for a marine invertebrate species whose free-swimming larvae are capable of planktonic dispersal as long as favorable water conditions exist. We found a significant correlation between geographic and genetic distances supporting the premise that coastal populations are isolated by distance. Genetic structure among remnant populations was not limited to broad geographic regions but was also present at sub-regional scales in both Puget Sound WA and San Francisco Bay CA. Until it can be determined whether genetically differentiated O. lurida populations are locally adapted, ...