Identifier

etd-04112013-110621

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

Alternative or supplemental management activities may be necessary to restore and enhance oyster production on Louisiana public oyster reefs. The production of wild oysters is variable due to anthropogenic and environmental factors that affect recruitment, growth and survival. The availability and structure of cultch material for larval recruitment and survival is particularly important to maintain oyster production. Beginning in 2011, the Sea Grant Oyster Hatchery on Grand Isle, LA and the Louisiana Department of Wildlife and Fisheries (LDWF) collaborated to test the survival of hatchery-produced spat and hatchery-produced larvae deployed on public oyster grounds and cultch plant sites. In 2011, a preliminary study was conducted on hatchery-produced spat survival in Hackberry Bay, LA, where 100% mortality of hatchery-produced spat was observed. Survival of hatchery-produced spat was also tested in Mississippi Sound, LA (Round Island site) and California Bay, LA, where sampling took place in September and November 2012 and January 2013. No hatchery-produced spat were collected at either of these sites, suggesting 100% mortality. No significant differences were observed between the numbers of wild spat oysters on treated plots, plots with hatchery-produced spat, to untreated plots (P>0.05). In 2012, LDWF released hatchery-produced larvae at four sites at Calcasieu Lake and the sites were monitored monthly using standard LDWF sampling procedures. For most of the sites, few to no spat existed. Possible causes of hatchery-produced spat and larval mortality are sedimentation, predation, water quality and absence of suitable settling material. To increase survival, future studies should focus on ways to minimize causes of hatchery-produced spat and larval mortality.

Date

2013

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Supan, John E.

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