Further analysis of the particle tracking results is underway to provide the relative contribution of each area of the bay, the effects of meteorological and river forcing on these contributions, and potential modifications to this pattern in the context of a scenario where a storm would result in breaching of the sand dune in front of the seed collection area.Ĭo-Funded by: Entreprise Baie Acadienne Inc. A particle tracking module was coupled with the hydrodynamic model in order to investigate in more detail the transport of oyster larvae within Bouctouche Bay. The results from this experiment showed that the seed collection area is located in a retention zone of the bay where renewal by Northumberland Strait waters is slowest and indicated that water circulation within Bouctouche Bay is sensitive to meteorological forcing (wind and atmospheric pressure). This modelling will also help researchers evaluate the possible repercussions of one (or more) spat evolution scenarios on the hydrodynamics (examining the erosion effects on the flow of water and nutrients) and overall spat collection potential within the bay. This project studied the factors influencing oyster spat collection in Bouctouche Bay, New Brunswick by using modelling techniques to reproduce the oyster larval transport from spawning to recruitment for environmental conditions observed in situ (in the field) and assessing the relative contribution of the various larval sources (wild versus cultured stock). To properly manage these fluctuations, an in-depth understanding of the various factors influencing collection rates and recruitment numbers within the system is needed. In 2009, lower than average oyster spat collection rates were a source of concern for producers. The oyster culture industry in New Brunswick depends on the oyster spat collected at four sites–Bouctouche Bay, Cocagne Bay, Caraquet Bay, and Miramichi Bay. Photo: Jeffery Clements (DFO) Assessment of Oyster Spat Collection Potential in Bouctouche Bay, New Brunswick (A) shells not impacted, (B) shells mildly impacted, and (C) shells severely impacted. Project Team: Daniel Bourque, Mary Stephenson, Janelle McLaughlin, Jeff Clements (DFO)Ĭollaborators: Serge Gaudet (Huîtres Aquador Oysters Inc.)Ĭontact: Crassostrea virginica shells with varying degrees of mud blister impact from Polydora websteri. Project Lead: Daniel Bourque, Mary Stephenson (DFO) To help identify the current impact of Polydora on New Brunswick oyster growing areas, this project aims to: 1) document the presentation and level of the infestation of Polydora 2) document the impact of Polydora on overall oyster health and 3) document distribution and infestation level of Polydora in relation to environmental conditions.įunded by: DFO–Aquaculture Collaborative Research and Development Program (DFO–ACRDP)Ĭo-Funded by: Huîtres Aquador Oysters Inc. This unusual increase could ultimately lead to serious impacts on oyster populations and result in economic losses for the aquaculture industry. Some reports have indicated that heavy infestations can result in low meat quality, abscesses, alteration of growth patterns, and weakened shells (increasing predator susceptibility). However, there have been sporadic increases of infestation rates observed in off-bottom (or suspension) oyster growing sites in New Brunswick. Commonly found in intertidal and subtidal areas in Atlantic Canada, its presence among New Brunswick oyster populations has normally been minor and usually of low intensity with burrows containing little or no mud. Known simply as a “mudworm” or “blisterworm”, Polydora websteri has the ability to bore into the shells of live and dead shellfish. Shellfish: Oysters Investigating Polydora Outbreak in New Brunswick Off-Bottom Cultured OystersĪ better understanding of the increased intensity and prevalence of Polydora related to environmental conditions and their impact on oyster health would assist industry in developing management and mitigation strategies.
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