![]() basibiont), but they can also alter the ecological functioning of the exploited ecosystem. Epibionts have not only consequences for the species they overgrow (i.e. Biofouling development is generally considered as a plague for bivalve aquaculture, and its control results in additional costs that can represent up to 30% of total operational costs of the industry. Immersed infrastructures and shells of the reared species create new substrate for a wide range of epibionts, mainly composed of suspension feeders. dianthus.īivalve aquaculture is worldwide impacted by biofouling development. The results of this study indicated that an optimal oyster cage depth for biofouling mitigation could not be determined and highlighted the challenges to aquaculture associated with biofouling of H. dianthus spawned frequently during a reproductive season ranging from at least June 20 to August 30 in Eel Lake at temperatures ~ 18-22 ☌. The mean % of positive PCR results significantly increased from 18.7 to 65.0% from June to August. dianthus was detected throughout the summer in all locations and depths monitored. Subsequently, no significant differences between sites and depths were found and H. dianthus in most sites and depths on June 20 th, indicating a spawning event had occurred. dianthus using eDNA was completed at four sites (three fouled, one non-fouled), and at three depths (0.3 m, 1.5 m, and 3.0 m) in Eel Lake. ![]() Water samples were collected from Eel Lake from June to August 2013, and eDNA was extracted. dianthus COI4F/R was chosen for monitoring. Specificity and sensitivity of primers were tested, and the primer set H. dianthus in Eel Lake, species-specific primers associated with the COI gene were developed. dianthus larvae in Eel Lake, biofouling could be mitigated by determining an optimal depth that oyster cages should be maintained at during its active spawning period. It was hypothesized that by understanding the spawning behaviour and spatial/temporal patterns of H. Heavy biofouling on the oyster lease resulted in the need to develop mitigation strategies. The species was identified as Hydroides dianthus (Verrill, 1873), and this morphological identification was confirmed by comparing a newly sequenced COI gene fragment with H. In 2012, an invasion by a serpulid tubeworm, unknown to the Atlantic Canada region, caused heavy biofouling on an oyster lease in Eel Lake, Argyle, Nova Scotia. Ongoing mussel settlement during September may, however, necessitate one additional handling in early October prior to sinking of the bags for the winter. In general, given the current fouling community, turning floating bags once in mid-August following the barnacle settlement in late July would likely be sufficient to control most species. With regard to fouling control, bag turning was effective in eliminating the settlement of barnacles and mussels on the bags, but not on the oysters. ![]() ![]() Biodeposition rates under the bags were also similar among handling treatments and did not significantly exceed reference levels even immediately following bag turning events. Maintenance activity aimed at reducing fouling levels did not, however, enhance oyster performance growth and survival rates were similar in bags turned bi-weekly, monthly, once in mid-August or never. Over the 4 month study period (June–October 2006) the fouling biomass increased exponentially to a maximum of 300 g dry wt. The impact of different bag turning frequencies on fouling levels, oyster production, biodeposition rates and the settlement of fouling species was assessed at two sites in northern New Brunswick. Fouling levels on the floating bags used for oyster culture are typically controlled by periodic turning in order to expose the accumulated biomass to air drying. Commercially-viable aquaculture of the Eastern oyster (Crassostrea virginica) in New Brunswick, Canada, depends on optimizing production strategies during the short growing season while minimizing environmental impacts.
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