Aquaculture | Year: 2014
In the Gulf of St. Lawrence estuaries, mesh bags containing cultured oysters ( Crassostrea virginica) are lowered onto the bottom in autumn prior to the formation of a thick ice cover. The oysters remain quiescent and unattended in near-freezing waters for four to five months, during which time they are susceptible to accidental burial by sedimenting particles. The objectives of this study were (1) to gain insight into the mechanism cueing the spring awakening of oysters, (2) to determine the approximate burial depth that oysters can withstand, and (3) to estimate the time it takes for mortality to occur under conditions of excessive siltation. Results indicate that water temperature is the primary factor controlling the timing of awakening, with the majority of oysters suddenly opening their valves when temperatures increased to 2.61. ±. 0.66. °C. Supplementing the diet to mimic spring bloom conditions had no modulating influence on awakening behaviour. Oysters buried under 20. mm of sediment initially exhibited erratic valve movements and sometimes remained closed for days. Within 2. weeks, however, they did succeed in expulsing the overlying silt around their valve margins and in resuming normal valve, including circadian rhythmicity. By comparison, burial under 40 or 60. mm of silt invariably led to death within 11.7. ±. 1.3. days. It is concluded that oysters should be re-suspended as soon as the ice cover breaks apart and moves offshore in the spring. © 2014. Source
Integrated environmental assessment and management | Year: 2013
Determining the sensitivity of a diversity of species to spilled oil and chemically dispersed oil continues to be a significant challenge in spill response and impact assessment. We used standardized tests from the literature to develop species sensitivity distributions (SSDs) of acute aquatic toxicity values for several petroleum products and 2 Corexit oil dispersants. Fifth percentile hazard concentrations (HC5s) were computed from the SSDs and used to assess relative oil product toxicity and in evaluating the feasibility of establishing toxicity benchmarks for a community of species. The sensitivity of mysids (Americamysis bahia) and silversides (Menidia beryllina) were evaluated within the SSDs to determine if these common test species were appropriate surrogates for a broader range of species. In general, SSD development was limited by the availability of acute toxicity values that met standardization criteria for a diversity of species. Pooled SSDs were also developed for crude oil and Corexit dispersants because there was only small variability in the HC5s among the individual oil or dispersant products. The sensitivity of mysids and silversides varied across the oil and dispersant products, with the majority of toxicity values greater than the HC5. Application of SSDs appears to be a reasonable approach to developing oil product toxicity benchmarks, but additional toxicity data are needed for a larger range of species conducted under standardized test conditions. © 2013 SETAC. Source
Evolutionary Applications | Year: 2011
Fisheries-induced evolution has been hypothesized to delay the recovery of collapsed fish stocks through effects on their productivity. The cod stock in the southern Gulf of St. Lawrence (SGSL) collapsed in the early 1990s and has shown no recovery since then, due mainly to high natural mortality of adult cod. Age and size at maturation of SGSL cod decreased sharply over time in cohorts produced in the 1950s and 1960s, likely reflecting an evolutionary response to intensified fishing, and have remained low since then, despite severe reductions in fishing mortality over the past 15years. A predicted consequence of early maturation is increased natural mortality due to higher costs to reproduction. Early maturation may be a cause of increases in natural mortality of SGSL cod in the 1970s but does not appear to be related to the much larger increases since then. Instead, the current high natural mortality of SGSL cod appears to be primarily a cause, rather than a consequence, of the continued early maturation in this population, now replacing fishing mortality as the agent of selection favouring early maturity. This striking example of the failure to reverse fisheries-induced evolution by relaxing fishing pressure emphasizes the need for management strategies that minimize the chances of harvest-induced genetic change. © 2010 Crown in the right of Canada. Source
Agency: Cordis | Branch: FP7 | Program: CSA-CA | Phase: INCO.2013-1.1 | Award Amount: 2.35M | Year: 2014
INCONET-GCC2s overall goal is to support the institutional bi-regional policy dialogue in Science, Technology and Innovation, to strengthen the bi-regional cooperation between research and innovation actors, especially in the context of the upcoming Horizon 2020 programme and finally to monitor progress in the bi-regional STI cooperation. INCONET-GCC2 builds on the results of previous cooperation activities with the Arab Gulf Countries (INCONET-GCC 1st phase, www.icnonet-gcc.eu) while it focuses on selected societal challenges of mutual interest as identified during the previous collaboration. INCONET-GCC2 explores now to achieve win-win across national, multidisciplinary and cross-sectoral approaches can be spurred in response to these issues while also realising and underpinning new pathbreaking kinds of capacity-building and organising clustering activities around the selected research priorities. Specifically: (1) Implement a series of analyses feeding the policy dialogue and increasing its efficiency, monitoring INCONET-GCC2s own activities, with particular emphasis on their sustainability, and implementing coherent dissemination activities in order to increase its visibility and impact; (2) Built of best practices towards the future in order to promote joint research though clustering activities within the selected societal challenges and organise thematic workshops in Health, Energy, Innovation and Security and ICT, Food towards EU-GCC Joint Call for proposals; (3) Enhance capacity building through the delivery of the facilitation of researcher mobility, summer schools, the support of the NCPs and their expansion in order to cover the selected societal challenges and the organisation of information days and brokerage events in all Arab Gulf countries; (4) Roadmap future research activities and provide recommendations to the EC and the national regulatory and funding authorities; (5)Raise awareness and disseminate information.
Gulf | Date: 2015-09-10
A multi-layer liner system for application to a substrate, comprising a primer layer, a first moisture barrier layer, the first moisture barrier layer being impervious to moisture, a second moisture barrier layer, a foam layer, the foam layer being sandwiched between the first moisture barrier layer and the second moisture barrier layer, and an anchor assembly extending outwardly from the substrate into the multi-layer liner.