Search

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of the green sea urchin (Strongylocentrotus droebachiensis) fishery in British Columbia, Canada, is presented as an example of how a precautionary approach was applied to avert collapse of a developing invertebrate fishery and to rebuild towards a sustainable fishery. We consider four components: (1) identification of the appropriate spatial scales; (2) development of scientifically-supported management strategies; (3) consideration of uncertainties; and (4) collaborations amongst scientists, fishery managers, and stakeholders. The green sea urchin fishery in British Columbia has experienced three periods: a “developing” period during which effort and landings increased, but catch per unit of effort (CPUE) declined; a “crisis” period during which effort and landings peaked and CPUE reached a minimum; and a “rebuilding to sustainable” period during which landings and effort stabilised and CPUE increased. Passive management actions (minimum size limit, seasonal closures) were introduced at the beginning of the fishery, but were unable to limit exploitation. Subsequent to the crisis period, active management measures (large area closures, quotas, and an individual quota system) were implemented based on scientific studies and appear to have stabilised the fishery. The availability of fishing logbook information from the inception of the fishery and the development of positive relationships amongst all participants in the fishery were central elements of this rebuilding process. The long time series of logbook information provided sufficient data contrasts to use two surplus production modelling techniques to develop biological reference points for management regulations. The green sea urchin fishery is now a small but important, and apparently stable, component of the dive fisheries in British Columbia. [Copyright &y& Elsevier]

The identification of homogeneous flood regions is essential for regional flood frequency analysis. Despite the type of regionalization framework considered (e.g., region of influence or hierarchical clustering), selecting flood-related attributes to reflect flood generating mechanisms is required to discriminate flood regimes among catchments. To understand how different attributes perform across Canada for identifying homogeneous regions, this study examines five distinctive attributes (i.e., geographical proximity, flood seasonality, physiographic variables, monthly precipitation pattern, and monthly temperature pattern) for their ability to identify homogeneous regions at 186 gauging sites with their annual maximum flow data. We propose a novel region revision procedure to complement the well-known region of influence and L-Moments techniques that automates the identification of homogeneous regions across continental domains. Results are presented spatially for Canada to assess patterning of homogeneous regions. Memberships of two selected regions are investigated to provide insight into membership characteristics. Sites in eastern Canada are highly likely to identify homogeneous flood regions, while the western prairie and mountainous regions are not. Overall, it is revealed that the success of identifying homogeneous regions depends on local hydrological complexities, whether the considered attribute(s) reflect primary flooding mechanism(s), and on whether catchment sites are clustered in a small geographic region. Formation of effective pooling groups affords the extension of record lengths across the Canadian domain (where gauges typically have <50 years of record), facilitating more comprehensive analysis of higher return period flood needs for climate change assessment. [ABSTRACT FROM AUTHOR]