How do commercial fishing licences relate to access?

Commercial fishing licences are central to fisheries management systems. They define and allocate harvest rights, place rules upon authorized harvesters and, in some cases, require holders to pay user fees. In this paper, we ask how licences and licensing relate to access, itself a broader concept defined as the opportunity to derive benefits from resources and that draws attention to how institutions and social structures enable and constrain different individuals and groups. Using published literature, reports and publicly available licence data for fisheries off of British Columbia, Canada, we overview licensing history and examine all major commercial licence types in the jurisdiction. Using a network approach, we also describe the diverse suite of licence portfolios held in 2017. Results show that there were 6,563 commercial fishing licences registered by 2,377 unique holders, including a handful that hold ‘access‐rich’ and a much larger number who hold ‘access‐constrained’ portfolios. The literature review and analysis support two broadly applicable conclusions. First, that licensing history shapes access and that limited entry policies continue to influence who benefits from fisheries resources well beyond implementation. Second, that analysing licence holdings suggests business strategies and fishing prospects available to different harvesters and other commercial fisheries participants in a jurisdiction. In response to demand for greater attention to human dimensions and to the perception that indicators are challenging to develop and integrate, we advance conceptual thinking and practical approaches relevant to fisheries research and evaluation.     

The prevalence of lice (Bovicola ovis) infested sheep flocks in Western Australia (1987–1993)

SUMMARY The proportion of wool bale brands with a positive test for sheep lice in baled wool decreased from 29.5% in 1987/88 to 23.2% in 1990/91 before increasing to 38.2% in 1992/93. Changes in the proportion of wool bale brands with a positive test for lice were highly correlated with changes in the Wool Market Price Indicator. The increase in the proportion of positive lice tests since 1990/91 was associated with an increase in failures to eradicate lice from flocks. These failures were partly a consequence of the reduced use of lousicidal treatments, the development of resistance to synthetic pyrethroid chemicals and an increase in the transmission of lice between flocks.     

Attending to spatial social–ecological sensitivities to improve trade‐off analysis in natural resource management

Balancing trade‐offs amongst social–ecological objectives is a central aim of natural resource management. However, objectives and resources often have spatial dimensions, which are usually ignored in trade‐off analyses. We examine how simultaneously integrating social–ecological benefits and their spatial complexities can improve trade‐off analysis. We use Pacific herring (Clupea pallasii, Clupeidae)—an ecologically important forage fish with social, cultural and economic value to communities and commercial fisheries—as a case study. By combining spatial management strategy evaluation with social benefits analysis, we illustrate when policies aimed at aggregate stocks versus spatially segregated substocks of fish fail to balance trade‐offs amongst social–ecological objectives. Spatial measures (e.g. area‐based closures) may achieve some objectives but produce alternative trade‐offs that are sensitive to assumptions about fish population dynamics and social complexities. Our analyses identify policies that are inefficient (e.g. yielding economic costs without producing social or ecological gains), highlight management strategies that generate trade‐offs and indicate when costs are distributed unequally for different user groups. We also point to strategies with outcomes that are robust to spatial uncertainties and reveal research priorities by identifying which performance metrics exhibit sensitivity to spatial ecological assumptions. Collectively, our analyses demonstrate how incorporating social objectives and spatial dynamics into management strategy evaluation can reveal trade‐offs and the implications of management decisions.     

Intermittent plate tectonics?

Although it is commonly assumed that subduction has operated continuously on Earth without interruption, subduction zones are routinely terminated by ocean closure and supercontinent assembly. Under certain circumstances, this could lead to a dramatic loss of subduction, globally. Closure of a Pacific-type basin, for example, would eliminate most subduction, unless this loss were compensated for by comparable subduction initiation elsewhere. Given the evidence for Pacific-type closure in Earth's past, the absence of a direct mechanism for termination/initiation compensation, and recent data supporting a minimum in subduction flux in the Mesoproterozoic, we hypothesize that dramatic reductions or temporary cessations of subduction have occurred in Earth's history. Such deviations in the continuity of plate tectonics have important consequences for Earth's thermal and continental evolution.     

The association of iron and manganese with bacteria on marine macroparticulate material

Evidence of in situ metal (iron and manganese) deposition onto bacteria associated with rapidly sinking particles in the open ocean is reported. Below 100 meters, bacteria are found with extracellular capsules containing metal precipitates; the frequency of these capsules increases with depth. The capsular metal deposits appear to contribute a major portion of the weakly bound fraction of the particulate iron flux.