Understanding and managing fish populations: Keeping the toolbox fit for purpose

Wild fish populations are currently experiencing unprecedented pressures, which are projected to intensify in the coming decades. Developing a thorough understanding of the influences of both biotic and abiotic factors on fish populations is a salient issue in contemporary fish conservation and management. During the 50th Anniversary Symposium of The Fisheries Society of the British Isles at the University of Exeter, UK, in July 2017, scientists from diverse research backgrounds gathered to discuss key topics under the broad umbrella of ‘Understanding Fish Populations’. Below, the output of one such discussion group is detailed, focusing on tools used to investigate natural fish populations. Five main groups of approaches were identified: tagging and telemetry; molecular tools; survey tools; statistical and modelling tools; tissue analyses. The appraisal covered current challenges and potential solutions for each of these topics. In addition, three key themes were identified as applicable across all tool-based applications. These included data management, public engagement, and fisheries policy and governance. The continued innovation of tools and capacity to integrate interdisciplinary approaches into the future assessment and management of fish populations is highlighted as an important focus for the next 50 years of fisheries research

A comparison of particles recoiling from high pt direct photons and π°'s at the isr

We have studied the distribution of charged particles recoiling from high pT(> 3.5 GeV/c) direct photons and neutral pions in pp collisions at √s = 63 GeV. One expects a different mixture of quark and gluon initiated jets in the two cases, with predominantly u-quark jets recoiling from direct photons. No significant differences are observed in our momentum range apart from the charge composition, with a larger positive to negative ratio for particles with pT > 1 GeV/c opposite direct photons than opposite π°. © 1986 IOP Publishing Ltd