33 research outputs found
Trade-based estimation of bluefin tuna catches in the Eastern Atlantic and Mediterranean, 2005-2011
The Eastern Atlantic and Mediterranean stock of Bluefin tuna Thunnus thynnus (BFTE) has long been considered overfished and at risk of collapse. Although ICCAT quotas for this stock have decreased considerably over the past years, uncertainty exists about the degree of catch beyond this quota. The extent of such catch is an important piece of information in stock assessment models as well as being an indicator of the effectiveness of fisheries management. We present a model using Bluefin tuna trade data to infer actual catches. Basing our calculations on 25 countries involved in BFTE trade, we estimate that between 2005 and 2011, allowable quotas were exceeded by 44 percent. This gap between catch and quotas has slightly increased over past years, leading to estimated excess catches of 57 percent for the period between 2008 and 2011. To improve assessments, preparation and design of BFTE management, we suggest that the estimated total removals reported in this paper be included in stock assessment models for BFTE. An implication of our findings is that ICCAT member states should take stronger measures to monitor and enforce compliance with quotas
High pT π0 production from αα and αp collisions at the CERN ISR
The invariant cross sections for π0 meson production in alpha-alpha and alpha-proton collisions at the ISR were meas- ured up to transverse momenta of 7 GeV c and 8 GeV c, respectively. These measurements are compared with π0 production in pp collisions at the same values of s/nucleon, and the variation of the nuclear A-dependence with pT is determined. © 1982
A comparison of the production of pi0 mesons in p and pp interactions at the CERN ISR
A comparison of pp and pp interactions was made at \sqrt{s}=52.7 GeV at the CERN ISR. The quantities compared were the charged and neutral multiplicities, the total neutral transverse energy, Sigma E /sub T/, up to 12 GeV, and the single\pi^{0} inclusive cross section up to p/sub T/=5 GeV/c. No significant differences were observed
Observation of jet structure in high transverse energy events at the CERN Intersecting Storage Rings
Three-jet events at the CERN intersecting storage rings
Three-jet events have been observed in pp collisions at s = 62.3 GeV. The data were collected using a total neutral energy trigger with a threshold at 25 GeV. These events appear predominantly as two jets, with some appearing as three jets. A novel analysis for the extraction of 2-jet and 3-jet events is described, and some of the event properties are discussed. The relative numbers of two- and three-jet events are studied within the framework of leading-order QCD, and yield a value of αs(K3/K2) = 0.19 ± 0.02 (stat.) ± 0.04 (syst.). © 1988
High production from and collisions at the CERN ISR
The invariant cross sections for\pi^{0} meson production in alpha- alpha and alpha-proton collisions at the ISR were measured up to transverse momenta of 7 GeV/c and 8 GeV/c, respectively. These measurements are compared with\pi^{0} production in pp collisions at the same values of \sqrt{s}/nucleon, and the variation of the nuclear A-dependence with p/sub T/ is determined