Assessing the reliability of catch and size statistics estimated using electronic monitoring data collected on Seychelles flagged tuna purse seiners

Fisheries data forms the basis of fisheries management, simply because without these data it is practically impossible for fisheries managers to know the status of fish stocks, let alone manage them. Having an economy highly dependent on fisheries, Seychelles together with a Spanish organisation of purse seine fishing companies operating in the Indian Ocean, the Producers’ Organisation of Large Tuna Freezers (OPAGAC), initiated a process of testing technology-based at-sea monitoring systems to better manage the tropical tuna fishery. The Satlink Electronic Monitoring System (EMS) was tested during a seven-month period in 2016 on two Seychelles flagged tuna purse seine vessels. Data collected using EMS was compared to data collected from oversampling of catches in port from selected fish wells. Total retained tuna catch, catch by species and size distribution were compared between the two methods. Results indicated that EMS was more reliable for estimating total retained skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) as well as for estimating proportions of the total catch by species and proportions of the total catch by commercial size category of bigeye tuna (Thunnus obesus). However, EMS was less reliable for estimating total retained bigeye tuna and assessing fish size distributions. EMS also failed to provide accurate estimates for total retained bycatch. This was due to the set-up of the cameras on the lower deck, that prevented dry observers from obtaining accurate estimates of the number of bycatch retained in each fish tank. Overall, EMS seems capable of producing reliable catch estimates, however, both system configuration and data review protocols require further adjustments in order for EMS to be able to obtain more precise and accurate estimates of catch and size

Resurrection of Mesoplodon hotaula Deraniyagala 1963: A new species of beaked whale in the tropical Indo-Pacific

We present genetic and morphological evidence supporting the recognition of a previously synonymized species of Mesoplodon beaked whale in the tropical Indo-Pacific, Mesoplodon hotaula. Although the new species is closely-related to the rare ginkgo-toothed beaked whale M. ginkgodens, we show that these two lineages can be differentiated by maternally (mitochondrial DNA), biparentally (autosomal), and paternally (Y chromosome) inherited DNA sequences, as well as by morphological features. The reciprocal monophyly of the mtDNA genealogies and the largely parapatric distribution of these lineages is consistent with reproductive isolation. The new lineage is currently known from at least seven specimens: Sri Lanka (1), Gilbert Islands, Republic of Kiribati (1+), Palmyra Atoll, Northern Line Islands, U.S.A. (3), Maldives (1), and Seychelles (1). The type specimen (Sri Lanka) was described as a new species, M. hotaula, in 1963, but later synonymized with M. ginkgodens. This discovery brings the total number of Mesoplodon species to 15, making it, by far, the most speciose yet least known genus of cetaceans.Keywords: Species delimitation, Mesoplodon, Nuclear introns, Taxonomy, Y-chromosome, mtDNA, Morphology, Speciation, Beaked whal

Assessing the reliability of catch and size statistics estimated using electronic monitoring data collected on Seychelles flagged tuna purse seiners

Fisheries data forms the basis of fisheries management, simply because without these data it is practically impossible for fisheries managers to know the status of fish stocks, let alone manage them. Having an economy highly dependent on fisheries, Seychelles together with a Spanish organisation of purse seine fishing companies operating in the Indian Ocean, the Producers’ Organisation of Large Tuna Freezers (OPAGAC), initiated a process of testing technology-based at-sea monitoring systems to better manage the tropical tuna fishery. The Satlink Electronic Monitoring System (EMS) was tested during a seven-month period in 2016 on two Seychelles flagged tuna purse seine vessels. Data collected using EMS was compared to data collected from oversampling of catches in port from selected fish wells. Total retained tuna catch, catch by species and size distribution were compared between the two methods. Results indicated that EMS was more reliable for estimating total retained skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) as well as for estimating proportions of the total catch by species and proportions of the total catch by commercial size category of bigeye tuna (Thunnus obesus). However, EMS was less reliable for estimating total retained bigeye tuna and assessing fish size distributions. EMS also failed to provide accurate estimates for total retained bycatch. This was due to the set-up of the cameras on the lower deck, that prevented dry observers from obtaining accurate estimates of the number of bycatch retained in each fish tank. Overall, EMS seems capable of producing reliable catch estimates, however, both system configuration and data review protocols require further adjustments in order for EMS to be able to obtain more precise and accurate estimates of catch and size

Avaliação do posicionamento de parafusos subcondrais utilizados em placas para tratamento das fraturas distais do rádio Evaluation of the position of subchondral screws used in distal radius fracture plates

As fraturas distais do rádio são as mais freqüentes do membro superior. São classificadas em estáveis e instáveis. As instáveis requerem tratamento cirúrgico. Não está definido na literatura qual o melhor método de fixação, mas existe atualmente uma tendência à utilização das placas com parafusos bloqueados. Um dos aspectos técnicos importantes é o posicionamento dos parafusos distais junto ao osso subcondral, proporcionando suporte mais adequado. A avaliação da localização desses parafusos é feita com radioscopia e radiografias, mas freqüentemente existem dúvidas quanto ao correto posicionamento. Os objetivos deste estudo são: avaliar se é possível determinar com precisão por meio de radiografias, a localização dos parafusos distais no rádio e se a experiência do avaliadorinfluencia nesta análise. Foram utilizados punhos de cadáveres. Cada rádio recebeu três parafusos junto à superfície articular distal. Por meio de incidências radiográficas clássicas e anguladas, médicos especialistas e não-especialistas em cirurgia da mão avaliaram a posição de cada parafuso, se intra ou extra-articular. Os índices de acerto foram submetidos à análise estatística.As radiografias provaram ainda ser um bom método de avaliação, não havendo melhora da precisão na localização dos parafusos com as incidências anguladas. A experiência profissional do avaliador não teve influência nos resultados.<br>The distal radius fractures are the most common fractures on upper limbs. They are classified as stable and unstable. The unstable ones require surgical treatment. However, literature does not define the best fixation method, but, today, a trend is seen towards using the locked screw plate. An important technical aspect is the distal screws positioning in the subchondral bone, with an adequate support. Fluoroscopy and radiographs are used to evaluate screws position, but there are usually doubts about the accurate positioning. The objectives of this study are to evaluate if it is possible to determine precisely the screw positioning by means of radiographs and if the previous experience of the investigator may improve the results. Cadavers' fists were used in this study. Three screws were introduced to each radius next to the distal joint surface. Specialized hand surgeons and not specialized physicians evaluated the X-ray images, at classic and angled planes, to provide the accurate positioning of each screw, intra or extra joint. The accuracy rate was submitted to statistical analysis. The X-ray images were proven to be a good evaluation method. The X-ray images captured at angled plane resulted in no improvements in the analysis of the screws positioning. Neither did the evaluator experience influence the results