Spatio-temporal distribution of the swordfish Xiphias gladius (Linnaeus, 1758) caught by the Brazilian longline fleet

Studies relating the populational structure of target species to operational and environmental variables contributedirectly to the management of the fisheries in these resources. Therefore, this study aimed to provide dataon fishing and ecology of the swordfish (Xiphias gladius) caught by the Brazilian longline fleet operating inthe western Atlantic between 2010 and 2016. Generalized additive mixed models were used to evaluate therelationship between explanatory variables and responses based on Catch Per Unit of Effort (CPUE) data.Results show that the Brazilian longline fleet catches the swordfish mostly between latitudes of 5°N to 30°S andlongitudes of 20° to 50°W and that the swordfish prefers temperatures under 25°C at depths below 60 meters.The species showed a tendency toward intermediate light intensity, predominating in the crescent moon phase,and a preference for areas with low chlorophyll concentrations. Our findings on operational and environmentalinteractions with swordfish CPUE suggest areas and times that can be used by fishing fleets and governmentinstitutions as a starting point for swordfish management strategies

MATERIALIZING THE LANDSCAPE: DRONES, GEODESY, AND 3D PRINTERS IN A VIABLE AND ECONOMIC SOLUTION FOR 3D MODELING

In recent years, environmental modeling has become increasingly crucial for understanding and mitigating the impacts of human activities on the environment. However, traditional methods for environmental mapping, primarily those of physical understanding, face challenges related to accuracy, time, and cost. In this sense, this work aimed to evaluate the technical feasibility of altimetric mapping and 3D model construction using drones, precision geodesy, and 3D printing as an extremely effective and low-cost alternative for environmental modeling. The study focused spatially on the boundaries of the IFRN/Campus Macau terrain. The study was conducted in five stages: I) Literature review; II) Geodetic survey (GNSS); III) Aerophotogrammetric survey; IV) Processing of geodetic and aerophotogrammetric data; and V) 3D printing. A protocol was obtained for the elaboration with high vertical and horizontal accuracy of the Digital Surface Model (DSM), orthomosaic, and 3D model (virtual and physical) of the mapped environment. Regarding the 3D model, its printing allowed for a perfect understanding of the geomorphology of the mapped environment and the existing physical structures. The applied technique could be useful in various areas, such as enhancing the planning stage in civil construction, architecture, and environmental studies. Also becoming a great ally in future geomorphological and tactile cartography studies

Report on the 2020 ICCAT workshop on small tunas biology studies for growth and reproduction

This report describes the 2020 ICCAT workshop on small tunas biology studies for growth and reproduction, hosted by the Instituto Español de Oceanografía, Málaga, Spain. The major objectives of the workshop were: 1) starting the creation of ageing and reproduction reference sets and, 2) providing more training for the ongoing sample collection and processing to the teams involved in these studies. As approved by the SCRS in 2017, the Small Tuna Species Group intersessional meeting decided to prioritize the collection of biological samples aiming at growth, maturity and stock structure studies on three species: little tunny (Euthynnus alletteratus), Atlantic Bonito (Sarda sarda) and wahoo (Acanthocybium solandri), based on their economic importance and the lack of knowledge on their biology. This work will contribute to the next major advance in the assessment of these three species

DinÃmica populacional e pesca de atuns em cardumes associados no AtlÃntico oeste equatorial

O presente trabalho tem por objetivo a caracterizaÃÃo dos aspectos tecnolÃgicos e da composiÃÃo das capturas, complementados com estudos sobre o crescimento e a alimentaÃÃo das principais espÃcies na pesca de atuns e afins em cardumes associados no AtlÃntico Oeste Equatorial. Para tanto, foram acompanhados 109 desembarques em Areia Branca, RN, no perÃodo entre jun/2010 e mai/2013, assim como o embarque em nove cruzeiros de pesca no perÃodo entre fev/2011 e dez/2012. O estudo de idade e crescimento, foi realizado com base nas leituras de anÃis etÃrios nos espinhos dorsais e microincrementos diÃrios de otÃlitos de Thunnus albacares ajustados aos modelos de crescimento de von Bertalanffy, Gompertz e LogÃstico, os quais foram selecionados a partir dos valores de AIC (Akaikeâs Criterion Information). O estudo de alimentaÃÃo foi desenvolvido por meio da identificaÃÃo e avaliaÃÃo dos itens alimentares presentes no conteÃdo estomacal de T. obesus e T. albacares. Foram observadas 9 embarcaÃÃes, com comprimento total mÃdio de 13,4 m, as quais utilizam diversas tÃcnicas de captura como a linha de mÃo, vara e linha, corrico e corso, com o uso de iscas artificiais e naturais. Os desembarques totalizaram 691.533 kg de pescado, dentre os quais, as espÃcies alvo foram a albacora bandolim e a albacora laje, sendo retidas tambem espÃcies como o dourado, agulhÃo negro, bonito-listrado, cavala empinge, peixe rei e ainda, ocasionalmente, espÃcies como espadarte e cangulo. Os valores de L ̅_∞ foram estimados em 175,13 e 171,6 cm para os dados observados e retrocalculados a partir dos espinhos dorsais e em 166,6; 171,14; e 155,38 cm respectivamente para os dados agrupados, para machos e fÃmeas a partir dos microincrementos diÃrios de otÃlitos. Os principais itens alimentares observados na dieta de ambos os predadores foram os peixes das famÃlias Myctophidae, Exocoetidae, Bramidae e Nomeidae, sendo observadas com menor frequÃncia os cefalÃpodes e os crustÃceos. Podemos concluir que os resultados obtidos fornecem informaÃÃes essÃnciais que ajudarÃo a compreender as atividades de pesca, bem como ampliarÃo os conhecimentos sobre a biologia das principais espÃcies capturadas.The present study aims to characterize the technolo gical features and the catch composition, complemented with studies on the age a nd growth and feeding of the target species in the fishery for tunas in associated schools in the western equatorial Atlantic. For this purpose, a total of 109 landings by the fleet based on Areia Branca, RN, were observed in the period from June 2010 to M ay 2013, as well as on board in nine fishing cruises in the period from February 2011 to December 2012. The age and growth study was performed based on readings of age rings of the dorsal spines and daily microincrements present in the otolith of Thunnus albacares, adjusted to von Bertalanffy , Gompertz and Logistic growth models, which were selected based on their AIC (Akaike 's Information Criterion) valu es. The feeding study was developed through the identification and assessment of food items present in the stomach contents from T. obesus and T. albacares . The fleet consisted of 9 boats, with an average length overall of 13.4 m, which use various fishing techniques such as handline, rod and line and trolling, combined with natural baits or lures. Landings amounted 691,533 kg, from which, the target species were bigeye and yellowfin tunas, as well as bycatch, species such as dolphinfish, blue marlin, skipjack, wahoo, rainbow runner and, even occasionally, species such as swordfish and triggerfish. The values of L were estimated at 175.13 and 171.6 cm for the obser ved and backcalculated data from the dorsal spines and 166.6, 171.14 and 155.38 cm, respectively for the pooled data, males and females based on otolith daily microstructure. The main food items observed in the diet of both predators were the following fish families: Myctophidae, Exocoetidae, Bramidae and Nomeidae. Cephalopods and crustaceans were occasionally observed. We can conclude that results provide essential information that will ass ist in the understanding of fishing activities as well as expand the knowledge on the biology of the target species

Fisheries biology of rays Dasyatis guttata (Bloch & Schneider, 1801) and Dasyatis Americana Hildebrand & Schroeder, 1928 in the state of CearÃ

As raias das espÃcies Dasyatis guttata e Dasyatis americana constituem importantes recursos pesqueiros no Estado do CearÃ. O objetivo geral desta DissertaÃÃo à estudar a biologia pesqueira dessas espÃcies com vistas ao uso das informaÃÃes como constituintes de eventuais medidas de gerenciamento de sua exploraÃÃo. Dentro desse contexto geral, foram abordados aspectos relacionados com a biometria e suas relaÃÃes morfomÃtricas, dieta alimentar e reproduÃÃo, quanto ao comprimento mÃdio na 1 maturidade sexual e fecundidade. As amostragens foram realizadas nos MunicÃpios de Fortaleza, Caucaia e Aquiraz, no Estado do CearÃ, Brasil, a partir da captura como fauna acompanhante das pescarias com rede-de-arrasto e rede-de-espera, e dos desembarques das pescarias com linha-de-mÃo e mergulho (arpÃo), durante os perÃodos de julho e agosto de 1997; fevereiro a julho de 1999; agosto de 2000; marÃo a junho de 2001; outubro a dezembro de 2003; e janeiro de 2004 a maio de 2005. O crescimento relativo das medidas lineares comprimento do disco (CD), distÃncia focinho-olho (FO), distÃncia focinho-boca (FB), largura da boca (LB), comprimento dos clÃspers (CC) e peso total (PT) â variÃveis dependentes, como proporÃÃo da largura do disco (LD) â variÃvel independente, foi estimado atravÃs do Ãndice MorfomÃtrico (IM) e das relaÃÃes moformÃtricas lineares CD/LD, FO/LD, FB/LD, LB/LD e CC/LD e PT/LD. A ocorrÃncia de dimorfometria sexual foi avaliada atravÃs do teste t, aplicado ao coeficiente angular para machos (b1) e fÃmeas (b2). DiferenÃas no tamanho entre machos e fÃmeas tambÃm foram avaliadas pelo teste t. A alimentaÃÃo foi analisada quanto ao Ãndice de RepleÃÃo Estomacal, e quanto à dieta pelos mÃtodos da freqÃÃncia de ocorrÃncia, avaliaÃÃo volumÃtrica e avaliaÃÃo gravimÃtrica. A reproduÃÃo foi estudada quanto ao desenvolvimento da maturaÃÃo sexual e estimaÃÃo do comprimento na 1Â. maturidade sexual atravÃs do mÃtodo da ogiva. A fecundidade das espÃcies foi estimada atravÃs da contagem do nÃmero de embriÃes por fÃmea grÃvida. A anÃlise dos dados permitiu a obtenÃÃo dos seguintes resultados: (1) D guttata foi considerada como espÃcie-alvo das pescarias com linha-de-mÃo, sendo tambÃm capturada como fauna acompanhante nas pescarias direcionadas a camarÃes e lagostas com redes de arrasto e de espera, enquanto D. americana foi considerada como espÃcie-alvo das pescarias com linha-de-mÃo e mergulho, sendo capturadas em fundos lamosos e arenosos, respectivamente; (2) D. americana apresentou um porte bem maior que D. guttata, as fÃmeas sÃo maiores do que os machos; (3) foram observadas diferenÃas entre sexos quanto ao crescimento relativo das variÃveis âdistÃncia focinho-bocaâ em ambas as espÃcies, e âdistÃncia focinho-olhoâ em D. americana; (3) a dieta apresentou a seguinte estrutura: alimentos essenciais - crustÃceos (D. guttata), crustÃceos e peixes (D. americana); alimentos secundÃrios - peixes, poliquetas e sipunculas (D. guttata); alimentos ocasionais - moluscos e outros (D. guttata), poliquetas, sipunculas e moluscos (D. americana); (4) D. americana parece fazer um melhor aproveitamento dos itens alimentares disponÃveis, como o indica seu maior Ãndice de repleÃÃo estomacal; (5) a capacidade de reproduÃÃo à atingida nas classes de 50-60 cm LD e 60-70 cm LD (machos) e 60-70 cm LD e 80-90 cm LD fÃmeas), para D. guttata e D. americana, respectivamente; (6) os clÃspers apresentaram comprimentos mÃdios de 11,2 e 11,8 cm em D. guttata e D. americana, com proporÃÃes praticamente iguais nas duas espÃcies, valores que definem o tamanho mÃdio na 1Â. maturidade funcional; (7) s D. guttata e D. americana apresentaram baixa fecundidade e neonatos com tamanho mÃdio de nascimento estimados em 14,0 cm LD e 29,0 cm LD, respectivamente.The stingray species are important fishing resources in Cearà State, Brazil. The main objective of this Dissertation was to study the fishery biology of the species Dasyatis guttata e Dasyatis americana, with the aim of using the results as tools in the issuing and enforcing of the appropriate measures for managing their exploitation. Various aspects were studied, such as: biometry, morphometric relationships, feeding diet, and reproductive activity as to the maturation development and mean size at the first sexual maturity and fecundity. Sampling for the stocks was carried out in Fortaleza, Caucaia and Aquiraz counties, in Cearà State, Brazil, as by-catch material by the trawlnet and gillnet fisheries and landings from the hook-and-line fishery and harpooning fisheries, during the period of July and August of 1997; February to July of 1999; August of 2000; March to June of 2001; October to December of 2003; and January of 2004 to May of 2005 . The relative growth of the body measures disk length (DL), distance snout-eye (SE), distance snout-mouth (SM), mouth breadth (MB), claspers length (CL) and total weight (TW) â dependent variables â as a proportion of disk width (DW) â independent variable - was estimated by means of the Morphometric Index and the morphometric relationships DL/DW, SE/DW, SM/DW, MB/DW e CL/DW and TW/DW. The occurrence of sexual dimorphism was assessed through Studentâs t-test applied to the slope coefficient for males (b1) and females (b2). Differences in size between males and females were also evaluated by means of the t-test. Feeding was investigated by the Index of Gut Fullness and diet by the frequency of occurrence and volumetric and gravimetric evaluation methods. Reproduction was investigated as to gonad development and estimation of the mean size at first sexual maturity, the latter by the ogive method. Fecundity of both species was estimating by counting the number of embryos per pregnant female. The data analysis generetd the following results: (1) Dasyatis guttata was considered a target specie of hook-and-line fishery, being also caught as by-catch in the shrimp and lobster fisheries with trawlnets and gillnets and Dasyatis americana was a target species of hook-and-line fishery and harpooning fisheries, they are caught in mud and sand bottoms, respectively; (2) D. americana was larger that D. guttata, and likewise, females were bigger than males; (3) sex differences as to relative growth of variables âdistance snout-mouthâ in both species, and âdistance snout-eyeâ in D. americana; (3) the feeding diet has the following structure: essential foods - crustaceans (D. guttata), crustaceans and fish (D. americana); secondary foods â fish, worms, fish and sipunculids (D. guttata); occasional foods â mollusks and other items (D. guttata), worms, sipunculids and mollusks (D. americana); (4) the stingray D. americana seems to make the most of the ingested food as indicated by the Index of Gut Fullness; (5) the onset of reproduction is attained in length classes de 50-60 cm DW and e 60-70 cm DW (males), and 60-70 cm DW e 80-90 cm DW (females), for D. guttata and D. americana, respectively; (6) the mean length of claspers was estimated as 11.2cm (D. guttata) and e 11.8 cm (D. americana), with roughly equal proportions in both species, values which are thought to define the mean size at first functional maturity; (7) D. guttata e D. americana showed a low fecundity index, with the mean length free-living neonates being estimated as 14.0 cm DW and 29.0 cm DW, respectively

Composição das capturas na pesca de atuns e afins em cardumes associados no atlântico oeste equatorial

The present study aims to characterize the catch composition of the fishery for tunas in associated schools in the western equatorial Atlantic. For this purpose, a total of 109 landings on Areia Branca-RN, were observed, from June 2010 to May 2013, as well as on board in nine fishing cruises, from February 2011 to December 2012. The monitored fleet consisted of 9 boats, with an average length overall of 13.4 m. Landings amounted 691,533 kg (6,344.3 +/- 292.7 kg), with a predominance of bigeye and yellowfin tunas, and other bycatch species, such as dolphinfish, blue marlin, skipjack tuna, wahoo, and rainbow runner. Occasionally, other species such as swordfish and triggerfish were also observed.Departamento de Ciências Animais. Universidade Federal Rural do Semi Árido - UFERSA. Av. Francisco Mota, 572 – Bairro Pres. Costa e Silva – CEP: 59.625-900 – Mossoró – RN – BrasiUniversidade Federal de São Paulo – UNIFESP. Av. Dona Ana Costa, 95 - Vila Matias, Santos - SP, CEP: 11060-001Departamento de Pesca e Aquicultura. Universidade Federal Rural de Pernambuco – UFRPE. Av. Dom Manoel de Medeiros s/n. Dois Irmãos. CEP: 52171900 - Recife, PE – BrasilInstituto de Ciências do Mar. Universidade Federal do Ceará – UFC. Av. da Abolição, 3207 – CEP: 60.165-081 – Fortaleza – CE – BrasilUniversidade Federal de São Paulo – UNIFESP. Av. Dona Ana Costa, 95 - Vila Matias, Santos - SP, CEP: 11060-001Web of Scienc

Differentiation of Spatial Units of Genus <i>Euthynnus</i> from the Eastern Atlantic and the Mediterranean Using Otolith Shape Analysis

The shape of sagitta otoliths was used to compare individuals of little tunny (Euthynnus alleteratus) harvested on board commercial fishing vessels from the coastal areas along the Eastern Atlantic, including the Mediterranean Sea. Fish sampling and selection was designed to cover possible seasonal changes and tuna size. The research encompassed both morphometric and shape analyses of left sagittal otoliths extracted of 504 fish specimens. Four shape indices (Circularity, Roundness, Rectangularity, and Form-Factor) were significantly different between two groups, showing a statistical differentiation between two clear spatial units. The degree of divergence was even more pronounced along the rostrum, postrostrum, and excisura of the generated otolith outlines between these two groups. One group corresponds to the samples from the coastal areas in the Northeast Temperate Atlantic and Mediterranean Sea (NETAM Area) and a second group from the coastal areas off the Eastern Tropical Atlantic coast of Africa (ETA Area). This study is the first to use otolith shape to differentiate tunas from separate spatial units. These results could be used to re-classify previously collected samples and to correct time series of data collected