Experiential-Informed Data Reconstruction for Fishery Sustainability and Policies in the Azores

Fishery analysis is critical in maintaining the long-term sustainability of species and the livelihoods of millions of people who depend on fishing for food and income. The fishing gear, or metier, is a key factor significantly impacting marine habitats, selectively targeting species and fish sizes. Analysis of commercial catches or landings by metier in fishery stock assessment and management is crucial, providing robust estimates of fishing efforts and their impact on marine ecosystems. In this paper, we focus on a unique data set from the Azores' fishing data collection programs between 2010 and 2017, where little information on metiers is available and sparse throughout our timeline. Our main objective is to tackle the task of data set reconstruction, leveraging domain knowledge and machine learning methods to retrieve or associate metier-related information to each fish landing. We empirically validate the feasibility of this task using a diverse set of modeling approaches and demonstrate how it provides new insights into different fisheries' behavior and the impact of metiers over time, which are essential for future fish population assessments, management, and conservation efforts

Migrações na fase pelágica do Cherne, Polyprion americanus (Schneider, 1801), evidenciadas por marcação e recaptura

Vários chernes juvenis, Polyprion americanus (Schneider. 1801) foram capturados à superfície da água e marcados em vários locais próximos das ilhas do Grupo Central dos Açores. Um dos exemplares foi recapturado 3 meses depois ter sido marcado, a 217 km do local onde tinha sido libertado e a uma profundidade de 254 m. A recaptura deste espécime indica que o cherne passa para uma vida demersal quando atinge um comprimento total de cerca de 50 cm.ABSTRACT: Pelagic juvenile wreckfish, Polyprion americanus (Schneider, 1801) were tagged in the surface waters around the Central Group of the Azores. One wreckfish was recaptured three months after tagging, and 217 km from its release point. It had settled to the bottom in 254 m of water. The recapture of this specimen suggests that wreckfish take up a demersal life at a total length of about 50 cm

Dynamics of Fisheries in the Azores Islands: A Network Analysis Approach

In the context of the global seafood industry, the Azores archipelago (Portugal) plays a pivotal role due to its vast maritime domain. This study employs complex network analysis techniques to investigate the dynamics of Azores fisheries, using time series data converted into networks. We uncover associations between Tunas and specific islands, consistent links among fish classifications, and identify other pivotal nodes within the fishing network. Remarkably, nodes with high degrees and a local clustering coefficient of one provide crucial insights into the fishing ecosystem. This study highlights the value of network analysis for understanding fisheries complexities and offers insights into sustainable management and the preservation of marine ecosystems. It also emphasizes the urgency for ongoing research and data collection to enrich our understanding of this multifaceted domain

Predicting interactions between common dolphins and the pole-and-line tuna fishery in the Azores

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS ONE 11 (2016): e0164107, doi:10.1371/journal.pone.0164107.Common dolphins (Delphinus delphis) are responsible for the large majority of interactions with the pole-and-line tuna fishery in the Azores but the underlying drivers remain poorly understood. In this study we investigate the influence of various environmental and fisheries-related factors in promoting the interaction of common dolphins with this fishery and estimate the resultant catch losses. We analysed 15 years of fishery and cetacean interaction data (1998–2012) collected by observers placed aboard tuna fishing vessels. Dolphins interacted in less than 3% of the fishing events observed during the study period. The probability of dolphin interaction varied significantly between years with no evident trend over time. Generalized additive modeling results suggest that fishing duration, sea surface temperature and prey abundance in the region were the most important factors explaining common dolphin interaction. Dolphin interaction had no impact on the catches of albacore, skipjack and yellowfin tuna but resulted in significantly lower catches of bigeye tuna, with a predicted median annual loss of 13.5% in the number of fish captured. However, impact on bigeye catches varied considerably both by year and fishing area. Our work shows that rates of common dolphin interaction with the pole-and-line tuna fishery in the Azores are low and showed no signs of increase over the study period. Although overall economic impact was low, the interaction may lead to significant losses in some years. These findings emphasize the need for continued monitoring and for further research into the consequences and economic viability of potential mitigation measures.This work was funded by Fundação para a Ciência e a Tecnologia (FCT) and DRCT/SRCTE, though FEDER, the Competitiveness Factors Operational (COMPETE), QREN European Social Fund, the Portuguese Ministry for Science and Education, under research projects TRACE (PTDC/MAR/74071/2006), FCT Exploratory Project (IF/00943/2013/CP1199/CT0001), and MAPCET (M2.1.2/F/012/2011). We acknowledge the support of Fundação para a Ciência e Tecnologia (FCT), through the strategic project UID/MAR/04292/2013 granted to MARE. We thank the Azorean Regional Government for funding POPA, the Ship-owners Association and the Association of the Tuna Canning Industries for their support to the program. MJC was supported by a DRCT doctoral grant (M3.1.2/F/008/2009). MAS was supported by POPH, QREN, European Social Fund and Portuguese Ministry for Science and Education, through an FCT Investigator grant (IF/00943/2013)

Dietas da abrótea (Phycis phycis) e do congro (Conger conger) dos Açores durante a primavera de 1996 e 1997

The forkbeard, Phycis phycis, and conger eel, Conger conger, are two coastal species, with a wide bathymetric and geographical distribution. The longline fleet of the Azores catches these two important commercial species. Few studies on their diet composition were found in literature. Data were collected during the demersal cruise surveys that took place aboard the R/V “Arquipélago” during the spring of 1996 and 1997. Stomachs of 53 forkbeards and 95 conger eels were examined to define their diets. Both species fed primarily on fishes, mainly on two benthopelagic species (Capros aper and Macroramphosus scolopax). However, the relative importance of fish was higher for conger eel than for forkbeard, which fed secondarily on decapods. Prey composition of the diet did not vary between sexes, predator size or areas. However, some differences were found on diet composition between depth strata. Prey composition indicates that both predators have the ability to feed near the bottom on benthic prey or in the water column on benthopelagic species

Primeiro registo do tubarão-anão, Squaliolus laticaudus (Smith & Radcliffe, 1912) nos Açores, estendendo a sua distribuição ocidental no Atlântico Nordeste

A presente nota documenta a primeira observação do tubarão-anão, Squaliolus laticaudus (Smith & Radcliffe, 1912), nos Açores, estendendo a sua distribuição ocidental no Atlântico Nordeste até ao arquipélago. A ocorrência da espécie nos arquipélagos macaronésicos é igualmente discutida.ABSTRACT: This paper reports the first observation of the spined pygmy shark, Squaliolus laticaudus, from the Azores, extending its westernmost distribution in the North-eastern Atlantic as far as this archipelago. The occurrence of this species in the Macaronesian archipelagos is also discussed

Preliminary Results on Feeding Ecology of Stomiiforme Fishes of the Northern Mid-Atlantic

Few previous studies have focused specifically on the role of the mid-ocean ridges in the ecology of pelagic fishes. This study targets on a dominant nekton component of the mid- Atlantic mesopelagic ichthyofauna - the Stomiiformes - and their food resources including zooplankton and other nekton. Its main goal is to characterize the diets of several species of these midwater fish towards understanding the trophic pathways of the deep-pelagic nekton of the northern MAR. The study material was provided by the G. O. Sars 2004 Expedition under the International project MAR-ECO. On the lab fish were dissected and diet items were identified to the lowest taxonomical level possible. Preliminary results for 8 of the 12 species proposed for this study are presented. Amphipoda and Pteropoda seem to be important in Argyropelecus aculeatus feeding, while in Sternoptix diaphana diet amphipods are clearly the most common prey. Of the identifiable items in the guts of Maurolicus mulleri and Vinciguerria attenuata copepods constitute half of the occurrences but ostracods are also relevant. These four species show more planktivorous affinities when compared with the remaining species. Cyclothone microdon and Sigmops bathyphilum had the fewest identifiable items in the guts. In C. microdon while the stomachs were not completely empty it was very frequent to have a mass of unidentifiable jelly-like material. This may indicate that this species eats gelatinous plankton. Stomias boa reveals a piscivorous behaviour. Malacosteus niger is also a predator but occasionally eats copepods. Future work includes study of the remaining species: Sigmops elongatum, Argyropelecus hemigymnus, Borostomias antarcticus and Chauliodus sloani and more detailed analyses for all the target species, consisting on determination of prey biomass and feeding guilds, calculation of the fish daily ration and predation impact of the midwater fish assemblage on their prey in an attempt to design a food web model of the nekton community associated with the MAR

Staining techniques for ageing tope shark, Galeorhinus galeus (Linnaeus, 1758), from the Azores : a comparison based on precision analysis.

A vertebrae sample of tope shark, Galeorhinus galeus (Linnaeus, 1758), stratified by sizeclasses,was used to test between different staining techniques of enhancing vertebral growth ring visibility. Four techniques were tested: alizarin red, silver nitrate and cobalt nitrate staining, and the “deep-coned vertebrae” technique. The latter was discarded due to its unsuitability for tope shark vertebrae. The cobalt nitrate original protocol was modified. Upon staining, each vertebra was subject to three replicated independent readings, by a single reader. Within-reader consistency and bias of growth ring counts determination were evaluated using four different precision indices: percent of agreement (PA), average percent error (APE), coefficient of variation (V) and index of precision (D). Results indicated that the vertebrae stained with the cobalt nitrate technique showed both better optic enhancement of growth rings and higher degree of count consistency, comparatively to the alizarin red and silver stained vertebrae. Conclusively, the cobalt nitrate was the most efficient staining technique upon tope shark vertebrae, among the methods tested herein

Nueva contribución a las características reproductivas del Helicolenus Dactylopterus Dactylopterus en el Atlántico noreste (Archipíelago de Azores)

This work describes and identifies the macroscopic and corresponding microscopic changes of the gonads of an important commercial fish species, Helicolenus dactylopterus dactylopterus, from Azores Archipelago. The new contribution relates the macroscopic scale with the histological stages. The annual changes in the gonad, together with the analysis of the monthly gonadosomatic indices, and complementary observations with scanning electron microscopy, allow us to conclude that the females are internally inseminated between July and November and spawn between January and March. There is a separation between female and male reproductive cycles. The overall sex-ratio observed was 1:1, but seasonal and length related differences were observed. This suggests differences and changes in availability, probably related to the annual reproductive cycle and changes in feeding behaviourEste trabajo describe e identifica las etapas de madurez macroscópicas y correspondientes etapas microscópicas de las gónadas de una especie comercial importante, Helicolenus dactylopterus dactylopterus, de la pesquería del archipiélago de las Azores. La nueva contribución relaciona la escala macroscópica con las etapas histológicas. Los cambios anuales de las gónadas, junto con el análisis de los índices gonadosomáticos y con las complementarias observaciones con microscopía electrónica (SEM), permiten concluir que las hembras son inseminadas internamente entre julio y noviembre y desovan entre enero y marzo. Hay una separación entre los ciclos reproductivos de las hembras y los machos. En general la proporción sexual es 1:1; pero desviaciones de esta proporción fueron registradas estacionalmente y para para ciertas clases de talla. Estas desviaciones sugieren diferencias y cambios en la disponibilidad, relacionadas probablemente con los cambios reproductivos anuales y con el comportamiento alimentario.  

Annotated list of fishes caught by the R/V ARQUIPÉLAGO off the Cape Verde archipelago.

A prospective survey was carried out in October - November of 2000, in the Cape Verde archipelago, by the R/V ARQUIPÉLAGO. The main objective was to determine the species composition and relative abundance of the demersal fish resources living in the waters of the Cape Verde archipelago. A list of fishes caught with bottom longline during the survey is presented in this document, along with information about the area, depth limits and the relative abundance of the species in the catches. Ninety-seven different species from 49 families were identified from 20 long-line sets. To our knowledge, the following 12 species were recorded for the first time from the waters of Cape Verde islands: Etmopterus princeps, Etmopterus pusillus, Gymnothorax maderensis, Myroconger compressus, Laemonema robustum, Beryx splendens, Scorpaena elongata, Serranus atricauda, Taractes rubescens, Taracthichthys longipinnis, Pagrus africanus and Cathidermis sufflamen. The species Laemonema robustum, were new to the CLOFETA area