Alba Jurado-Ruzafa

Instituto Español de Oceanografia | IEO · Centro Oceanográfico de Canarias

Studies have described the presence of different population units of blue jack mackerel, Trachurus picturatus, in the NE Atlantic region. However, the hypothesis of several populations has been subtly questioned due to the high similarity in the otolith shape among some regions. It suggests the possibility of migrations processes connecting them, e...

Sardinella aurita has become an important source of fish protein-intake in NW African countries, where one stock is considered from Morocco to south Senegal, performing seasonal reproductive migrations along the coast. Although data are limited for the fisheries involved and for life-history knowledge of the species in the area, a precautionary app...

The genetic polymorphism and phenotypic plasticity are key in ecology and evolution. The morphological variability of the contour of fish otoliths has been extensively used for the delimitation of stocks. These studies are conventionally based on average phenotype using elliptic Fourier analysis and lineal discriminant analysis as classifier. Consi...

The common octopus, Octopus vulgaris, is a very important demersal fishery resource targeted, among other fleets, by freezer bottom-trawlers in the Mauritanian Economic Exclusive Zone (MEEZ). From August 2010 to September 2011, a total of 1696 octopuses caught in the MEEZ where analysed. Many organisms trapped into the octopuses' mantle were found...

Atlantic chub mackerel is a pelagic species present in the Atlantic Ocean that in recent decades has expanded northwards in the eastern Atlantic. Fish samples were collected in scientific surveys and commercial catches between 2011 and 2019. We analysed the geographical variation of the biological parameters (age, length, weight and condition), as...

While data from life history traits do not show conclusive results, the two morphometric techniques (body shape-truss network and otolith shape) show more reliable information for stock identification. Following these techniques, two independent stocks of P. caeruleostictus can be distinguished for Guinea-Bissau and Guinea. A more in-depth analysis...

Length-weight relationships (LWR) were determined for Brotula barbata, Dentex angolensis, Dentex macrophthalmus, Neomerinthe folgori and Scorpaena stephanica using individual fish records collected between July 2002 and January 2003, during a pilot project of experimental fishing over the shelf off Guinea Bissau. Fishes were caught by commercial ve...

Small-scale fisheries in Canary Islands is made by small boats with passive fishing gears performing polyvalenceand with multiple aim species, with local landing and selling of the catches, with great socio-economic and cultura limportance at the local scale and with a fishers behavior highly influenced by the search of the economic viability of th...

Based on the previous work from WKARHOM3 (ICES, 2018), the Working Group on Biological Parameters (ICES, 2020) identified the need for a new otolith exchange followed by an age reading Workshop. The Workshop on Age reading of Horse Mackerel, Mediterranean Horse Mackerel and Blue Jack Mackerel (Trachurus trachurus, T. mediterraneus and T. picturatus...

Anisakidae is a nematode family known as a danger for human health causing different stomach diseases (anisakidosis) and allergic reactions by the ingestion of L3 larvae stage individuals present in untreated raw (non-frozen) or undercooked marine fish, e.g.: anchovies marinated in vinegar, sushi. Anisakids presents a wide distribution and involves...

WGCEPH worked on six Terms of Reference. These involved reporting on the status of stocks; reviewing advances in stock identification, assessment for fisheries management and for the Marine Strategy Framework Directive (MSFD), including some exploratory stock assessments; reviewing impacts of human activities on cephalopods; developing identificati...

Mercury is a very dangerous toxic metal that bioaccumulates very easily in organisms, and it migrates through the food web. The specimens studied in this study were Scomber colias. In the results obtained for the years 1973, 1992, and 2021, the concentration of mercury has been decreasing considerably over the decades, starting with 0.23 ± 0.04 mg/...

The small pelagic fish (SPF, i.e. Scomber colias, Trachurus spp, Sardina pilchardus and Sardinella spp) in the Canary Islands archipelago (Spain) are mainly targeted by artisanal purse-seiners, whose monitoring is included in the EU Data Collection Framework. The waters in the archipelago (located in the coastal transition zone of the Canary Curren...

Small pelagic fish (SPF) present relatively short life cycles, with fast growth, high mobility and plankton-base feeding. Therefore, they are highly sensitive to fluctuations in environmental conditions, including those related to Climate Change, and fishing. On the one hand, reproductive traits have been recently described for all these species in...

In the last decade there has been a growing interest in the Atlantic chub mackerel, Scomber colias, due to a noticeable expansion of this species in the East Atlantic Ocean from areas of greater abundance off northwest Africa to Atlantic Iberian waters and the Mediterranean Sea (ICES, 2021). To implement sustainable management measures in the curre...

Small pelagic fish in the Canary Islands (CE Atlantic, from 29°27'N to 27°37'N and from 18°12'W to 13°17’W) are mainly targeted by artisanal purse-seiners, whose activity is monitored by the Canary Oceanographic Centre (IEO-CSIC) in the Data Collection Framework since 2013. The Atlantic chub mackerel (Scomber colias) is the main of the four species...

Small pelagic fish in the Canary Islands (CE Atlantic, from 29°27'N to 27°37'N and from 18°12'W to 13°17’W) are mainly targeted by artisanal purse-seiners, whose activity is monitored by the Canary Oceanographic Centre (IEO-CSIC) in the Data Collection Framework since 2013. The Atlantic chub mackerel (Scomber colias) is the main of the four species...

The present study aims to investigate the reproductive biology of the small pelagic Sardinella aurita Valenciennes, 1847 in the Canary Islands, to enable its reliable assessment and advise on appropriate management measures for a fishing resource showing a declining trend in landings. Reproductive biology and sexual patterns of round sardinella wer...

The European sardine ( Sardina pilchardus , Walbaum 1792) is indisputably a commercially important species. Previous studies using uneven sampling or a limited number of makers have presented sometimes conflicting evidence for the genetic structure of S. pilchardus populations. Here we show that whole genome data from 108 individuals from 16 sampli...

Abstract: In waters off The Canary Islands, small pelagic fish are targeted by an artisanal purse seine fleet. This fishery has been monitored within the EU Data Collection Framework since 2013. The status assessment of the most important commercial species (i.e. Scomber colias, Trachurus spp, Sardinella spp and Sardina pilchardus) are included in...

Abstract: In the Canary Islands, the small-scale fleet performs daily fishing trips, being the small pelagic species usually caught with purse-seines. In 2017, a monthly programme of scientific observations was launched to characterize the catches of the artisanal purse-seine fleet, whose discards were considered irrelevant. Here we present a summa...

The Canary Islands Artisanal Fisheries are composed by around 750 units (source: Gobierno de Canarias) with a mean age of 42 years old. The fleet is also of small size in general terms (80% of vessels are smaller than 10 m in length), and targets more than one hundred different species with fishery interest. First Sale Spots (FSS) of The Canary Isl...

Abstract: The Atlantic chub mackerel (Scomber colias) is one of the main fishing resources for the fisheries targeting small pelagics in NW African waters. This species is expanding its geographical distribution through higher latitudes in southern European Atlantic waters, and it has become an important fishing resource in Iberian Atlantic waters...

Whole genome sequence data is an ideal tool for characterizing processes in ecology and evolution. New population genomics data analysis pipelines based on genotype likelihoods allow for a significant reduction in cost by efficiently extracting information from low coverage sequence data. We demonstrate the robustness of such approaches with a geno...

Length-weight relationships (LWR) of twelve fish species collected by fish pots (half an inch mesh size), bottom horizontal longlines (hook size 3/0) and set gillnets (80 mm mesh size) from two Marine Protected Areas in the Canary Islands were determined using individual fish records collected at least once a year during ten scientific surveys betw...

Figure 1 of the paper 'Taxonomic Diversity Hidden Inside the Mantle of Octopus vulgaris: Valuable Source of Information', with high resolution

Entre 2013 y 2019 se realizaron muestreos biológicos mensuales de las principales especies capturadas por la flota artesanal de cerco en las Islas Canarias, que incluyen la caballa (Scomber colias), el chicharro (Trachurus picturatus), la sardina de ley (Sardina pilchardus) y la alacha (Sardinella aurita). Excepto para la alacha (que se reproduce d...

Studies of the content of heavy metals and trace elements in fish and other marine organisms are of great importance to know the state of the marine ecosystem. This study has been carried out in northwestern African waters, Scomber colias being the target species, sampling a total of 345 specimens over 2 years. For the determination of metals and t...

Toxic metal and trace element levels in the ocean are increasing heterogeneously in the world, which is why it is important to assess their concentrations in organisms of fishing interest. The study of metal concentrations in different fishing grounds is of vital importance for nutritional control. In this study, two fishing grounds have been studi...

The Atlantic chub mackerel Scomber colias has become an increasingly important commercial species in the European Atlantic waters in the last 10–15 years, probably through an expansion process from NW African waters and due to market needs. However, at present there are no assessment or advice requirements. In the WK framework, available informatio...

Working document included in: ICES. 2021. Second Workshop on Atlantic chub mackerel (Scomber colias) (WKCOLIAS2). ICES Scientific Reports. 3:18. https://doi.org/10.17895/ices.pub.8142 pp. 179-190

The otolith, found in both inner ears of bony fish, has mainly been used to estimate fish age. Another application that has been developing significantly in recent years, however, is the use of otolith shape as a tool for stock identification. Often, studies have directly used the shape asymmetry between the right and left otoliths. We tested the m...

Whole genome sequence data is an ideal tool for characterizing processes in ecology and evolution. Despite the lowering in sequencing costs, it can be challenging to produce a genome and high-coverage resequencing data for a non-model species. New population genomics data analysis pipelines based on genotype likelihoods allow for a significant redu...

Marine organisms are exposed to great changes caused by man due to discharges into the oceans, so the study of marine pollution is of great value for each ecosystem. For this study, 963 specimens of pelagic fish have been collected, of which 345 are Scomber colias, 294 are Trachurus picturatus and 324 are Sardina pilchardus, it was wanted to study...

Marine fishes are exposed to great human-induced alterations due to the indiscriminate discharges into the sea, increasing marine pollution. For this study, 324 specimens of Sardina pilchardus from the Canary Islands were analized during a period of 2 years (June 2016 to May 2018). The concentration of 11 metals and trace elements (Al, B, Cd, Cr, C...

Marine organisms are exposed to great changes induced by human beings due, among others, to discharges into the oceans, increasing marine pollution. For this study, 294 specimens of Trachurus picturatus from the Canary Islands were analyzed during a period of 2 years. The concentration of 11 anthropic metals and trace elements was determined in eac...

This manual was developed within the framework of the project “Study on improvement for the analysis and exploitation of observer reports in EU fisheries from NW African waters”, Specific Contract No 12 in the Framework Contract EASME / EMFF / 2016/008, and consolidated by all the institutions involved in the “Workshop on the standardization of obs...

All marine organisms bio-accumulate metals and trace elements in a different way, and there are great differences depending on the level of taxonomic classes. A total of 660 samples of 22 species of different taxonomic class types have been used for this study, all samples were measured with atomic emission spectrometry with inductively coupled pla...

This work presents the analysis of 20 heavy metals concentrations (Al, Pb, Sr, V and Zn) in 80 muscle samples of two species widely consumed by humans, such as the European sardine (Sardina pilchardus) and the blue jack mackerel (Trachurus picturatus). Both species have similar metal concentrations, with significant differences in Ba, Ca, Ni, Pb an...

Otolith’s shape analysis has demonstrated to be a reliable and low-cost tool for fish stock identification. The blue jack mackerel, Trachurus picturatus, is a benthopelagic species occurring in the eastern Atlantic from the Bay of Biscay to Mauritania (including Azores, Madeira and the Canary Islands), and the Mediterranean Sea. In the Canary Islan...

The marine organisms are exposed to great human-induced alterations due to the indiscriminate discharges into the sea, which is why the study of marine pollution is of great value for each ecosystem. Each organism bioaccumulates distantly the heavy metals and trace elements in its organism. Because of this it is possible to classify different group...

The main small pelagic fish species targeted by fishers in the Canary Islands are, in order of importance in landings: the Atlantic chub mackerel Scomber colias, horse mackerels Trachurus spp, the European pilchard Sardina pilchardus and sardinella Sardinella spp. In this study we evaluate seasonal relationships between selected oceanographic varia...

Otolith shape analysis is an efficient fish stock identification tool. However, most applications used left and right otoliths or only one of them arbitrarily chosen without testing for biases resulting from potential directional bilateral asymmetry (DA) in otolith shape, i.e., a unimodal population-level deviation form bilateral symmetry between r...

Status assessment of exploited fish populations is a general requirement to ensure sustainability of fisheries in both global and local contexts. The blue jack mackerel Trachurus picturatus (Bowdich, 1825) remains unassessed in a data-limited fishery in the eastern central Atlantic, within the waters of the Canary Islands (Spain) off the coast of n...

Description and trends of cephalopod catches in SSF of the Canary Islands. The study was performed under requirements of the WP4 of INTERREG Project CEPHS & CHEFS (https://www.cephsandchefs.com)

The present contribution shows the result of the last two years collaboration between the Asociación Canaria de Pescadores Submarinos Responsables (ACPESUR) and the Spanish Institute of Oceanography (SIO) to depict the catches of the spear fishing taking place at Canary Islands. SIO staff has sampled the catches of approximately fifteen competition...

The present study aims to estimate the age and the growth of Brachydeuterus auritus, off Togo waters, in order to stock assessment. The otoliths were extracted from commercial landings by Togolese marine fisheries and analyzed in the Spanish Institute of Oceanography laboratories in Tenerife. The results showed that Total Length of the fish (TL) is...

Age, growth and natural mortality were analyzed for Atlantic chub mackerel Scomber colias Gmelin 1789, collected from commercial landings from Mauritanian waters between 2005 and 2011. A total of 4599 specimens were sampled, ranging from 12.4 cm to 49.0 cm of total length. Length-weight relationships showed statistically significant differences bet...

Description of the SSF of demersal resources in Canary islands. DEMERSAL STOCKS FISHED BY THE ARTISANAL FLEET IN CANARY ISLANDS

The main targeted species by the artisanal purse-seine fishery in the Canary Islands (NE Atlantic), by landing volume, are: Atlantic chub mackerel Scomber colias, Sardinellas (mainly Sardinella aurita), Jack mackerels (mainly Trachurus picturatus) and European pilchard Sardina pilchardus. This study aims to attempt to evaluate seasonal relations be...

The long-term monitoring of small-scale fisheries (SSFs) is essential for the assessment and sustainable management of marine resources in the Canary Islands, where fisheries are mostly artisanal. Here, marine ecosystems are very sensitive to imbalances, with oligotrophic waters and a mixing of temperate, tropical and subtropical species. The SSF t...

The Small-Scale Fisheries (SSF) in the Canary Islands are not an exception. They have been traditionally under-studied and not enough historical statistics are available. Therefore, most of the exploited resources remain unassessed. After tunas, the small pelagic fish (targeted by artisanal purse-seiners) are the most captured group in the area. Th...

The blue jack mackerel 'Trachurus picturatus' (Bowdich, 1825) is an important fishery resource in the Canary Islands. However, scientific studies on this population are scarce and it is not possible to apply conventional models to assess its exploitation status. Firstly, we addressed the study of the artisanal purse-seine fishery as the main anthro...

The ICES Planning Group on Commercial Catch, Discards and Biological Sampling (PGCCDBS) identified the need of the Horse Mackerel, Mediterranean Horse Mackerel and Blue Jack Mackerel (Trachurus trachurus, T. mediterreaneus and T. picturatus) otolith exchange to take place in 2015. It was the forth exchange. The IFREMER institute and the COISPA Tecn...

From January 2010 to September 2011, a total of 4044 Octopus vulgaris (2554 males and 1490 females) caught in Mauritanian waters were analyzed, and some biological aspects were addressed based on data from commercial catches. Dorsal Mantle Length (DML) – Body Weight (BW) relationship was obtained (BW=0.36·DML3.05; R2=0.86). Males outnumbered female...

First approach to the growth of Trachurus picturatus (Bowdich, 1825) from the Canary Islands (Spain)

eighteen Spanish freezing trawlers targeted to cephalopods (which operated in Mauritanian waters showed at map) kept weekly samples of selected octopuses. Every specimen was labeled individually with the catch date, and conserved frozen. A total of 4044 defrosted octopuses (2554 males and 1490 females) were analyzed. Photo by A.L. Godar Moreira Eve...

Age estimation of the cephalopod Octopus vulgaris by using beaks has improved in recent years, but maximum age and longevity in the wild have not been confirmed due to the low availability of senescent wild octopuses. In this study, a beak analysis of lateral wall surfaces (LWS) from 20 spent specimens confirmed the 1-year lifecycle of the species...

The reproductive cycle of the blue jack mackerel, Trachurus picturatus, had not been described for the Canary Islands. Between March 2005 and March 2006 monthly samples of T. picturatus were collected randomly at the central fishery wharf from the commercial catches of purse-seiners in Tenerife Island waters (Canary Islands). Some 2472 specimens we...

Beaks have been used for ageing cephalopods, mainly in octopods where statoliths are not suitable for ageing. Recently it has been validated the daily deposition of beak increments in Octopus vulgaris (Cuvier, 1797) both, in the internal lateral wall surfaces (LWS) (Canali et al., 2011; Perales-Raya et al., under review) and also in the rostrum sag...

The 30% of the catches off Mauritanian waters carried obtained by the European industrial pelagic freezer trawl fleet are landed in a Spanish port (Las Palmas de Gran Canaria, Canary Islands). The activity of this fleet is targeted to catch small pelagic species such as sardine (Sardina pilchardus (Walbaum, 1792)), round and flat sardinella (Sardin...

El 30% de la captura realizada en aguas de Mauritania por la Flota Industrial Europea de arrastre pelágico se descarga en puerto español (Las Palmas de Gran Canaria, Islas Canarias). La actividad de estos barcos está orientada a los peces pequeños pelágicos, principalmente a sardina (Sardina pilchardus (Walbaum, 1792)), alacha (Sardinella aurita Va...

European fishery off Mauritania (one of the most productive and most intensively exploited regions in the world) targeted to small pelagic fish accounts for 30% of the total catches in the area. The Instituto Español de Oceanografía (IEO), through its Centro Oceanográfico de Canarias, follows up the activity of these vessels that land at Spanish po...

Jurado-Ruzafa, A. & M.T.G. Santamaría. 2011. Notes on the recruitment of the blue jack mackerel Trachurus picturatus (Bowdich, 1825) off the Canary Islands (Carangidae, Perciformes). VIERAEA 39: 219-224.

La pesquería de peces pequeños pelágicos en aguas de Mauritania por parte de la Flota Industrial Europea de arrastre pelágico está dirigida a la captura de sardina (Sardina pilchardus (Walbaum, 1792)), alacha (Sardinella aurita Valenciennes, 1847), machuelo (Sardinella maderensis (Lowe, 1838)), caballa (Scomber colias Gmelin, 1789) y jureles (Trach...

Poster

Since 1963 the Spanish cephalopod-targeted trawl fishery has been developed in the Saharan Bank. This fishery is carried out by freezer trawlers using bottom trawl gear. This fleet operates under Community licences in Guinea Bissau and Mauritanian waters, and lands at the port of Las Palmas de Gran Canaria (Canary Islands). Since the mid-70’s resea...

Reproductive cycle and related biological parameters of Trachurus picturatus from the Canary Islands (NE Atlantic, Spain)

La Reserva Marina de Punta de La Restinga – Mar de Las Calmas, creada en 1996 como zona de protección de interés pesquero con el fin principal de apoyar a los pescadores profesionales de bajura para mantener su actividad y forma de vida, consta de tres niveles de protección diferentes: la reserva integral (máxima protección), las zonas de usos rest...