Oceanographic Center of Canarias

Reinold S., Herrera A., Saliu F., Hernández-González C., Martinez I., Lasagni M., Gómez M.

The presence of microplastics (MPs) in the marine environment is a concerning topic due to the ecotoxicological effects and possible seafood contamination. Data is needed to evaluate human exposure and assess risks, in the context of a healthy and beneficial seafood consumption. While microplastic ingestion by wild fish has been reported since the early 70‘s, farmed fish are rarely investigated. Here, for the first time the presence of microplastics in fish cultivated in the coastal water of Tenerife (Canary Island, Spain) was evaluated. From 83 examined individuals, 65% displayed microplastics in their gastrointestinal tracts, with averages between 0.6 ± 0.8 (SD) and 2.7 ± 1.85 (SD) particles per fish. The total number of microplastics detected was 119. Fibres (81%) and fragments (12%) were the predominant shapes. FTIR analysis showed that fibres were mostly composed by Cellulose (55%) and Nylon (27%), whereas fragments by PE (25%) and PP (25%).

Pita P., Ainsworth G.B., Alba B., Anderson A.B., Antelo M., Alós J., Artetxe I., Baudrier J., Castro J.J., Chicharro B., Erzini K., Ferter K., Freitas M., García-de-la-Fuente L., García-Charton J.A., et. al.

This work is the result of an international research effort to determine the main impacts of the COVID-19 pandemic on marine recreational fishing. Changes were assessed on (1) access to fishing, derived from lockdowns and other mobility restrictions; (2) ecosystems, because of alterations in fishing intensity and human presence; (3) the blue economy, derived from alterations in the investments and expenses of the fishers; and (4) society, in relation to variations in fishers’ health and well-being. For this, a consultation with experts from 16 countries was carried out, as well as an international online survey aimed at recreational fishers, that included specific questions designed to capture fishers’ heterogeneity in relation to behavior, skills and know-how, and vital involvement. Fishers’ participation in the online survey (5,998 recreational fishers in 15 countries) was promoted through a marketing campaign. The sensitivity of the fishers’ clustering procedure, based on the captured heterogeneity, was evaluated by SIMPER analysis and by generalized linear models. Results from the expert consultation highlighted a worldwide reduction in marine recreational fishing activity. Lower human-driven pressures are expected to generate some benefits for marine ecosystems. However, experts also identified high negative impacts on the blue economy, as well as on fisher health and well-being because of the loss of recreational fishing opportunities. Most (98%) of the fishers who participated in the online survey were identified as advanced, showing a much higher degree of commitment to recreational fishing than basic fishers (2%). Advanced fishers were, in general, more pessimistic about the impacts of COVID-19, reporting higher reductions in physical activity and fish consumption, as well as poorer quality of night rest, foul mood, and raised more concerns about their health status. Controlled and safe access to marine recreational fisheries during pandemics would provide benefits to the health and well-being of people and reduce negative socioeconomic impacts, especially for vulnerable social groups.

Vega-Moreno D., Abaroa-Pérez B., Rein-Loring P.D., Presas-Navarro C., Fraile-Nuez E., Machín F.

Nowadays it is widely known that pollution by microplastics (MP) at the open ocean covers immense areas. Buoyant plastics tend to accumulate in areas of convergence at the sea surface such as subtropical gyres, while non-buoyant plastics accumulate at the seafloor. However, previous studies have revealed that the total amount of plastic in the different oceans is not well correlated with the concentrations measured at the sea surface and the sea floor, evidencing a significant amount of missing plastic in the oceans. This deviation could be related to an underestimation of the role played by small fragments of plastic and fibers in the oceans. Furthermore, microplastic fragments with a density lower than the density of seawater have been gathered hundreds of meters below the sea surface in the Pacific Ocean due to their size and shape. The main objective of this study is to carry out, for the first time, an equivalent analysis along the water column for the Atlantic Ocean. In that sense, a total number of 51 samples were collected during four different oceanographic cruises between February and December 2019, from the sea surface down to 1150 m depth at the open ocean waters of the Canary Islands region (Spain). For each sample, 72 l of seawater were filtered on board with a mesh size of 100 μm, where the presence of microplastics has been clearly observed. Our results reveal the presence of microplastics at least up to 1150 m depth, at the Northeastern Atlantic Subtropical Gyre with noticeable seasonal differences. The spatial distribution of these small fragments and fibers at the water column is mainly related to the oceanic dynamics and mesoscale convective flows, overcoming the MP motion induced by their own buoyancy. Moreover, these microplastics have being transported by the ocean dynamics as passive drifters. • Microplastic (MP) present at the water column until at least 1150 m depth • MP transported by oceanic dynamic as passive drifters horizontally and vertically • MP distribution related with convergence areas and mesoscale convective flows • Differences at MP vertical distribution according to season and latitude

Mercado J.M., Cortés D., Gómez-Jakobsen F., García-Gómez C., Ouaissa S., Yebra L., Ferrera I., Valcárcel-Pérez N., López M., García-Muñoz R., Ramos A., Bernardeau J., Belando M.D., Fraile-Nuez E., Ruíz J.M.

Monthly samplings carried out in 2016-2019 and satellite color images from 2002 to 2019 have been combined to determine the onset and causative species of the ecosystem disruptive algal bloom (EDAB) that affects the Mar Menor coastal lagoon (Western Mediterranean Sea) since 2015. Substantial changes in satellite spectral reflectance attributable to increasing abundance of Synechococcus were registered in 2014. Furthermore, cell abundances of this species in 2016 were the largest ever obtained in the lagoon (6 106 cells mL-1), with values similar to those reported for other Mediterranean hypertrophic estuaries and coastal lagoons. These results suggest that the early changes leading to the EDAB started in 2014 and that Synechococcus played a relevant role in its development. Moreover, diatom and dinoflagellate abundances changed substantially in 2016-2019, ranging from 102 to more than 104 cells mL-1. Some of these changes were linked to flood, suggesting that EDAB has modified substantially the homeostatic capacity of the lagoon.

Siemer J.P., Machín F., González‐Vega A., Arrieta J.M., Gutiérrez‐Guerra M.A., Pérez‐Hernández M.D., Vélez‐Belchí P., Hernández‐Guerra A., Fraile‐Nuez E.

The global upper ocean has been warming during the last decades accompanied with a chlorophyll-a (Chl-a) and productivity decrease. Whereas subtropical gyres show similar trends, Eastern Boundary Upwelling Systems are thought to increase in productivity due to increased trade winds. This study analyzes recent trends in sea surface temperature (SST), Chl-a, net primary production (NPP) and meridional wind stress in the Eastern North Atlantic subtropical gyre (NASE) in order to examine if the global trends can be detected in open ocean and upwelling areas and how the ocean biota responds. Satellite data of such variables of the last 15–40 years were analyzed to calculate mean trends in upwelling areas in the Canary upwelling system and open ocean areas around the Azores, Madeira and the Canary Islands. Our results show significant warming in the area with a maximum of 2.7°C per century for the Azores. Moreover, a general decreasing trend for Chl-a and NPP seems to be more evident in the permanent upwelling areas, which will be responsible for a loss of 0.13% of the global NPP per century. Our results also highlight a significant expansion of the oceanic desert area of 10% with an increase in unproductive days of up to 84 days in the last 20 years. The competitive relationship of stratification and wind stress in the Canary upwelling system might be a more plausible explanation for the decrease in Chl-a and NPP in upwelling areas linked to the increase in upwelling favorable wind stress and the surface warming.

Lishchenko F., Perales-Raya C., Barrett C., Oesterwind D., Power A.M., Larivain A., Laptikhovsky V., Karatza A., Badouvas N., Lishchenko A., Pierce G.J.

With the depletion of many commercial fish stocks and an increasing demand for marine protein for human consumption, cephalopods have become more important as a fishery resource. In EU waters, cephalopod stocks are not routinely assessed and exploitation of these species by large-scale fisheries is largely unregulated. For sustainable exploitation, adequate assessment and scientifically-supported management strategies are needed. However, there is still a lack of data on stock status and inadequate knowledge of the life history and ecology of these species. The present review examined more than 200 scientific articles, on life history and ecology of European cephalopods, published since 2013. It describes recent contributions to knowledge in the context of previously identified research priorities, along with recent advances towards sustainable fishing and aquaculture. It also identifies outstanding knowledge gaps. While some priority areas, such as the development of the species identification guides and evaluation of climate change impacts on cephalopods, have seen significant advances, other challenges remain for the future. These include monitoring of the life history traits and fishery status for the main commercially exploited species in the area, implementation of improved species identification methods during scientific surveys and fisheries monitoring, development of tools to identify stock units, and the study of the environmental and anthropogenic impacts on the stocks of cephalopods inhabiting European waters.

Villanova-Solano C., Díaz-Peña F.J., Hernández-Sánchez C., González-Sálamo J., González-Pleiter M., Vega-Moreno D., Fernández-Piñas F., Fraile-Nuez E., Machín F., Hernández-Borges J.

In this work, the microplastic content of sediments collected in July 2020 between 5 and 7 m depth was studied in four locations of La Palma island (Canary Islands, Spain). At each sampling location, three samples were taken parallel to the shoreline. The microplastic content in each sampling corer was studied every 2.5 cm depth after digestion with a H2O2 solution followed by flotation in a saturated NaCl solution. Visualization of the final filtrates under a stereomicroscope revealed that all the sediment samples evaluated contained mostly microfibers (98.3%) which were mainly white/colorless (86.0%) and blue (9.8%), with an average length of 2423 ± 2235 (SD) mm and an average concentration of 2682 ± 827 items per kg of dry weight, being the total number of items found 1,019. Fourier Transform Infrared microscopy analysis of 13.9% (n = 139) of the microfibers also showed that they were mainly cellulosic (81.3%). No significant differences were found between the depths of the sediment. However, significant differences were found between the number of fibers from the sampling sites at the east and west of the island. Such variability could be driven by the winds and ocean mesoscale dynamics in the area. This study confirms the wide distribution of microfibers in sediments from an oceanic island like La Palma, providing their first report in marine sediments of the Canary Islands.

Png-Gonzalez L., Comas-González R., Calvo-Manazza M., Follana-Berná G., Ballesteros E., Díaz-Tapia P., Falcón J.M., García Raso J.E., Gofas S., González-Porto M., López E., Ramos-Esplá A.A., Velasco E., Carbonell A.

The introduction of new non-indigenous species (NIS) in Spanish marine waters is addressed under Descriptor 2 of the European Union’s Marine Strategy Framework Directive. National baseline inventories of NIS have been compiled and updated for the three subregions (Western Mediterranean Sea, WMED; Bay of Biscay–Iberian Coast, ABI; Macaronesia, AMA) with data from 1800 to 2021. An overall of 574 species were identified with an alien, cryptogenic, crypto-expanding, or debatable status, mostly invertebrates (~65%) and primary producers (~22%). Of 412 alien species, 80.51% were reported in ABI, 67.82% in WMED, and 66.67% in AMA. Cryptogenic species are more abundant in the WMED (25.25%), compared to AMA (19.77%) and ABI (18.46%). ABI harbors more established species (62.56%) than AMA (45.2%) and WMED (43.56%), contrary to casual records (AMA 31.64%, WMED 23.76%, ABI 13.85%). Invasive species are more abundant (14.36%) in WMED. The ‘transport-stowaway’ pathway accounted for 142 (79.33%), 123 (67.58%), and 169 (85.21%) records in WMED, ABI, and AMA, respectively. The second most common pathway was ‘transport-contaminant’ related to mariculture (~10% of the total), prevalently in ABI with 42 species (23.08%). The Canary Islands stand out for species introduced through oil platforms from throughout the world. ‘Unaided’ was a relevant pathway of secondary introduction into the WMED, particularly of Lessepsian species progressing westwards. Temporal trends in newly introduced species show similar behavior among subregions.

Lozano-Bilbao E., Jurado-Ruzafa A., Lozano G., Jiménez S., Hardisson A., Rubio C., Weller D.G., Paz S., Gutiérrez Á.J.

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 the development and ontogeny in the three species observing if there were variations in their metallic content. The study covered a total of 2 years, from June 2016 to May 2018.16 samples of each species were studied each month, during the 2 years of sampling, from the samplings carried out by the Canary Islands Oceanographic Center of the Spanish Institute Oceanography (COC-IEO) in the markets of the Island of Tenerife. The concentration of 11 anthropic metals was determined in each sample using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) technique. Statistical studies were carried out with factors such as the oceanographic season, and the level of maturity of the gonads. S. colias was the species that presented the highest concentration in a greater number of metals. S. pilchardus presents higher concentration in Cu, Li and Zn, in the warm season. These are metals of a very anthropic character on coasts; This species tends to get closer to the coasts compared to the other two and is the cause of its higher concentration in these metals due to the influence of pollution linked to the coast. The immature specimens of the three species had a higher concentration in more metals than the mature specimens.

Lozano-Bilbao E., Lozano G., Jiménez S., Jurado-Ruzafa A., Hardisson A., Rubio C., Weller D., Paz S., Gutiérrez Á.J.

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, Cu, Fe, Li, Ni, Pb, V and Zn) was determined in each individual using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) technique. Statistical analyses were carried out considering the following factors: oceanographic season, maturity of the gonads in the seasons, size of the specimens. Sardina pilchardus specimens captured in the hot season presented higher Ni, Li and Pb levels than the specimens caught in the cold season. Immature specimens had higher concentration in more metals than the mature specimens. This fact may be due to the fact that these specimens require a much higher metabolic rate due to their growth and do not detoxify like mature specimens. Significant differences were found in the concentration of metals in all the analyzes performed.