European Atlantic Ocean Research Articles

Assessing the effect of onshore and offshore Wave Energy Converters on seafloor integrity combining image-based and acoustic methods

The European Atlantic Ocean offers great opportunities for the development of projects for renewable energy extraction, and the Marine Renewable Energy sector is developing different technologies for energy converters, including Wave Energy Converters. Besides, the European Commission is adopting measures and politics to increase the installed capacity of ocean energy. However, there are still uncertainties on the potential environmental effects of wave energy converters, which led regulators and stakeholders to perceive their operation as a risky activity. To overcome the non-technological barriers that could hinder the development of marine renewable energies, and improve the knowledge on the impacts on the seafloor integrity (among others), SafeWAVE project set an Environmental Research Demonstration Strategy based on the collection, processing, modelling, analysis and sharing of environmental data collected in Aguçadoura (Portugal), Armintza (Spain) and Le Croisic (France) representing different types of technology, locations and project scales. Video recordings were carried out, using Remotely Operated Vehicles, to identify the environmental impacts of the moorings on the seafloor morphology. That information was completed by side scan sonar campaigns using an Autonomous Underwater Vehicle. The video recordings were useful also to assess the attraction effect of the moorings to epibenthic invertebrates and fishes, whereas the side scan sonar provided quantitative information on the area affected by physical alteration (<1% of the total area occupied by the devices at Armintza and Le Croisic).

The contribution of the SafeWAVE EU project to the future development of ocean energy

The European Atlantic Ocean offers a high potential for marine renewable energy (MRE), which is targeted to be at least 32% of the EU’s gross final consumption by 2030. The European Commission is supporting the development of the ocean energy sector through an array of activities and policies: the Green Deal, the Energy Union, the Strategic Energy Technology Plan (SET-Plan) and the Sustainable Blue Economy Strategy. The nascent status of the MRE sector and Wave Energy (WE) in particular, yields many unknowns about its potential environmental pressures and impacts. Wave Energy Converters’ (WECs) operation in the marine environment is still perceived by regulators and stakeholders as a risky activity. The complexity of MRE licensing processes is also indicated as one of the main barriers to the development of the sector. The lack of clarity of procedures, the varied number of authorities to be consulted and the early stage of Marine Spatial Planning (MSP) implementation are examples of the issues identified that may delay the permitting of the projects. Finally, there is also a need to provide more information on the sector to the general public. Only with an informed society would be possible to carry out fruitful public debates on MRE implementation at the local level. These non-technological barriers that could hinder the future development of WE in EU were addressed by the WESE project funded by EMFF in 2018. The present project builds on the results of the WESE project and aims to move forward through the following specific objectives:
 
 Development of an Environmental Research Demonstration Strategy based on the collection, processing, modelling, analysis and sharing of environmental data collected in WE sites from different European countries where WECs are currently operating (Mutriku power plant and BIMEP in Spain, Aguçadoura in Portugal and SEMREV in France).
 Development of a Consenting and Planning Strategy through providing guidance to ocean energy developers and to public authorities tasked with consenting and licensing of WE projects in France and Ireland; this strategy will build on country-specific licensing guidance and on the application of the MSP decision support tools (i.e. WEC-ERA[1] and VAPEM[2] tools) developed for Spain and Portugal in the framework of the WESE project; the results will complete guidance to ocean energy developers and public authorities for most of the EU countries in the Atlantic Arch.
 Development of a Public Education and Engagement Strategy to work collaboratively with coastal communities in France, Ireland, Portugal and Spain, to co-develop and demonstrate a framework for education and public engagement (EPE) of MRE enhancing ocean literacy and improving the quality of public debates.
 
 The project will finish in September 2023. In this contribution we present the main outcomes, results and lessons learnt during the project.
 [1] https://aztidata.es/wec-era/;
 [2] https://aztidata.es/vapem/

Trophic shift in young‐of‐the‐year Mugilidae during salt‐marsh colonization

This study investigated the trophic shift of young-of-the-year (YOY) thinlip grey mullet Liza ramada and golden grey mullet Liza aurata during their recruitment in a salt marsh located on the European Atlantic Ocean coast. Stable-isotope signatures (δ(13) C and δ(15) N) of the fishes followed a pattern, having enrichments in (13) C and (15) N with increasing fork length (LF ): δ(13) C in fishes < 30 mm ranged from -19.5 to -15.0‰, whereas in fishes > 30 mm δ(13) C ranged from -15.8 to -12.7‰, closer to the level in salt-marsh food resources. Large differences between the δ(15) N values of mugilids and those of food sources (6·0‰ on average) showed that YOY are secondary consumers, similar to older individuals, when feeding in the salt marsh. YOY mugilids shift from browsing on pelagic prey to grazing on benthic resources from the salt marsh before reaching 30 mm LF. The results highlight the role of European salt marshes as nurseries for juvenile mugilids.

Seasonal autoregressive modeling of a skew storm surge series

Autoregressive (AR) models have been widely used in several geophysical applications, as they represent a simple and practical option for modeling stochastic series. In this paper, we show that AR models can be adapted and are useful for the description of skew surge (i.e., a surge occurring at the time of a high tide) series. Namely, seasonal AR models of skew surge series are built on 35 sites located along the coasts of the European Atlantic Ocean, the English Channel and the Southern part of the North Sea. These models are presented and discussed. The estimation of the distribution of the residuals, modeled using a Normal Inverse Gaussian (NIG) distribution, is also discussed. AR models are advantageous for a number of reasons: (i) they provide information on the correlation length of the surge phenomena, (ii) they can be used to forecast short-term surge occurrences based on a limited set of past observations and (iii) they provide plausible information about longer series, which may have larger extremes than what is observed, permitting a statistical description of simulated extremes. These three characteristics and benefits are examined and discussed for a selected site, the Saint-Nazaire harbor (France), with respect to the storm surge that occurred during the Xynthia storm of February 2010.

Colonisation of fish and crabs of wave energy foundations and the effects of manufactured holes – A field experiment

Several Western European countries are planning for a significant development of offshore renewable energy along the European Atlantic Ocean coast, including many thousands of wave energy devices and wind turbines. There is an increasing interest in articulating the added values of the creation of artificial hard bottom habitats through the construction of offshore renewable energy devices, for the benefit of fisheries management and conservation. The Lysekil Project is a test park for wave power located about 100 km north of Gothenburg at the Swedish west coast. A wave energy device consists of a linear wave power generator attached to a foundation on the seabed, and connected by a wire to a buoy at the surface. Our field experiment examined the function of wave energy foundations as artificial reefs. In addition, potentials for enhancing the abundance of associated fish and crustaceans through manufactured holes of the foundations were also investigated. Assemblages of mobile organisms were examined by visual censuses in July and August 2007, 3 months after deployment of the foundations. Results generally show low densities of mobile organisms, but a significantly higher abundance of fish and crabs on the foundations compared to surrounding soft bottoms. Further, while fish numbers were not influenced by increased habitat complexity (holes), it had a significantly positive effect on quantities of edible crab ( Cancer pagurus) , on average leading to an almost five-fold increase in densities of this species. Densities of spiny starfish ( Marthasterias glacialis) were negatively affected by the presence of holes, potentially due to increased predator abundance (e.g. C. pagurus). These results suggest a species-specific response to enhanced habitat complexity.

Distinctive morphological features, life-cycle phases and seasonal variations in subtropical populations of Dictyota dichotoma (Dictyotales, Phaeophyceae)

Abstract Although it has been suggested that the distribution of Dictyota dichotoma is probably restricted to the European Atlantic Ocean and the Mediterranean Sea, its occurrence in the Canary Islands (new southernmost distribution limit) is confirmed by nuclear ribosomal sequence data (LSU rDNA). Even though D. dichotoma has been described and illustrated prominently in early studies of brown algae, the species remains difficult to characterize due to considerable morphological plasticity. An exhaustive analysis of several quantitative characters confirms significant morphological variation both seasonally and between life-cycle phases. The species may be characterized in the Canary Islands only by the following qualitative features: erect thallus attached by a single holdfast, subdichotomous branches always of similar width, straight terminal segments and smooth margins and an entirely unilayered medulla. In the Canary Islands, D. dichotoma is an aseasonal annual with at least three overlapping generations in which sporophytes and gametophytes grow simultaneously. Thallus life span seems to be less than 3 months. The species occurs throughout the year, but as cryptic microthalli in autumn. Two abundance peaks were detected with the maximum value in February (6.2 thalli m-2). The optimum reproductive stage (88.3% fertile specimens) occurred in winter and the maximum vegetative stage (maximum thallus length: 18.6 cm) in summer. Sporophytes outnumbered gametophytes throughout the year, with ratios decreasing from 13.2±1.1 in winter to 1.9±0.2 in summer. Gametophytes made up to 25% of the population and fertile thalli were always dominant. The populations from the Canaries exhibited a temporal displacement compared to northern populations with the favorable period in the coldest season (winter) and the resting period in the warmest season (autumn).

Aphanocladia ecorticata nov. sp. (Rhodophyta, Rhodomelaceae) from the South African south coast

Aphanocladia ecorticata is described as a new species for the South African south coast. Its principal character, distinguishing it from all other species in the genus, is the absence of cortication. In addition, it is of smaller size, especially the maximum diameters of the main axes. There are now six described species of Aphanocladia , and two more taxa in the literature which appear to belong in the genus. Of these, seven occur in regions of the southern hemisphere, and one in the Mediterranean Sea and the adjacent European Atlantic Ocean. This is the first record of the genus in the Indian Ocean.

The dimensional units of Nephrops norvegicus (L.) distribution: from burrows to populations

Biogeographia vol. XXV - 2004 (Printed December, 30 q&#39; 2004) Marine Biogeography of the Mediterranean Sea: patterns and dynamics of biodiversity The dimensional units of N6]?/770105 norvegicus (L.) distribution: from burrows to populations JACOPO AGUZZI*, FRANCESC MAYNOU, JOAN BAPTISTA COMPANY, GUIOMAR ROTLLANT, FRANCESC SARDA Imtitut de Ciemie: del Mar (CS1 C), hzssezg Marz’zim de la Barceloneta 3749, 08003 Barcelona (Spain) *e—mzzz&#39;[: jzzguzzz&#39;@m2z&#39;mLrz. csiaes Key words: Decapoda, Nep/Jrops rzoruegicut, burrows, patches, metapopulation, larvae. SUMMARY Nap/7211,»: noruegimt is a burrowing decapod inhabiting muddy bottoms of the continental shelves and slopes of European Atlantic and the Mediterranean seas. Several aspects concerning N uorvegim: geographical and bathyrnetric distribution are revised in relation to its biology. Burrows are considered the ultimate small-scale unity of distribution, while patches the intermediate one. Larval migration among patches determines the geographic and bathymetric distribution of populations. Ecologicil factors determining patchiness are considered along with implication for morphology and genetics of populations. Issues for further researches concerning N. narvegimt distribution and commercial exploitation are proposed. INTRODUCTION The biogeographical aspects of Nap/Jrops narvegicm (L.) distribution are intriguing for three main reasons. As a first instance, its distribution range is mainly known due to the commercial fishing fleet and to survey projects of research (see below), which identify the exploitable grounds where density meets commercial criteria required by the fishery. In this sense, for those few areas where the commercial fishery is absent, no conclusion on N norvegicus presence can be drawn. As a second instance, a two—dimensional aspect in the species distribution should be considered: the species occupies a wide geographic range (from the European Atlantic Ocean, down to the Mediterranean including Morocco), and a wide bathymetric range (spanning from the subtidal regions of the upper shelf in the Atlantic and North Sea, to the slopes of the western—central Mediterranean)

Changes in the Euro‐Atlantic fish species composition resulting from fishing and ocean warming

Studies of actual ichtyological biodiversity in the European Atlantic Ocean and estimation of changes in the relative abundance of fish species in catches off Arcachon, on the shelf and in the Bassin d'Arcachon, from 1727 to the present day are made. These show that some previously dominant species are now rare. Several disappeared to the south of the Bay of Biscay, such as the bottom‐living elasmobranchs with low reproduction rates (Echinorhinus brucus, Squatina squatina, Raja batis, R. brachyura, R. clavata, Dasyatis pastinaca, Myliobatis aquila, Galeorhinus galeus, Mustelus asterias), and teleostean fishes Trigla lyra and Eutrigla gurnardus. Overfishing with most fishing gears, but especially bottom trawls is responsible for their reduction. An additional study was made on tropical species which were not recorded before 1950 to the north of Portugal. The species include Zenopsis conchifer, Cyttopsis roseus, Chaunax spp., Sphoeroides pacbygaster. Tarpon atlanticus, Seriola rivoliana, S. dumerili, S. carpenteri, Lichia amia, Pomatomus saltator, Aluterus monoceros, Pisodonophis semicinctus, Lamprogrammus niger. Northward extensions in the distribution in Euro‐Atlantic sea waters of tropical fish are compared with results obtained in other regions of the South French Atlantic continental shelf. Ichthyological observations support previous results: 68.3% of the new records were fished on upper slope (200 to 600 m); 19.5% from the continental shelf (0 to 200 m). Among them, some 66.7% of captures from the south of the Bay of Biscay; 12.2% of the new records were found in the middle slope (900 to 1100 m). These results confirm the following: (1) a northern extension of tropical fishes on the upper slope in the south of Portugal has increased since 1963, and while it began in 1969 on the continental shelf, only increased from 1981; (2) the rate of colonisation of new‐comers was low for several species. About 30 years have passed between the record of Zenopsis conchifer and that of Cyttopsis roseus from off Portugal and northwestern Ireland, but only 5 years in the case of Sphoeroides pacbygaster, and (3) the northward expansion is evident to 52°00'N for continental shelf species, to 55°30'N for upper slope, and to 60°00'N for mid‐slope species.