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Map of North Atlantic area showing dominant ocean currents. Background image ©2010 Google-Imagery ©2010 TerraMetrics, NASA.
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The Scottish Government has ambitious targets for renewable energy production, to which offshore renewables could make a substantial contribution. However, the new marine energy industries must develop on a sustainable basis, ensuring that environmental impacts are assessed, and if necessary, minimised through appropriate mitigation. The likelihood...
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– The purpose of this paper is to quantify the impact of the constraints of the power take-off system (PTO) on the power extraction of a point absorber wave energy converter (WEC). Such constraints include power, torque and maximum stroke limitations. Two different concepts, unidirectional and bidirectional point absorbers, are analysed, wh...
Blue growth must be obtained sustainably in European seas. Offshore oil and gas exploration continues to expand into deeper waters along the NW European shelf edge, and the competition for sea space on the European continental shelf is accelerating. At the same time national resources to monitor anthropogenic environmental impact are reducing. In o...
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Nowadays, the last deployments in wave energy show still an immature level of development, typical of pre-commercial stages. Several devices are being tested under real sea conditions but very few devices are becoming ready for commercialization yet. Reliability assessment on wave energy converters has been identified as one of the most important c...
Citations
... The sea trout 484 originating from rivers in this region are known to make long marine migrations, 485 predominately migrating south along the east English North Sea coast. For instance, many 486 sea trout tagged in the River Tweed have been caught in drift net fisheries along the East 487Anglian coast as well as in Dutch, German and Danish waters(Malcolm et al., 2010). This 488 migration pattern has been confirmed using genetic assignment tests(Bekkevold et al., 489 2021). ...
Populations of anadromous brown trout, also known as sea trout, have suffered recent marked declines in abundance due to multiple factors, including climate change and human activities. While much is known about their freshwater phase, less is known about the species’ marine feeding migrations. This situation is hindering the effective management and conservation of anadromous trout in the marine environment. Using a panel of 95 single nucleotide polymorphism markers we developed a genetic baseline, which demonstrated strong regional structuring of genetic diversity in trout populations around the English Channel and adjacent waters. Extensive baseline testing showed this structuring allowed high-confidence assignment of known-origin individuals to region of origin. This study presents new data on the movements of anadromous trout in the English Channel and southern North Sea. Assignment of anadromous trout sampled from 12 marine and estuarine localities highlighted contrasting results for these areas. The majority of these fisheries are composed predominately of stocks local to the sampling location. However, there were multiple cases of long-distance movements of anadromous trout, with several individuals originating from rivers in northeast England being caught in the English Channel and southern North Sea, in some cases more than 1000 km from their natal region. These results have implications for the management of sea trout in inshore waters around the English Channel and southern North Sea.
... Assessment at population level consequences (displacement, avoidance), direct and indirect effects on wildlife populations and cumulative effects of MREDs need to be developed (Maxwell et al., 2013;Ronconia et al., 2015). Additionally to the studies reporting the MREDs effects on marine mammals and fishes (Knaap et al., 2022;Malcolm et al., 2010;Villegas-Amtmann et al., 2015) it is urgent to develop research dedicated to the impact on benthic and sessile organisms (Mavraki et al., 2020;Solé et al., 2021b), which are unable to escape from the acoustic exposure, in order to further develop models that will contribute to implementing mitigation measures. ...
The installation of marine renewable energy devices (MREDs, wind turbines and converters of wave, tidal and ocean thermal energy) has increased quickly in the last decade. There is a lack of knowledge concerning the effects of MREDs on benthic invertebrates that live in contact with the seabed. The European common cuttlefish (Sepia officinalis) is the most abundant cephalopod in the Northeast Atlantic and one of the three most valuable resources for English Channel fisheries. A project to build an offshore wind farm in the French bay of Saint-Brieuc, near the English Channel, raised concern about the possible acoustic impact on local cuttlefish communities. In this study, consisting of six exposure experiments, three types of noise were considered: 3 levels of pile-driving and 3 levels of drilling. The objectives were to assess possible associated changes in hatching and larva survival, and behavioural and ultrastructural effects on sensory organs of all life stages of S. officinalis populations. After exposure, damage was observed in the statocyst sensory epithelia (hair cell extrusion) in adults compared to controls, and no anti-predator reaction was observed. The exposed larvae showed a decreased survival rate with an increasing received sound level when they were exposed to maximum pile-driving and drilling sound levels (170 dB re 1 μPa² and 167 dB re 1 μPa², respectively). However, sound pressure levels's lower than 163 dB re 1 μPa² were not found to elicit severe damage. Simulating a scenario of immobile organisms, eggs were exposed to a combination of both pile driving and drilling as they would be exposed to all operations without a chance to escape. In this scenario a decrease of hatching success was observed with increasing received sound levels.
... Similar to seabirds, any significant changes in the behavior of fish as a result of avoidance or displacement due to FOWT may lead to increased energy expenditure from, for example increased search time for conspecifics or prey items. This behavior could cause alterations to aggregations, spawning events and migration patterns and may also influence the ecological community structure if species of ecological importance avoid impacted areas altogether (Malcolm et al., 2010). Connections between species in ecological communities can be highly complex and impacts on one species in a community can often impact more than one species. ...
Offshore wind energy is expanding globally and new floating wind turbine technology now allows wind energy developments in areas previously too deep for fixed-platform turbines. Floating offshore wind has the potential to greatly expand our renewable energy portfolio, but with rapid expansion planned globally, concerns exist regarding impacts to marine species and habitats. Floating turbines currently exist in three countries but large-scale and rapid expansion is planned in over a dozen. This technology comes with unique potential ecological impacts. Here, we outline the various floating wind turbine configurations, and consider the potential impacts on marine mammals, seabirds, fishes and benthic ecosystems. We focus on the unique risks floating turbines may pose with respect to: primary and secondary entanglement of marine life in debris ensnared on mooring lines used to stabilize floating turbines or dynamic inter-array cables; behavioral modification and displacement, such as seabird attraction to perching opportunities; turbine and vessel collision; and benthic habitat degradation from turbine infrastructure, for example from scour from anchors and inter-array cables. We highlight mitigation techniques that can be applied by managers or mandated through policy, such as entanglement deterrents or the use of cable and mooring line monitoring technologies to monitor for and reduce entanglement potential, or smart siting to reduce impacts to critical habitats. We recommend turbine configurations that are likely to have the lower ecological impacts, particularly taut or semi-taut mooring configurations, and we recommend studies and technologies still needed that will allow for floating turbines to be applied with limited ecological impacts, for example entanglement monitoring and deterrent technologies. Our review underscores additional research and mitigation techniques are required for floating technology, beyond those needed for pile-driven offshore or inshore turbines, and that understanding and mitigating the unique impacts from this technology is critical to sustainability of marine ecosystems.
... Studies have been carried out on the movements of returning adult salmon in North Sea coastal waters (Hawkins, Urquhart and Shearer, 1979;Smith et al., 1981;Westerberg, 1982, Malcolm et al., 2010, within estuaries (Stasko, 1975;Smith and Hawkins, 1995,) and within rivers (McCleave, Power and Rommel, 1978;Hawkins and Smith 1986). The returning multi-sea-winter adults may arrive at the Scottish coast and enter the estuary of the Dee as early as February and March, and may subsequently be found within the main part of the River Dee throughout the spring, summer and autumn. ...
... The sea stage has been viewed as a feeding migration (Northcote, 1984), with the Atlantic salmon moving into productive marine feeding grounds in the subarctic. There is hardly any information available on the juvenile migratory routes (Malcolm et al., 2010). However, post-smolts of unknown river origin were examined by Shelton et al., (1997), and they migrated northwards off the western coast of Scotland along the continental shelf edge, apparently making use of the dominant ocean currents. ...
The stocks of the Atlantic salmon (Salmo salar) have declined in the sea and in many rivers in North America and Europe in recent years and are experiencing a crisis. Despite their high degree of legal protection, the quality of their aquatic environments within rivers and in the sea, including local coastal waters, appears to be deteriorating. Salmon survival, has declined both within the sea and within rivers. The status of the Atlantic salmon stocks is considered here, together with the adverse effects of different sources, and those steps that may need to be taken to improve the condition of the salmon. This paper is intended to assist management bodies in taking steps to resolve the problems that exist for salmon, both within rivers and in the sea. It makes particular use of information available from the River Dee in Scotland.
... Studies have been carried out on the movements of returning adult salmon in North Sea coastal waters [24,34] within estuaries [51,52,56,62] and within rivers [23,36]. The returning multi-sea-winter adults may arrive at the Scottish coast and enter the estuary of the Dee as early as February and March, and may subsequently be found within the main part of the River Dee throughout the spring, summer and autumn. ...
... The sea stage has been viewed as a feeding migration [45], with the salmon moving into productive marine feeding grounds in the subarctic. There is hardly any information available on the juvenile migratory routes [34]. However, post-smolts of unknown river origin were examined by [49] and they migrated northwards off the western coast of Scotland along the continental shelf edge, apparently making use of the dominant ocean currents. ...
The stocks of the Atlantic salmon (Salmo salar) in many rivers in North America and Europe have declined in recent years and are experiencing a crisis. Despite their high degree of legal protection, the quality of their aquatic environments within rivers and in the sea, including local coastal waters, appears to be deteriorating. Salmon survival, has declined both within the sea and within rivers. The status of the Atlantic salmon stocks is considered here, together with the adverse effects of different sources, and those steps that may need to be taken to improve the condition of the salmon. This paper is intended to assist management bodies in taking steps to resolve the problems that exist for salmon, both within rivers and in the sea. It makes particular use of information available on the River Dee in Scotland.
... This knowledge gap is particularly important because these coastal waters are highenergy environments that are increasingly being developed for generation of marine renewable energy via tidal-flow, wind, and wave devices. Numerous productive rivers of high conservation value that also support high-value salmon fisheries discharge into the same coastal waters (Malcolm et al., 2010). There is therefore potential for negative interactions between renewable developments and migrating smolts (Malcolm et al., 2010). ...
... Numerous productive rivers of high conservation value that also support high-value salmon fisheries discharge into the same coastal waters (Malcolm et al., 2010). There is therefore potential for negative interactions between renewable developments and migrating smolts (Malcolm et al., 2010). Potential impacts are physical impact, acoustic, and electromagnetic impacts (Gill et al., 2012, Harding et al. 2016. ...
Migration from fresh water to the marine environment is a crucial, transitional stage in the development of Atlantic salmon (Salmo Salar). This study used a combination of acoustic tracking, instrument data, and hydrodynamic modelling to examine behaviour of juvenile salmon (smolts) during their transition from fresh water to the marine environment. The study focuses on a high-energy coastal environment in northern Scotland, which is currently being developed for renewable energy extraction and where there is potential for negative impacts on salmon with energy extraction devices and structures. Thirty-four smolts were captured in the River Wick in Caithness and tagged with acoustic tags transmitting at 69 kHz. The Telemac–Mascaret modelling suite was utilized to construct a three-dimensional model of the study area and surrounding waters to estimate smolt-current interactions during detection times. Timing of migration was linked to low-light conditions, with smolts mainly exiting the river at night and when the moon was below the horizon. The movement of most of the tags conformed with modelled tidal currents and the tracks matched modelled marine tidal patterns. Smolts were detected only on a single tide suggesting that they rapidly cleared the vicinity of the receiver array.
... Another shortcoming of Metric 2 is that the presence alone of indicator species does not provide a full picture of the ecological status of these important species. Other studies show that migratory fish in particular may be in real decline due to pressures outwith the transitional watereither upstream in the freshwaters or in coastal or offshore marine waters during their migrations (Malcolm et al., 2010). Both salmon and sea trout, for example, are known to be in decline throughout Scotland and it is suspected that factors affecting their growth and survival at sea may be an important contributor (Ashley, 2019;Kettle-White, 2018;Middlemas, 2019;Reynolds, 2004;Todd et al., 2008;Todd, 2014). ...
The history of monitoring transitional water fish in Scotland is briefly outlined. The requirements of the EU Water Framework Directive are explained and how this applies to the monitoring of transitional water fish communities in Scotland is described. The development of a monitoring programme for Scotland is outlined, including sampling methods and strategies. Six transitional waters were selected as representative for Scotland covering three different types of transitional water. A multi-metric tool, the Transitional Water Fish Classification Index was used to assess the ecological status of the fish communities in these waters and the operation of the different metrics and the creation of appropriate reference conditions is explained. The assessment tool was applied to survey data from 2005 to 2018, although only the more recent data fully met the tool requirements. The species composition and abundances in the respective transitional waters were compared. The fully valid surveys were all classed as of Good or High status, indicating the fish communities in all the representative transitional waters appeared to be in good ecological health. The efficacy of the different metrics is considered and some issues with Metric 2, enumerating migratory species, are discussed at length. A new multi-metric tool, the Estuarine Multi-metric Fish Index, is briefly discussed and its introduction for the assessments in Scotland is recommended.
... The recruitment of glass eels in the North Sea region has declined more severely than elsewhere in Europe (ICES, 2019b), and the northern North Sea constitutes one of the areas with the lowest number of sampling and monitoring stations (especially in Norway and Scotland) (ICES, 2019b). Specifically, the migratory routes of glass eels through the Shetland Channel into the North Sea have only been inferred, but never directly assessed through sampling programs at sea (Malcolm et al., 2010). Establishing such a sampling program is challenging due to the low abundance of glass eels in shelf water. ...
... This difference in transport, coupled with the westerly winds dominating this area, causes most fish stocks recruiting to the North Sea to pass through the northern passage (Turrell, 1992). This is also considered to be the case for glass eels (Malcolm et al., 2010). ...
... The geographical proximity of the Scottish coast to the NAC and the Shetland Channel, with currents flowing close the Scottish coasts into the North Sea (Figure 2a), is probably a key factor for the high potential recruitment to this area. Currently, no sampling of glass eels off the coast has been conducted in Scotland, and the only evidence of the presence of eels in the country comes from data on yellow eel in freshwater collected by the Scottish Fisheries Coordination Centre (SFCC) (Malcolm et al., 2010). Most of the eel sampling in Scottish freshwaters was conducted by electrofishing, for which eels were not the target species. ...
The European eel hatches in the Sargasso Sea and migrates across the Atlantic Ocean toward Europe. At the continental shelf, larvae metamorphose into glass eels and then recruit to coastal habitats and estuaries. Among other cues, glass eels orient in situ using lunar cues, but what role this lunar compass plays in their recruitment to the coast is unknown. To assess this, we incorporated empirical in situ observations of glass eel swimming and lunar‐driven orientation into a biophysical advection model. We simulated dispersal of glass eels drifting with the North Atlantic Current to test the hypothesis that lunar‐driven swimming and orientation behavior affects recruitment to North Sea coasts. Particles were released from the continental slope north of Scotland, an obligate passage for migrating eel larvae. Four numerical experiments were conducted: one with passive drift and three including glass eel swimming speeds (ranging from 3 to 12 cm/s) and lunar‐driven orientation. With a speed of 3 cm/s, the lunar compass increased recruitment to the North Sea coasts of Southwestern Norway and Scotland by 34%–40%. Conversely, orientation behavior decreased recruitment to northern areas like Iceland (−46%), the Faroe Islands (−39%) and Northern Norway (−49%). Behavior affected the timing of recruitment to Southwestern Norway, causing peaks of abundance in May–June, but not to other regions. These results show that lunar‐driven orientation and swimming behavior observed in glass eels substantially increases their recruitment to North Sea coasts. Results agree with the distribution of eel in northern Europe, which decreases in abundance with increasing latitude.
... Repeat spawning females were not included in the present analysis because they are considered to represent only a small proportion of spawner abundance in Scotland (Malcolm et al., 2010). However, the proportion of repeat spawners has increased in some areas. ...
Using data from wild Atlantic salmon Salmo salar returning to spawn in seven Scottish rivers, we developed a model of fecundity based on individual body size and key developmental traits. We used a novel approach to model selection which maximises predictive accuracy for application to target river stocks to select the best from a suite of Bayesian hierarchical models. This approach aims to ensure the optimal model within the candidate set includes covariates that best predict out‐of‐sample data to estimate fecundity in areas where no direct observations are available. In addition to body size, the final model included the developmental characteristics of age at smolting and years spent at sea. Using two independent long‐term monitoring datasets, the consequences of ignoring these characteristics was revealed by comparing predictions from the best model with models that omitted them.
... Certaines études montrent également que la distance parcourue par les truites de mer durant leurs phases migratrices est variable (Malcolm et al. 2010;Degerman et al. 2012;Aldvén et al. 2015). Il semblerait, en effet, que la distance de cette migration puisse être assez courte (<100Km) ou plus longue mais fixe (Malcolm et al. 2010;Degerman et al. 2012;Aldvén et al. 2015). ...
... Certaines études montrent également que la distance parcourue par les truites de mer durant leurs phases migratrices est variable (Malcolm et al. 2010;Degerman et al. 2012;Aldvén et al. 2015). Il semblerait, en effet, que la distance de cette migration puisse être assez courte (<100Km) ou plus longue mais fixe (Malcolm et al. 2010;Degerman et al. 2012;Aldvén et al. 2015). Contrairement au saumon atlantique, qui réalise une longue migration, la truite de mer a tendance à migrer selon une direction qui suivrait les côtes. ...
La dispersion, caractérisée par les mouvements d’individus dans l’espace et dans le temps, conduit à la production d’un flux de gènes et permet la connectivité des populations. Comprendre les facteurs qui façonnent les flux de gènes et la structuration des populations est d’une importance capitale pour améliorer les pratiques de gestion et de conservation des espèces. Celles caractérisées par une anadromie facultative, telles que la truite commune (Salmo trutta L.), sont des modèles de choix pour étudier le rôle de la diversité écotypique et comportementale, sous l’effet des activités anthropiques, sur le fonctionnement des populations. En utilisant la génétique des populations cette thèse se propose donc d’analyser la structuration des populations de la truite commune dans le fond du Golfe de Gascogne mais également de déterminer l’influence combinée de la dispersion de la truite de mer, de son comportement reproducteur et des activités anthropiques (repeuplements, transport de reproducteur) sur leur fonctionnement. Cette thèse aborde également la contribution des populations de truites communes (via leur origine natale) au stock de truites de mer capturées par la pêche professionnelle, sur le même site d’étude, en couplant de la génétique des populations et de la microchimie des otolithes. Nos résultats montrent une structuration génétique forte des populations de truite commune avec la présence de sept populations distinctes dans le bassin de l’Adour. Ceci semble être en partie expliqué par un comportement marqué de fidélité au site de naissance des truites de mer, couplé à un mouvement directionnel de celles-ci du sud (Espagne) vers le nord qui ne semble pas résulter en une dispersion effective (i.e. mouvement suivi d’une reproduction). En outre, les repeuplements récents, semblent impacter faiblement la structuration génétique des populations sauvages. Certains flux de gènes détectés localement semblent être dus à d’autres activités anthropiques, telles que le transport de reproducteurs. Les truites de mer capturées par la pêche professionnelle proviennent majoritairement de la population du gave d’Oloron et peu des populations des Nives et du Gave de Pau. La raison pourrait se trouver en premier lieu dans le fait que le Gave de Pau est fortement impacté par la présence de barrières à la migration et en second lieu dans les différences phénotypiques (taille plus petite) présentées par les truites de mer des Nives, par rapport à celle des gaves. Ceci suggère donc une différenciation de cette population et peut expliquer que la pêche professionnelle les capture dans une moindre proportion. Cette thèse a d’autre part pu démontrer les difficultés dans l’assignation d’une origine natale via la génétique lorsque les signatures génétiques sont relativement proches. Elle confirme l’utilité d’un couplage génétique des populations - microchimie des otolithes pour assigner des individus à leur origine natale à une échelle plus fine que le bassin. Les résultats obtenus au cours des trois années de thèse ont permis la détermination de populations génétiquement distinctes dont l’une contribue très largement à l’activité de pêche professionnelle. Ces populations peuvent être considérées comme de potentielles unités de gestion qui pourront servir de base à l‘élaboration de plans de gestion et de conservation. La meilleure compréhension de la biologie et du fonctionnement de la truite commune, et de l’impact des activités anthropiques sur la structuration des populations, acquise lors de cette thèse, pourra également permettre d’améliorer la prise de décisions des gestionnaires locaux pour la conservation et la gestion des populations de truites communes.
