Effects Of Offshore Wind Farms Research Articles

A new method for quantifying redistribution of seabirds within operational offshore wind farms finds no evidence of within-wind farm displacement

The climate crisis is driving a rapid increase in size and number of offshore wind farms to reduce carbon emissions from electricity generation. However, there are concerns about the potential impact of offshore wind farms on the marine environment. Seabirds are considered to be at risk of being displaced from preferred foraging habitat, by construction and operation of offshore wind farms, resulting in reduced energy intake or elevated energetic costs and consequent decreases in survival and/or productivity. Typically, displacement or avoidance behaviour is assessed by comparing abundance and spatial distributions of seabirds before and after an offshore wind farm is constructed. However, seabird distributions are highly variable through time and space and so discerning a change in distribution caused by an offshore wind farm from other environmental variables can be challenging. We present a new method that controls for temporal variation by examining the location of individual seabirds relative to turbines. Mean seabird density at different distances from individual turbines (0-400m) was calculated from data collected on a total of 12 digital aerial surveys of the Beatrice Offshore Wind Farm (UK), in May-August in 2019 and 2021. Mean densities of common guillemot (Uria aalge), razorbill (Alca torda), Atlantic puffin (Fratercula arctica) and black-legged kittiwake (Rissa tridactyla), both flying and sat on the water, were calculated. If the presence of turbines had no effect on seabird distribution, there should be no relationship between distance from turbine and seabird density. This was tested by simulating a relocation of turbines, relative to seabird distribution, and recalculating seabird density over 0-400m from simulated turbine locations. This was repeated to generate a bootstrapped distribution of expected densities against which observed density was compared. If displacement was occurring, mean observed density close to turbines would be significantly lower than expected density, derived from the bootstrap distribution. Overall, observed mean density did not differ significantly from expected density, i.e. no displacement effect was detected. There was a slight tendency for guillemot and razorbill, when sat on the water, to be at higher densities than expected, near turbines, suggestive of possible attraction to turbines, and for flying birds to be at lower densities than expected, near turbines, suggestive of possible avoidance. No flying razorbills were recorded within 100m of turbines but sample sizes were small. Kittiwake tended to show no avoidance or attraction behaviour, although flying kittiwake density was slightly lower than expected at 200m from turbines. Puffins sat on the water were recorded in densities similar to the expected density. Overall, no effect of turbine rotor speed was found, i.e. birds were not more likely to be displaced/avoid turbines at higher or lower rotor speeds. The results of the turbine relocation analysis gave a more consistent and more easily interpreted assessment of displacement/avoidance behaviour than the typical approaches of comparing abundance and seabird distribution through time. We strongly encourage application of this new approach to post-construction spatial distribution data from other offshore wind farms, to build the evidence base on the effects of offshore wind farms on seabirds.

Correction to: A paradigm for understanding whole ecosystem effects of offshore wind farms in shelf seas

Correction to: A paradigm for understanding whole ecosystem effects of offshore wind farms in shelf seas

Cumulative effects of offshore wind farms on common guillemots (Uria aalge) in the southern North Sea - climate versus biodiversity?

Governments are under increasing pressure to reduce greenhouse gas emissions, and large-scale wind farms are being developed in marine environments worldwide. However, top predators are strongly affected by environmental change and anthropogenic activities. Common guillemots (Uria aalge, hereafter guillemots), as one of the world’s most numerous seabird species, are prone to interference with offshore wind farms (OWFs). This study assessed the cumulative impacts of all operating OWFs on guillemots in the German North Sea. These estimates were applied to quantify the possible conflicts between guillemot occurrence and current German government plans to implement large-scale OWFs. If OWFs were implemented according to the current maritime spatial plan for the German Exclusive Economic zone, they would cover 13% of the German North Sea. Guillemot numbers peak during autumn, with German North Sea offshore waters hosting approximately 90,000 individuals. Guillemot density in autumn was significantly reduced within a radius of 19.5 km around operating OWFs. Applying this disturbance distance to current installation plans, about 70% of the German North Sea would be affected, and an estimated 68% of guillemots in the German North Sea would experience habitat loss. This highlights the possible threat to guillemots in the southern North Sea if the current German government plans are implemented. The current estimates are highly relevant to decisions regarding marine spatial planning and management recommendations. Such evaluations are essential for developing sustainable scenarios including reducing the human CO2 footprint, whilst also conserving biodiversity.

Minimal chemical pollution, increased offshore wind farms and energy production sustainability

Minimal chemical pollution, increased offshore wind farms and energy production sustainability Coordinator of the Anemoi project, Bavo De Witte (ILVO), discusses the path to minimal chemical pollution and increasing the sustainability of offshore wind energy. Offshore wind energy production is a relatively sustainable yet fast-growing industry, contributing to the UN development goals on green energy and climate actions. Europe’s total offshore wind power capacity as of September 2023 is 32 GW (1), only 20% of the European target to produce >150 GW by 2030. The vast increase in offshore energy production urged different European countries to monitor the potential effects of offshore wind farms (OWFs) on the marine ecosystem, including the impact of underwater noise, the introduction of novel habitats, and the exclusion of fisheries. However, the potential risk of chemical emissions by OWF structures remains largely unknown though estimated to be small.

The effect of offshore wind farms on the variation of the phytoplankton population

Ocean and coastal areas have the opportunity to harness renewable energy with a rapidly growing rate of investment. Among the categories of marine energy, offshore wind energy produces an enormous amount of electricity for over 15 countries. The devices used for harvesting renewable energy can directly or indirectly affect habitat change, climate change, material-energy cycling, and the development of new communities. Studying their impacts can help fill the knowledge gap related to topics such as global carbon management and the reduction of ecological risks. This study aims to investigate changes in phytoplankton population after offshore wind farm (OWF) construction events at intervals of 2, 4, 7, 11, 18, 30, 50, and 80 days. The wind farms selected for this study are located in the North Sea, which is the most active area for OWF activity. The necessary information for this study was gathered from the Copernicus Marine Environment Monitoring Service (CMEMS) and the 4 C Offshore database. Python package in Jupyter Notebook and SPSS (version 25) were used to identify significant changes with a 95% confidence interval, along with their effect size. The results of the study are reported in four sets based on the eutrophication status of the studied OWFs. The events that have a diminishing effect on the phytoplankton population include foundation installation, array cable installation, and fully commissioning. Turbine installation was the only event where primary producers experienced growth afterward. The occurrence and duration of phytoplankton population changes during different eutrophication zones vary. The findings of this study can be beneficial for governments and various organizations when making decisions about the fishing industry, coastal management, ecosystem-based management, and ecological studies.

A paradigm for understanding whole ecosystem effects of offshore wind farms in shelf seas

Abstract With the rapid expansion of offshore windfarms (OWFs) globally, there is an urgent need to assess and predict effects on marine species, habitats, and ecosystem functioning. Doing so at shelf-wide scale while simultaneously accounting for the concurrent influence of climate change will require dynamic, multitrophic, multiscalar, ecosystem-centric approaches. However, as such studies and the study system itself (shelf seas) are complex, we propose to structure future environmental research according to the investigative cycle framework. This will allow the formulation and testing of specific hypotheses built on ecological theory, thereby streamlining the process, and allowing adaptability in the face of technological advancements (e.g. floating offshore wind) and shifting socio-economic and political climates. We outline a strategy by which to accelerate our understanding of environmental effects of OWF development on shelf seas, which is illustrated throughout by a North Sea case study. Priorities for future studies include ascertaining the extent to which OWFs may change levels of primary production; whether wind energy extraction will have knock-on effects on biophysical ecosystem drivers; whether pelagic fishes mediate changes in top predator distributions over space and time; and how any effects observed at localized levels will scale and interact with climate change and fisheries displacement effects.

Avoidance of offshore wind farms by Sandwich Terns increases with turbine density

Abstract The expanding use of wind farms as a source of renewable energy can impact bird populations due to collisions and other factors. Globally, seabirds are one of the avian taxonomic groups most threatened by anthropogenic disturbance; adequately assessing the potential impact of offshore wind farms (OWFs) is important for developing strategies to avoid or minimize harm to their populations. We estimated avoidance rates of OWFs—the degree to which birds show reduced utilization of OWF areas—by Sandwich Terns (Thalasseus sandvicensis) at 2 breeding colonies in western Europe: Scolt Head (United Kingdom) and De Putten (the Netherlands). The foraging ranges of birds from each colony overlapped with multiple OWFs. We modeled GPS tracking data using integrated step selection functions (iSSFs) to estimate the relative selection of habitats at the scale of time between successive GPS relocations—in our case, 10 min, in which Sandwich Terns traveled ~2 km on average. Besides the effects of OWFs and the direct surroundings of OWFs, iSSFs considered distance from the colony and habitat characteristics (water depth and sediment grain size) as well as movement characteristics. Macro-avoidance rates, where 1 means complete avoidance, were estimated at 0.54 (95% CI: 0.35, 0.7) for birds originating from Scolt Head and 0.41 (95% CI: 0.21, 0.56) for those from De Putten. Estimates for individual OWFs also indicated avoidance but were associated with considerable uncertainty. Our results were inconclusive with regard to the behavioral response to the areas directly surrounding OWFs (within 1.5 km); estimates suggested indifference and avoidance, and were associated with large uncertainty. Avoidance rate of OWFs significantly increased with turbine density, suggesting that OWF design may help to reduce the impact of OWFs on Sandwich Terns. The partial avoidance of OWFs by Sandwich Terns implies that the species will experience risks of collision and habitat loss due to OWFs constructed within their foraging ranges.

Behavioral responses to offshore windfarms during migration of a declining shorebird species revealed by GPS-telemetry

EU member countries and the UK are currently installing numerous offshore windfarms (OWFs) in the Baltic and North Seas to achieve decarbonization of their energy systems. OWFs may have adverse effects on birds; however, estimates of collision risks and barrier effects for migratory species are notably lacking, but are essential to inform marine spatial planning. We therefore compiled an international dataset consisting of 259 migration tracks for 143 Global Positioning System-tagged Eurasian curlews (Numenius arquata arquata) from seven European countries recorded over 6 years, to assess individual response behaviors when approaching OWFs in the North and Baltic Seas at two different spatial scales (i.e. up to 3.5 km and up to 30 km distance). Generalized additive mixed models revealed a significant small-scale increase in flight altitudes, which was strongest at 0–500 m from the OWF and which was more pronounced during autumn than during spring, due to higher proportions of time spent migrating at rotor level. Furthermore, four different small-scale integrated step selection models consistently detected horizontal avoidance responses in about 70% of approaching curlews, which was strongest at approximately 450 m from the OWFs. No distinct, large-scale avoidance effects were observed on the horizontal plane, although they could possibly have been confounded by changes in flight altitudes close to land. Overall, 28.8% of the flight tracks crossed OWFs at least once during migration. Flight altitudes within the OWFs overlapped with the rotor level to a high degree in autumn (50%) but to a significantly lesser extent in spring (18.5%). Approximately 15.8% and 5.8% of the entire curlew population were estimated to be at increased risk during autumn and spring migration, respectively. Our data clearly show strong small-scale avoidance responses, which are likely to reduce collision risk, but simultaneously highlight the substantial barrier effect of OWFs for migrating species. Although alterations in flight paths of curlews due to OWFs seem to be moderate with respect to the overall migration route, there is an urgent need to quantify the respective energetic costs, given the massive ongoing construction of OWFs in both sea areas.

Large-scale effects of offshore wind farms on seabirds of high conservation concern

The North Sea is a key area worldwide for the installation of offshore wind farms (OWFs). We analysed data from multiple sources to quantify the effects of OWFs on seabirds from the family Gaviidae (loons) in the German North Sea. The distribution and abundance of loons changed substantially from the period before to the period after OWF construction. Densities of loons were significantly reduced at distances of up to 9–12 km from the OWF footprints. Abundance declined by 94% within the OWF + 1 km zone and by 52% within the OWF + 10 km zone. The observed redistribution was a large-scale effect, with birds aggregating within the study area at large distances from the OWFs. Although renewable energies will be needed to provide a large share of our energy demands in the future, it is necessary to minimize the costs in terms of less-adaptable species, to avoid amplifying the biodiversity crisis.

Ecological effects of offshore wind farms on Atlantic cod (Gadus morhua) in the southern North Sea

Evaluating the ecological effects of the rapid expansion of offshore renewables at local, regional and ecosystem-wide scales is essential to understand the overall socio-ecological trade-offs also for other sectors such as fisheries. Hence, little is known about the ecological impact on demersal fish. To shed light on this topic, we studied the effects of an offshore wind farm in the southern North Sea on different life stages of Atlantic cod (Gadus morhua) using a combination of sampling methods at varying spatial and temporal scales. Our investigations of diet composition and trophic niches indicate that cod utilizes wind turbine piles with scour protection as feeding grounds. Furthermore, collected information on cod adults and early life stages during winter spawning season suggest that spawning activity occurred in winter across the wider wind farm area. We conclude that wind turbine foundations with a scour protection can function as artificial reefs that have local positive effects on the resilience of local cod populations. With our study we contribute to urgently needed observational evidence regarding the ecological impact of offshore wind farm installations to inform area-based management and future monitoring activities.

Metabolomics for in situ monitoring of attached Crassostrea gigas and Mytilus edulis: Effects of offshore wind farms on aquatic organisms

While offshore wind power has support from countries around the world, studies show that offshore wind farms (OWFs) may affect marine organisms. Environmental metabolomics is a high-throughput method that provides a snapshot of an organism's metabolic state. To elucidate the effects of OWFs on aquatic organisms, we studied, in situ, Crassostrea gigas and Mytilus edulis attached within and outside of OWFs and their reef areas. Our results show that epinephrine, sulphaniline, and inosine 5′-monophosphate were significantly increased and L-carnitine was significantly reduced in both Crassostrea and Mytilus species from the OWFs. This may be related to immune response, oxidative stress, energy metabolism and osmotic pressure regulation of aquatic organisms. Our study shows that active selection of biological monitoring methods for risk assessment is necessary and that metabolomics of attached shellfish is useful in elucidating the metabolic pathways of aquatic organisms in OWFs.

An integrated conceptual model to characterize the effects of offshore wind farms on ecosystem services

Offshore wind farm development has become a key measure of energy transition in recent years. Coastal territories are particularly favorable to the development of offshore wind farms due to their high energy potential. However, these areas are also hotspots of biodiversity, provide attractive landscapes and are under strong anthropogenic pressures. Preserving and sharing the natural and cultural resources of coastal territories while intensifying renewable marine energies, represents one of the most important challenges for future management of coastal environments. Consequently, systemic models that consider all the effects of offshore wind farms on ecosystems and society are essential. Here, we propose a conceptual model for studying these effects, by mobilizing the concept of ecosystem service in a systemic and integrated assessment approach. To that aim, we reviewed the literature and compiled experts’ knowledge in order to characterize the effects of offshore wind farms on food webs during the construction and operation phases. Then, we analyzed the contribution of trophic compartments on ecosystem functions, ecosystem services and beneficiaries, and how offshore wind farms modify the relationships between these compartments of the marine coastal social-ecological systems. Our approach helps identify the causal chains that generate the most important modifications in this system. This information could then be used to predict impacts of offshore wind farms on ecosystem services, and to suggest management trade-offs. This study reveals the need for further studies relating marine biodiversity to ecosystem services, and developing systemic approaches at different scales. The analysis of the effects of offshore wind farms on ecosystem services is crucial since it is linked to strong ecological, socio-economic and political issues.

A first estimate of the effect of offshore wind farms on sedimentary organic carbon stocks in the Southern North Sea

Offshore wind farms (OWFs) can increase the transfer and stock of organic carbon (OC) in the surrounding sediments during their operational phase, while their construction and decommissioning release carbon. To answer the question whether sediments of OWFs trap more OC than they release, we estimate the net carbon effect over the entire life cycle (construction, operational and decommissioning phases) of OWFs in the Southern North Sea. Based on existing studies we compare the increased OC flux due to the colonization of organisms at the foundations of wind turbines and the OC loss due to sediment-disturbing activities during construction and decommissioning. Our results show that the areal intensity of carbon release in the disturbed areas is about 43.5 times higher than that of carbon trapping in the entire area of the OWFs. However, since the disturbed areas only account for about 0.50 ± 0.06% of the total area of the OWFs, in absolute terms about 4.6 ± 1.4 times more carbon is trapped in the sediment of the OWFs than is released. Due to limited data availability and the resulting need for extensive assumptions, our estimates only represent orders of magnitude. We therefore provide sensitivity estimates that define the limits of our calculations in terms of disturbance depth, remineralisation ratio, scour protection measures and heterogenous OC contents. In addition, we identify shortcomings of our extrapolation. Further research, especially more advanced impact assessments of construction and decommissioning processes must follow to improve the understanding of impacts of OWFs on sedimentary OC.

Effects of offshore wind farms on suspended particulate matter derived from satellite remote sensing

Effects of offshore wind farms on suspended particulate matter derived from satellite remote sensing

Acoustic Assessment of Fishery Resources in Jinwan Offshore Wind Farm Area

After more than ten years of offshore wind farm (OWF) construction, the total installed capacity of China ranks first in the world. The effect of OWF on fish communities—to attract or banish—differs among fish species and wind farms. Studies on the effects of OWFs are limited in China and results from other regions may not be transferable due to different environmental and biological conditions. In October 2019, an acoustic survey was conducted in Jinwan OWF, outside the Pearl River Estuary, northern South China Sea, China, to assess the fish resources (biomass and abundance), community diversity, and distribution information of this area. According to the Index of Relative Importance (IRI), Harpadon nehereus and Brionobutis koilomatodon were the dominant fish species in the study area. The mean Shannon–Weiner diversity index was 1.74. The mean Margalef richness index and Pielou uniformity index were 2.51 and 0.84, respectively. The ABC curve indicated that the fish community was undisturbed. The mean acoustically-derived biomass and abundance densities were 195.40 ± 254.32 kg/km2 and 6506.83 ± 11,098.96 individuals/km2, respectively. The fishery resources had evident aggregate distribution patterns, and the southern part of the study area had more biomass than the northern part. Seven environmental factors were selected by canonical correspondence analysis (CCA) analysis to reveal the correlation between fish assemblages and environmental factors, including nitrate (NO3−), ammonium (NH4+), dissolved oxygen (DO), water depth, pH, Chlorophyll a (Chl a), and phosphate (PO4+). However, the CCA only accounted for 45.49% of the total variation, indicating that other unexplained stresses affect the fish assemblage in Jinwan OWF. This is the first study to examine the fish distribution patterns and community structures of the Jinwan OWF area. In addition, it will help all sectors of society to more scientifically and objectively understand offshore wind farm projects. In future studies, control areas with more trawl samples can be set up to explore the long-term impact of OWF facilities on local fish communities.

The Issue of Using Ordinal Quantities to Estimate the Vulnerability of Seabirds to Wind Farms

The article is a follow-up study to research on analysing methodological approaches to estimate anthropogenic impacts on marine biota. The work examines relevant publications about the vulnerability of seabirds to the effects of offshore wind farms, relying upon the provisions of the measurement theory and the median theorem for ordinal quantities. It has been shown that the final ranking of sensitivity of certain bird species to wind farms, or indices of a risk of collisions with turbine blades and indices of a risk of birds’ displacement by wind farms, can vary at permissible monotonic transformations of the values of initial factors since all of these are estimated on ordinal scales. We conclude such estimates are incorrect. The summation of the two indices (exposure to collisions with turbine blades and to habitat change) of the birds’ species vulnerability in the context of the proposed models is incorrect. It has been demonstrated that the model based on dividing factors into primary and aggravation, when the latter are incorporated into the formula of computation through the exponent of primary factors, is incorrect: when primary factors have maximum values (equal to 1), the effect of aggravation factors is no longer taken into account; with some values of factors in the model, infinite vulnerability values can be obtained. The models are to operate within the entire presented range of initial data, but that is not fulfilled. Thus, none of the analysed models are correct, and an approach is needed, based on the use of metric values. Considering that the bird flight altitude primarily determines the impact of wind farms on birds, the proposals have been formulated to take into account the impact of various factors on the flight altitude.

Adjustable Capacity Evaluation Method Based on Step-by-Step Power Mapping of Offshore Wind Farms

Offshore wind power has developed rapidly in recent years, but its scale still lags far behind onshore wind power. Offshore wind power still has great development potential. One of the key factors restricting the development of offshore wind power is the unsatisfactory control effect of offshore wind farms, and the reason is that the adjustable capacity of the wind farm cannot be obtained accurately and quickly. Aims to meet the high precision requirements for adjustable capacity evaluation of offshore wind farms, this paper establishes a step-by-step power mapping framework based on the division of power transmission processes in offshore wind farms, considering the loss of each transmission process in detail. By establishing a step-by-step mapping from the wind turbine power to the injected power at the grid connection point of the offshore wind farm, the adjustable capacity of the offshore wind farm can be estimated based on the maximum theoretical power of the wind turbines. The performance of proposed method has been demonstrated in a real offshore wind farm.

Review on Research about Wake Effects of Offshore Wind Turbines

In recent years, the construction of offshore wind farms is developing rapidly. As the wake effect of the upstream wind turbines seriously affect the performance of the downstream wind turbines, the wake effect of offshore wind turbines has become one of the research hotspots. First, this article reviews the research methods of wake effects, including CFD numerical simulation method, wind turbine wake model based on roughness and engineering wake models. However, there is no general model that can be used directly. Then it puts forward some factors that affect the wake of offshore wind turbines. The turbulence intensity in offshore wind fields is lower than that in onshore wind fields. This makes the wake recovery length of offshore wind turbines longer than that of onshore wind turbines. Floating offshore wind turbines are simultaneously disturbed by wind loads and wave loads. Unsteady movement of the platform caused by wave loads. It affects the development and changes of the wake of wind turbines. In this regard, the focus of research on the wake effects of offshore wind farms will be the proposal of accurate prediction models for the wake effects of sea wind farms.

Effects of Offshore Wind Farms on Suspended Particulate Matter Derived from Satellite Remote Sensing

Effects of Offshore Wind Farms on Suspended Particulate Matter Derived from Satellite Remote Sensing

Ecological Effects of Offshore Wind Farms on Atlantic Cod (Gadus Morhua) in the Southern North Sea

Ecological Effects of Offshore Wind Farms on Atlantic Cod (Gadus Morhua) in the Southern North Sea