OD Nature News

Fifteen years into the programme, monitoring of the ecological effects of Belgian offshore wind farms continues to provide new insights. That is an important conclusion of the latest WinMon.BE report that summarizes the findings on bottom-dwelling invertebrates, fish, harbour porpoises and birds. Only through sustained and adaptive monitoring can we ensure that we design and build offshore wind farms in the most eco-friendly way.

At present, eight offshore wind farms are operational in the Belgian part of the North Sea, totalling an installed capacity of 2.26 Gigawatt (GW) and consisting of 399 offshore wind turbines. Together they occupy an area of 238 km² along the border with Dutch waters and produce an average of 8 TWh annually. This accounts for around a third of gross electricity production from renewable energy sources in Belgium.

The impacts on the marine ecosystem, both positive and negative, have been investigated through the WinMon.BE monitoring and research programme from the very start of the construction of the first wind farm in 2008. The scientific insights obtained have always informed the management and development of this first Belgian offshore wind farm zone. In their latest report, scientists of the Institute of Natural Sciences, the Research Institute for Nature and Forest (INBO), the Marine Biology Research Group of Ghent University and the Research Institute for Agriculture, Fisheries and Food (ILVO) discuss the latest findings from 2022, summarize some trends from 15 years of monitoring, and identify where additional research and the development of additional mitigation measures is needed.

Macrobenthos

Long-term impacts of offshore wind farms on the macrobenthic communities (roughly the organisms that live on the seabed and are visible to the naked eye) that inhabit the surrounding natural soft sediments were investigated over a time span of 13 years (2008–2020). The sediments around and between the wind turbines were also studied in this context.

Because wind turbines interfere with water currents, fine sediments settle more easily here. The sediments in wind farms also get organically enriched by the feces of organisms that colonized the turbines themselves (such as mussels, anemones and crustaceans), and by dead animals that fall from the turbines. For the macrobenthos, a higher abundance, species richness and diversity was found around the wind turbines. Furthermore, higher abundances were also documented in the gullies between sandbanks on which the wind farms are typically constructed. The macrobenthos community continues to change, no stable state has yet been reached after 13 years of offshore wind farm operations.

In addition, macrobenthic diversity, abundance and species richness were also correlated with climate-related predictors (sea surface temperature and its natural variability on a time scale of several decades) which demonstrates the importance of also including such environmental variables in the study.

Demersal Fish

Changes in species distribution patterns were identified for demersal fish, as exemplified for plaice Pleuronectes platessa, a species extensively studied in terms of its spatial distribution, diet and movement patterns in relation to offshore wind farms. A combination of visual diving transects (at the turbine scale), beam trawl samples (at the wind farm scale) and the follow-up of tagged animals demonstrated the significance of the scour protection layer and the sandy patches in between the turbines as a feeding habitat for plaice.

The findings suggest that offshore wind farms serve as a refuge for plaice, potentially mitigating direct fishing mortality and likely enhancing plaice production. It was previously documented that fishing vessels caught more plaice for the same fishing effort just outside the wind farms than at the same places before the construction of the wind farms. However, it remains to be investigated whether this is a true spillover effect that continues to manifest itself in the longer term, and also in the context of the anticipated large-scale expansion of offshore renewable energy zones in the broader North Sea.

Harbour Porpoise

Altered species distribution patterns in relation to the presence of offshore wind farms are not independent of other human activities, such as shipping, fisheries and mariculture. This is particularly the case for highly mobile species like marine mammals. Aerial survey data (2009-2022) allowed for an analysis of the distribution patterns of the harbour porpoise Phocoena phocoena in function of both environmental drivers and anthropogenic stressors.

The distribution of harbour porpoise followed a consistent seasonal pattern, with the highest densities in spring. It was shown that the species prefers the western part of the Belgian North Sea waters, revealing a strong overlap with the marine protected area ‘Vlaamse Banken’. The distribution was also negatively correlated with marine traffic intensity and distance to the closest offshore wind farm. However, it is essential to exercise caution to avoid overinterpreting these correlations. Further monitoring and research is recommended to better understand the interaction between natural factors, such as prey availability, and anthropogenic stressors, driving the spatial distribution of harbour porpoises.

Seabirds

The monitoring strategy for seabirds not only aims to detect displacement responses, it is also designed to detect avoidance (or attraction) distances and the effect of turbine density on seabird displacement. The results presented at this stage (data from February 2021 to April 2023) need to be considered as indicative since more data and advanced spatial modelling are needed.

Nevertheless, based on the currently available data, it is interesting to see that the observed responses are in line with what has been found before and elsewhere for several seabird species. The results indicate an attraction effect for great black-backed gull Larus marinus and great cormorant Phalacrocorax carbo, and an avoidance effect for northern gannet Morus bassanus. On the other hand, avoidance of common guillemots Uria aalge was no longer noticed and an increased number of razorbills Alca torda was observed in the wind farms.

Migrating Birds

As the southern North Sea is one of the main migration flyways in Europe, mitigating the impacts of offshore wind farms also entails measures to reduce collision numbers for migrating birds. The highest flight intensities at sea are recorded at night during spring and autumn migration, mainly of migrating passerines. Normally, these migrate at higher altitudes, but a portion flies at rotor height of the wind turbines and are thus at risk of collision. Especially adverse weather conditions bring large numbers of passerines into the range of the turbine rotors.

Temporarily stopping the turbine operation during high collision risk events for songbirds is expected to substantially prevent collision mortality. However, this management measure has not yet been applied regularly but has already been tested in the Netherlands, among others. Site-specific monitoring programmes remain necessary to assess the effectiveness and the finetuning of the measure. Furthermore, a regional approach may be most appropriate to maximize the efficiency and ecological benefits of such measure.

Long-Term and Adaptive Monitoring

Most environmental monitoring programmes for offshore wind farms are halted five years after installation. WinMon.BE, on the other hand, has adopted a philosophy of long-term investigation, spanning the full life cycle of offshore wind farms, from construction through the operational phase to the final decommissioning. The programme shows that progressive changes in the marine ecosystem are still observed fifteen years after the first installation of offshore wind turbines in the Belgian part of the North Sea, as was the case for the macrobenthos communities. This underlines the importance of long-term research for a sound offshore wind farm management.

The monitoring programme must also be adaptive. Not only continued, but also new research is indispensable to further the understanding on how marine ecosystems respond to wind farms. This research should not only focus on the attraction of hard substrate species (with wind turbines representing artificial hard substrates), but also on species that are less evidently impacted by offshore wind farms, such as plaice and other demersal fish.

Steven Degraer (Institute of Natural Sciences/MARECO), coordinator of the WinMon.BE consortium: “We need to keep critically reflecting on the efficiency and effectiveness of the monitoring and research programme to ensure that we collect the best data, as shown with the re-designed monitoring programme for seabirds. As demonstrated for marine mammals, we need to address the most pertinent questions and contextualise offshore wind farm effects. Progressive insights are necessary to feed evidence-based, efficient and effective mitigation measures, and to develop and design eco-friendly offshore wind farms”.

It’s not over yet for WinMon.BE

An additional Belgian zone for offshore renewable energy, the Princess Elisabeth Zone, anticipating an installed capacity of between 3.15 and 3.5 GW on an area of 285 km², has been designated in the marine spatial plan 2020-2026. The progressive insights of WinMon.BE are also used to guide the design of this zone in an environment-sensitive manner, and also during the construction and operational phases of future wind farms, WinMon.BE will document and learn to understand the effects on the marine ecosystem. As the Princess Elisabeth Zone overlaps with the marine protected area ‘Vlaamse Banken’, additional knowledge on the nature-inclusive design of wind farms was gathered in the EDEN2000 study “Exploring options for a nature-proof Development of offshore wind farms inside a Natura 2000 area” (2019-2023).

Moreover, Belgium is not the only country that is investing in wind farms in the southern North Sea. Many parks are already operational, under construction or planned in our neighboring countries, and there is a declaration of intent to install 300GW of wind energy in the North Sea by 2050. Therefore, cumulative ecological effects on a larger geographical scale than the Belgian part of the North Sea are also a concern. The results of WinMon.BE and EDEN2000 can also be directly used in the context of the Greater North Sea Basin Initiative, which strengthens cooperation on marine spatial planning between the North Sea countries. An additional reason why it is important that the monitoring of the ecological effects of offshore wind farms continues!

“WinMon.BE still has a long future ahead of it. It is also encouraging that the programme serves as an example for the environmental monitoring in offshore wind farms in an international context. Discussions are ongoing with policymakers and scientists from various countries, who wish to draw inspiration from the Belgian example” Steven Degraer concludes.

 

About WinMon.BE

The Monitoring Programme WinMon.BE is commissioned by the Federal Government as part of the environmental permit conditions for offshore wind farms. For the monitoring, use was made of the research vessel Belgica (ship time on RV Belgica was made available by BELSPO and the Institute of Natural Sciences), the research vessel Simon Stevin (operated by the Flanders Marine Institute), several private vessels, the Belgian scientific diving team and the aerial surveillance aircraft of the Institute of Natural Sciences.

WinMon.BE is a cooperation between the Institute of Natural Sciences, the Research Institute for Nature and Forest (INBO), the Marine Biology Research Group of Ghent University and the Research Institute for Agriculture, Fisheries and Food (ILVO), and is coordinated by the Marine Ecology and Management team (MARECO) of the Institute of Natural Sciences. MARECO also coordinated the EDEN2000 study with respect to the anticipated ecological effects of future offshore wind farms in the Princess Elisabeth Zone.

On the morning of Friday 22 December 2023, a dead Common dolphin (Delphinus delphis) washed up on the beach of Ostend, near the western harbour wall. It was a female measuring 2.07 meters in length.

The Common dolphin is a rare species in the North Sea but is the most common dolphin species in the Bay of Biscay and in the adjacent Atlantic Ocean. In the Bay of Biscay, thousands die in fishing nets every year.

It was no less than the third time in 2023 that a dead Common dolphin washed up on a Belgian beach, which is very exceptional. The specimen on 22 December was by far the freshest of the three and was therefore collected for further research. However, this will not take place until 2024, and will hopefully shed light on the health condition, cause of death and area of origin of the unfortunate animal.

Betoncentrale Van den Braembussche has applied on October 31^th, 2023 for the prolongation of its concession for sand extraction in the Belgian part of the North Sea. This application is subject to an environmental impact assessment procedure.

The application and the environmental impact assessment report, including a design of appropriate assessment, can be downloaded below (in Dutch).

Application

Environmental impact assessment report (original 2020)

Environmental impact assessment report (update 2022)

Environmental impact assessment report (annex study day 2021)

 

Results of the consultations

Objection 4Sea-20240112

 

The public consultation runs from December, 8^th 2023 until January, 7^th 2024.

Any interested party can submit its views, comments and objections to Ms. Brigitte Lauwaert by letter or email until January, 22^th 2024.

Institute of Natural Sciences/MUMM
Attn. Ms. Brigitte Lauwaert
Vautierstraat 29
1000 Brussels

blauwaert@naturalsciences.be

In the Quality Status Report 2023, the 16 contracting parties to the OSPAR Convention, including Belgium, assess the status of the Northeast Atlantic Ocean. The report confirms that climate change and ocean acidification have become drivers of major change. Biodiversity and habitats remain at risk, but a turnaround is noticed with respect to the chemical quality of the marine environment.

More than 400 scientists and policy makers from around the North-East Atlantic have worked together to produce a holistic assessment of the North-East Atlantic marine area: the OSPAR Quality Status Report 2023 (QSR). The work was carried out under the umbrella of the OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic. It examines the current state of the marine environment and ecosystems, and the human activities benefiting from the marine environment and interacting with it.

Dr Patrick Roose, Operational Director of the Department ‘Natural Environment’ of the Institute of Natural Sciences was one of the coordinators of this titanic work. He summarizes the situation as follows: “There is an ever-more pressing need to address drivers of degradation and biodiversity loss and thereby increase the health and resilience of marine ecosystems in the North-East Atlantic. This area also includes our North Sea. Climate change and ocean acidification have now become drivers of major changes that imperil much of the North-East Atlantic’s marine biodiversity. As such, they now add to the effects of the hitherto ‘traditional’ drivers, such as overexploitation and chemical pollution.”

Biodiversity in peril

The report shows that many parts of the North-East Atlantic still suffer from declining biodiversity and continued habitat degradation, despite the measures that have already been taken by OSPAR Contracting Parties. The impacts of fisheries and other human activities on biodiversity and habitat quality are still deeply felt, and other forms of degradation such as noise pollution are of growing concern.

Although the status of habitats and individual species varies greatly, some general statements can be made: Benthic habitats continue to be damaged, whereas plankton, the base of the marine food web, is impacted in pelagic habitats. The state of marine food webs is of great concern. More and more fish stocks are being fished sustainably, but the overall status of marine fish remains unfavorable. Marine birds are generally still in trouble. Many marine mammals, especially northern seal populations and small toothed cetaceans, remain at risk while the status of some other marine mammals remains unknown. We also appear to know relatively little about the status of marine turtles.

Areas of improvement

Fortunately, the environmental quality has improved in some areas: The most serious hazardous substances such as PCBs, PAHs, and organochlorides remain a cause for concern (mostly because they remain in the system for a long time), but releases have decreased substantially. Pollution by radioactive substances has been prevented, and discharges by the oil and gas industry have been greatly reduced and continue to decrease. Marine litter levels remain high but are better tracked, with significant steps having been taken to reduce it.

Eutrophication, the process in which a water body becomes overly enriched with nutrients, persists but a gradual reduction of the excess nutrients has been witnessed in many parts of the North-East Atlantic. The introduction of new non-indigenous species, another traditional driver of biodiversity loss, also appears to have decreased in the marine environment. As a community, we must ensure that we continue these trends in the right direction. Furthermore, we must also be careful with optimism in the face of climate change and ocean acidification. After all, the impacts of these man-caused phenomena are now clearly measurable and put ecosystems at further risk.

Appropriate measures

The findings from the Quality Status Report 2023 will be used to help OSPAR deliver its North-East Atlantic Environment Strategy 2030, a roadmap to achieving the vision of a clean, healthy and biologically diverse North-East Atlantic Ocean, which is productive, used sustainably and resilient to climate change and ocean acidification.

Dr Roose provides some important nuances: “The general conclusions of the QSR contain no major surprises, but we must become better at developing the necessary science-based policy, and therefore at translating scientific insights into effective measures. To be effective, we need to pool our efforts and move to international evaluations and joint measures. It makes no sense to assess everything on a national basis as there are no borders in the seas, and no undesirable effects can be overcome in national parts of a bigger basin.”

There is also additional work to be done for science: “Still, there are indicators for which we have insufficient data and can better coordinate the data collection. Sufficient, continuous and coordinated data collection is key, in other words, so is continuous policy support. Also, not all assessment methods and thresholds are already sufficiently established, particularly for cumulative effects” Dr Roose adds.

About OSPAR and the QSR

OSPAR – the Oslo and Paris Commission – is the mechanism by which 15 Governments and the EU cooperate to protect the marine environment of the North-East Atlantic. The fifteen Governments are Belgium, Denmark, Finland, France, Germany, Iceland, Ireland, Luxembourg, The Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

OSPAR started in 1972 with the Oslo Convention against dumping and was broadened to cover land-based sources of marine pollution and the offshore industry by the Paris Convention of 1974. The two conventions were unified, updated and extended by the 1992 OSPAR Convention. A new annex on biodiversity and ecosystems was adopted in 1998 to cover non-polluting human activities that can adversely affect the sea. More information on the OSPAR website and YouTube.

The Quality Status Report (QSR) 2023 is the most authoritative assessment of the whole North-East Atlantic and reflects the collective work of the 16 Contracting Parties to the OSPAR Convention. It assesses the status of various components of the North-East Atlantic and examines how conditions have changed since the last QSR in 2010.

Publication of the QSR 2023 was announced at the Annual Science Conference of the International Council for the Exploration of the Sea (ICES) in Bilbao, Spain, on September 13, 2023. In Belgium, the results, with a focus on the North Sea, were presented during the event ‘Nature restoration in our North Sea’, organized by the FPS Public Health, Food Chain Safety and Environment, on December 5, 2023 in Bruges.

The Belgian input for the QSR came about thanks to the cooperation of many actors, all of which are explicitly thanked for their cooperation: the Directorate-General for the Environment (FPS Public Health, Food Chain Safety and Environment), the Institute of Natural Sciences, the Federal Agency for Nuclear Control (FANC), the Flanders Environment Agency (VMM), the Research Institute for Nature and Forest (INBO), the Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), the Flanders Marine Institute (VLIZ), Maritime Access (Department Mobility and Public Works), the Public Waste Agency of Flanders (OVAM) and the Directorate-General Shipping (FPS Mobility and Transport).

On Saturday, November 25, 2023, a live Loggerhead turtle washed up on the beach of Bredene. This species has never before been identified with certainty in Belgium. The animal is currently being closely monitored in SEA LIFE Blankenberge.

Strong northwesterly winds are known to cause all kinds of dead and living material from the sea to wash up on our coasts, and the storm of November 24-25, 2023 was no different. Sometimes surprising animals or objects are also found in the wash-up. In the afternoon of November 25, walkers on the beach of Bredene came across nothing less than a live sea turtle.

The young animal, with a carapace length of only 14 cm, was recovered from the beach by the Ostend fire brigade and reported to the experts of the Institute of Natural Sciences, who identified it as a very young Loggerhead turtle (Caretta caretta). The Institute then arranged for the transport of the lost animal to Sea Life Blankenberge.

First time in Belgium?

Although the Loggerhead Turtle is not exclusively confined to warm waters and is one of the most widespread sea turtles, the North Sea falls outside the range of this species. A number of strandings are known from the Netherlands, including from the 21st century, but as far as we know there have been no confirmed sightings from Belgium. Some old cases are questionable or involve sea turtles of unknown identity. Bredene’s turtle could therefore go down as the first confirmed Loggerhead turtle in Belgium.

When Loggerhead turtles hatch from the egg, their carapace is only 4 to 5 cm long. The carapace of adult animals can reach a length of more than one meter. The animals that previously washed up in the Netherlands had widely varying carapace lengths, from about 20 cm to almost a meter. These therefore involved animals of varying ages, but most were immature. Female Loggerhead turtles only reproduce when they reach a carapace length of 70-80 cm, and are then at least almost 20 (to more than 30) years old.

Atlantic origin?

The Loggerhead turtle is found in all oceans except the polar regions. Like all sea turtles, they lay eggs on beaches. The closest laying beaches to us are in the Mediterranean Sea, but that does not mean that the Bredene turtle comes from there. In the Atlantic Ocean, the main breeding areas should be sought in the Cape Verde Islands (East Atlantic) and in the south-east of North America (Florida, Gulf of Mexico; West Atlantic), and an Atlantic origin is certainly possible in the case of the Bredene Loggerhead turtle.

This can be explained as follows. Immature Loggerhead turtles from North America and Cape Verde make a multi-year tour of the Atlantic Ocean before returning to their native areas. During this life stage, strong currents can cause them to drift away, with the youngest – and therefore smallest – specimens being at greatest risk. Western currents in the Atlantic Ocean mainly occur in autumn and winter, so it is no coincidence that sea turtles in the North Sea also appear most often during this period.

The northwesterly storm of November 24-25, 2023 also caused a lot of material to wash ashore that certainly has an Atlantic origin. In addition to driftwood and other objects with Atlantic biological growth (such as many goose barnacles), this also included buoys from the United States and Canada. It is therefore not unlikely that the Loggerhead Turtle came to us from the Atlantic Ocean on November 25 with the same westerly current.

However, it cannot be deduced from this where the Belgian Loggerhead Turtle was born. For another species that previously washed up along North Sea coasts, the Kemp’s Ridley Turtle (with a dead specimen in Belgium, on January 6, 2012 in Nieuwpoort), a transatlantic origin is the only possibility, because this species only reproduces in the Gulf of Mexico.

Rehabilitation

Because sea turtles that wash up alive in our region have ended up in an area that is unfavorable to them, shelter is always being considered. The Bredene Loggerhead Turtle also had damage to the back of the carapace. SEA LIFE Blankenberge is authorized to take sea turtles into care and organized an initial examination by a veterinarian immediately upon the animal’s arrival. The weight was 770 g, some barnacles were professionally removed from the abdominal shield and a course of antibiotics was started. Additional examination will follow on November 26, during which the animal will be internally screened with x-ray.

The Loggerhead Turtle stays in SEA LIFE Blankenberge in a tank of a suitable size for the animal, where the water temperature is systematically raised. It is still too early to determine whether the animal can be released back into the wild, and where or when that could possibly happen.

Scientists of the Institute of Natural Sciences have concluded the first sampling campaign of the littoral modules within the EcoMPV project (Eco-designing Marine Photovoltaic Installations). This sampling event, conducted on October 23, 2023, aims to investigate the habitat provisioning effect of artificial floating structures for marine fouling fauna and fish, one of EcoMPV’s objectives.

For this purpose, three littoral modules were designed and developed by Jan De Nul Group, in collaboration with the Institute of Natural Sciences and EMBRC Belgium (European Marine Biological Resource Centre). These floating modules act as the foundation for various settlement plates, constructed out of materials interesting for marine offshore installations. The littoral modules were deployed in May/June 2023 in the safety zone of Mermaid offshore wind farm by the RV Belgica and the Zeetijger. This test site closely resembles the water mass present in the Princess Elizabeth Zone (PEZ), a newly designated zone for offshore energy production.

During the campaign, the scientific diving team of the Institute of Natural Sciences retrieved the first batch of settlement plates from each littoral module. On board of the RV Belgica, each plate was photographed for quantitative coverage image analysis and subsequently preserved for taxonomic analysis. The data collected from the littoral modules will provide a comprehensive understanding of early colonization processes, offering crucial insights for the development of eco-friendly marine photovoltaic installations. The EcoMPV project is financed by the Energy Transition Fund of the FPS Economy, GD Energy.

After the completion of the EcoMPV project, the littoral modules will be integrated as scientific equipment in the Artificial Hard Substrate Garden. This is an innovative in-situ experimental platform, managed by the Institute of Natural Sciences, that consists of flexible and modular artificial hard substrate devices. It is designed to study the impacts of man-made structures, including mariculture installations, renewable energy devices, antifouling treatments, coastal protection structures, and more, on marine environments. Graphic designer Hendrik Gheerardyn has recently crafted an informative infographic providing an overview of the devices and their respective sampling range.

The Artificial Hard Substrate Garden is offered as an EMBRC research service to both the scientific community and the industry. For further details, please visit the MARECO website or contact Wannes De Clercq (wdeclercq@naturalsciences.be).

 

This news item was originally published on the EMBRC website on Nov 9^th, 2023.

Text: Wannes De Clercq, MARECO, Institute of Natural Sciences

Collaborating with researchers from Germany, the Netherlands, Sweden, and Denmark, researchers from the Institute of Natural Sciences (Ward Van Roy and colleagues) assessed the effectiveness of ship emission regulations that have been in place in the North and Baltic Seas for more than 15 years. The findings of this study were published today, October 26^th, 2023,  in the leading scientific journal Nature Communications Earth and Environment. The study was based on more than 110,000 remote ship plume measurements and on-board inspections. Remote measurements were conducted using various fixed monitoring stations and aerial measurements using drones, helicopters, and fixed-wing aircraft.

The data revealed a substantial improvement in compliance rates for sulfur emission limits since the initiation of these measurements. This positive trend was observed across the Baltic Sea and the North Sea. Nevertheless, it was observed that the introduction of the global cap limit of 0.5% FSC (fuel sulfur content) led to a slight increase in SO₂ emissions in the SECA (Sulfur Emission Control Area) from 2020 onward, possibly due to the increased use of scrubbers and the fuel price inflations.

In contrast to the successful reduction of SO₂ emissions from ships, the international ship emission regulations appeared to have no impact on the nitrogen oxide (NO_x) emissions from ships. In fact, there was even an increase observed of ships’ NOx emissions. This outcome can be attributed to various regulatory gaps in the NO_x regulations, an issue on which the Institute of Natural Sciences and other researchers have published before.

These research findings are of particular importance to policymakers and other stakeholders responsible for environmental regulation and enforcement, as they offer valuable insights for developing more effective regulations and strategies for the implementation of emission regulations and their enforcement at sea and in ports.

The full study can be consulted here, with a ‘Behind the paper’ blog post being accessible here.