Author: Kelle Moreau

By the end of 2020, 399 offshore wind turbines will have been installed in the Belgian part of the North Sea. During the past decade, scientists have monitored their impact on the marine environment. For the occasion of Global Wind Day 2020, the scientific partners and the Belgian Offshore Platform summarize what we have learned so far about the longer-term effects onto a variety of ecosystem components, from seafloor invertebrates over fish to birds and marine mammals. The environmental impacts of offshore wind farms prove not to be black or white: turbine foundations do initiate diverse ‘reefs’ of seafloor invertebrates around the turbines but are no equivalent alternatives for species-rich natural hard substrates, wind farms attract some seabird species but deter others, piling sound impact on harbour porpoises exists but is short-lived, offshore wind farms locally benefit the fish fauna and do not influence fisheries in a negative way. These nuanced insights allow to further trigger mitigation of the unwanted impacts and to promote the impacts deemed good towards a maximum environment-friendly development of offshore wind farms.

Offshore Wind Energy in Belgium

Belgium is a world leader in the offshore wind industry. In the ‘first offshore wind phase’, a zone of 238 km² was reserved for wind farm construction along the border with the Netherlands. From 2008 onwards, 341 wind turbines with a total production capacity of 1775 MW were constructed in this zone, grouped in seven wind farms. The six first wind farms have produced 4.6 TWh of electricity in 2019, representing about 6% of Belgium’s total electricity consumption. The seventh wind farm is operational since May 2020, and an eighth wind farm will begin to produce energy in the second half of 2020, bringing the total number of turbines to 399. The production capacity will then increase to 2262 MW and the production of an average of 8 TWh or approximately 10 % of Belgium’s total electricity demand. A second wind zone of 281 km² close to the French border (the ‘second offshore wind phase’) is established in the new Belgian Marine Spatial Plan for the period 2020-2026. This zone intends to add a minimum of 2,000 MW to the total Belgian offshore wind energy production capacity.

During the past decade of offshore wind farm construction, the technology and construction practices have changed drastically. Changes include an evolution in foundation types (from gravity-based and jacket foundations to XL monopile wind turbines), an expansion of the construction area towards more offshore waters and an increase in the size and capacity of the wind turbines (from 3 MW turbines with a 90 m rotor diameter to 9.5 MW turbines with a 164 m rotor diameter).

Monitoring Ecological Impact

As the installation of wind turbines at sea inevitably has a certain ecological impact, developers do not only need domain concessions but also an environmental permit. These are only issued if an assessment based on current insights shows that the impact of a wind farm on the marine environment is likely to be acceptable. They also impose a monitoring programme that assesses whether the predictions were accurate and whether certain environmental effects were overlooked or should become subject to adjusted environmental conditions.

Annemie Vermeylen, secretary-general of the Belgian Offshore Platform, the (non-profit) association of investors and owners of wind farms in the Belgian part of the North Sea, explains why and how the sector is involved: “The generation of wind energy at sea is part of the ongoing transition to the production of sustainable, green energy, which is widely supported by society. In order to be entitled to rightfully use the term ‘sustainable’, wind farm operators are contributing to the funding of scientific research on the impact of wind farms on the marine environment.”

The monitoring programme WinMon.BE has evaluated the environmental impact of both the construction and operational phases of the Belgian offshore wind farms from the start. “With this programme, we develop a proper understanding of the impact of the offshore wind industry on different scales. We learn to distinguish between shorter- and longer-term effects, and gain insight into the impact of individual wind turbines as well as of all wind farms combined“, says Steven Degraer of the Royal Belgian Institute of Natural Sciences, coordinator of WinMon.BE. “In order to understand the cumulative impact of wind farms in the southern North Sea we also need to look beyond our borders. For example, 344 km² are set apart for wind farm construction in the adjacent Dutch Borssele area, and 122 km² in the French Dunkerque zone, while marine fauna doesn’t know national borders” Degraer adds.

Effects are Diverse

As WinMon.BE evolved to be the basis for the understanding of effects of offshore wind farms on different spatial and temporal scales, onto a variety of ecosystem components (from seafloor invertebrates over fish to birds and marine mammals) and also on the seabed itself, it is difficult to summarise the impact as ‘positive’ or ‘negative’. The series of WinMon.BE reports describe all the results of ten years of monitoring of offshore wind farms in the Belgian part of the North Sea in detail. Main lessons learnt include:

• Impact is often specific to sites, foundation-types or even individual turbines

This highlights the importance of a continued monitoring at the different sites and turbine types.

• Foundations are not a long-term alternative for species-rich natural hard substrates

There are three succession stages in the fouling communities on wind turbine foundations. Earlier reports describing these as biodiversity hotspots generally refer to the species-rich second stage (characterized by large numbers of suspension feeders, such as the small amphipod crustacean Jassa herdmani), but continued monitoring now shows that a third, possibly climax stage follows. This has a lower species diversity, with frilled anemone and blue mussel as the dominant species.

• Foundations have a ‘reef effect’

Sediment fining and higher densities (biomass) and diversity (species richness) of seafloor communities (e.g. worms, shellfish, crustaceans and starfish) are consistently observed in closer vicinity of the wind turbines. Species associated with hard substrates also appear and increase in abundance in the surrounding soft sediments. Over time, the ‘reef effect’ of a single turbine may expand to the level of wind farms.

• Effects of wind farms can differ substantially between species within the same species group

Monitoring showed avoidance of the wind farm area by northern gannet, common guillemot and razorbill. In contrast, great cormorant, herring gull and greater black-backed gull are attracted to the wind farms. Apart from birds, it is also clear that differences in attraction exist among invertebrate and fish species.

• The direct sound impact from turbine installation is short-lived

The high impulsive sound levels produced during offshore wind farm construction (pile driving) result in displacement and disturbance of harbour porpoises, the most common cetacean in the southern North Sea. During pile driving, detections decrease in areas up to 20 km around the construction sites, but this is no longer the case once the wind turbines have been installed.

• New habitats attract some unexpected visitors

Some species that were only rarely observed in the Belgian part of the North Sea, are now more regularly found in association with the wind farms. These include at least four rock-loving species of fish that dwell around the base of the foundations, but also a number of non-indigenous invertebrates that occur in the zones near the water surface (intertidal and splash zones). The latter habitats are largely new to the offshore part of the Belgian North Sea. It was also demonstrated that the offshore wind farms are visited by migrating Nathusius’ pipistrelles, a species of bat.

• Fisheries are not negatively affected by the presence of the Belgian offshore wind farms

The exclusion of fisheries from the Belgian offshore wind farms, probably in combination with increased food availability near the turbines, leads to a refugium effect for some fish species. An analysis of the fishing activity and efficiency showed that fishing had only subtly changed over the years, and that fishermen have adapted to the new situation by increasing their fishing effort at the edges of the wind farms. Catch rates of sole remained comparable to those in the wider area, catch rates of plaice were even higher around some wind farms.

Mitigation Measures and Future Research

“The current cooperation model, in which the offshore wind industry and scientists document the impact of both the construction and operational phases, also allows us to design, test and improve mitigation measures to directly manage unwanted effects on the marine ecosystem” says Degraer. A selection of impact mitigation techniques is also presented in the WinMon.BE reports. An obvious example is the sound mitigation, e.g. by means of Big Bubble Curtains and acoustic deterrent devices, that mitigate the impact of impulsive sound on marine mammals and potentially also on other marine organisms. But mitigating solutions don’t necessarily have to be high tech, e.g. curtailing the activity of turbines when bird migration or bat activity is high, can lower the risk on collisions. Offshore wind farms, on the other hand, also offer great opportunities for strengthening positive impacts like the reef effect attracting fish and increasing biodiversity. This knowledge may be used to take action to further promote biodiversity inside wind farms.

Although our understanding of the effects of wind turbines on the marine environment and its inhabitants has grown significantly over the past 10 years, there is still much scope for future research. The modelling of bird and bat collision risks and the monitoring of the impact of continuous underwater sound that is generated by operational turbines are examples of fields that we have started to explore but cannot yet report on. Also what the longer-term effects on fish populations are, and how the observed behavioral changes impact individual fitness, reproductive success and survival of animals remains yet unknown. In addition, it is also important to further extend the time series of all variables that we have monitored to see if the patterns that we have seen so far are perpetuated.

 

The Monitoring Programme WinMon.BE is a cooperation between the Royal Belgian Institute of Natural Sciences (RBINS), the Research Institute Nature and Forest (INBO), the Research Institute for Agriculture, Fisheries and Food (ILVO) and the Marine Biology Research Group of Ghent University, and is coordinated by the Marine Ecology and Management team (MARECO) of the Royal Belgian Institute of Natural Sciences.

Global Wind Day is a worldwide event that occurs annually on 15 June. It is a day for discovering wind energy, its power and the possibilities it holds to reshape our energy systems, decarbonise our economies and boost jobs and growth.

In the morning of Sunday June 7th, 2020, the police of Middelkerke was contacted about the stranding of a live young porpoise (Phocoena phocoena). Experts from RBINS also went to the spot and found out that it was a recently born individual, a female with a length of 82 cm. Not only the limited length indicates a very young animal, also the fetal folds on the flanks and the hairs on the snout are characteristics that are only found in ‘neonates’. Fetal folds are due to the fact that cetaceans are bent dorso-laterally in the womb, and the hairs on the snout are a reminder that they are mammals. Both characteristics disappear soon after birth.

Porpoises of such a young age are fully dependent on their mother, it is impossible to keep them alive in a shelter without that mother. After consultation with the specialized veterinarians of Sea Life Blankenberge and the Bouddewijn Seapark of Bruges, it was therefore decided to put the animal back into the sea. A policeman and an RBINS expert needed several attempts to get the porpoise past the surf without it quickly returning to the beach.

Even though a return to the sea was the only option, those involved knew that the survival of the animal was by no means guaranteed. After all, the young porpoise was already very weakened, no mother could be identified in the area with certainty, and the strong surf also made a possible reunion of mother and child difficult. The fear came true: on Monday 8 June 2020, the young porpoise was found dead on the beach.

 

Foam in Scheveningen due to lots of algae and strong northerly wind

The metre-high foam during the fatal accident of five surfers on 11 May in Scheveningen, the Netherlands, was most probably caused by an exceptional combination of a lot of algal remains and a strong wind from the north-northeast. Dutch and Belgian researchers from various organisations concluded this in a report on the cause of the foam formation. The authors have to confine themselves to conclusions that seem most reasonable at the moment and the available data will be analysed further. The researchers advise to now mainly provide information to water sports enthusiasts and coastguard partners, because the development of an adequate automated warning system will take time.

Reconstruction of the last four days

On Monday the 11th of May, five surfers unfortunately lost their lives off the coast of Scheveningen in the Dutch province of Zuid-Holland. In order to gain insight into the circumstances in which the accident occurred, scientists from all kinds of disciplines joined forces. In their report, they outline the most plausible scenario of the day of the accident.

The reconstruction of the available data shows that a concurrence of weather conditions from the end of April led to the large amount of foam that had accumulated on that day in the corner of the Northern Harbour Head and the beach of Scheveningen. It is most likely that abundant sunlight in the preceding period first caused the growth of exceptionally large amounts of algae in the sea. Around the 10th of May the bloom was decreasing, as a consequence of reduced light due to clouds and of more blending due to the increasing wave action. As a result, algal residues were released into the sea. On Monday 11 May the north-northeast wind blew more or less parallel to the coast and reached force 7 Beaufort at the beginning of the afternoon. The wind then drove the foam that had formed to the south, causing it to accumulate against obstacles that protrude into the sea at right angles to the beach, such as Scheveningen’s Northern Harbour Head.

Colony-forming algae

Algae researcher Katja Philippart of the Royal Netherlands Institute for Sea Research (NIOZ) coordinated this research and explained how so many algae could be present in the sea water at the beginning of May. “This species of algae with the scientific name Phaeocystis globosa can live in the sea as solitary cells or in colonies. In colonies, the cells are held together by a mucilaginous protective matrix and the algae can rapidly increase in biomass”.

In order to form these colonies, the algae need a lot of light and a large supply of the nutrients nitrogen and phosphate. At the beginning of May, the conditions were ideal to make this happen and the algae colonies reached a very large biomass. A lack of light and a stronger mixing makes the colonies disintegrate again. Philippart: “The clouds of Sunday 10 May probably triggered the disintegration of the colonies into loose, solitary cells. This caused the sugary remains of the matrix to end up in the sea, and due to infections with viruses the proteins from the cells were also released into the water. When proteins and sugars are mixed together by wind and waves, you get foam”.

Satellite images reveal algal blooms and foam patterns

The Remote Sensing and Ecosystem Monitoring (REMSEM) team of the Royal Belgian Institute of Natural Sciences (RBINS) has extensive expertise in the use of remote sensing instruments, and analysed and interpreted a combination of images from the Sentinel-2 and Sentinel-3 satellites from the period before the tragic accident. Dimitry Van der Zande concludes that these are useful for the observation of algal biomass and foam in seawater: “A time series of Sentinel-3 images with a spatial accuracy of 300m shows a strong algal bloom in the vicinity of Scheveningen and along the coast of Zuid-Holland at the end of April 2020. High concentrations were still measurable near the coast at the beginning of May. The high resolution Sentinel-2 images, which show a detail of 10m, can then be used to detect the foam”.

The detection and combination of such satellite information can contribute to an automatic coastal foam alert system. However, satellites do not provide a continuous stream of images from a fixed location, and, due to cloud cover, they also only provide a partial image. Therefore, as foam accumulation along the coast can be rapid and very localised, satellite imagery is not suitable as the sole source for a foam warning system. The actual observation of foam formation is best done with cameras.

Researchers advise more prevention

Despite the fact that the researchers were able to determine the most likely scenario for the occurrence of the exceptional amount of foam on 11 May, it will be difficult to set up a reliable automated warning system. After all, not only the amount of algae and foam must be accurately monitored, but also the current wind strength and direction must be predictable in real time, in great detail and very locally. That is why the researchers of this study plead for more information to be given to water sports enthusiasts, their clubs and the coastguard partners in the short term, so that they are able to evaluate any risk on the accumulation of foam themselves.

Shortly after the incident in Scheveningen, the Maritime Rescue and Coordination Centre (MRCC) in Ostend contacted the Belgian investigators with the question whether such a foam incident could also occur on our coast. Unfortunately, the answer was that in similar circumstances this is not inconceivable. The MRCC is the first hotline for emergencies at sea and therefore closely follows the development of a warning system. Dries Boodts, acting head of the MRCC: “We also want to follow this advice on our coast. The satellite information provided to us by the RBINS is very useful in this context, to serve as an early warning. It will help to urge users of the sea to increased vigilance and will also be useful in planning Search and Rescue operations. We look forward to the development of further opportunities to provide everyone at sea with the most detailed information possible. Better safe than sorry.”

Read the full report on the website of NIOZ.

Ecologists, algae researchers, weather and water experts from the following research institutes, universities, government agencies and consultancy firms participated in the analysis:  Royal Netherlands Institute for Sea Research (NIOZ), Utrecht University (UU), Deltares, University of Amsterdam (UvA), Delft University of Technology (TUD), Water Insight, Groningen University (RUG), Bureau Waardenburg (BuWa), Rijkswaterstaat, Istituto di Scienze del Mare (ISMAR)-CNR (Italy), Royal Belgian Institute of Natural Sciences (RBINS; Belgium), Netherlands Institute of Ecology (NIOO) and Highland Statistics.

Building up a scientific basis for negotiating fisheries measures in the Belgian part of the North Sea is the task of the VISNAT2 project. The ultimate goal is to protect as much valuable seabed as possible, without harming important economic activities such as fishing.

The European Habitats Directive and the Marine Strategy Framework Directive (MSFD) require Belgium to define areas to protect certain underwater habitats. More specifically, these are shallow sandbanks (Habitat 1110) and beds of gravel and shellfish (Habitat 1170). It is essential for the protection of these habitats that bottom disturbance caused by human activities (e.g. fishing) is excluded. The search for the best location for these protected areas seeks to maximise ecological value but also to minimise economic impact. In other words, we want to protect as much as possible without damaging important economic activities, such as fishing.

For the time being, 3 search zones have been demarcated in the Marine Spatial Plan. It is now up to researchers to identify the most ecologically valuable zones within these areas. This is done on the basis of an evaluation of biological data. For each of the zones, the economic importance for all Member States with fishing interests is calculated simultaneously. Data from both research lines will feed the MARXAN spatial planning tool. Through this tool 4 scenarios with proposals for bottom protection areas with fisheries measures will be developed, where the ecological value is high and the economic impact as low as possible.

In order to make this process possible, four essential research tasks are being carried out together with the Research Institute for Agriculture, Fisheries and Food (ILVO):

1. An update of the habitat suitability map for macrobenthos – invertebrates living in the seabed – and of the biological assessment map, which will allow the delimitation of the most ecologically valuable areas.
2. An update of the fishing activity of the different Member States active in the Belgian part of the North Sea, necessary to map the most economically valuable zones for fishing.
3. A risk analysis concerning the sensitivity of different habitat types to bottom-impacting fisheries.
4. A demarcation of potential zones for fisheries measures based on the previous information and using the MARXAN spatial planning tool.

The aim of this project is to build up a scientific basis for the negotiation of fisheries measures in the Belgian part of the North Sea, as laid down in the Marine Spatial Plan. These negotiations will be conducted with Flanders and with the European member states, in order to present a Delegated Regulation for the European Commission. Such a Delegated Regulation contains rules that give further substance to previously adopted legislation, in this case in function of the protection of marine areas.

Project : VISNAT2
Duration : 2020-2021
Financing : FPS Health, Food Chain Safety and Environment
Collaboration : Reseach Institute for Agriculture, Fisheries and Food (ILVO)
Contact : Gert Vanhoey (gert.vanhoey@ilvo.vlaanderen.be), Steven Degraer (sdegraer@naturalsciences.be)

Text : Sofie Vandendriessche (ILVO) – Kelle Moreau (RBINS)

The rapidly developing offshore wind industry in the North Sea gives rise to concerns on the impact of wind turbines on the marine environment, including effects on ecosystem functioning. In a PhD study promoted by Ghent University and the Royal Belgian Institute of Natural Sciences, Ninon Mavraki studied the food-web ecology of offshore wind farms. The results show that they do influence the local food web properties, with the occurrence of fouling organisms slightly reducing the local annual primary producer (phytoplankton) standing stock and at the same time being an important food resource for certain fish species. Moreover, the importance of erosion protection layers around wind turbines was highlighted in this thesis, with high food web complexity, invertebrate species exploiting a wider range of food resources, and certain fish species remaining in the area for a prolonged time to feed.

In order to meet the growing demand for sustainable energy, the offshore wind industry is rapidly developing in the North Sea. As installing offshore wind turbines means introducing artificial hard substrates to soft-bottom areas, the practice has the potential to induce changes to the marine environment. Multiple vertebrate and invertebrate species colonise these structures. These don’t only change the local biodiversity but also influence the surrounding environment. These observations give rise to questions about the magnitude and mechanisms of these effects, including effects on ecosystem functioning.

In her PhD thesis, Ninon Mavraki investigated the effects of offshore wind farms on the local food web at two levels: a detailed food web structure on a gravity-based foundation in the Belgian part of the North Sea and a quantification of local effects on primary productivity and on fish. Colonising assemblages and fish were sampled along the entire depth gradient of the foundation to develop insights in the in situ food web structure, while laboratory experiments with fully colonised PVC panels allowed for detailed ex situ observation of the carbon assimilation by colonising species.

Food Web Structure

In the first part of the study, the food web structure of the colonising assemblages along the depth gradient of an offshore wind turbine, its erosion protection layer and the surrounding soft substrate were investigated. For this purpose, stable isotope analysis was performed on the organisms collected from the different zones. Stable isotopes are alternative forms of chemical elements (carbon and nitrogen in this case) with different molecular weights, that are found naturally. Their analysis is used to trace the flow of energy through food webs and assess trophic levels.

The results showed that structural community differences and associated differences in food web structure occur in different depth zones. The highest complexity was found at the erosion protection layer and the surrounding soft substrate, where organic matter accumulates. A species-specific study supported these results and demonstrated that the organisms occurring in these two zones exploited a wider range of resources compared to the organisms found higher up at the turbine. Most of the investigated invertebrate species were found to be trophic generalists, with depth-specific resource use strategies. Resource partitioning was detected both between and within the assemblages, contributing to the co-existence of species within and across the depth zones.

 

Carbon Assimilation and Primary Productivity

The second part of the study quantified the carbon assimilation by colonising assemblages that typically occur at offshore wind turbines. The results indicated that the blue mussel Mytilus edulis showed the highest carbon assimilation per unit of biomass, while the local amphipod Jassa herdmani population as a whole assimilated the highest amount of carbon. These species contributed the most to the local consumption of the primary producer standing stock (phytoplankton, or ‘vegetable’ plankton), since their assimilation was ca. 97 % of the total faunal carbon assimilation. The results of this experiment were upscaled to the total number of all the currently installed turbines in the Belgian part of the North Sea, leading to an estimated 1.3 % of the local annual primary producer standing stock that is grazed upon by M. edulis and J. herdmani. Also when the amount of carbon is taken into account that is not assimilated by the soft sediment fauna due to the loss of their habitat by the installation of offshore wind turbines, the data suggest that the total carbon assimilation increases remarkably in presence of offshore wind turbines and their colonisers.

Fish

The feeding ecology of fish species that are attracted to offshore wind farms was also studied. To this end, stomach content and stable isotope analyses were performed to respectively investigate the short- and long-term dietary composition of a selection of abundantly present fish species. Species that are highly associated with the erosion protection layers, living on and/or near the basis of the wind turbines (shorthorn sculpin Myoxocephalus scorpius, pouting Trisopterus luscus and Atlantic cod Gadus morhua), appeared to use these artificial reefs as feeding grounds for a prolonged period, feeding on the abundant and energy-rich colonising species J. herdmani and Pisidia longicornis (long-clawed porcelain crab). Horse Mackerel Trachurus trachurus was shown to feed only occasionally on the colonising fauna, using the artificial reefs as oases of enhanced resources. These dietary results confirm the hypothesis that their local production could potentially be increased. However, this study did not support such statement for truly pelagic fish species. The Atlantic mackerel Scomber scombrus for instance did not appear to use the artificial habitats of offshore wind farms as feeding grounds at all. The analyses for this species indicated a diet based on zooplankton.

 

After a scientifically highly qualitative and visually very clear presentation of her thesis ‘On the food-web ecology of offshore wind farms, the kingdom of suspension feeders’ (online and live streamed on YouTube due to Covid-19 restrictions), prof. dr. Steven Degraer and prof. dr. Jan Vanaverbeke (RBINS, UGent) and the members of the Examination Commission (president: prof. dr. Ann Vanreusel, UGent; secretary: prof. dr. Tom Moens, UGent) proudly attributed the title of Doctor in Science – Marine Science to Ourania (Ninon) Mavraki (formerly Master in Marine Biology, University of Patras, Greece) on Monday 18 May 2020.

Congratulations Ninon!

On 20 March 2020, the new Belgian marine spatial plan (2020-2026) came into force. The plan provides a spatial arrangement, integrating the various utility functions of the Belgian part of the North Sea.

 Did you know that Belgium has 37% marine protected area, far above the European average of 8.9%? And that, in relation to the surface area, our country provides more offshore space for renewable energy than any other country in the world?

Nature conservation, green energy, shipping, fishing, sand extraction, defence and many more activities take place in our little Belgian part of the North Sea on a daily basis. To ensure that all these activities are safely combined, the federal government draws up a marine spatial plan every six years. On land this kind of spatial planning has existed for a long time, but at sea it is quite unique in the world. Many countries come to Belgium to see how we do it in order to attribute a rightful place at sea to all activities and stakeholders.

More info and the complete marine spatial plan.

What’s new in the plan?

The first plan covered the period 2014-2020. On 20 March 2020, the Marine Spatial Plan 2020-2026 came into force. This new plan 2026 foresees, among other things, these novelties:

• a second offshore energy zone, the Princess Elisabeth zone, which aims to almost double the energy capacity (from 10% of Belgium’s electricity needs at the end of this year to 20% by 2025/2026).
• an additional nature reserve on the Dutch border
• three new search zones for soil protection measures
• five specific zones within which commercial and industrial activities can be developed. Sustainable development, in particular, will be at the heart of these areas.

Philippe De Backer: “Belgium was a pioneer with a first marine spatial plan and we are now the first to revise this plan. It’s been a long but exciting journey where the balance between economy, ecology and safety was central. I would like to thank all stakeholders, citizens and organisations for their constructive contribution to this process and I am satisfied that this new marine spatial plan will allow the North Sea to develop further in terms of the blue economy, with respect for the marine environment and the protected Natura 2000 nature areas.”

A Brand New Brochure

The brochure ‘Something’s moving at sea. The marine spatial plan 2020-2026‘ contains a lot of facts and summarises the marine spatial plan 2020-2026 in an accessible way. It gives an overview of the most important activities in our North Sea on the basis of specific maps. You can also test your knowledge with a short quiz.

Order the brochure at the FPS Public Health, Food Chain Safety and Environment.

The Marine Atlas project

In order to make the geographical information from the Marine Spatial Plan accessible to a broad community of potential users, it was made available on the marineatlas.be website. Currently, the marine atlas contains validated and fully documented geographical layers from the Belgian marine spatial plans adopted by royal decrees in 2014 and 2019. The content will be regularly expanded with data on the different themes of the European ‘INSPIRE’ Directive, such as environmental monitoring, energy sources and energy production, geology, etc. to name but a few. The Marine Atlas is a joint initiative of several Belgian federal administrations and is developed and maintained by a team of experts from the Scientific Service Management Unit of the North Sea Mathematical Model (MUMM) and the Geocell of the Royal Belgian Institute of Natural Sciences.

 

The marine spatial plan was drawn up by the Marine Environment Department of the FPS Public Health, Food Chain Safety and Environment on behalf of the Minister for the North Sea, Philippe De Backer. Because of its major impact, it was drawn up in close collaboration with all those involved. NGOs, companies, government bodies, interest groups and citizens passed on their proposals and comments during two consultation rounds. The sustainability aspect was also given extra attention, for example through the Strategic Environmental Impact Assessment (SEA). After the contributions had been processed, the new MSP was signed by the King on 22 May 2019.

Text: Jesse Verhalle, Mieke Van de Velde, Kelle Moreau

Sulphur Oxides (SOx) in atmospheric ship emissions resulting from the burning of fuel are known to be harmful to human and ecosystem health. Since January 1^st, 2020, the International Maritime Organisation (IMO) further lowered the limit for sulphur content in ship fuel, resulting in an increased number of exhaust gas cleaning systems (scrubbers) installed on board of ships. These systems reduce the sulphur content in the air emissions, but some discharge the SOx directly in the water. Here they contribute to ocean acidification and potentially create problems for a range of marine organisms. The Royal Belgian Institute of Natural Sciences used a biogeochemical model to quantify the potential impact in the southern North Sea. The results showed that the largest changes occur in areas of high traffic density, such as along the Belgian and Dutch coasts and in the vicinity of large harbours, where the changes are sufficiently big to contribute to environmental degradation and a loss of economic potential.

Sulphur Oxides (SOx) in atmospheric ship emissions, resulting from the burning of fuel, are known to cause respiratory problems, lead to more acid rain and contribute to ocean acidification. As such they are harmful to both human and ecosystem health. To address this problem, the International Maritime Organisation (IMO) further lowered the limit for sulphur content in ship fuel to 0.5% since January 1^st, 2020 (from 4.5% in 2005-2011 and 3.5% in 2012-2019). The regulations are even more strict in the North Sea Sulphur Emission Control Area, to which the intensively navigated Belgian waters belong, where the sulphur concentration in the fuel cannot exceed 0.1%. To comply with the regulations, solutions include the use of low sulphur fuel and the application of other methods that limit the SOx air emissions caused by the burning of high sulphur fuel to the same extent.

Scrubbers

Due to the price difference between high and low sulphur fuels, the installation of exhaust gas cleaning systems known as scrubbers, is economically more cost-effective than reducing the sulphur content in the fuel (in normal economic conditions). Therefore, the new regulations tend to result in an increased number of scrubbers being installed on board of ships. Scrubbers are devices that ‘wash’ the exhaust gases of ships and remove certain particulates or gases from it, in this case the sulphur oxides. The resulting wash water can either be collected on board (closed-loop scrubber) or be discarded in the open sea (open-loop scrubber), whereas hybrid scrubbers can switch from open to closed modes. The cheaper open-loop scrubbers are more commonly applied than closed-loop scrubbers, leading to a displacement of the sulphur emissions from the air to the water.

Ocean acidification

Despite the positive effect of scrubbers on air pollution, questions arise on their potential impact on the marine environment. When the wash water from open-loop scrubbers is discharged into the sea, the SOx are neutralized by the sea water. This however lowers the pH of the sea water (a lower pH means more acidic water) and thus contributes to the acidification of the ocean. This process adds to the ongoing climate-change driven ocean acidification resulting from the uptake of atmospheric CO₂. Negative effects of ocean acidification have already been observed affecting marine organisms such as clams, oysters, prawns and even fish. More acidic waters compromise the creation of shells and skeletons and can lead to the dissolution of existing structures. Furthermore, some studies have shown effects on the ability of fish to smell, hear and see, and their general cognitive functioning. More acidic waters may also have an economic impact for fisheries and aquaculture, as quality loss has been shown for certain species of prawns and clams, in terms of taste, texture, appearance and nutritious properties.

Situation in the southern North Sea

On behalf of the Federal Public Service Mobility and Transport, the Royal Belgian Institute of Natural Sciences performed a study in which an advanced biogeochemical model was used to quantify the potential impact of SOx discharges from maritime traffic on water acidification in the southern North Sea. “In the English Channel and the Southern North Sea, the results show a pH decrease between 0.004 and 0.010 pH units (on a scale of only 14 units) among different maritime traffic scenarios” says Valérie Dulière, lead author of the study. “In areas of high traffic density, such as the shipping lanes along the Belgian and Dutch coasts and in the vicinity of large harbours, the pH changes can be 5 to 12 times larger than average. The modelled changes indicate a potential negative impact on the water quality in ports, estuaries and coastal waters” Dulière adds.

The estimated pH decrease attributed to the shipping sector is also significant when compared to the ongoing acidification resulting from climate change (0.0017-0.0027 pH units per year). The pH change in response to SOx pollution due to shipping with open-loop scrubbers is 2 to 4 times bigger than the contribution of climate change when averaged over the whole study area, and up to 10 to 50 times bigger in more local areas. The impact of ocean acidification due to maritime traffic should therefore be considered in ecosystem assessment studies, together with climate change.

The full report of the study can be consulted here: Potential impact of wash water effluents from scrubbers on water acidification in the southern North Sea_Final report.

Videos of the presentation of the study are also available:

– part1_Scientific background and study context

– part2_Methodology and assumptions

– part3_Results and conclusions

Given the important modelling conclusions, a precautionary approach is recommended. Policy, science and industry continue to work together to find ways to reduce the impact of sulphur compounds in the emissions and wash water discharges of ships.

 

After this study was completed, the COVID-19 crisis started to reshape the year 2020 in an unforeseen way. It is observed that the ship traffic density estimation for the year 2020 on which the calculations were based to estimate the quantity of SOx in emissions and wash water discharges is lower than expected. Nevertheless, this study still brings some very useful information on how the use of open-loop and hybrid (set in open-mode) scrubbers can contribute to the acidification of the southern North Sea, in a business as usual situation. It is also noted that the current unfavorable economic climate led to the cancellation of many orders for scrubber installations, and it is hoped that the companies concerned will consider switching to the use of low sulphur fuel when resuming normal operations.

The Royal Belgian Institute of Natural Sciences is also heavily involved in the monitoring of the sulphur emissions from ships at sea. More information on this can be found on the new website of the aerial survey team, the video that focuses on sulphur emission monitoring, and in the annual report 2019.

Framed in the national aerial survey programme, the scientific service MUMM performed a total of 246 flight hours over the North Sea in 2019. This contribution lists the most important results, with focus on the core tasks: surveillance of marine pollution and monitoring of the marine environment. Thirteen cases of operational discharges by ships have been observed, and suspect sulphur values have been measured in the smoke plumes of 51 vessels. With this sulphur emission monitoring effort, Belgium keeps on playing an international pioneering role which keeps on arousing interest, even from far outside Europe. The plane also successfully participated in an internationally coordinated surveillance mission of the oil and gas installations in the central part of the North Sea. Furthermore, some important marine mammal counts were performed, and windmill construction sites monitored.

Overview of Surveillance Flights

A total of 246 flight hours have been performed in the framework of the national North Sea aerial survey programme in 2019. This programme is organised by the scientific service MUMM (Management Unit of the Mathematical Model of the North Sea) of the Royal Belgian Institute of Natural Sciences, in collaboration with the Ministry of Defence. Most of the flight hours concerned national flights (183 hours):

• 173 hours in the context of the Belgian Coastguard
  • 129 hours of pollution control: 67 hours for the detection of discharges of oil and other harmful substances (MARPOL Annex I, II and V) and 62 hours for the monitoring of sulphur emissions from ships (enforcement of MARPOL Annex VI / SECA – Sulphur Emission Control Area, see below);
  • 43 hours of fishery control, on behalf of the Flemish Fishery Inspection Services;
  • 1 hour in response to a specific call for the search of a whale
• 10 hours for marine mammal monitoring

A smaller part (63 hours) was spent on international missions, of which 35 hours on sulphur emission monitoring in Dutch waters on behalf of the Dutch competent authorities, 24 hours on the Tour d’horizon-mission for surveillance of offshore oil and gas installations in the North Sea (an international mission framed in the Bonn Agreement), and 4 hours for an international oil combating exercise organised by the Netherlands.

Operational Discharges from Ships

Fortunately, the Belgian waters have not been affected by pollution as a result of shipping accidents (accidental pollution) in 2019. On the other hand, 13 cases of operational discharges from ships have been observed:

• One minor oil spill was observed in front of Ostend. However, the slick could not be linked to a ship.

• Twelve spills of other harmful substances than oil (MARPOL Annex II). In one of these cases, a detection by night, a link could be made with a ship. A port state control was requested in the next port of call. This made clear that it consisted of a permitted discharge of palm oil (MARPOL Annex II).

These figures show that although the number of oil spills has greatly decreased in the last decade (first graph), the number of spills of other harmful substances is still a common problem, and even appears to rise (second graph).

Oil Pollution in Belgian Ports

During transit (from Antwerp airport – the home base of the aircraft – to the North Sea), 2 oil spills have been observed in the port of Antwerp. These spills were immediately reported to the competent authorities to ensure follow-up.

Monitoring of Sulphur Emissions from Ships at Sea

In order to monitor compliance with the stringent fuel sulphur content limits for ships sailing in the North Sea Sulphur Emission Control Area, 96 hours of sniffer flights were conducted over the Belgian and Dutch waters. Of the 1241 vessels that were inspected at sea, 51 showed suspiciously high sulphur values in their exhaust plumes. These cases were systematically reported to the competent maritime inspection services for a further follow-up in port.

At this moment Belgium is one of the few countries performing such offshore monitoring of sulphur emissions of individual ships. The obtained experience and results, also in terms of subsequent port inspections of suspected vessels and pursuit of offenders, have led to considerable interest in Europe and beyond. In this context, the RBINS scientists participated in various international forums in 2019, including the « Shipping and Environment Conference » in Sweden, the « Sulphur Experts Meeting » in Denmark and the « European Maritime Safety Agency Surveillance Training » in the Netherlands. At  the BONN Ministerial Meeting 2019 The Belgian experience was a major driver to include MARPOL Annex VI in the work package area of the Bonn Agreement.

International ‘Tour d’Horizon’ Mission

During the annual TdH-mission for the surveillance of offshore platforms in the central part of the North Sea (in Dutch, German, Danish, Norwegian and British waters), performed in the framework of the Bonn Agreement, the Belgian surveillance aircraft detected 32 pollutions, 23 of which concerned oil detections that could be directly linked to offshore installations. 4 other detections could also be linked to platforms but could not be observed visually due to heavy fog. The 5 remaining detections – 3 oil spills, 1 detection of another harmful substance, and 1 detection of an unknown pollutant – were made without a vessel or platform in the vicinity. All these detections were systematically reported for further follow-up to the competent coastal State, in accordance with agreed international procedures.

Participation in International Oil-Combating Exercise

In April, the aircraft took part, together with the Dutch and German coastguard aircrafts, in an international oil combating exercise organized by Rijkswaterstaat (The Netherlands). The purpose of this exercise was to improve the knowledge on impact and efficiency of the use of dispersants, with manual removal being the first option in in Belgium and The Netherlands). The aircraft played an important role in mapping and monitoring the dispersed versus the naturally weathered oil spill at sea.

Marine Mammal Monitoring off the Belgian Coast

In June, 2 seals and 52 harbour porpoises (including 6 juveniles) were spotted. August brought along 5 seals and 42 harbour porpoises (also including 6 juveniles). The resulting estimate of average density was 0.72 (0.41-1.27) and 0.62 (0.38-1.00) harbour porpoises per km² of sea area, respectively, or about 2,500 and 2,100 animals.

In 2019, no less than 3 new offshore wind farms were built in het Belgian part of the North Sea. The marine mammal monitoring campaigns are carried out to monitor the environmental effects of these wind farms. The aircraft monitored to what extent the permit conditions regarding the correct placement of a « bubble curtain » were respected, which ensures a reduction in noise disturbance for marine mammals among others.

 

In order to clearly and completely summarise for the press and public the activities of the RBINS (MUMM) surveillance aircraft, the legal frameworks within which these activities take place, and the technical background of the tasks carried out, MUMM published a new website in March 2020. Be sure to watch the video that focuses on sulphur emission monitoring, one of the trademarks and pioneering tasks of the Belgian air surveillance.

Sorry, this entry is only available in Français and Nederlands.