Category: news

To monitor the ecological impact of wind turbines at sea, our institute coordinates an extensive monitoring programme that detects the environmental effects. The programme is fully operational since 2008. A new report that describes the most recent results, has just become available.

As of 2016, 232 wind turbines are operational in the Belgian Part of the North Sea, with a total capacity of 870 Megawatt. To reach the national target of the production of 13% renewable electricity by 2020, the number of wind turbines in this area is planned to rise to 500. Together these will have a capacity of 2200 Megawatt, covering up to 10 % of the total electricity needs of Belgium. With 238 km² reserved for offshore wind farms in Belgian waters and 344 km² in the adjacent Dutch Borssele area, ecological impacts are inevitable.

The Royal Belgian Institute of Natural Sciences coordinates the monitoring, and specifically covers hydro-geomorphology, underwater noise, hard substrate invertebrates, radar detection of seabirds, marine mammals and socio-economic aspects. For soft substrate invertebrates, fish and seabirds, the programme relies on the additional expertise of Ghent University, the Institute for Agricultural and Fisheries Research (ILVO) and the Research Institute for Nature and Forest (INBO).

Due to the size of the area and the multitude of disciplines, comprehensive monitoring of the ecosystem in the wind farms remains challenging. The scientific follow-up focuses mainly on the disciplines that provide the most relevant information for the management. To safely differentiate between natural and anthropogenically induced variability, the programme is continuously being optimised.

Some remarkable results from the new report

Numbers, densities and biomass of invertebrates and fish living on or associated with the sea floor: the results indicate that the soft sediment ecosystem in between the turbines (at distances > 200 m) has not changed dramatically five to six years after construction, and that species assemblages within the offshore wind farms are mainly structured by temporal variability playing at larger spatial scales (e.g. temperature fluctuations, hydrodynamic changes, plankton blooms). However, plaice seems to be positively affected by the offshore wind farms. This could possibly be linked to locally increased food availability and/or the exclusion of fisheries inside the wind farms.

Biodiversity of natural hard substrates (e.g. gravel beds) versus artificial substrates (e.g. turbine foundations and scour protection): as natural hard substrates harbour a much higher species number and also more unique species than the artificial substrates, it seems that artificial hard substrates cannot act as equal alternatives for the loss of natural hard substrates.

Impact of underwater noise caused by pile driving activities on fish and marine mammals: in a field experiment with caged cod, the scientists detected a steep increase in swim bladder injuries with decreasing distance from the sound source. Additionally, many internal bleedings and a high degree of abnormal swimming behaviour were observed after piling, all hints for a reduced survival rate in the long term. With the current sound limits applicable to Belgian waters, negative effects of this type of underwater noise can occur in fish within a radius of 750 m from the pile driving location. During piling, harbour porpoise detections decreased by up to 75% up to 20 kilometre from the location of the piling event. Simultaneously, porpoise detections nearly doubled at larger distances, which may be due to active attempts of these animals to escape from the underwater noise.

Presence and behaviour of birds: Four species were shown to avoid the wind farm on the Thornton-bank (northern gannet, little gull, black-legged kittiwake and common guillemot), while three others (great black-backed gull, herring gull and sandwich tern) proved to be attracted. When zooming into the behaviour of some species, a continued study of the observed shifts (e.g. decrease of the time spent flying, foraging on fauna growing on the foundations) may shed a new light onto the anticipated collision risk of large gulls with wind turbines. Besides seabirds, also large numbers of non-seabirds are known to migrate at sea. As the victims disappear in the water and cannot be counted, a bird radar is used to unravel the migration patterns. In the future, the recorded bird fluxes will be analysed with an explanatory model, and the collision potential will also be estimated for such birds.

Over the past weeks, horrendous messages appeared in the press about grey seals that ‘shall’ attack swimmers along our coastline. Some nuancing is required.

Those that followed the media over the last two weeks must have noticed it : newspapers, websites and news programs on TV and radio warned for grey seals, which were portrayed as murderous creatures that make our beaches and coastal waters unsafe and will soon start violating tourists.

It all started with an article in La Dernière Heure (DH) « Il va y avoir des attaques de phoques en Belgique » (« There will be attacks of grey seals in Belgium »; Wednesday 9 August), based on an interview with our science communicator Kelle Moreau. Also the front page of the paper unequivocally and alarmistically advertised: « Alerte aux phoques tueurs à la côte belge » (« Warning for killing seals along the Belgian coast »). Het Laatste Nieuws (HLN) copied the message (« Seals will attack swimmers at the coast »), be it in a drastically reduced form in which particularly the sensation remained. Subsequently, the unfortunate message was spread widely, both by the French and the Dutch-speaking press.

We want to nuance a number of things :

The intention of the article in La Dernière Heure was to inform about the strandings of marine mammals and rare fishes on the Flemish beaches in 2016. Predation by grey seals was mentioned as one of the causes of death of stranded harbour porpoises, in the context of which the journalist asked whether it can be excluded that a grey seal would ever attack a human being. Our science communicator responded that such an event cannot be excluded, but that such cases would rather qualify as accidents rather than manifestations of aggression or attempted predation. Grey seals are big and strong animals, with substantial teeth and claws, that could easily wound a human being as a consequence of « disturbance » (of a resting animal on a beach, a mother with cub, …), « confusion » (a foraging animal in turbid water may mistake a human being for something else?) or even of playful behaviour. However, our biologists believe that the chance of such an interaction with a grey seal in our waters remains very small (but exists), and that panic is unnecessary. We must definitely not avoid our coastal waters and beaches, and the grey seal is absolutely not an unwanted guest on our coast. The only message is that we should realise that grey seals are predators, that we should have a healthy respect for these animals, and best leave them alone.

The fact that grey seals have harbour porpoises on their menu was also shown for the first time by researchers of our institute, after a few porpoises washed ashore in 2011 with wounds that – after analysis – appeared to have been inflicted by grey seals. Initially, this news caused great disbelief. Only after confirmation by analyses of foreign scientists, this new phenomenon was widely accepted.

As part of the implementation of the Royal Decree on marine species protection in the Belgian national waters, annual reports on observations and strandings of marine mammals in Belgium are compiled.

The new marine mammal report (download on http://www.marinemammals.be/reports) presents an overview of marine mammals and remarkable fish washed ashore in Belgium in 2016. It also focusses on the causes of death, revalidation and release of animals that were taken into care, and briefly introduces the research on the influence of offshore windmill parks on the harbour porpoise.

The most remarkable stranding of 2016 undoubtedly concerned a narwhal, an Arctic animal that was last observed in the North Sea almost 70 years ago. Also two humpback whales were seen, and a basking shark and two ocean sunfishes washed ashore.

With 137 animals, the number of harbour porpoises that washed ashore was again very high. The major causes of death were incidental catch in fishing gear and predation by grey seals. Harbour porpoises were shown to avoid an area up to a distance of 20 km during the construction of offshore wind turbines.

White-beaked dolphins were reported on one day only, in contrast to bottlenose dolphins that were regular and prominent guests again. In April a severely decomposed male bottlenose dolphin washed ashore, followed by a heavily decomposed dolphin along the Scheldt a few days later. The species could not be determined anymore.

The number of strandings of dead and dying seals remained similar to previous years: six harbour seals, 11 grey and 12 unidentified seals. SEA LIFE Blankenberge took care of record high numbers: 15 grey and 24 common seals, including an albino animal. No less than 12 grey and 20 common seals could be returned to the wild after revalidation.

In the Activity Report 2016 of our North Sea aerial survey programme published earlier this year, MUMM already mentioned the recent purchase of a new instrument, a so-called sniffer sensor, that allows MUMM to monitor the sulphur emissions from ships at sea with the surveillance aircraft.

These new “sulphur monitoring flights” of MUMM were initiated in the framework of the European pilot project ‘CompMon’, with the aim to facilitate and contribute to the enforcement of the stringent sulphur emission regulations as determined in Annex VI of the MARPOL 73/78 Convention and the European Sulphur Directive. The limitation of sulphur emissions from ships at sea is in fact a European top priority, for various important public health related and environmental reasons (fine dust, acid rain, climate change).

In 2016 MUMM monitored the sulphur emission of ca. 1300 ships at sea. For 120 of these ships suspect sulphur values have been measured (= ca. 10%). Each suspicious observation was systematically reported to the maritime inspection service of the Belgian Directorate-General for Shipping, for a further follow-up in port – if needed in cooperation with other competent port authorities in the framework of the European ‘Port State Control’ network.

The results and experiences gained from these flights have now been presented and discussed at the annual meeting of OTSOPA, the technical working group of the Bonn Agreement, held in Norway at the end of May 2017. The Bonn Agreement is the mechanism by which the North Sea States, and the European Union, work together to prevent and combat maritime pollution in the North Sea. It is under this agreement that the aerial surveillance efforts above the North Sea have been coordinated since the early ‘90s, although the initial aim was mainly to detect and combat oil spills at sea.

Following MUMM’s presentation on the remarkable results of the sulphur monitoring flights above the North Sea, OTSOPA agreed on the importance of this new type of surveillance mission. OTSOPA furthermore decided to submit a request to the next Contracting Parties meeting of the Bonn Agreement later this year to approve the start-up of sub-regional sulphur emission monitoring operations above the entire North Sea, coordinated in the framework of this agreement.

Earlier in May 2017, MUMM also presented the same offshore sulphur monitoring results to the annual meeting of the North Sea Network of Investigators and Prosecutors (NSN), who have decided to give a high priority to the prosecution of sulphur emission offences.

With these international efforts our country currently plays a leading role on the matter. In the meantime, MUMM continues to execute regular sulphur monitoring flights at sea.

Belgium’s Secretary of State for the North Sea Philippe De Backer reacts very positively: “With these controls Belgium really performs a pioneer role. It helps us keeping our North Sea clean. Also internationally these efforts are being noticed. It is therefore good that these controls will be extended over the entire North Sea region.”