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Saltmarshes are among nature’s best defenses against rising sea levels, acting as natural barriers that protect coastlines. New research shows that dense vegetation on saltmarshes makes them more vulnerable to sea level rise because the vegetation hinders sediment transport. A surprising twist, as it was believed that dense vegetation played a crucial role in helping these ecosystems survive.

Using advanced computer modeling, the research team, led by Olivier Gourgue and Jean-Philippe Belliard from the University of Antwerp (Global Change Ecology Centre, department Ecosphere) and the Institute of Natural Sciences, examined how saltmarsh landscapes evolve over time. They discovered that while dense plants do trap sediment near tidal channels, they also block its movement toward the interior of the marsh. This means that instead of spreading evenly across the marshland, much of the sediment stays concentrated near the edges. Over time, this can lead to lower elevation levels in the marsh interior, making it harder for the ecosystem to keep up with rising sea levels.

These findings challenge the long-held assumption that denser vegetation always improves a marsh’s ability to survive environmental changes. By revealing how plant density affects sediment transport, the study, published in Limnology and Oceanography Letters, highlights the complexity of nature’s balancing act.

Saltmarshes and rising sea levels

A powerful numerical model called ‘Demeter’ was used to simulate 200 years of marsh development under different vegetation conditions. The model helped isolate the impact of plants on sediment movement, something difficult to observe in the field.

The computer predictions were later confirmed by real-world observations in China, where coastal areas with denser plant growth display the same uneven sediment patterns that increase vulnerability to rising seas. By combining their theoretical modelling with field observations published in Global Change Biology, Olivier Gourgue, Jean-Philippe Belliard and their collaborators provided a more complete picture of how marshes function over time.

Saltmarshes are critical for coastal protection, wildlife habitats and carbon storage. If they can’t maintain their elevation against rising seas, they may disappear. This would lead to increased coastal erosion, loss of biodiversity and reduced carbon sequestration.

Balancing sediment and vegetation

This research suggests that conservation efforts need to consider more than just planting more vegetation. It’s about understanding the entire sediment transport system and ensuring that marshes receive enough material to grow at a healthy pace. This carries important implications for policymakers and conservationists.

As Olivier Gourgue points out: “Coastal restoration projects often focus on planting more vegetation to stabilize wetlands. However, our findings suggest that encouraging a mix of plant densities or even allowing natural processes to determine vegetation growth may be more effective in the long run.”

Additionally, it’s crucial to ensure that sediment supply is maintained. Human activities such as damming rivers and dredging waterways can reduce the amount of sediment reaching saltmarshes, further endangering their survival and functioning as coastal protection. By understanding the delicate balance between vegetation and sediment movement, we can better protect these vital ecosystems and the benefits they provide for both nature and people.

The study that was published in Limnology and Oceanography Letters was the result of a collaboration between researchers affiliated to the ECOSPHERE Research Group of the University of Antwerp (Belgium), the Department of Earth and Environment of Boston University (USA), the Operational Directorate Natural Environment of the Institute of Natural Sciences (Belgium) and the Department of Physical Geography of Utrecht University (The Netherlands). For the Global Change Biology paper, the Belgian researchers collaborated with colleagues of the State Key Laboratory of Water Environment Simulation of Beijing Normal University, the Environmental Research Center of Duke Kunshan University and the State Key Laboratory of Estuarine and Coastal Research of East China Normal University (China).

A new European Marine Board Future Science Brief led by Professor Dr Sylvia Sander of GEOMAR Helmholtz Centre for Ocean Research Kiel warns that without better understanding of deep-sea ecosystems, sustainable management is impossible. The report, launched on 11 April 2025 via an online webinar, stresses the urgent need for targeted research and policy action to protect these critical but largely unexplored environments.

The deep sea, defined in this report as waters and seabed below 200 metres, makes up around 90% of the ocean’s volume. It plays a crucial role in biodiversity, climate regulation, and the global carbon cycle. Yet, this vast realm is increasingly threatened by oil extraction, fishing, mining, and climate change.

The European Marine Board’s Deep Sea and Ocean Health Working Group, comprising eleven researchers, presents ten key recommendations for sustainable governance and conservation. These include establishing an international scientific committee, improving environmental impact assessments, investing in long-term monitoring, enhancing education and technology transfer, and applying FAIR (Findable, Accessible, Interoperable, Reusable) data principles.

“The ocean is a connected system,” says Prof. Sander. “The deep sea cannot be managed separately from the rest of the marine environment.”

Historically considered inhospitable, the deep sea is now known to host complex ecosystems, including hydrothermal vents and abyssal plains. However, much remains unexplored. It’s estimated that 90% of deep-sea organisms are still undescribed, and key scientific gaps persist across physical oceanography, marine geochemistry, and ecosystem functioning.

Challenges in technology also hinder data collection. Current monitoring systems are often not suited for extreme depths, limiting our ability to track the impacts of activities like deep-sea mining. Understanding these systems is critical to ensure decisions are science-based and support long-term sustainability.

Human activities are already disrupting the deep sea, with warming, acidification, and oxygen loss accelerating due to climate change. Overexploitation of marine resources adds further stress. As the ocean regulates CO₂, produces over half of Earth’s oxygen, and supports life, its degradation poses global risks.

The authors see 2025 as a pivotal moment for ocean health. Achieving net-zero emissions by 2050 and curbing biodiversity loss now are essential to avoid irreversible impacts. “Climate change is one of the most alarming threats to life on Earth,” says Sander. “Combined with biodiversity loss, it could disrupt ocean systems permanently.”

Europe, the report suggests, has a unique opportunity to lead. Through strong international engagement and funding of transdisciplinary research, the EU can champion global deep-sea protection. This includes supporting underrepresented nations in research and recognising science as a human right.

Only through global collaboration and increased scientific investment can the deep sea, and the broader ocean, be preserved for future generations.

Download the publication here.

The Institute of Natural Sciences also focuses on research into the ecological structure and functioning of the deep sea. The assessment of the potential impact of human activities and the formulation of related policy advice are also given attention.

The Belgian Federal State is represented in the European Marine Board (EMB) by the Belgian Science Policy Office (BELSPO) and in the EMB Communication Panel by the Institute of Natural Sciences.

Early March, a passer-by found a dead dolphin washed ashore at the Scheldekaai in Burcht. The press attention for this exceptional find brought an even more remarkable fact to light: at the end of January, a ferryman had filmed a live dolphin further upstream in the Scheldt.

It was a strange surprise for Kobe Vercruyssen when he found a dead dolphin along the Scheldt in Burcht on 7 March 2025. The animal was lying about fifteen metres from the quay wall, and threatened to float back into the river with the rising tide. The news spread quickly via social media. Thanks to the quick response of Kobe and René Maes, who had rushed to the scene in the meantime, the carcass was tied to the quay wall with a rope so that it would not be lost.

After reporting to various authorities, the shelter ‘Wilde Dieren in Nood/Vogelopvangcentrum Brasschaat-Kapellen’ (VOC) eventually arrived on the scene to pick up the dolphin. The Antwerp fire brigade had to intervene to get the animal out of the water, after which the VOC brought the dolphin to the shed of the Agency for Nature and Forests (ANB) in Kalmthout for further examination.

Identification and cause of death

Analysis by ANB staff and the Mammal Working Group of Natuurpunt Antwerpen Noord & Kempen, in consultation with the Institute for Natural Sciences, determined that the animal was a young female with a length of 166 cm and an estimated weight of 70 to 80 kg. The skin was largely gone, making it difficult to determine what species it was. The teeth best match a common dolphin (Delphinus delphis), but a striped dolphin (Stenella coeruleoalba) could not be completely ruled out.

Because the carcass was already in an advanced state of decomposition, no exact cause of death could be determined. It was eventually taken away for destruction.

“The discovery and recovery of the Burcht dolphin was an example of rapid and efficient cooperation between citizens and various organisations, including Natuurpunt Waasland, Wilde Dieren in Nood/Vogelopvangcentrum Brasschaat-Kapellen, the Agency for Nature and Forests, the Institute of Natural Sciences and the Mammal Working Group of Natuurpunt Antwerpen Noord & Kempen. Despite the sad circumstances, this event offered a unique opportunity to study a rare marine mammal up close,” says Johan Neegers of the aforementioned mammal working group.

A surprising twist

The press attention that followed brought to light an even stranger fact, if possible. The discovery of the dead dolphin in Burcht reminded ferryman Nils Verbeeck of a special encounter that had happened to him more than a month earlier on the Scheldt, a long way upstream from Burcht. It prompted him to contact the Institute of Natural Sciences about it.

Nils appeared to have seen nothing less than a living dolphin in Hamme on January 31, 2025, and made a short movie of it that proved this beyond doubt. From the images it could be concluded that it was a common dolphin. It is very likely that this was the same animal that was found dead in Burcht 35 days later.

Common – and striped – dolphins are not adapted to life in rivers. They are species with a pelagic lifestyle, which means that they prefer the open sea and generally stay far away from coasts. Initially, it was suspected that the dead animal from Burcht had been drifted into the Scheldt by the tides, but this had to be adjusted based on the observation in Hamme. Why this dolphin swam so far up the Scheldt is not known. On the other hand, it is less surprising that she did not survive her visit to the river.

Rare appearance

Jan Haelters of the Institute of Natural Sciences explains how special the find is: “After the bottlenose dolphin and the white-beaked dolphin, the common dolphin is the most expected dolphin species in Belgian waters. Nevertheless, it remains a rare appearance here. In the past ten years, only a few cases of living common dolphins are known from our country, with an additional handful of observations where the identity could not be determined with certainty.”

Strandings of common dolphins are also rare in Belgium. On 22 December 2023, a recently deceased and therefore easily recognisable individual washed up in Ostend, but the other recent dolphins that possibly belonged to this species (one each in 2016, 2019 and 2020, and two more in 2023) were too decomposed to be assigned to this species with certainty. The common dolphin of Burcht and Hamme is not the first to be observed in the Scheldt, but as far as is known it is the one that swam the furthest up the river. In the Dutch part of the Scheldt, a common dolphin was observed near ‘s-Gravenpolder from the end of July to the beginning of September 2002. This animal was found dead in Saeftinghe on 8 April 2003.

The striped dolphin is even rarer in Belgian waters. This species has only been documented here with certainty twice: a stranding of a dead animal in 1981 and a sighting of a live animal from 15 to 19 May 2009. The latter also swam in the Scheldt (Doel and Verrebroek), did not survive this either and was found dead on 21 May of that year.

All persons and institutions involved are thanked for the smooth cooperation and flow of information. Forest rangers Bram Vereecken and Lucas Bergmans of the Agency for Nature and Forests respectively ensured the rapid internal reporting of the dolphin and the general coordination of the recovery and measurement of the carcass. Wilde Dieren in Nood/Vogelopvangcentrum Brasschaat-Kapellen ensured the transport to the ANB warehouse in Kalmthout.

Additional thanks go to Johan Neegers (Mammal Working Group Natuurpunt Antwerpen Noord & Kempen), René Maes (Natuurpunt Waasland), Jan Haelters (Institute of Natural Sciences) and Jaap van der Hiele (Stichting ReddingsTeam Zeediere, the Netherlands) for their cooperation on the text, and to Nils Verbeeck (Boottochten Jan Plezier), René Maes, Arlette Strubbe (Natuurpunt Waasland), Dafne Van Mieghem (Wilde Dieren in Nood/Vogelopvangcentrum Brasschaat-Kapellen) and Geert Steel (Mammal Working Group Natuurpunt Antwerpen Noord & Kempen) for providing the images.

On Wednesday 2 April 2025, the European Marine Board (EMB) will host its 9th Forum on ‘Addressing coastal and water resilience on the land-sea interface’.

EMB’s open Fora provide an opportunity to bring together the marine science and policy communities to jointly discuss important issues.

The 9th EMB Forum will discuss ‘Addressing coastal and water resilience on the land-sea interface’. This one day event will consider aspects such as policy and governance for the land-sea interface, pollution crossing the land-sea interface, and coastal adaptation and livability on the land-sea interface.

• Date: 2 April 2025
• Venue: Institute of Natural Sciences, Rue Vautier / Vautierstraat 29, 1000 Brussels, Belgium and online

A draft agenda for this event can be found here. Please note that some speakers are still TBC and will be confirmed in due course.

Registration for this event is open for both in person and online attendance. You can register here. Please note that in-person registration will close on Tuesday 25 March.

If you have any qustions about the event or your participation, please contact info@marineboard.eu

This event is being co-hosted by the Institute of Natural Sciences. This event is endorsed as being in support of the UN Decade of Ocean Science for Sustainable Development. It is also a recognised action in support of the EU Mission: Restore our Ocean and Waters.

The Belgian Federal State is represented in the EMB by the Belgian Science Policy Office (BELSPO) and in the EMB Communication Panel by the Institute of Natural Sciences.

The increasing noise of ships crossing the North Sea is changing the marine environment. A new large-scale study analyzing aerial observations of marine mammals and shipping data has shown that harbour porpoises avoid areas with heavy shipping traffic. This avoidance could disrupt their feeding patterns and social behavior.

Researchers combined aerial observations of marine mammals with data from the Automatic Identification System (AIS) of vessels to map the impact of shipping on the distribution of harbour porpoises (Phocoena phocoena). Shipping intensity was used as a measure of noise intensity. Underwater noise can disturb harbour porpoises and make their environment less suitable as a habitat.

Between 2015 and 2022, researchers in Belgium and neighboring countries recorded 6,511 groups of harbour porpoises. The study compared different variables, such as ship noise, ship proximity, and frequency of ship passages, to determine which factor best explained the presence, or absence, of harbour porpoises in certain areas. The international research team was led by Rémi Pigeault of the Institute for Terrestrial and Aquatic Wildlife Research (ITAW) at the University of Veterinary Medicine Hannover (Germany), with contributions from Jan Haelters of the Institute for Natural Sciences.

The results show a correlation between high ship density and the reduced presence of harbour porpoises. The further from shipping routes, the less porpoises were affected but the impact remained noticeable up to 9 kilometers away. The study, published in Marine Pollution Bulletin in November 2024, confirms the increasing impact of underwater noise on marine ecosystems.

The impact of maritime traffic

The North Sea is one of the busiest maritime regions in the world, and shipping traffic is expected to increase further due to the expansion of offshore industries such as wind farms and oil and gas installations. Shipping generates underwater noise that travels over long distances, affecting marine life.

Harbour porpoises rely on echolocation to hunt, navigate, and communicate. Their extremely sensitive hearing makes them vulnerable to noise pollution. Previous studies have shown that loud ship noises cause porpoises to exhibit avoidance behaviors, such as rapid diving, increased swimming effort and interrupted feeding.

The results indicated that models incorporating real ship movements predicted porpoise distribution more accurately than those based solely on theoretical noise levels. “The ‘forced’ displacement of porpoises due to shipping can limit their ability to search for food”, explains Jan Haelters.

Implications for conservation and policy

The study highlights the need to consider the impact of shipping on marine life and to take measures where possible. As Rémi Pigeault states: “With increasing ship traffic and the expansion of offshore industries, it is essential to implement measures that minimize noise pollution and protect important porpoise habitats before the disturbance becomes irreversible.”

One potential solution is the designation of marine protected areas where shipping activities are restricted to safeguard vulnerable species. Another approach involves developing technologies that produce less underwater noise pollution. Seasonal restrictions on shipping or other noise-intensive human activities in crucial feeding and breeding areas for porpoises could also be an effective measure.

This research provides valuable insights that can contribute to sustainable marine planning, ensuring that harbour porpoises and other marine species in the North Sea continue to thrive.

On Monday the 17^th of February, a fin whale was spotted at the C-Power wind farm in Belgian waters. This is the first confirmed sighting, backed by images, of a live individual of this species in Belgium in recent times.

It must have been quite a surprise when an employee of the C-Power wind farm noticed a large cetacean in the wind farm on Monday the 17^th of February, several dozen kilometers off the Belgian coast. The animal was filmed, and the footage was sent to the Institute of Natural Sciences, which coordinates the monitoring of the effects of offshore wind farms on the marine environment. The images allowed experts to identify the animal as a fin whale (Balaenoptera physalus), appearing to be a thin individual.

How rare?

All fin whales previously seen in Belgium and confirmed to be fin whales were dead specimens. A sighting of a fin whale at the C-Power wind farm is therefore highly exceptional. This is the first documented case, with images, of a living individual in Belgian waters.

In the 20^th century, three strandings of fin whales were recorded along the Belgian coast. Severely decomposed specimens washed ashore in 1939 and 1978, followed by the stranding of a recently deceased whale in November 1997 (Ostend). A piece of stranded skin in September 1994 (also in Ostend) could not be definitively identified as belonging to a fin whale.

Although six Belgian cases have been recorded in the 21^st century, they all involved dead whales. Four were fin whales struck by large ships. The first was observed only at sea (June 7, 2004), while the remaining three were found when ships entered ports (September 22 2009, Antwerp; November 9 2015, Ghent; August 29 2023, Antwerp).

A carcass spotted at sea on October 24, 2018, washed ashore in De Haan on October 25 under controlled conditions. Another dead whale drifted along the Belgian coast on September 30, 2022, before washing up in the Dutch town of Westkapelle on October 2.

An ocean giant with asymmetrical coloring

Reaching up to 27 meters in length, the fin whale is the second-largest whale species and thus the second-largest animal on Earth, surpassed only by the blue whale. It has a brownish-gray back and a white underside. A distinctive feature is its asymmetrical head coloring: the lower left jaw is dark, while the lower right jaw is white or light gray. The white right lower jaw is just visible in the footage taken at the C-Power wind farm.

Like many other large whales, the fin whale is a cosmopolitan species, meaning it is found in all major oceans, from polar to tropical waters. It feeds on krill, schools of fish and squid. The shallow North Sea does not provide an ideal habitat for the species. While fin whales generally migrate to northern feeding grounds in summer and southern breeding areas in winter, their migration patterns in the Atlantic Ocean are not well understood. Some individuals even remain in higher latitudes year-round.

Increase in Belgian cases

The population of fin whales in the North Atlantic is slowly recovering from the historical decline caused by whaling. Only Japan, Norway, and Iceland still allow whaling. A growing number of fin whales in deeper Atlantic waters increases the likelihood of a stray individual ending up in the shallow North Sea.

Additionally, the rising number of ships at sea has led to an increase in incidents involving large marine mammals. A significant portion of the fin whales that have ended up in Belgian waters died due to collisions with large ships, likely outside Belgian waters.

Finally, the chance of reporting unusual marine fauna – whether dead or alive – has greatly increased in recent decades due to the higher number of people at sea and the ease with which sightings, photos, and videos can now be shared.

In June 2024, the European Marine Board (EMB) published its Future Science Brief No. 11 ‘Marine habitat mapping’ during a ‘Brown bag lunch’ event hosted by DG Environment in Brussels. This document highlights current methods and future trends in the acquisition of data from the seabed and water column, discusses combining data to produce maps using modelling approaches and presents recommendations for adopting fit-for-purpose habitat classification schemes. It also provides an overview of what has been mapped within the European sea-basins, highlights the need to increase the quality and resolution of marine habitat maps, identifies critical gaps in habitat types and geographic extent, and describes the need to improve the assessment and communication of uncertainty and confidence in maps.

In October 2024, EMB launched its flagship foresight publication Navigating the Future VI “Placing the Ocean within the wider Earth system” in a dedicated event in Brussels. This document explores the critical role of the Ocean in relation to global climate, biodiversity, fresh water, and people, offering strategic direction regarding the future of marine research and policy. You can rewatch a recording of the event here and access the EMB slides here.

In December 2024, EMB published its Policy Brief No. 12 ‘Requirements for Coastal Resilience in Europe’. This Policy Brief presents key policy, scientific and community recommendations for building coastal resilience and enhancing the capacity to cope with impacts from coastal pressures, summarising the main messages and recommendations from the EMB Position Paper No. 27 “Building Coastal Resilience in Europe”. The recommendations from this document will be further discussed at the 9th EMB Forum on ‘Addressing coastal and water resilience on the land-sea interface‘ to be held on 2 April 2025 at the Institute of Natural Sciences in Brussels.

The way in which EMB publications and their high-quality science-policy recommendations contribute to the Ocean Decade and its Challenges are highlighted inside each individual document.

More EMB publications can be found here.

The Belgian Federal State is represented in the EMB by the Belgian Science Policy Office (BELSPO) and in the EMB Communication Panel by the Institute of Natural Sciences.