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DAM PILOT MISSIONS

Exclusion of bottom trawling in protected areas of the North Sea and Baltic Sea

Two DAM pilot missions have been under way since March 2020, as part of the research mission “Protection and Sustainable Use of Marine Areas”, providing a unique opportunity to study the effects of excluding bottom trawling from marine protected areas in the North Sea and Baltic Sea. This so-called mobile bottom-contact fishing is designed to catch demersal (bottom-dwelling) fish such as plaice, sole, cod and shrimp.

Bottom trawling can have a significant impact on the seabed and the marine communities that inhabit it and can therefore clash with conservation objectives. For this reason, bottom trawling is to be banned in the coming years, at least in parts of Germany’s and Europe’s marine protected areas. The two DAM pilot missions offer a unique opportunity to observe how protected areas develop when bottom trawling is discontinued. Their findings form an important basis for an effective management of the protected areas.

In its research mission “Protection and Sustainable Use of Marine Areas”, the DAM brings together German expertise in marine research, integrating protagonists from specialist authorities, industry and nature conservation in order to come up with scientifically based courses of action for policy-makers. Protecting the North Sea and Baltic Sea and using them sustainably is a cross-cutting issue that affects fishery, domestic, environmental, transport, economic and scientific policies in equal measure, both on a national (federal and state) and a European level.

North Sea brown shrimp
North Sea brown shrimp | Picture: DAM

Shrimp, plaice, sole, turbot and cod are in great demand on our dinner tables. However, catching them can impair benthic habitats and cause large numbers of juvenile fish and other marine life to become by-catch.

 

Beam trawl used to target brown shrimp
Beam trawl used to target brown shrimp | Picture: Alfred Wegener Institute / Sina Löschke

Mobile bottom-contact fishing uses various types of bottom trawls: in beam trawling, a wooden or metal crossbar holds open the net, sliding across the seabed on shoes. When used to catch flatfish, the nets are fitted with tickler chains; beam trawls for catching shrimps are fitted with roller gear. Bottom trawls which are kept open horizontally by large rectangular otter boards are called otter trawls.

“Exclusion of mobile bottom-contact fishing in marine protected areas of the German Exclusive Economic Zone of the North Sea and Baltic Sea”
This umbrella term covers two pilot missions, in the North Sea and in the Baltic Sea. Short titles: “MGF North Sea” and “MGF Baltic Sea” („MGF“ stands for „mobile grundberührende Fischerei“, i.e. mobile bottom-contact fishing)

Pilot mission “MGF Nordsee”

Project partners:
– Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research AWI
– Carl von Ossietzky University of Oldenburg UOL
– The Thünen Institute Thünen
– Senckenberg am Meer, Senckenberg Society for Nature Research SAM
– Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research HZG

Project leader: Prof. Dr. Karen Wilshire (AWI)
Coordinator: Dr. Sabine Horn (AWI)
e-mail: sabine.horn@awi.de

Pilot mission “MGF Ostsee”

Project partners:
– Leibniz Institute for Baltic Sea Research Warnemünde IOW
– University of Rostock Rostock
– Senckenberg am Meer, Senckenberg Society for Nature Research SAM
– University of Cologne Köln
– The Thünen Institute Thünen
– Helmholtz Centre for Ocean Research Kiel GEOMAR
– German Research Centre for Geosciences GFZ

Project leader: Prof. Dr. Klaus Jürgens (IOW)
Coordinator: Dr. Christina Schmidt (IOW)
e-mail: christina.schmidt@io-warnemuende.de

LIFE ON THE SEABED IN THE NORTH SEA AND BALTIC SEA

Starfish
Starfish | Picture: Dirk Schories
Plaice on a sandy seabed
Plaice | Picture: Dirk Schories
Lumpfish
Lumpfish | Picture: Dirk Schories
Turbot
Turbot | Picture: Dirk Schories
Starfish on an bed of blue mussels
Starfish on an bed of blue mussels | Picture: Dirk Schories
Plumose anemone
Plumose anemone | Picture: Dirk Schories
Cod
Cod | Picture: Dirk Schories
Dover sole
Dover sole | Picture: Dirk Schories
Siphons of cockle
Siphons of cockle | Picture: Dirk Schories
Sea squirts
Sea squirts | Picture: Dirk Schories
Sea anemones and mussels
Sea anemones and mussels | Picture: Dirk Schories
Blue mussels
Blue mussels | Picture: Dirk Schories
Hermit crab
Hermit crab | Picture: Dirk Schories
Dahlia anemone
Dahlia anemone | Picture: Dirk Schories
Eelpout
Eelpout | Picture: Dirk Schories
Green sea urchin
Green sea urchin | Picture: Dirk Schories
Hooknose
Hooknose | Picture: Dirk Schories
Plumose anemones
Plumose anemones | Picture: Dirk Schories
Pipefish
Pipefish | Picture: Dirk Schories

CONTEXT: PROTECTION AND USE OF THE North Sea AND BALTIC SEA

The following paragraphs provide background information on the DAM pilot missions. More specifically, they describe the protection and use of those areas of the North Sea and Baltic Sea that are part of the German Exclusive Economic Zone (EEZ). Maritime spatial planning determines the ways in which these areas may be used and also specifies the marine protected areas. The framework for assessing the environmental status of the North and Baltic Seas is provided by the European Marine Strategy Framework Directive. Bottom trawling is one of the human uses that will be banned in the protected areas in the near future, in order to prevent negative impacts on benthic habitats.

Maritime spatial planning: Growing competition for space in oceans and seas

Advertisements for tourist destinations on the North Sea and Baltic Sea praise “the endless expanse of the sea”; but in many places, the vast horizons are interrupted by brisk shipping traffic and wind turbines. Just like on land, different ways of utilising the seas are increasingly competing for space, which is also limited in the North Sea and Baltic Sea. Shipping, offshore wind power, fishing, mining and other operations all require space, and so do the needs of environmental and nature conservation.

Maritime spatial planning is meant to reconcile the interests of the various different users and of marine and climate protection such as to enable future-oriented and sustainable developments. Some areas in the North Sea and Baltic Sea have been designated Marine Protected Areas (MPAs). In these areas, human interventions and exploitation are to be excluded or regulated in such a way that existing habitats with their biodiversity are preserved and the resilience of the oceans in the face of influences such as climate change is strengthened. In Germany, maritime spatial planning is governed by so-called spatial development plans, which apply to the Exclusive Economic Zone (EEZ), i.e. the area of sea extending from the territorial waters (12 nautical miles) up to a maximum of 200 nautical miles. These are the responsibility of the Federal Ministry of the Interior, Building and Community (BMI) and the Federal Maritime and Hydrographic Agency (BSH).

Beach atmosphere at the North Sea
Beach atmosphere at the North Sea | Picture: DAM

People spending their holidays along the coast of the North Sea and Baltic Sea can enjoy expansive views of the horizon from the beaches. Standing here, it is hard to imagine that the seas on our doorstep are among the most intensively used marine areas in the world.

Picture: Federal Maritime and Hydrographic Agency

Maritime spatial planning is meant to coordinate the interests of users and the needs of conservation to achieve a sustainable development of the seas. Corresponding spatial development plans are in place for the German Exclusive Economic Zone (EEZ) in the North Sea and Baltic Sea:

Marine protected areas: Conservation of ecosystems and biodiversity 

The German Exclusive Economic Zone (EEZ) in the North Sea and Baltic Sea contains six marine protected areas, which belong to the so-called Natura 2000 areas, a connected network of protected areas within the European Union. The protection of endangered wild fauna and flora in their natural habitats is governed in the Natura 2000 areas by the Birds Directive and the Habitats Directive. 

Marine protected areas are subject to management plans which set out conservation measures and their implementation. Generally speaking, individual uses are permissible as long as they do not prevent the conservation objectives for the specific site from being achieved. In Germany, the federal government – represented by the Federal Agency for Nature Conservation (BfN) and the Federal Ministry of the Environment (BMU) – is responsible for implementing these plans in the Natura 2000 areas within the EEZ. Measures for marine nature conservation are necessary in order to counter the destruction of habitats and the loss of biodiversity, as well as achieving a good environmental status for the North Sea and Baltic Sea, in accordance with the European Marine Strategy Framework Directive.

The Thünen Institute and the Federal Agency for Nature Conservation (BfN) are jointly working on proposals for fisheries-related measures in the areas of the EEZ covered by the Habitats Directive, with a view to striking a sensible balance between the need to protect the marine environment and the legitimate interests of sustainable marine fishery.

Picture: Federal Agency for Nature Conservation

The European network of protected areas, Natura 2000, aims to protect natural habitats as well as wild fauna and flora. The ten Natura 2000 areas in Germany’s Exclusive Economic Zone (EEZ) in the North Sea and Baltic Sea have been protected since 22 September 2017 in the form of six nature reserves:

Marine Strategy Framework Directive: Environmental status not yet good

Oceans play a central role for our climate, are among the most important ecosystems on earth, are rich in biodiversity, provide raw materials and food, serve as transport routes and offer valuable recreational areas. Seas and oceans influence human lives in many different ways. Healthy oceans, which are protected and used sustainably, are therefore of vital interest to society as a whole. The European Marine Strategy Framework Directive provides a uniform regulatory framework for the environmental status of the North Sea and Baltic Sea. It calls upon EU member states to take the necessary measures to achieve a good environmental status in the marine environment by the end of 2020, as described in that Directive.

The 2018 status report for the German North Sea areas states: “Marine biodiversity and marine ecosystems have continued to be subject to high pressures in 2011–2016. The areas of the North Sea that are managed by Germany have not yet achieved a good status.” The same wording is also found in the status report for Germany’s Baltic Sea areas. The causes of this poor status of the marine environment are complex; the reasons mentioned include:

  • pressure on benthic habitats, especially over large areas, due to bottom trawling
  • excessive influx of nutrients (“overfertilisation”) and pollutants
  • extensive exposure to marine waste and underwater noise
  • pressure on biodiversity and ecosystem functions due to invasive species and commercial fishing
  • in addition to the effects of climate change, which can amplify the negative impact.
Plastic waste
Plastic waste | Picture: Dirk Schories

Rubbish washed up on the beach is a visible sign of marine pollution. However, the bulk of pollution to the North Sea and Baltic Sea is invisible to us. Nevertheless, its effects can be grave.

Effects of bottom trawling 

So-called mobile bottom-contact fishing uses bottom trawls to catch plaice, sole, cod and North Sea shrimp. Such fishing methods can have a significant impact on the seabed and its inhabitants, bringing them into conflict with conservation objectives. A number of different research projects have shown that intensive fishing on the seabed can have a significant negative impact on the biodiversity and composition of the communities living there.

Habitats such as sandbanks, reefs, mussel beds or ross worm reefs can be damaged to varying degrees depending on the fishing areas and methods. Long-lived species and species that are sensitive to disruption, such as large mussels or sea urchins, are declining in favour of robust, opportunistic species such as worms or starfish. Another problem is by-catch: in addition to the edible fish that are sought, juvenile fish that are too small to be marketed also end up in the nets, as do mussels, snails, crabs, starfish and sea urchins. Many of these creatures are thrown back into the sea and do not survive. For this reason, bottom trawling is to be banned in the coming years, at least in parts of Germany’s and Europe’s marine protected areas. Until now, it has been permitted everywhere, notwithstanding the protection status.

Beam trawl on the fishing research vessel Clupea
Beam trawl on the fishing research vessel Clupea | Picture: Thünen-Institut für Ostseefischerei / Ina Hennings

Taking samples from the seabed: a 3-metre beam trawl on the fisheries research vessel Clupea, leaving Rostock in July 2020.

Ecosystem research and management in protected areas

At present, there are virtually no undisturbed seabeds in Germany’s North Sea and Baltic Sea areas. The DAM pilot missions therefore offer a unique opportunity to observe how marine protected areas – with their ecosystem functions and seabed biodiversity – will develop in the future if bottom trawling is discontinued. The results will provide an important basis for the future management of the protected areas in the North Sea and Baltic Sea.

In addition, the data from the first observations will form the basis for future monitoring, allowing changes to be detected in plenty of time, so that countermeasures or additional protective measures can be taken if necessary. The proposed measures are meant to help to achieve a “good environmental status” in the North Sea and Baltic Sea, in accordance with the European Marine Strategy Framework Directive, and to provide a basis for establishing potential sustainable uses. The initiative is being conducted in close cooperation with the Federal Agency for Nature Conservation (BfN) and is integrated into the DAM research mission “Protection and Sustainable Use of Marine Areas”.

Catch from a bottom trawl
Catch from a bottom trawl | Picture: Thünen-Institut für Ostseefischerei / Ina Hennings

Ended up in the bottom trawl: Catch for research purposes in the Fehmarn Belt, alongside a designated Natura 2000 site in July 2020. The basket contains flatfish (mainly dab, some plaice and flounder), herring and sprat, as well as a lumpfish (the greenish blue fish). Also valves of the ocean quahog.

Sorting a beam trawl catch
Sorting a beam trawl catch | Picture: Thünen-Institut für Ostseefischerei / Ina Hennings

Sorting the catch from a beam trawl off Nienhagen near Rostock in July 2020: many ocean quahogs live in the soft seabed and also end up in the net. Ocean quahogs can live to be over 30 years old in the Baltic Sea and over 200 years in the deep and cold waters around Iceland. 

Size analysis of turbot
Size analysis of turbot | Picture: Thünen-Institut für Ostseefischerei / Martin Paar

Analysing the size of turbot: In order to determine the status of fish stocks in the North Sea and Baltic Sea, fish are caught and measured for research purposes.

 

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