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 Protection and Conservation of Biodiversity and Ecosystems

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 Protection and Conservation of
Biodiversity and Ecosystems

What are the problems?

Pressures are still present and even increasing

Pressures such as the removal of species (e.g. by fishing), loss of and damage to habitats, the introduction of non-indigenous species Chapter 9, obstacles to species migration and poor water quality are still present. Some pressures are even increasing in parts of the OSPAR area and all can act in synergy or be exacerbated by climate change. These pressures result in loss of biodiversity, including declines in the abundance and variety of species and habitats. Interruption of ecological processes, such as spawning, migration, and biological communication, may also occur.

Severe decline in some species and habitats

The most sensitive features are those that are easily damaged and slow to recover. Some never recover. Reefs of the cold-water coral Lophelia pertusa are slow-growing and delicate and can be severely damaged by bottom trawl fisheries. The common skate is a long-lived species that has a slow rate of reproduction and is particularly vulnerable to capture by bottom-trawl fisheries. Species that are near extinction over their entire range include the Azorean limpet, the European sturgeon, and the northern right whale. Numbers of blue whales in the OSPAR area are still at a low level and recovering only very slowly, despite more than 40 years protection from commercial whaling.

Lack of attention to conserving biodiversity

Historically, the management of human activities in the marine environment has not paid enough attention to conserving biodiversity. One of the reasons is that clear evidence of the impacts on species, habitats and ecological processes has only developed in recent decades and still remains scarce in some instances, especially for deeper waters. Another reason is that long-term sustainability has not always been the focus of management. Furthermore, the importance of biodiversity to the proper functioning of habitats is still being debated. OSPAR is working with other international bodies to remedy this, but national management plans still pay too little attention to impacts on species and habitats. Scientific knowledge and practices for assessing biodiversity status are still evolving and an adaptive approach to management planning needs to be used, taking account of better scientific evidence as it becomes available.

Pressures at the coast differ from those offshore

Coastal waters contain feeding grounds, spawning and nursery areas, and feature on migration routes for seabirds and some fish species. These areas also host intense and varied human activities, which exert a wide range of pressures and can lead to the damage or loss of key habitats in estuaries and intertidal areas. Salt marshes and seagrass beds, which are highly productive and act as natural carbon sinks, are under pressure from relative sea-level rise and coastal development. Key areas of the shelf seas, including offshore banks and reefs, and frontal zones between different water masses, play important roles in pelagic productivity. Fishing is recognised as a key pressure on species and habitats in the shelf seas and there continues to be a need for information about ecologically important areas to guide improvements in management.

Areas deeper than 200 m cover about 83% of the OSPAR area. The protection of marine biodiversity from human activities such as fishing or the future development of seabed mining and bioprospecting in these vast deep-sea areas is particularly challenging. The full extent of some specialised deep-sea habitats, for example hydrothermal vent fields, is still being revealed.

Box 10.1 Deep-sea vents and seeps

Hydrothermal vents occur around submarine hot springs or super­heated jets. The mineral-rich water supports biological communities that derive their energy from dissolved chemicals, such as hydrogen sulphide (H2S), rather than from solar radiation. One typical form of hydrothermal vent, a ‘black smoker’ is shown in the photo below (upper). The plume consists of hot water escaping from the seafloor containing (black) metal sulphides. Chemotrophic bacteria metabolise the H2S and support a unique community of animals that feed on them, or with which they have long-term interactions. The photo below (lower) shows a specialised community of hydrothermal vent shrimps. Hydrothermal vent fields in the OSPAR area (see map) occupy small areas of the seabed at depths of 850 to 4000 m, associated with the Mid-Atlantic Ridge in Regions I and V. Vents are relatively short-lived, generally existing for only a few decades, thus the exact number and locations of vents are not known.

Cold seeps occur where methane and H2S are released from the seabed at near-ambient temperatures and also provide energy for a bacterial-based food chain. They are common in European waters and can form a variety of large-scale to small-scale features on the seafloor. The Håkon Mosby mud volcano is one of the largest such features in the OSPAR area, measuring over 1 km across. The communities on different cold seeps frequently differ in terms of species composition. This indicates that there is a high variability in ecosystem processes and associated biodiversity at different spatial scales.

The physical structures of vents in particular may be at risk from activities such as mineral extraction, bioprospecting and, in future, tourism. Scientific research can also cause physical damage. Protected area designation is among the approaches being taken forward to manage human impacts on hydrothermal vents. OSPAR has agreed a code of conduct for responsible marine research in the deep seas and High Seas of the OSPAR area.

Background document for oceanic ridges with hydrothermal vents

Marine biodiversity still poorly known and understood

While knowledge of biodiversity in shallow, coastal areas has much improved over the past few decades, there are still large gaps with respect to the organisms and communities living in areas deeper than 200 m. Bacteria and viruses are thought to play a crucial role as drivers of food webs and global biogeochemical cycles, but this is not sufficiently understood. There are especially gaps in understanding how they will respond to environmental change caused by human activities, including climate change. There are also major gaps in understanding of bottom habitats and their functions for benthic species and communities. There is an ongoing need for major exploratory research initiatives to address these various gaps and support efforts to protect and conserve ecosystems and biodiversity.