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The problem of coastal ecosystems

Posted by lorenzo fantacuzzi in Climate Change, Nature, Pollution, 29 Aug 2010

Although the Mediterranean sea covers only one per cent of the world’s marine areas, it contains some six per cent of its marine species. Some of the world’s most endangered species, can be found in the Mediterranean. Fish stocks are down to 20 per cent of natural levels in some areas and the Mediterranean is now a net importer of fish.

Today, 82 million people live in coastal cities; by 2025 there will be an estimated 150-170 million. The southern countries account for 32 per cent of the region’s population; by 2025 that is expected to have reached 60 per cent.

Seasonal population pressures are also expected. Over 100 million tourists flock to Mediterranean beaches every year and this number is expected to double by 2025. In order to cater for this booming business, natural habitats have been replaced by modern resorts and the extra pollution generated is often dumped untreated into the sea, threatening the entire eco-equilibrium of the region.

The sea is also a major oil transportation route and up to one million tons of crude oil are discharged annually from accidental spills, illegal bunkering and tank cleaning practices, as well as inadequate harbour facilities.

Europe’s coastline is estimated to stretch almost 185,000 km. The terrestrial part of the coastal zones totals some 560,000 km2 in 24 European countries. Coastal regions host almost half of the human population of EU countries with a sea border.

The highest population density is found in the coastal regions of Malta, Belgium, the Netherlands, United Kingdom, Portugal, Italy and Spain, whereas the lowest population densities are in Estonia, Sweden, and Finland.

European coasts provide a vivid juxtaposition of natural and artificial environments. They are very rich ecosystems, providing vital and highly dynamic resources for nature, but are often also the most urbanised areas of these countries.The evolution of coastal habitats depends on changes of the land and inherently dynamic nature of the marine environment. Their varied habitats, including salt-adapted scrub and grasslands, sheer cliffs and rocky shores, sandy beaches and tidal areas, estuaries and lagoons, provide breeding grounds and habitats for marine organisms, as well as for waterfowl, shorebirds and other wildlife.

They are places where people live and work, providing ports and harbours, locations for industry and business, holiday destinations and areas for recreation and enjoyment. Their rich biodiversity, particularly fish and shellfish, is a major source of Europe’s food and economic prosperity

Europe’s coastal zones are under multiple pressures and face a large number of economic, social and environmental problems.Coastal habitats are fragile and are being destroyed to make way for housing, industry, agricultural land, and infrastructure for tourism and transport.

In 2006 the total area of coastal ecosystems was 21,030 km2, 26% made up of dunes, salt marshes and salt pans and the remaining 74% comprising intertidal flats, lagoons and estuaries. Europe’s coastal zones however have experienced rapid rates of development, with an increase in artificial surfaces between 1990 and 2000 of 7,5 %. In the period 2000–2006, this trend continued, with a 4,9 % expansion in artificial surfaces implying a slight acceleration in the annualised growth rate from 0,75 % to 0,82 %.

In a recent survey, the EEA (2010) shows how Mediterranean coastal wetlands have been under constant pressure from urbanisation between 1990 and 2000, particularly in Spain and southern Italy

Pollution from land-based activities reaches the coast through rivers, which can accumulate significant loads of agro-pesticides, nutrients, heavy metals and industrial chemical compounds.

In general, nitrogen and phosphorus loads in coastal waters have been decreasing since the 1980s due to improved waste water treatment. In some countries, however, waste water is still released directly into the sea without any prior treatment.

Eutrophication is an adverse change in ecosystems, which affects many coastal areas.It is caused by increased inflows of nutrients both from rivers and direct discharges, including precipitation.

High nitrate and phosphate loads lead to flourishing of blue-green algae, which can choke all other aquatic life through its high oxygen consumption. Blue-green algae can directly threaten human health, for instance in bathing areas.

As long-lived components of coastal ecosystems, sea grasses can serve as useful indicators of nutrient concentrations and water quality.

The recent global climate change has imposed additional pressure on coastal ecosystems by accelerating sea level rise, increased water temperatures, storms, erosion and flooding.

Coastal seas experiencing rapid surface warming are often surrounded by major industrial/population agglomerations, with likely direct anthropogenic influence.

Freshwater inflows play a particular role in modulating and exacerbating the global warming effects.

Alien species are a major cause of biodiversity loss and the highest numbers are found in the Mediterranean Sea. They can affect marine and coastal ecosystems through predation, competition, habitat modification and introducing pathogens.

Warming of marine and coastal waters and direct human destruction of habitats can assist the introduction of new (alien) species. Increasing water temperatures significantly affect the species composition and turnover of coastal ecosystems, as shown in benthic and rock dwelling species communities on the Swedish coast. Alien species become competitive with natives in changed environmental conditions when unintentionally (e.g. in ship ballast water) or intentionally transported into coastal waters (e.g. The Pacific oyster (Crassostrea gigas) in the northern Wadden Sea) in Europe

There is growing evidence that alien species tend to prosper in disturbed habitats and new ecological niches in both terrestrial marine coastal areas becoming invasive. In 2002, the EU recognised that the ‘coastal zone is of great environmental, economic, social, cultural and recreational importance to Europe’ and that ‘coastal zones possess a unique biodiversity in terms of flora and fauna’ in its recommendation for the implementation of Integrated Coastal ZonenManagement (ICZM) in Europe.

For the Mediterranean, fourteen Contracting Parties to the Convention for the Protection of the Mediterranean Sea Against Pollution (Barcelona Convention) signed a new Protocol on Integrated Coastal Zone Management in the Mediterranean in Madrid in 2008. Among a wide range of provisions, the Protocol calls for using the ecosystem approach to ensure sustainable development of coastal zones. In 2009, the European Commission adopted a Green Paper on Reform of the Common Fisheries Policy presenting a vision for restoring Europe’s fish stocks and achieving maximum sustainable yields, which would have a strong positive impact on coastal economies.

Together, the different policy instruments with their approaches and efforts to protect habitat types and species of Community interest can significantly contribute to safeguarding the prosperity and ecological status of our coastal ecosystems in Europe.

This is particularly so when supported by other policy instruments that aim to ensure good status of ecosystems, for example the EU Marine Strategy Framework Directive and the EU Water Framework Directive.

Indeed, the principle of  ’working with natural processes and respecting the carrying capacity of ecosystems, which will make human activities more environmentally friendly, socially responsible and economically sound in the long run’, which is set out in the EU ICZM Recommendation, should be used to guide the management of coastal areas and could arguably be used as the general principle for managing other ecosystems.

Many policy and legal instruments aim to improve the management of coastal areas, but they must be better streamlined in order to safeguard Europe’s coastal biodiversity. Coordinated action global, regional and local levels will be key to sustainable management of coastal ecosystems.

Lorenzo Fantacuzzi

Tags: Climate change, coastal, ecosystems, environmental, EU, Europe, Mediterranean, sea, warming, Wildlife & Flora