The coastal zone and “Exclusive Economic Zone” of Sierra Leone covers an area of about 155,000 km2 from Kiragba in the north to Mano in the south. Sierra Leone’s coastline measures 560 km, much of which is sheltered. The sheltered coast is dominated by extensive mangrove systems (230 km) and mudflats. Only 150 km of the coastline is significantly developed or urbanized and this includes Freetown (the capital).
Currently about 70 hotels and tourist resorts are found along the Western Area Peninsula coastline. Elsewhere the coastline is largely undeveloped except for some fish landing sites and cold storage infrastructure used to process and store fish and shrimps. The contribution of the coastal zone to the national economy is significant.
The coastal zone of Sierra Leone is one of the most densely populated areas of the country and is already vulnerable to a number of natural and man-made hazards including inundations from the major rivers flowing through Sierra Leone to the coast, flash floods which come down from a number of rivers during the monsoon period and also saline intrusions due to decreased low water flows in the dry season. Because of all these characteristics the coastal zone of the country is particularly vulnerable to climate change impact.
This report provides a description of the coastal and marine environment of Sierra Leone as well as the oceanography of its coastal waters. The report further deals with the pressures and impacts of anthropogenic activities that directly affect the quality of the coastal and marine environment, such as fishing, shipping, ports and harbor development, submarine cable and pipelines, off shore hydrocarbon exploration and exploitation, other marine based energy industries and offshore mining industries. It looks at other uses of ocean space such as waste disposal/discharge, marine debris, tourism and recreation, and the potential impacts of climate change and sea level rise.
The report also provides a qualitative assessment of the state of the coastal and marine habitats as well as the current and future risks to the marine environment. The assessment is the result of the national workshop for production of the National State of the Coast Report, which was organized in Freetown, Sierra Leone from 4–7 February 2014. The methodology used at the workshop was based upon Expert Elicitation to assess the state of the marine environment in Sierra Leone. A total of 50 scientists and experts from Sierra Leone attended the workshop. The workshop was organized by the Environment Protection Agency of Sierra Leone, in cooperation with the Abidjan Convention and under the guidance of experts from GRID-Arendal.
The qualitative assessment of marine and coastal habitats showed that most habitats are still in good and very good condition, and the trend during the last 5 years has been stable. A total of 13 habitat types were assessed. Condition of the seabed habitat of the inner shelf zones are believed to be improving. This is related to restrictions on bottom trawling which were implemented in recent years.
A total of 29 biodiversity parameters (species and species groups) were assessed. On average, biodiversity is assessed to be still in good condition for most places. Some species and species groups have strongly declined during the past 5 years, and are in poor condition: shark and rays, some bird species such as terns, demersal fish assemblages, small pelagic fish species and crustaceans. Declines in fish stocks can be attributed to overfishing.
It can be assumed that the ecological functioning of the marine ecosystem along the coast of Sierra Leone is still largely intact, as large stretches of the coast and marine zone are unexploited and undeveloped with limited pressures on the marine ecosystem. Two ecological processes have been assessed: spatial and physical disjunctions and biological migration processes. Spatial/physical disjunctions are still in good condition as infrastructures (ports etc.) which impact the coastal and marine environment are still limited.
The condition of 16 physical and chemical processes has been assessed. On average, condition of physical and chemical processes, which are important to support marine habitats and species, are in a good to very good condition. An increased sedimentation is observed in several estuaries and bays along the coast and is problematic for these habitats (siltation). This phenomenon is related to intensification of agriculture and mining in inland areas. An increased turbidity is observed in the vicinity of Freetown. This is related to pollution, eutrophication and increased sediment and nutrient loads.
A number of pressures have been analysed for their impact on the environment and socio-economy. Artisanal fisheries exert little pressure on the marine environment, while it contributes significantly to the local economy and local communities. Industrial fisheries exerts a more profound impact on the environment, but it is assessed that the impact so far is still limited. Industrial fisheries scores high in terms of costs and benefits for the local economy and society.
The environmental impact of shipping is currently limited. The contribution of shipping to the local economy is rising, as shipping is increasing and brings economical developments. In general, considering the limited port infrastructure, the impact of ports in Sierra Leone on the overall marine environment is limited. Social and economic benefits are rising as new port developments are underway. Submarine cables and pipelines presently exert almost no pressure on the coastal and marine environment of the country, as there are very few. Benefits of submarine cables and pipelines are high considering the value for communication and transport. Exploration and prospecting for oil and gas is in progress. Oil pollution of the beaches from sources external to Sierra Leone is a common characteristic. Oil pollution is usually limited, but medium to large pollution events have been recorded with a temporary serious nuisance. At this stage no visible effect on the coastal and marine environment has emerged yet. Marine pollution can be serious in some spots but, most of the time it is almost insignificant in most places. Pollution due to untreated industrial wastewater is currently limited as the few industries in Sierra Leone are mainly of a nonpolluting type. The Freetown sewage waters get directly into the sea but they were formerly not considered as a serious pollution problem due to their limited volume. However, various reports and studies conducted in relation to coastal and marine pollution in Sierra Leone have revealed that the management domestic waste including sewage is a serious problem. The intense rate of urbanization is prominent along the Freetown Peninsula or Western Area, much of which is poorly planned or unplanned. Marine litter pollution hot spots are associated with this area. Marine litter also originates from shipping.
Tourism infrastructure along the coast of Sierra Leone is currently limited and little pressure exists from this sector on the marine environment.
A total of 12 potential risks for the marine environment in Sierra Leone have been assessed at the workshop. The assessment examined whether the risk is likely to exert a significant effect in a 5 or 50 years timeframe. The assessment is based on likelihood of occurrence and consequence for the environment.
Shipping, coastal erosion, climate change and mining are identified as high risk factors that could have a high impact on the marine environment within 5 years. Fishing, oil and gas exploitation, pollution, tourism, port facilities and overfishing were identified as significant risks to the marine environment within 5 years. Harmful algal blooms and eutrophication were identified as moderate to low risk within the 5 year timeframe. Considering a 50 year timeframe, the risks of all these factors will increase with several of the factors moving from the ‘significant’ to ‘high’ risk category. Eutrophication is considered as a moderate risk.
The general outlook for the coastal and marine environment of Sierra Leone could be said to have improved over the last five years. This is due to considerable awareness and positive national and regional actions which have resulted in conscientious environmental stewardship and its sustainability nationally and within the region.