Towards Implementing Integrated Coastal Zone Management in the Gambia: Coastal Adaptation to Climate Change and Human Impacts in the High Risk Zone
Our understanding of the impacts of climate change for a low-lying coastal state has increased exponentially since the Intergovernmental Panel on Climate Change Third Assessment Report. There is scientific consensus, based on an overwhelming number of reports and publications that the global climate is changing and there are large potential impacts of continued adverse consequences of hazards related to climate change and human impacts due to global warming. Warming of the climate system is clear. The pace and degree of change is considered unprecedented over decades to the millennia. The atmosphere and ocean have warmed, the amounts of snow and ice sheets have diminished, there are longer and more frequent marine heat waves and the concentration of greenhouse gas have increased.
Likewise, due to an increase in human use on coastal systems and low-lying area, the impacts of climate change is exacerbated by increasing human-induced pressures. These pressures which include drainage of coastal wetlands, deforestation and reclamation, discharge of sewage, fertilizers and contaminants into coastal waters have resulted in a dramatic increase of atmospheric concentration of carbon dioxide (CO2), methane and nitrous oxide. Equally, extractive activities such as sand mining and hydrocarbon production, harvest of fisheries including other living resources, the introduction of invasive species etc. also result to consequential impacts on the coastal ecosystem. The goods and services these ecosystems provide are of prime importance to environmental function and sustainability and include (i) providing food, fiber, fodder, shelter, medicines and energy; (ii) processing and storing carbon and nutrients; (iii) assimilating wastes; (iv) purifying water, regulating water runoff and moderating floods; (v) building soils and reducing soil degradation; (vi) providing opportunities for recreation and tourism; and (vii) housing the Earth’s entire reservoir of genetic and species diversity. However, they are reduced by a large-scale ecosystem conversion for agriculture, industry as well as urban development.
Coastal systems and low-lying states are predominantly sensitive to three key drivers related to climate change impacts. These are (i) sea level rise, (ii) coastal erosion and (iii) storm surges. As climate changes, coastlines are continuously shaped by these drivers and the impacts are progressively threatening coastal properties, infrastructure, cultural and aesthetic assets. Sea level rise for instance is recognized as a major threat since the issue of anthropogenic global climate change came into focus in the 1980s. The 2007 report of the Intergovernmental Panel on Climate Change (IPCC) presented sea level rise scenarios ranging between 0.18 to above 0.80.
Furthermore, in its Fifth Assessment Report 2013, IPCC stated that the rate of sea level rise has been on the increase since the mid-19th century and this scenario of change exceeds the mean rate during the previous two millennia. Additionally, Masson-Delmotte et al. (2018) noted that projected sea level rise will have adverse impacts on coastal systems and low-lying states resulting to submergence, coastal flooding and rapid spread of diseases and loss of biodiversity.
Many coastal states are experiencing shoreline erosion and ecosystem losses due to intense storm surges, flooding, altered wind patterns, offshore bathymetric changes and/or reduced fluvial sediment input. However, few studies have unambiguously indicated that since coastlines are retreating, sea level rise is not necessary the primary driver. Coastal erosion is one of the most apparent indicator of climate change and human impacts. It poses serious global threats to coastal landscapes and communities in the 21st century, and expose high concentrations of population and built assets to risk. Globally, it is estimated that as many as 20 million people live within the coastal and low-lying areas and over 200 million people at risk of short-term elevated sea level events leading to increased shoreline retreat with the resultant physical, ecological as well as economic damages. Threats and risks are expected to further increase if the status quo remains business as usual without appropriate responses including climate mitigation (a global response) and/or adaptation (a local response).
In a recent study, it has been pointed out that the African continent is among the most vulnerable continents globally to climate change and human impacts and The Gambia, for instance, though not a substantial contributor, is cited among the ten main nation’s most at risk from coastal erosion because of its Low Elevation Coastal Zone (LECZ) as 50% of it lies below 20 meters above sea level and a further 30% below 10 meters above sea level. This makes the country and coastal communities including the capital, Banjul, very vulnerable to coastal lost.
Predictions relate this to elevated sea level rise. For instance, Jallow et al. (1996) used the Aerial Videotape-assisted Vulnerability Analysis (AVVA) to predict a 1-meter rise in sea level. He concluded that because of the country’s low coastal elevation, 92km2 of coastal land area will be lost and this corresponds to 8.7% of the total land area of the country. Similarly, Brown et al. (2011) used the Dynamic Interactive Vulnerability Assessment (DIVA) model to project sea level rise scenario for the country. By comparing this with the 1995 levels, he projected a rise in sea level of 0.13m in 2025, 0.35m in 2050, 0.72m in 2075 and 1.23m in 2100. In the event this happens without suitable protection measures, the capital city is expected to be lost in the next 50 to 60 years and 76,000 people would have to be displaced. Moreover, ecologically sensitive sites in Kombo St. Mary (Kanifing Municipality) and those along The Gambia River are also projected to be lost as the shoreline is retreating.
Compounding this challenge is the high rate of poverty within these coastal settlements. In contrast to the rest of the country, coastal occupants in The Gambia are heavily dependent on the natural resources such as forestry and fisheries for their daily sustenance. As a consequence, this makes it challenging to adapt to changing and unpredictable weather patterns as well as respond to and withstand climate change and related human activities. Multiple national assessments, for instance the National Adaptation Programme for Action (NAPA) for The Gambia indicates that these impacts on the coastal zone will include increased frequency and intensity of floods and severe erosion, rapid urbanization paralled by clearing of forests and woodlands and overfishing of particular species. As a result, this will lead to loss of livelihoods and biodiversity as well as destabilizing macro-economic growth and food insecurity thus promoting an increase in internal migration.
Like many coastal States, the 81km coastal zone of The Gambia serves as a zone of economic importance where its port, majority of tourism infrastructures, artisanal fishing activities as well as cultural and aesthetic practices prevail. However, these structures of economic and social importance as well as areas that support biodiversity (e.g. nesting grounds for marine turtles and migratory birds) are thus threatened by high rates of coastal erosion and other anthropogenic activities. It is estimated that about 200-300,000m3 of sediment are being eroded annually by a longshore transport to the south, towards The Gambia River which acts as a sediment trap.
To address these challenges, the Government of The Gambia undertook a beach nourishment programme in 2004 with the objective of reclaiming the lost land pursuance to protecting the tourism industry and other infrastructures as well as preserving ecologically sensitive sites from being lost. Despite this intervention, there were concerns as to whether this adaptation programme has effectively served the purpose since most of those reclaimed areas have been lost again. This was due to the fact that there has been massive sand mining from the beach over a stretch of several kilometers in the southern coastline resulting to sand deficit. This problem has increased the natural sand deficit by a factor of 3 to 4 causing erosion rates of the order of 4 to 5m per year in this area.
Given the lack of institutional and adaptive capacity to systematically identify and address these challenges in risk patterns, is the need to consider an integrated approach involving all the relevant stakeholders in order to come up with an effective line of action to avoid maladaptation within the coastal zone of The Gambia. Therefore, is the need to develop a blueprint towards implementing an Integrated Coastal Zone Management (ICZM) strategy/approach for the coastline of the country as a means to adapt to coastal erosion and other human activities, otherwise, the beach and the infrastructures within including the ecosystem components along this coastline will disappear resulting to more investments by the Government and its development partners in coastal adaptation.
Lamin Komma is a Senior Program Officer and Head of Coastal & Marine Environment Program National Environment Agency. MSc, Ocean Sustainability, Governance & Management – World Maritime University, Sweden. MSc, Tropical Marine Ecology & Fisheries Biology – James Cook University, Australia