83
water-related controls on biodiversity. As in certain areas of Africa, Cameroon is
characterized by a strong climatic variation since 1960. The rise of pluviometry is
palpable on annual, seasonal and monthly scales. Significant studies on variability
and the climatic fluctuations in relation to the development and the environment
showed rainfall deficits of about 20%. These values might be sometimes higher than
25% on the Atlantic coast and in the forest areas that confirms that “wet” Tropical
Africa is regularly under the effect of climatic variability (WTO and UNEP 2008).
In Cameroon, human activities appear to be the main factor influencing the structure and dynamic of mangroves. Mangrove deforestation is occurring at a rate of
1–2% per year, which implies that most forests will disappear within this century
(Alongi 2002; Feka and Manzano 2008). These disturbances in mangroves have
been attributed to a combination of such factors due to the absence of adequate
legislation regarding mangrove protection, and pollution in the peri-urban settings
(Nfotabong-Atheull et al. 2013; Fusi et al. 2016). Rapid population growth has
affected resources, including arable land, food supplies, water and energy, especially in developing countries where government policy-makers still pay little attention to protect these coastal ecosystems (Dahdouh-Guebas and Koedam 2008;
Walters et al. 2008).
Cameroon mangroves are rather protected by both Law n°94/01 of 20th January
1994 on the Management of Forest and Fauna and Law n°96/12 of 05th August
1996 on the Environmental Management Legal Framework. Article 94 of the last
law stipulates that “Mangrove ecosystems need particular protection in relation
with their importance in the conservation of marine biodiversity and the maintenance of coastal ecologic balances”. However, the application of these laws and
other specific regulations is not effective in the field and consequently exposes
Cameroon coastal natural resources and areas to overexploitation and degradation
(Din 2001; Din et al. 2008; Nfotabong-Atheull et al. 2009).
Pollution which is neglected in coastal Africa constitute the principal form of
environmental degradation in more industrialized countries. The scarcity of relevant
data could justify the lack of interest in the effects of pollutants on mangrove ecosystems functioning. A recent survey shows that the degradation of Cameroon estuarine and marine environment is also due to pollutants (Fusi et al. 2016). The main
source of contamination in the mangrove forest surrounding Douala is represented
by uncontrolled discharge of urban wastewater and persistent, illegal and indiscriminate use of DDT. These contaminants, together with four specific heavy metals (As,
Cr, Zn, Se) seem to affect the macrobenthonic assemblage, suggesting that Douala
mangrove is subjected to a complex patchwork of contamination (Fusi et al. 2016).
Urbanization in this context has involved the development of infrastructures and
voluntary resettlements. The lack of state and local relevant planning programs, the
poverty and the permanent demographic pressure in towns accelerate the depletions
easily appreciable on a short time. Mangroves suffer therefore natural and human
pressures. Coastal erosion, invasion by weeds, sea-level rise and climate change
damage these ecosystems. Massive degradation of mangroves in Cameroon is
mostly observed near the coastal cities. High household demands for fuel-wood
greatly affect plant populations. Uncontrolled wood cutting, unauthorized settlements,
3 Impact of Urbanization on the Evolution of Mangrove Ecosystems…
water-related controls on biodiversity. As in certain areas of Africa, Cameroon is
characterized by a strong climatic variation since 1960. The rise of pluviometry is
palpable on annual, seasonal and monthly scales. Significant studies on variability
and the climatic fluctuations in relation to the development and the environment
showed rainfall deficits of about 20%. These values might be sometimes higher than
25% on the Atlantic coast and in the forest areas that confirms that “wet” Tropical
Africa is regularly under the effect of climatic variability (WTO and UNEP 2008).
In Cameroon, human activities appear to be the main factor influencing the structure and dynamic of mangroves. Mangrove deforestation is occurring at a rate of
1–2% per year, which implies that most forests will disappear within this century
(Alongi 2002; Feka and Manzano 2008). These disturbances in mangroves have
been attributed to a combination of such factors due to the absence of adequate
legislation regarding mangrove protection, and pollution in the peri-urban settings
(Nfotabong-Atheull et al. 2013; Fusi et al. 2016). Rapid population growth has
affected resources, including arable land, food supplies, water and energy, especially in developing countries where government policy-makers still pay little attention to protect these coastal ecosystems (Dahdouh-Guebas and Koedam 2008;
Walters et al. 2008).
Cameroon mangroves are rather protected by both Law n°94/01 of 20th January
1994 on the Management of Forest and Fauna and Law n°96/12 of 05th August
1996 on the Environmental Management Legal Framework. Article 94 of the last
law stipulates that “Mangrove ecosystems need particular protection in relation
with their importance in the conservation of marine biodiversity and the maintenance of coastal ecologic balances”. However, the application of these laws and
other specific regulations is not effective in the field and consequently exposes
Cameroon coastal natural resources and areas to overexploitation and degradation
(Din 2001; Din et al. 2008; Nfotabong-Atheull et al. 2009).
Pollution which is neglected in coastal Africa constitute the principal form of
environmental degradation in more industrialized countries. The scarcity of relevant
data could justify the lack of interest in the effects of pollutants on mangrove ecosystems functioning. A recent survey shows that the degradation of Cameroon estuarine and marine environment is also due to pollutants (Fusi et al. 2016). The main
source of contamination in the mangrove forest surrounding Douala is represented
by uncontrolled discharge of urban wastewater and persistent, illegal and indiscriminate use of DDT. These contaminants, together with four specific heavy metals (As,
Cr, Zn, Se) seem to affect the macrobenthonic assemblage, suggesting that Douala
mangrove is subjected to a complex patchwork of contamination (Fusi et al. 2016).
Urbanization in this context has involved the development of infrastructures and
voluntary resettlements. The lack of state and local relevant planning programs, the
poverty and the permanent demographic pressure in towns accelerate the depletions
easily appreciable on a short time. Mangroves suffer therefore natural and human
pressures. Coastal erosion, invasion by weeds, sea-level rise and climate change
damage these ecosystems. Massive degradation of mangroves in Cameroon is
mostly observed near the coastal cities. High household demands for fuel-wood
greatly affect plant populations. Uncontrolled wood cutting, unauthorized settlements,
3 Impact of Urbanization on the Evolution of Mangrove Ecosystems…