The Role of Mangroves In Coastal Protection and Biodiversity

AquaWorld Blog ARTICLES The Role of Mangroves In Coastal Protection and Biodiversity
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Source: Dateline.ng/Fateema Bello

INTRODUCTION

 Mangroves are high-salinity-tolerant trees that can provide exceptional benefits to coastal protection and biodiversity. They are a unique group of salt-tolerant trees and shrubs that thrive in intertidal zones and estuaries along tropical and subtropical coastlines (Vardi, 2023). These resilient plants have adapted to extreme environmental conditions, including high salinity, tidal fluctuations, and oxygen-deficient soils. They play a crucial role in maintaining coastal ecosystems by offering protection against erosion, supporting biodiversity, and acting as significant carbon sinks (Alongi, 2014).

Mangroves effectively capture and store large quantities of carbon in both their biomass and soil, making them vital for climate regulation (Vardi, 2023). However, these ecosystems face increasing threats from human activities such as urbanization, deforestation, aquaculture, and climate change, which contribute to their rapid decline (Bouillon, 2003).

Despite the well-documented ecological and socio-economic benefits of mangroves, they continue to be degraded due to weak enforcement of conservation policies at both national and international levels (FAO, 2007). Human-induced destruction accounts for over 60% of global

mangrove loss, primarily through land reclamation, deforestation, pollution, sedimentation, and alterations to coastal landscapes and water flow (Zamboni et al., 2022).

GEOGRAPHIC DISTRIBUTION IN NIGERIA AND WORLDWIDE

 Globally, mangroves cover approximately 137,760 km², with major concentrations found in Southeast Asia, South America, and Africa (Giri et al., 2011). In Nigeria, mangroves are primarily located in the Niger Delta, stretching across coastal states such as Bayelsa, Delta and Rivers. The country boasts the largest mangrove forest in West Africa, covering an estimated 10,000 km².

The Niger Delta, which is the Africa’s largest river delta, is home to the continent’s most extensive mangrove forest. It is one of the fastest-growing regions in terms of population. According to Nababa et al. (2020), the Niger Delta mangroves account for approximately 5% of the world’s total mangrove cover and represent the third-largest mangrove forest globally. Wang et al. (2016) also reported that the Niger Delta mangrove ecosystem spans roughly 36,000 km², reinforcing its status as the world’s third-largest mangrove forest. This vast ecosystem extends along the coastline, covering nine Nigerian states: Ondo, Rivers, Bayelsa, Cross River, Delta, Edo, Akwa Ibom, Abia, and Imo (Aransiola, 2024).

KEY FACTS/FIGURES OF MARINE MANGROVES GLOBALLY

 Mangroves span approximately 150,000 square kilometresacross 118 countries and territories (Wikipedia, 2025).

  • More than 40% of the world’s mangrove area is located in four countries: Indonesia (19 of the world total), Brazil (9%), Nigeria (7%), and Mexico (6%)” (FAO, 2020).
  • Conversion for aquaculture, rice cultivation, and palm oil plantations, accounted for 43.3% of global mangrove loss between 2000 and 2020 (Marice et al., 2024).
  • Nigeria is home to the largest mangrove forest in Africa and the third-largest in the world, following India and Indonesia. The Niger Delta alone contains approximately 1 million hectares of mangrove forests, making up a substantial portion of Africa’s total

3.2 million hectares (Paulinus, 2021).

  • Mangroves play a crucial role in preventing coastal erosion by stabilizing sediments with their intricate root systems. They also act as natural barriers, reducing wave energy by up to 66%, which significantly minimizes storm damage (Mazda et al., 2006).
  • These ecosystems are biodiversity hotspots, supporting over 1,500 species of fish, birds, and mammals, contributing to global ecological balance (Polidoro et al., 2010).
  • In the Niger Delta, around 60% of local communities depend on mangrove forests for their livelihoods. These forests provide essential resources such as medicinal plants, fuelwood, construction materials, and vital support for fishing activities (Wikipedia, 2025).
ECOLOGICAL AND ECONOMIC IMPORTANCE OF MANGROVES
  • Carbon sequestration and climate regulation:

Mangroves play an important role in mitigating climate change by serving as highly effective carbon sinks. They store up to five times more carbon per hectare than tropical rainforests (Donato et al., 2011). Their complex root structures trap sediments, helping to reduce coastal erosion while also protecting shorelines from rising sea levels and storm surges.

  • Nursery grounds for fish and marine life:

Mangrove ecosystems serve as essential breeding and nursery habitats for numerous marine species. Many commercially valuable fish, shrimp, crabs, and shellfish depend on mangroves during their early life stages. These habitats are critical for sustaining fisheries, supporting biodiversity, and ensuring the livelihoods of coastal communities (Nagelkerken et al., 2008).

THREATS TO MANGROVE ECOSYSTEMS 
  • Deforestation and urbanization:

Mangrove forests are increasingly threatened by deforestation due to urban expansion, logging, and agricultural activities. Studies estimate that 20-35% of the world’s mangroves have been lost in the past 50 years (Valiela et al., 2001). In Nigeria, large tracts of mangrove forests are cleared for infrastructure projects, aquaculture, and agriculture (FAO, 2020).

  • Oil pollution and industrial waste:

The Niger Delta, a region abundant in petroleum resources, has suffered extensive environmental damage due to frequent oil spills and industrial pollution. While mangroves have the ability to absorb pollutants, excessive contamination weakens their resilience, leading to ecosystem degradation. According to UNEP (2011), oil pollution has drastically reduced the biodiversity of Nigerian mangroves, threatening their long-term sustainability and productivity.

MANGROVE CONSERVATION EFFORTS IN NIGERIA AND GLOBALLY

Several initiatives have been implemented to protect and restore mangrove forests both in Nigeria and worldwide. Organizations like the International Union for Conservation of Nature (IUCN), the World Wildlife Fund (WWF), and the Mangrove Action Project (MAP) actively support mangrove conservation through research, advocacy, and financial assistance. Global frameworks such as the Ramsar Convention and the UN Sustainable Development Goals (SDGs) emphasize the importance of mangrove restoration (UNEP, 2019).

In Nigeria, the Federal Government, in collaboration with organizations such as the Nigerian Conservation Foundation (NCF) and Wetlands International, has promoted afforestation and sustainable resource management. Additionally, Marine Protected Areas (MPAs) have been established to safeguard critical mangrove habitats. However, despite these efforts, enforcement remains weak due to insufficient funding, limited community engagement, and conflicting land-use policies. Mangrove ecosystems continue to be threatened by illegal logging, oil exploration, and encroachment (Akie, 2016).

Local communities play a vital role in mangrove conservation. Engaging indigenous groups in reforestation programs, ecotourism, and sustainable fisheries can significantly strengthen

protection efforts. In Nigeria, community-driven initiatives such as the Niger Delta Biodiversity Project aim to restore degraded mangrove forests and promote sustainable resource use.

CONCLUSION

Mangroves are an important part of the ecosystem that provides critical environmental, economic, and social benefits. They act as natural barriers against coastal erosion, support rich biodiversity, and play a significant role in climate regulation by storing vast amounts of carbon. Despite their importance, mangroves continue to face significant threats from deforestation, urbanization, oil pollution, and weak conservation enforcement.

Efforts to protect and restore mangrove forests must be strengthened through stricter policies, better community involvement, and an increase in investment in conservation initiatives. By adopting sustainable practices, strengthening enforcement, and involving local communities, we can help safeguard mangroves for the future. Protecting these ecosystems is not just about conservation, it is essential for the well-being of coastal communities and plays a key role in tackling climate change.

Autor:  Osita Destiny Odoh

REFERENCES
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