Niger Delta mangroves

Nigeria has extensive mangrove forests in the coastal region of the Niger Delta. Considered one of the most ecologically sensitive regions in the world, the Niger Delta mangrove forest is situated within a deltaic depositional environment. These mangrove forests serve a critical role in regional ecological and landscape composition, and support subsistence gathering practices, and market-based income opportunities. Anthropogenic development threatens the survival of Niger Delta mangrove populations.
Mangrove forests are found in 118 countries and territories worldwide, 75% of mangrove vegetation zones are located in intertidal tropic and sub-tropic habitats situated between 25° N and 25° S . Typically surrounding salient river deltas, mangrove regions support a variety of halophytes. These robust shrubs and trees, which have adapted to changing coastal conditions (such as inundation, sun exposure, anaerobic soil, and salinity concentration), play a substantive role in cultivating the biodiversity and wellbeing of the surrounding landscape.
Mangroves are coastal wetland forests located in the intertidal zones of tropical and subtropical estuaries, saline backwaters, deltas, creeks, and lagoons. The mangrove ecosystem represents specific areas where mangrove plants flourish. These halophytic plants, including trees, shrubs, palms, and ferns, grow in the intertidal zones of brackish waters or estuarine wetlands in tropical and subtropical regions. This unique environment within mangroves influences the morphology, anatomy, and behavior of a community of organisms, showcasing local adaptations. The mangrove forests play a crucial role in coastal stabilization, minimizing the impact of wave action and wind energy on the shoreline, and acting as excellent inland structure defenders. They also act as carbon sinks, sequestering a significant amount of carbon annually. Despite covering a small percentage of the Earth's surface, mangroves account for a substantial portion of terrestrial carbon input into the ocean. Additionally, mangroves are highly productive ecosystems, supporting coastal populations' livelihoods directly and indirectly and providing habitats for various wildlife populations, including wading birds and seabirds. These forests also serve as essential sources of food, medicine, fuel, and shelter for many people, particularly those in coastal regions.
Mangroves have a crucial ecological function in stabilizing coastal areas by mitigating the effects of wave action and wind energy on the shoreline, effectively acting as natural defenses for inland structures. The mangrove plants and the sediments surrounding them serve as carbon sinks, capturing approximately 22.8 million metric tons of carbon each year. In fact, they are superior in carbon sequestration compared to other blue carbon ecosystems, making them a significant nature-based response to climate change. Despite occupying a small fraction of the Earth's continental surface (approximately 0.1%), mangrove forests contribute 11% of all terrestrial carbon input into the ocean.
Mangroves stand out as highly productive ecosystems globally, offering essential support to the livelihoods of coastal communities both directly and indirectly. They provide habitats and sustenance to diverse wildlife populations, such as wading birds and seabirds. Additionally, mangroves play a crucial role as a significant resource for food, medicine, fuel, and housing for numerous individuals in Nigeria, especially those residing in coastal areas.
The Niger Delta mangrove is the third largest in the world and the largest in Africa. Since the 1960s oil and gas exploration has become an important economic activity, resulting in significant alteration of the landscape via pollution, urbanization and invasion.
African mangroves have faced significant challenges in recent times, experiencing substantial losses. The decline, devastation, and deterioration of mangrove forests can be linked to several factors such as urbanization, quarrying, salt and sand extraction, pollution from industries and agro-industrial chemicals, as well as petroleum and gas exploitation. Additionally, the absence of adequate legislation and deforestation for fish smoking contribute to this issue. The mangrove forest zone in Nigeria not only enhances the socio-economic prosperity of rural coastal communities but also holds promise in shielding them from severe weather occurrences intensified by climate change. The anticipated rise in sea levels is expected to heighten flooding in coastal areas at lower altitudes, subsequently amplifying the physical and socio-economic susceptibilities of coastal urban centers. Nigeria has been acknowledged as one of the most susceptible African nations to climate change, and its impacts are currently manifesting in various regions of the country.
In Nigeria, there are more than 2,000 industrial facilities, with approximately 80% of them concentrated in the coastal areas, particularly in urban hubs like Lagos, Port Harcourt, and nearby regions. The industries in Nigeria's coastal zone encompass a range of sectors including oil and gas, petrochemicals, iron and steel, fertilizer plants, aluminum smelting plants, as well as diverse manufacturing industries such as textiles, food processing, plastics, pharmaceuticals, cement production, soap and detergent manufacturing, paint production, brewing, and wood pulp and paper production. Considering that a significant portion of Nigeria's industrial facilities are situated in coastal states, and a growing population resides and works in areas vulnerable to climate change, the significance of mangrove deforestation and degradation cannot be overlooked. Hence, this study delved into the origins of mangrove deforestation and degradation within Nigeria's Niger Delta Region, analyzing the repercussions within a swiftly evolving climate context.
Biologically, six mangrove species make up these forests, including three species in the family Rhizophoraceae (Rhizophora racemosa (red mangrove; tall), Rhizophora harrisonii (red mangrove; dwarf), Rhizophora mangle (red mangrove; dwarf)), and species in the family Avicenniaceae (white mangrove) and Combretaceae. Of these species, Rhizophora racemosa occupies the greatest density of the forest, accounting for approximately 90% of all mangrove biota. Despite expansive geographic coverage, the Niger Delta mangrove forest has approximately 80% of its vegetation distributed in three states (Bayelsa, Delta, and River states).
Although the forest is composed of six mangrove species, mangrove growth is primarily situated in brackish muddy creek banks. Studies have indicated that Rhizophora racemosa (which is the tallest mangrove species) reaches its optimized growth potential when exposed to brackish water and soft mud, whereas R. racemosa's relatives, R. mangle and R. harrisonii, favor higher salinity and hard mud. In its natural state, mangrove soil or “chikoko” (a mixture of acid sulphate, silty clay, clay loam and peat), has a pH of 4 and 6 for mangroves inhabiting low-tide and high-tide locations, respectively. If salinity levels shift too much from these levels, mudflats become unsuitable for mangrove production, and the process of mangrove reforestation (from infertile mangrove land to productive mangrove mudflat) can take upwards of one century.
Three mangrove tree families and a total of six species are found in the Niger Delta region: the red mangrove (Rhizophoraceae) including Rhizophora racemosa, R. harisonii, and R. mangle, the white mangrove (Combretaceae) known as Laguncularia racemosa, and the black mangrove (Avicenniaceae) represented by A. germinas. The global preference for planting red mangroves in human-assisted mangrove rehabilitation is due to the ease of planting red mangrove propagules either directly in the field or by raising seedlings in the nursery. However, it's important to note that each mangrove species has unique ecological significance beyond the general ecosystem goods and services provided by mangroves. Therefore, preserving the diverse species and genetic diversity of mangrove ecosystems is essential to conserve their unique ecological roles. For instance, the black mangrove (A. germinas) plays a fundamental role in the reproductive output, net survival, and ecological niche of the mangrove topminnow, Aplocheilichthys spilauchen, as it lays eggs on algal mats that grow on vertically protruding roots of the black mangrove.
Planting mangroves is not the sole technique for restoration. Other approaches include assisted natural restoration, such as reestablishing tidal connectivity, and community-based ecological mangrove restoration, involving ecosystem design. Recent literature strongly advocates for ecologically oriented restoration that considers the causes of mangrove loss and emphasizes community-based ecological mangrove restoration (CBMER). This is a vital approach, especially given documented failures in mangrove planting. Moreover, planted mangroves often exhibit restricted species richness, abundance, and biodiversity even after extended periods.
The International Union for Conservation of Nature (IUCN) categorizes biodiversity into three main types: ecosystem diversity, species diversity, and genetic diversity. However, countries like Nigeria, which are members of the Convention on Biological Diversity (CBD), have often not adequately addressed genetics in their national biodiversity strategies and action plans. Genetic composition sets an organism apart from other species and significantly influences its ability to adapt to changing environments and climate change. It can even contribute to the establishment of new species in certain cases. Many conservationists emphasize that conserving genetic diversity forms the foundation of all conservation endeavors because it is essential for evolutionary adaptability, a crucial aspect for a species' long-term survival. In genetics, conservation biologists have two main goals to ensure species survival: firstly, to preserve high levels of heritable genetic variation and prevent detrimental alleles from becoming dominant, which can lead to decreased fitness and the accumulation of harmful mutations.
The restoration of native mangrove ecosystems in the Niger Delta is crucial for safeguarding the forests' reproductive and productive fitness, evolutionary capacity, and adaptability to environmental changes. The objective of preventing harmful allele fixation is to mitigate reductions in survival and reproductive capability that small populations may experience due to limited genetic diversity. Therefore, a sustainable mangrove restoration approach involves incorporating species diversity to achieve broad and enduring results.
In the coastal areas of Nigeria, the mangrove forest is distributed as follows:
The Niger Delta mangrove forests play critical roles for 60% of local peoples who rely on the land and sea for survival. The forests contribute local therapeutic, amenity, heritage, spiritual, and existence values. Responses from a survey conducted in 2007 and 2008 evaluating mangrove social value in three Niger Delta communities indicated approximately 85% of participant households had previously utilized mangrove vegetation as a medicinal remedy and between 65% and 71% of villagers recognized the mangrove forests as a place of repose. Further, each study village relied on the local mangrove forest for carrying out cultural traditions (relying on forest as an ancestral burying site or place of festivity such as in Buguma), spiritual significance, and the survival of locally resource-dependent communities.
Another study evaluating the socio-economic importance of mangrove forests to 950 households residing in Akassa, Bayelsa revealed a strong connection between mangroves and the primary and secondary occupations of individuals living in proximity to the forests. The study noted that while not all residents’ vocations directly relied on mangrove resource extraction, all households depended on the forest for resources to fulfill their basic physiological needs (such as fuelwood, mangrove material for medicine, wood to construct shelter, and forest space for hunting sustenance staples like snails, fish and crab). The Niger Delta mangrove forests directly (through raw materials) and indirectly (through forest-based products) offer economically beneficial resources for Nigerian rural and urban communities alike, with eight out of the ten most lucrative vocations dependent on thriving mangrove populations. These occupations include canoe carving, logging, timber harvesting, building, fishing, sawmilling, traditional medicine, and trading.
The Center for Environment and Human Rights Development (CEHRD), a non-governmental organization situated in the Niger Delta region, collaborated with various stakeholders, including local inhabitants, initiating multiple initiatives. These initiatives aimed at educating the local populace in systematic mangrove restoration and conservation practices. The projects encompassed practical training and focused group dialogues involving local communities, governmental bodies, coastal restoration specialists, regulatory bodies, non-profit organizations, and the academic sector. These efforts resulted in the formulation of a viable framework for the restoration and conservation of mangroves. In the subsequent sections, we elaborate on the responsibilities of stakeholders in attaining sustainable mangrove restoration and conservation.
Mangroves in Nigeria are situated within the domains of local communities. This confers a crucial responsibility regarding the protection, conservation, and restoration of these ecosystems upon the neighboring communities. Successful mangrove restoration heavily relies on the support, approval, and active involvement of the community, constituting a significant prerequisite for success. For instance, community activities like artisanal crude oil refining have been reported to degrade mangrove ecosystems. Communities engage in such makeshift livelihoods to supplement subsistence and fulfill social or family obligations. Consequently, the expectations and perspectives of local communities should be incorporated into the project's objectives, planning, and execution. Mangrove restoration advocates, decision-makers, experts, and other stakeholders should mobilize and involve communities in the decision-making process. While community members may lack the technical expertise required for restoring degraded mangroves, they can identify potential endemic species that are threatened, endangered, or locally extinct, contributing to remediation and restoration decisions. Integrating this kind of indigenous knowledge can result in invaluable restoration outcomes. Additionally, community members can gather foundational data to support scientific research and reporting. Engaging the community in such capacities promotes inclusivity and ensures project ownership by the local communities, thus ensuring the sustainability of mangrove restoration efforts.
Transferring skills and knowledge constitutes a vital element of a mangrove restoration framework. Interactions between experts and the local populace create opportunities for mutual development and dissemination of knowledge essential for effective mangrove restoration and conservation. Collaboration and involvement of both experts and local communities, facilitated through practical training, public education on the benefits of mangrove restoration and conservation, and active participation in restoration efforts in the field, enhance ownership, support, success, and access to local advantages. Over time, community members gain restoration skills and become proficient in independently rejuvenating degraded mangroves. This transformation has been evident in the Oproama community, where CEHRD facilitated a community-driven science initiative to gather foundational data for the Oproama coastal environment.
Community engagement fosters unity and cultivates peaceful cohabitation within local communities. This stems from the cultural significance and symbolic meanings that mangroves hold in coastal communities. The involvement of mangroves in performing arts is a notable example. For instance, the wood of the black mangrove (Avicennia germinas) is employed in crafting "elumene" masks, and its twigs and leaves adorn the mouth of the hippopotamus masquerade during presentations. The process of ecological restoration can thus establish a connection between people and nature, kindling the local population's interest in environmental concerns and nurturing reverence and care for the ecosystems.
The governmental role in decision-making and policy direction is significant. Policies encompass how governments or private entities define, manage, and address public issues. In Nigeria, a range of policy documents and instruments exist at various governance levels. At the Federal level, provisions in the 1999 Constitution, as amended, specifically Sections 20 and 16(2), highlight the need for environmental protection. Additionally, the 1989 National Policy on Environment, the Millennium Development Goals Project, and various international conventions ratified by Nigeria outline actions for environmental protection and restoration. However, some of these instruments may not fully align with the goals and policy recommendations outlined in the Geneva Road Map. Concerns also persist regarding the effectiveness of these regulatory instruments in achieving environmental sustainability.
The government bears the responsibility of formulating and enforcing a sustainable legislative framework to enhance mangrove conservation and restoration. A robust regulatory framework is essential to guide, regulate, and influence human behavior towards sustainable coastal practices, ultimately leading to successful mangrove protection and restoration. While ecological conservation policies exist, few specifically delineate requirements for mangrove protection and restoration. A thorough review of the regulations, particularly those enacted post-1960s, reveals that many of them primarily established agencies, expecting these agencies to develop environmental regulations. For instance, the Petroleum Act of 1968 mandated the Minister of Petroleum Resources to develop regulations addressing environmental degradation caused by oil spills. However, since around 2001, the Nigerian National Wetland Policy, which would have been a direct wetland policy, has remained in draft form without necessary actions to formalize it into a regulation or law.
Legislative instruments play a crucial role in promoting sustainable mangrove management, encouraging ecosystem conservation by stakeholders through co-ownership and effective management. Such instruments can provide incentives for investment in mangrove restoration, especially by the private sector. For instance, legislative declarations rewarding mangrove protection through co-management approaches can incentivize community vanguards, ensuring sustainable mangrove harvesting. These regulations outline governance structures and define stakeholders' roles, including experts and various professionals, in mangrove protection and restoration processes.
Local ecological protection and restoration regulations are vital tools to curb detrimental environmental behavior and attitudes that contribute to ecological degradation. Existing ecological management regulations in Nigeria, however, often lack robust penalties and disincentives, inadvertently encouraging pollution and environmental harm. Addressing issues such as unsustainable mangrove harvesting necessitates contextual mangrove regulations within local communities. The government, as a decision-maker, holds the responsibility of establishing a network of mangrove protected areas, covering biodiversity hotspots to enhance conservation efforts. Developing sustainable mangrove policies that facilitate the creation of networks of mangrove conservation areas can act as a buffer zone, encouraging initiatives, research, and creativity towards mangrove conservation. Collaboration with research institutions, local communities, and charities is essential for developing localized mangrove restoration and conservation policies that drive investment, research, and mapping of endemic and endangered species for adaptive management. Participatory policies can drive community-led campaigns, fostering behavioral changes and encouraging ecosystem conservation. Engaging community volunteers in mangrove restoration is vital, and sustainable mangrove conservation policies promoting co-management frameworks can sustain community involvement in mangrove protection and restoration activities. Overall, effective legislative instruments and localized regulations are indispensable for the successful and sustainable management of mangroves.
Non-Governmental Organizations (NGOs) and charitable entities play a vital role in mobilizing various stakeholders, building capacity, and instigating behavioral shifts to achieve conservation and restoration objectives. NGOs focusing on environmental issues, like CEHRD, are pivotal in educating and enhancing the capabilities of local communities, government agencies, and other stakeholders in mangrove restoration processes. In 2005, CEHRD pioneered community-driven mangrove restoration in the Niger Delta through practical training, awareness campaigns, skill development, and collaborative mangrove replantation efforts in oil spill-affected mangrove areas in Bodo Creek. CEHRD has also published a user-friendly mangrove restoration manual specific to the Niger Delta. Similarly, the Mangrove Action Project (MAP), a prominent global advocate for mangrove conservation, regularly publishes content related to mangroves in its MAP Bulletin and has produced a guide for ecologically sound mangrove restoration. NGOs possess the ability to secure funding for mangrove restoration, a long-term endeavor requiring persistent education and sensitization efforts.
Many supported mangrove restoration projects span 3 to 5 years, allowing for short-term monitoring of initial success indicators. Consequently, NGOs are equipped to continually mobilize funding and engage in sustained monitoring of mangrove restoration initiatives. Their significant role lies in raising public awareness about sustainable mangrove management, fostering an ongoing process of restoration and conservation. NGOs mobilize the public to actively participate in environmental monitoring, promote environmental consciousness, encourage citizen science, and advocate for biodiversity conservation.
The private sector holds a crucial position in advancing mangrove preservation and rejuvenation. This involvement from the private sector can manifest as a corporate social responsibility project, a biodiversity offset, or restoration initiative driven by the polluter pays principle, or a deliberate endeavor to improve local livelihoods. Biodiversity offsets refer to quantifiable conservation achievements stemming from actions aimed at compensating for notable remaining negative biodiversity effects resulting from project development, even after appropriate efforts to avoid, minimize, and restore have been undertaken. There has been a suggestion for private-sector-led initiatives focused on mangrove rehabilitation and management. These initiatives could stem from donor projects or corporate social responsibility efforts. There are various private funding sources available for mangrove rehabilitation, either directly or facilitated through regulatory mandates, and tapping into these can significantly accelerate mangrove restoration and collaborative management initiatives.
The involvement of the private sector can be encouraged through collaborations between the public and private sectors. This could involve developers allocating funds for ecological restoration as compensation for utilizing land and resources and engaging in activities driven by corporate social responsibility initiatives. Private contributions could be generated to support community-driven restoration initiatives or government-led restoration efforts, incentivizing co-management through enhanced utilization of compensation mechanisms and rewards for ecosystem services. In the Niger Delta, a substantial portion of oil exploration and production activities occurs within mangrove areas. These activities involve clearing mangroves to create pipeline corridors, establish coastal flow stations, and set up oil fields like the Bodo West oil field located at the core of the mangrove region. The proximity and frequent interaction between oil facilities, daily operations, and mangroves in the delta heighten the susceptibility and adverse effects of oil pollution on mangroves. A well-defined contingency response strategy and implementation are essential to prevent or minimize the impact of oil on mangroves in case of accidents or sabotage. This is primarily achieved by efficient booming and skimming to prevent oil from reaching or obstructing mangrove vegetation in creeks. The National Oil Spill Detection and Response Agency (NOSDRA), established by the NOSDRA Act (2006), is responsible for preventing and managing oil spills in Nigeria. NOSDRA has formulated a national oil spill contingency plan that oil companies can customize to effectively safeguard mangrove ecosystems during an oil spill. In the event of mangrove oiling, the entity owning the facility should provide adequate funding for the cleanup, remediation, and restoration of the impacted ecosystem, adhering to the polluter pays principle.
Given the potential challenges outlined for establishing and executing a mangrove ecosystem restoration initiative in the Niger Delta region, overcoming these hurdles involves the identification of native ecosystems slated for restoration and the construction of benchmark models. These models are crucial for devising and conveying a shared vision regarding project objectives and aspirations, aiming to prevent ecological shifts or substitutions. These benchmark models should mirror actual ecosystems central to conservation and restoration endeavors, preferably depicting mangrove ecosystems with minimal to no degradation. In accordance with, six fundamental ecosystem characteristics can be employed to define the reference environment:
Disturbance refers to alterations in the environmental conditions that interfere with the normal functioning of an ecosystem. These disturbances can occur at various scales in terms of space and time and are a natural part of many ecological communities. Examples of disturbances include activities like sand mining, oiling, and urban development. It is crucial in the context of restoration and reducing human-induced effects to distinguish between disturbances caused by humans and those that occur naturally.
This type of disturbance is instigated by human activities such as urbanization and industrialization. People construct structures like bridges, shopping centers, roads, educational institutions, medical facilities, and more in cleared mangrove forests. These actions eradicate the natural wetland system and devastate numerous forms of biodiversity that reside in this habitat (e.g., barnacles, mussels, periwinkles, crabs, etc.). In the course of oil and gas exploration, humans deliberately clear large areas of forest by bulldozing to create space for setting up camps, oil wells, and crude oil pipelines. The pipelines are utilized to convey petroleum products from oil wells to the refinery, and finished products are transported back through pipelines to tankers for product evacuation at the port. These pipelines are established by creating a designated right of way passage (ROW) through deforestation. Additionally, crude oil spills occur from these pipelines due to either deliberate tampering or mechanical failure, resulting in extensive destruction of the mangrove forest.
Natural disturbances are events stemming from natural forces and phenomena. Examples of these events include floods, erosion, hurricanes, tsunamis, and earthquakes. These occurrences are guided by prevailing weather conditions and can result in substantial damage to mangrove forests, ultimately causing changes in their arrangement and the types of species present. Natural disturbances are significant factors influencing the ecological dynamics and stability of mangrove ecosystems.
Ecological Succession refers to the gradual changes in a community over time, especially after a disturbance. Typically, an ecosystem evolves from a simple state with a few dominant pioneer species to a more complex community with many interdependent species. During restoration, the goal is to initiate, assist, or speed up these natural successional processes, depending on the severity of the disturbance. In instances of mild to moderate natural or human-induced disturbances, restoration efforts aim to quicken the ecosystem's natural progression of succession.
Habitat Fragmentation refers to the spatial disruptions in a biological system, where ecosystems are divided into smaller segments due to alterations in land use (e.g., agriculture) and natural disturbances. This process diminishes the size of populations and amplifies their isolation. Consequently, smaller and isolated populations become more susceptible to extinction, while the fragmentation of ecosystems degrades the quality of the habitat.
Ecosystem Function refers to the fundamental and vital processes within any natural system, encompassing nutrient cycles and the flow of energy. A comprehensive comprehension of ecosystem functions is essential to address potential degradation of ecological processes. These functions are emergent properties of the entire system, highlighting the significance of monitoring and management for the long-term stability of ecosystems. In the context of mangroves, ecosystem functions encompass three main aspects: (1) Provisioning of goods and services such as timber, fuel, food, medicine, and dyes; (2) Environmental and ecological services including regulatory services like coastal protection and climate regulation, and supporting services like acting as nurseries, promoting biodiversity, aiding in nutrient cycling, and facilitating soil formation; (3) Cultural services like spiritual significance, aesthetic value, recreational opportunities, and educational purposes.
Community Assembly refers to a comprehensive framework that can encompass almost all aspects of community ecology within a single conceptual structure. The theory of community assembly endeavors to elucidate why sites with comparable environmental conditions harbor distinct species assemblages. The underlying assumption is that species possess analogous niche requirements, implying that the formation of a community is a result of random variations from a shared pool of species.
Recent evidence emphasizes the significance of genetic diversity alongside species diversity in reinstating ecosystem functions. Consequently, ecological restoration efforts are progressively incorporating genetic processes into their management strategies. These processes can forecast the likelihood of a species effectively establishing itself at a restoration site.
Pollution refers to the introduction of harmful or poisonous substances into the environment, causing adverse effects on its components. In the case of mangroves, a significant pollution source is hydrocarbon pollution. This pollution transpires during crude oil spill incidents, commonly resulting from punctured pipelines both offshore and onshore. When crude oil spills into the water, it coats the roots of mangroves, effectively suffocating them and causing their demise. The ramifications of oil pollution in mangrove forests extend to an escalation in heavy metal concentration, inducing toxic conditions that result in the death of immature mangroves.
The ecological importance of mangroves expands well beyond the resources of their roots and wood. Playing a key part in many fish, invertebrate, crustacean, and mollusk species’ lifecycles, mangroves offer organisms a breeding ground, shelter, and sustenance (mangroves are capable of producing 3.65 tons of leaf matter per hectare per year, which is a key contribution to the food web that supports juvenile fish). Mangroves offer these services to approximately 75% of the local commercially harvested fish population; in a properly functioning mangrove ecosystem, this means ~1.08 tons of fish can be supported by one hectare of mangroves each year. Mangroves are also used as shelter and breeding grounds by small mammals, shore birds, reptiles, and insects. One study analyzing local species dependency on mangrove populations in Pagbilao Bay, Quezon, discovered that nearly 128 fish species, 56 bird species, and 9 species of paneid shrimp relied on mangrove survival for breeding and shelter requirements.
Beyond supplying a sundry of basic biological needs to marine and terrestrial organisms, mangrove populations are also essential in preventing erosion and preserving the surrounding coastal landscape. UNEP research has demonstrated that the mangrove's robust build is efficient at reducing the total destructive capability of storms and wind surges by 70 to 90 percent. Mangroves also help protect the health and overall biodiversity of surrounding ecosystems by acting as a water filter. Filtration is enabled by the mangrove's capability to absorb and store heavy metals that would otherwise result in the release of metal pollution into nearshore water bodies. Mangroves are also efficient sites of carbon storage. Gail Chmura, scientist at McGill University, revealed a mangrove's carbon storing capability is greater than that of a terrestrial forest; per-year, mangroves are capable of storing 42 million tons of carbon/hectare.
There are many environmental threats to the mangrove forests in the Niger Delta.
Oil extraction is the largest threat to Nigeria's mangrove forests. Comprising 97 percent of Nigeria's total exports, the oil-rich Niger Delta produces up to two million barrels of crude oil a day, which has placed Nigeria as the 9th oil producing country in the world. Such extensive oil extraction has come at great environmental and social cost. Since 1958, the Nigerian Federal Ministry of Environment has estimated 13 million barrels of oil have been spilled during extraction processes. These spills are the product of many factors, which include: unenforced drilling regulations, refinery leaks, pipeline corrosion, vandalism, and human error. The total number of annual spills has gradually increased since 1958, from approximately 250 spills per year to 500 spills per year. The Nigerian Oil Industry, which primarily extracts oil amongst the Niger Delta mangrove forests, has consequently deforested mangrove ecological zones for drilling purposes, and deteriorated the health of the surrounding mangroves. Petroleum has toxicological impacts on mangrove trees, but also causes direct physical damage. The toxic effects of both surface-level and sediment deposit oil exposure on mangrove health has been repeatedly scientifically documented. In 1986, scientists analyzing the impact of the Bahía las Minas oil spill on coastal vegetation reported clusters of dying mangroves in proximity to where oil had washed ashore. On average, studies revealed mangrove fatality rates were highest during the first six-months of a spill; thus, fresh crude oil spills had greater toxicity than “weathered” oil. Other natural experiments noted that factors such as mangrove exposure to water currents and spill contamination control plays a substantive role in predicting the extent of oil damage on a mangrove population. Oil contact with mangrove seedlings also revealed extensive damage; when placed in the presence of crude, greater than 96 percent of mangrove seedlings died.
Petroleum, which comprises hydrocarbon compound contaminants such as PAHs (Polycyclic aromatic hydrocarbons), has been connected to plant chlorophyll damage. As a result of PAH root absorption, mangrove leaf pigmentation is altered, limiting photosynthesis. Regardless of oil toxicity or soil absorption capacity, mangroves can be fatally damaged from surface-oil spills as oil coats cells that allow oxygen to reach the roots, resulting in oxygen deprivation and incapacity of necessary biological processes.
Historically, petroleum's detrimental impact on delta biodiversity (including threatening mangrove existence) has sparked non-violent and violent citizen responses. Communities facing threats to health, livelihoods and prosperity from the economic, environmental, and structural injustice resulting from local oil extraction have reacted together to fight for the indigenous right to existence and Niger Delta resource autonomy. While some movements such as the Movement for the Survival of the Ogoni People (MOSOP) relayed demands through non-violent protest, other organizations have responded to repeated degradative practices and governmentally unenforced industry regulations through violence. Established in 2006, the Movement for the Emancipation of the Niger Delta (MEND) is a rebel militant group challenging wealth polarization, environmental disregard, and economic instability brought about by delta oil production. Through monkeywrenching industry equipment, blowing-up pipelines, and kidnapping oil workers, MEND seeks to fracture Nigeria's oil economy. Despite justifying their violent actions by the need to obtain justice, MEND is recognized by various international governing bodies as a terrorist organization.
In addition to mangrove degradation from regional oil extraction practices, mass deforestation has threatened Niger Delta mangrove populations. A study published in 2011 by Oluseyi Fabiyi revealed that anthropogenic development was the chief agent driving deforestation in Southwestern Nigeria. These anthropogenic factors included agricultural growth and urban expansion. Fabiyi argued these variables led to greater deforestation rates than forest clearing resulting from oil extraction.
In a GIS analysis of deforestation patterns of Niger Delta wetlands conducted by Glory Enaruvbe and Ozien Atafo in 2014, water body area in the target location decreased by 7 percent in 11 years (between 2002 and 2013), and forest area decreased by four percent. Enaruvbe and Atafo noted that locals’ perceptions of economic opportunity and increased demand for ecological services guided increased deforestation patterns.
Numerous elements contribute to the depletion and deterioration of the mangrove forest within the Niger Delta Region of Nigeria. These encompass reclaiming land for constructing settlements, establishing fish farms, building roads and electrical infrastructure, timber logging, gathering fuelwood, engaging in oil exploration/exploitation, along with activities linked to it, improper waste disposal, and the invasion of Nypa fruticans.
The development of infrastructure stands as a primary factor driving mangrove deforestation in the Niger Delta Region of Nigeria. In recent times, particularly with the establishment of the Niger Delta Development Commission (NDDC) after extensive years of advocating against the marginalization of the Niger Delta Region (where Nigeria’s primary crude oil reserves are located), endeavors to enhance infrastructure have been initiated. However, these initiatives occasionally lead to mangrove destruction. Land reclamation for residential and public infrastructure construction represents a significant danger to the mangrove ecosystem in the Niger Delta region of Nigeria. In various regions of the area, mangrove forests are being cleared to make way for housing and public amenities, such as schools, especially in mangrove areas adjacent to access roads.
Massive fish farming operations constitute a significant factor contributing to the deforestation and degradation of mangroves in the Niger Delta region of Nigeria. An illustrative instance is evident in Buguma, Rivers State, where ONIDA, an Israeli company, engages in extensive fish farming. The establishment of this fish farm, boasting over forty ponds, resulted in the devastation and filling of a substantial area of the mangrove forest, crucial for the livelihoods of the local population. The primary motivation for situating the farm near the mangrove is to ensure a consistent supply of brackish water necessary for cultivating the targeted fish species, particularly the Barramundi, which is cultivated and imported from Australia. However, the overall contributions of such endeavors to the rural economy, considering the importation of nearly all farm necessities, including fish feed from Israel or Australia, raise significant questions.
The mangrove forest serves as a timber source, with its species being extensively utilized as fuel for small-scale industrial boilers due to their high thermal capacity. The red mangrove, specifically Rhizophora racemosa, stands as the most heavily exploited species, employed for various purposes including firewood, poles, and timber. The escalating demand for fuelwood prompts the depletion of mangroves in multiple regions of the Niger Delta, driven by the necessity to fulfill household energy requirements and generate income.
The oil and gas industry significantly contributes to mangrove fragmentation, deforestation, and degradation in the Niger Delta. Activities such as oil drilling, spillage, dredging of canals, and the construction of housing for oil workers pose substantial threats to the survival and effective functioning of the mangrove ecosystem in this region. Oil spills and leakages have inflicted significant damage on Nigeria's mangrove areas, affecting not only the mangroves themselves but also the fishing economy and overall water quality.
Nypa fruticans (Nipa palm) – an invasive alien species, is another major threat to the mangrove ecosystem in the Niger Delta Region. The species which was introduced in Nigeria for the control of riverbank erosion has become a big menace to the mangrove ecosystem. The deforestation and degradation of the mangroves for firewood gathering, the construction of navigational canals, villages, and the activities of oil companies, encourage their replacement by this fast colonizer (Nypa fruticans) which does not provide the enormous ecological services provided by mangroves. Tackling the menace of Nipa palm invasion of the mangrove ecosystem requires a holistic approach that will discourage mangrove deforestation and degradation, complete removal of the species in invaded areas, and massive regeneration of degraded mangroves. The Secretariat of the Convention on Biological Diversity observed that restoration of degraded habitats in addition to reintroduction of native species can enhance biological diversity and also enhance the resilience of ecosystems against future invasions. Efforts should also be made towards discovering other uses of the Nipa palm that will be beneficial to man.
Defecation, improper waste disposal, and the unsustainable use of non-timber resources are additional contributors to mangrove degradation in the Niger Delta region. Instances of constructing public toilets that discharge waste directly into the mangroves and disposing of waste in their vicinity have become prevalent in the area. Equally concerning is the unsustainable utilization of non-timber resources such as fish, periwinkle, crab, and others.
A significant factor contributing to the loss and deterioration of mangrove forests in the Niger Delta is the noticeable inadequacy in enforcing the environmental impact assessment (EIA) regulations. Often, projects are carried out prior to conducting the EIA, and even when the assessment is conducted before project execution, the process is frequently marred by irregularities tolerated by representatives of pertinent agencies responsible for ensuring due process and upholding standards. In certain instances, approval is granted for projects with substantial potential negative environmental impacts. In the Niger Delta Region, multinational oil corporations frequently evade accountability for pollution and spills, particularly in marine and coastal ecosystems, unlike the stringent regulations observed in many developed countries. Strict adherence to and rigorous compliance with the stipulations of the EIA regulations are imperative for ensuring sustainable development.
Despite exploitation, fragmentation, and degradation, no policy has been enacted in Nigeria with the sole purpose to conserve endangered mangrove forests. Although neither federal or state institutions have ratified protection efforts, citizens of the Niger Delta states have banded together in attempt to defend the depreciating mangrove populations. One coalition, the Mangrove Forest Conservation Society of Nigeria, established in 1995, has spread its vision of establishing peaceful and sustainable coexistence between regional rural development and mangrove ecosystems across numerous Niger Delta cities (such as Asaba, Benin, Calabar, Lagos, Port Harcourt, Uyo, and Yenegoa).
Unintentionally affecting mangrove conservation, in 1989, the National Policy on Environment was developed in Nigeria. This policy resulted in 14.2% of Nigeria's land mass qualifying as protected area, securing 988 nationally protected reserves and 12 protected areas under international conventions. According to the Nigerian Department of National Parks, the reserves collectively represent a variety of Nigeria's most essential ecological zones; among these signified zones are tropical and wetland forests. Despite federally declaring these 1,000 sites protected, under-regulation and mismanagement has resulted in anthropogenic exploitation of reserve resources. Deforestation has been propelled by demand for bushmeat, timber, and vegetation.
Although mangrove conservation policy has yet to be established in Nigeria, published studies have demonstrated the affirmative prospective impact human intervention can have on remediating and protecting mangrove forests. A 2013 GIS study conducted by Oluwagbenga Ol Orimoogunje and Opeyemi Ajibola- James analyzed the recovery capability of oil exposed mangroves in two polluted Niger Delta sites. Both sites contained contaminated areas greater than 20 km in size, but one site was remediated whereas the other was not. Mangrove health was monitored for four time periods via RENA and GPS imagery spanning 1986 to 2007. In 1986 (pre-spill), both locations contained a Normalized Difference Vegetation Index (NDVI) value of .32. NDVI, which measures the amount of infrared energy produced by a plant, allowed researchers to determine the health of the mangrove study population based on the infrared levels reflected off the canopy surface. This number served as starting point to determine the quantitative impact oil pollution had on mangrove health. In 2000, six years after the spill, NDVI values had changed. The remediated site contained a NDVI of .30 where the non-remediated site was evaluated at .27. After 2000, NDVI values began to increase in both fields, but the remediated site's NDVI remained higher than the non-remediated site (2007 remediated site had a NDVI of .36 whereas the non-remediated site's was .34). This study suggested that oil caused a decline in vegetation area and health, but that with remediation, health was mostly recovered, compared to sites that were not remediated.
The impacts of mangrove deforestation and degradation in the Niger Delta Region of Nigeria are significant, particularly given the region's vulnerability to climate change. This paper explores these implications in terms of climate change mitigation and adaptation, as well as the socio-economic effects of extreme weather events caused by climate change.
The crucial role of mangrove forests in mitigating climate change is widely acknowledged globally. These forests are highly carbon-rich among tropical forests, primarily due to their abundant plant production and sedimentation from rivers and tides. Studies have shown that mangroves exceed the annual mean carbon sequestration rates of various terrestrial forest ecosystems, including tropical rainforests, temperate rainforests, and boreal forests. Remarkably, a significant portion of mangroves' carbon, about 50-90%, is stored below ground, providing long-term sequestration. When compared to terrestrial ecosystems, mangroves release more carbon to the atmosphere and oceans when they undergo degradation or conversion to other land uses. For instance, deforestation of mangroves results in substantial carbon emissions, amounting to about 0.02-0.12 Pg carbon per year, approximately 10% of global deforestation emissions, despite mangroves covering only 0.7% of tropical forest area. Consequently, the destruction of mangrove forests in the Niger Delta Region not only releases stored carbon but also diminishes their potential to sequester future carbon.
It has been well-documented that coastal regions are vulnerable to significant impacts from climate change, including issues like beach and dune erosion caused by rising sea levels, extreme weather events, changes in runoff patterns, and increased flooding. Communities along coastlines worldwide are already witnessing the consequences of these impacts, resulting in extensive damages and losses.
However, mangrove forests and other marine and coastal ecosystems such as seagrass meadows play a vital role in helping coastal areas adapt to the effects of climate change. These ecosystems offer a range of services that aid in climate change adaptation, including the prevention of shoreline erosion, protection against storms and sea-level rise, maintenance of coastal water quality, and the provision of food security for many coastal communities globally. Additionally, they serve to shield adjacent marine ecosystems, including coral reefs, from land-based pollution, while also serving as habitats for various fish and invertebrates, some of which have significant commercial value.
Consequently, the ongoing pace of mangrove deforestation and degradation in the Niger Delta Region, with no efforts towards restoration, will undeniably heighten the susceptibility of coastal communities in the area to extreme weather events. There is substantial evidence from various parts of the world that supports this argument. Instances from nations affected by the 2004 Tsunami affirmed the critical roles mangrove forests played in safeguarding lives and property. The waves infiltrated significantly inland where mangroves and other coastal ecosystems had been decimated, leading to widespread flooding of farms, destruction of homes, and loss of livelihoods. The four countries most severely impacted by the 2004 Tsunami—Indonesia, Sri Lanka, India, and Thailand—saw a 28% reduction in their mangrove forests between 1980 and 2000. It is also widely accepted that the destruction of mangroves and reefs intensified the devastation caused by the 2005 Hurricane Katrina in the coastal states of the United States.
The economic and social impacts of mangrove deforestation and degradation are significant. While specific figures for Nigeria are not available, according to, mangrove forests contribute an estimated US$33–57,000 per hectare per year in goods and services to the economies of developing countries with mangroves. Furthermore, over 100 million people residing within 10 kilometers of large mangrove forests derive benefits from them. The emissions resulting from mangrove loss constitute nearly one fifth of global emissions from deforestation, resulting in economic losses ranging from US$6–42 billion annually. Additional socio-economic consequences may encompass effects on public health, employment, income generation, shifts in population and ethnic patterns, and the necessity for relocating families impacted by extreme weather events.
Although there have been no specific assessments measuring the monetary contributions of mangroves, in terms of the services and products they provide, to the Nigerian economy, mangroves yield tangible benefits such as fuelwood, crabs, shrimps, honey, medicine, dyes, thatch, salt, and periwinkles. These resources are essential for sustaining rural livelihoods and represent significant sources of income for rural inhabitants, particularly those residing in coastal communities. Apart from these evident goods, mangroves offer intangible services by acting as a protective barrier for coastal communities and serving as important breeding grounds for fish.
The economic repercussions of mangrove deforestation and degradation in the Niger Delta Region are profoundly significant, especially given that the region houses the oil industry, a major contributor to Nigeria's wealth. Lubeck et al. (2007)A considerable presence of oil infrastructure, including over 600 oil fields, 5,284 on- and off-shore oil wells, 10 export terminals, 275 flow stations, 4 refineries, and an LNG project, all situated in the Niger Delta Region. Additionally, there are numerous subsidiary companies, investments, and a substantial human population in the area. Consequently, the current extensive mangrove destruction, coupled with extreme weather events induced by climate change, is poised to result in substantial and profound economic losses.