**4. Establishing protected areas around mangrove forest in the Niger Delta**

The mangrove forest in the Niger Delta needs urgent protection due to the adverse impact of human activities, which had resulted in the decimation of their populations in many locations. Unabated destruction of the mangrove forest will result in local extinction of these species. Therefore, to reduce human impact on mangroves, protected areas need to be urgently established to restrict human entry into forest. This can be achieved in three ways:


Restricted areas can be declared by both state and federal government as national park to prevent the exploitation of its resources by land speculators. Inspiration can

**57**

**Figure 3.**

*Mangrove Habitat Loss and the Need for the Establishment of Conservation and Protected Areas…*

1.Niger Delta mangrove forest zones: these are areas in Nigeria that have the highest concentration of aquatic organisms in Africa (**Figure 3**). The problem is that the area has not been formally recognized as a global biodiversity hotspot by international agencies such as the the International Union for the Conservation of Nature (IUCN). The species range from plankton (phytoplankton and zooplankton), aquatic invertebrates (bivalves, crabs, mussel, periwinkles, hermit crabs, etc.), land insects (beetles, butterflies, mosquitoes, ants and termites), and vertebrates (monkeys, manatee, hippopotamus etc). It has five major species of mangroves amongst others. These include: red mangroves (*Rhizophora* spp.), black mangroves (*Avicennia* spp.), white mangroves (*Laguncularia germinans* spp.), buttonwood (*Conocarpus* spp.) and mangrove fern (Acrostichum aureum).

2.Cape floristic province: it has the greatest non-tropical concentration of higher plants species in the world. Five of South Africa's 12 endemic plant families are

found in the Fynbos. One hundred and sixty species are endemic.

*Some species found within the Niger Delta mangrove forest: (A)* Senilia senilis*, Anadara; (B)* Crassostrea

gasar*, oyster; (C)* Tympanotonus fuscatus*, periwinkle; and (D)* Uca tangeri*, male crab.*

be drawn from the first national park i.e. the Yellowstone National Park, that was established in the United States, in 1872 by President Grant [18]. It measures 300 square miles and had geological features, which is of national interest. As for mangrove forests in the Niger Delta there are no major natural features therein that makes them to attract the attention of government for protection. Nevertheless, the interest in the mangrove forest in the Niger Delta lies in the extraction of their resources such as oil and gas exploitation and exploration, tree felling for firewood production and sand dredging activity. Although the mangroves have no geological significance it has ecological significance because of the numerous ecosystem services they render to the environment (e.g., coastal protection from tidal flushing, biodiversity hotspot). The Niger Delta mangrove forest is a global biodiversity hotspot. Global biodiversity hotspots are often determined based on species richness and endemism, which are all found in the mangroves of the Niger Delta. These areas include: tropical rainforest, coral reef, alpine forest and Mediterranean areas. Four notable global

biodiversity hotspots based on the assessment of the author are:

*DOI: http://dx.doi.org/10.5772/intechopen.89623*

### *Mangrove Habitat Loss and the Need for the Establishment of Conservation and Protected Areas… DOI: http://dx.doi.org/10.5772/intechopen.89623*

be drawn from the first national park i.e. the Yellowstone National Park, that was established in the United States, in 1872 by President Grant [18]. It measures 300 square miles and had geological features, which is of national interest. As for mangrove forests in the Niger Delta there are no major natural features therein that makes them to attract the attention of government for protection. Nevertheless, the interest in the mangrove forest in the Niger Delta lies in the extraction of their resources such as oil and gas exploitation and exploration, tree felling for firewood production and sand dredging activity. Although the mangroves have no geological significance it has ecological significance because of the numerous ecosystem services they render to the environment (e.g., coastal protection from tidal flushing, biodiversity hotspot).

The Niger Delta mangrove forest is a global biodiversity hotspot. Global biodiversity hotspots are often determined based on species richness and endemism, which are all found in the mangroves of the Niger Delta. These areas include: tropical rainforest, coral reef, alpine forest and Mediterranean areas. Four notable global biodiversity hotspots based on the assessment of the author are:


#### **Figure 3.**

*Habitats of the World - Biodiversity and Threats*

**3. Estimation of population viability**

not survive they are not viable.

data into the PVA.

into forest. This can be achieved in three ways:

2.By purchase of private lands

1.By law (public lands) for state or federal level

To understand the population dynamics of mangrove forest in the face of anthropogenic action, the minimum viable population size (MVP) needs to be estimated. It is defined as the smallest isolated population size that has 99% survival probability for 100 years period [17]. It is a crucial tool of conservation for the prevention of extinction of species. For perennial plant such as mangroves, it should have a minimum population size of 500–5000 individuals in a given location from year to year. This means any isolated forest below 500 tree stands is not a viable population and has the risk of going into extinction within a short time would be

high. Two methods can be employed in determining the MVP. They are:

1.Study of viability of population at different sizes: this method is like a trial and error where different isolated populations are observed for some time to see if there will be survival. If the tree stands survive they are viable, but if they do

2.Population viability analysis (PVA): this method is a mathematical model that can be applied to studying mangrove population. Here assumptions are made to simplify factors that cause population decline. This method can be used for any species to determine the viability of population. Two types of PVA approaches include: (i) count-based PVA: this involves the collection of information from a number of individuals in a population for a period of time. The steps include: (a) counting the population size for some time (b) calculating population growth rate each year, and (c) constructing a model that predicts future population size based on the growth obtained. (ii) Demographic PVA: it uses demographic information explicitly in the PVA. It incorporates life history

**4. Establishing protected areas around mangrove forest in the Niger Delta**

The mangrove forest in the Niger Delta needs urgent protection due to the adverse impact of human activities, which had resulted in the decimation of their populations in many locations. Unabated destruction of the mangrove forest will result in local extinction of these species. Therefore, to reduce human impact on mangroves, protected areas need to be urgently established to restrict human entry

3.By conservation easement, which would restricts developmental rights within mangrove forest. Deeds of property to land owners within and around mangrove forests should be revoked or restricted to prevent the destruction of mangrove forest for purpose of building or establishing of any kind of developmental project (e.g., resort). Furthermore, persons who own land within this area can be compensated and asked to relinquish ownership for the sake of conserving the forests.

Restricted areas can be declared by both state and federal government as national park to prevent the exploitation of its resources by land speculators. Inspiration can

**56**

*Some species found within the Niger Delta mangrove forest: (A)* Senilia senilis*, Anadara; (B)* Crassostrea gasar*, oyster; (C)* Tympanotonus fuscatus*, periwinkle; and (D)* Uca tangeri*, male crab.*


Biodiversity hotspots in Africa are more often grouped together without the recognition of the rich biodiversity across different locations. For instance, the entire forest biodiversity in West Africa was grouped as "West African forests" by [19]. Whereas, each country in this region possess rich supply of biodiversity. Niger Delta area in Nigeria has the third largest mangrove forest in the world, and the largest in Africa, i.e., 1 million hectare out of 3.2 hectare in the whole of Africa.

Based on the importance of the biodiversity hotspots to the environment, it is pertinent to protect them for future generation. This is because only 6% of the earth's surface is protected. Half of these are scientific reserves and national parks (1.3%). They vary greatly from country to country. There are already six major parks in Nigeria [7]. But there is a need for mangrove forest parks in critical areas of the region aimed at forestalling the degradation of the forest. Two kinds of protection to be considered (**Figure 4**) are


#### **Figure 4.**

*A design of (A) strict and (B) limited protection of mangrove forest in the Niger Delta, Nigeria. Limited protection has more accessibility and resource exploitation than the strict protection.*

**59**

**Figure 5.**

*Mangrove Habitat Loss and the Need for the Establishment of Conservation and Protected Areas…*

In the past, conservation of biodiversity hotspot was mainly focused on species richness, but now it considers ecosystem integrity, water quality, climate impacts, unique adaptations, ecosystem services, intact fauna and flora, specialized/unique

In other to establish priority for protecting mangrove zones, the following need

a.what to preserve in terms of species, community and ecosystem? Here the mangrove species (red, black and white) are to be protected along with other flora and fauna communities and the entire ecosystem in identified locations. In this type of protection, firstly, species approach and historical records can be used to determine endangered species, taxonomic uniqueness and endemic species. Secondly, the community and ecosystem approach (modern tactics) can be used, which focuses on protecting the ecosystem to preserve the communities and species within. In this approach, the species and ecosystem are not mutually exclusive. This is because if the ecosystem is healthy and intact, the species will equally be

b.where to preserve? (a) Gap analysis can be used: It is the use of various remote sensing data to build overlaid sets of maps of various parameters (e.g., vegetation, soils, protected areas, species distribution) to identify spatial gaps in species protection and management programs (**Figure 5**). This can be performed at local, regional and global levels. It is done for both threatened and common species. It is typically done using GIS via map overlays. However, the use of gap analysis is becoming old-fashioned because currently small drones called unmanned aerial vehicles (UAV) are now deployed to study forest including protected and unprotected areas (**Figure 6**). It can also be used to study the impact of invasion on man-

*A three-dimensional reconstruction of tree canopy and gaps within some mangrove forests captured with a DJI* 

*DOI: http://dx.doi.org/10.5772/intechopen.89623*

3.The goal of a particular protected area:

healthy and intact.

grove forest [20].

*drone at Eagle Island, Niger Delta, Nigeria.*

habitat and ecological processes.

to be considered:

*Mangrove Habitat Loss and the Need for the Establishment of Conservation and Protected Areas… DOI: http://dx.doi.org/10.5772/intechopen.89623*

In the past, conservation of biodiversity hotspot was mainly focused on species richness, but now it considers ecosystem integrity, water quality, climate impacts, unique adaptations, ecosystem services, intact fauna and flora, specialized/unique habitat and ecological processes.

In other to establish priority for protecting mangrove zones, the following need to be considered:

3.The goal of a particular protected area:

*Habitats of the World - Biodiversity and Threats*

are found in this area.

(**Figure 4**) are

mangrove research.

source of all agricultural production in the US.

3.California Floristic Province: has the largest avian breeding ground in the US. It has large number of endemic species with many threatened. It is the

4.Mountains of Southwestern China: it is the most endemic rich temperate flora in the world. Golden monkey, giant panda, red panda and snub nose monkeys

Biodiversity hotspots in Africa are more often grouped together without the recognition of the rich biodiversity across different locations. For instance, the entire forest biodiversity in West Africa was grouped as "West African forests" by [19]. Whereas, each country in this region possess rich supply of biodiversity. Niger Delta area in Nigeria has the third largest mangrove forest in the world, and the largest in Africa, i.e., 1 million hectare out of 3.2 hectare in the whole of Africa. Based on the importance of the biodiversity hotspots to the environment, it is pertinent to protect them for future generation. This is because only 6% of the earth's surface is protected. Half of these are scientific reserves and national parks (1.3%). They vary greatly from country to country. There are already six major parks in Nigeria [7]. But there is a need for mangrove forest parks in critical areas of the region aimed at forestalling the degradation of the forest. Two kinds of protection to be considered

1.**Strict protection**: in this type of protection, no resource extraction is allowed. Here trees will not be felled for firewood production and aquatic organisms will not be harvested for commercial or subsistence purposes. The sole aim of this kind of protection is biodiversity conservation. However, there might be some allowances for scientific and educational uses to increase knowledge in

2.**Limited protection**: Here some resource extraction can be allowed such as hunting, fishing, logging, use of stem for firewood production, tourism and recreation, etc. In this type of protection there is much more human impact, but the primary goal is the management of the natural resources for multiple goals.

*A design of (A) strict and (B) limited protection of mangrove forest in the Niger Delta, Nigeria. Limited* 

*protection has more accessibility and resource exploitation than the strict protection.*

**58**

**Figure 4.**


#### **Figure 5.**

*A three-dimensional reconstruction of tree canopy and gaps within some mangrove forests captured with a DJI drone at Eagle Island, Niger Delta, Nigeria.*

#### **Figure 6.**

*(a) RGB imagery of mosaicked mangrove forest at Eagle Island, Niger Delta Nigeria (Source: [20]). (b) Mosaicked image of mangrove forest that has been processed with visible atmospherically resistance index (VARI) to show areas of stress caused by Nypa palms and depicted by red and yellow color (Source: [20]).*

The protection of mangrove forest should follow the principles of reserve design such as:


In terms of size, the bigger the terrain the better for the proliferation of species. According to the species-area relationship, bigger reserve has more resource, greater population with greater biodiversity leading to lower probability of extinction [21]. This is because small populations are prone to more extinction of species than large populations. Similarly, rather than have one large reserve it is good to

**61**

**Author details**

Choba, Nigeria

Aroloye O. Numbere

*Mangrove Habitat Loss and the Need for the Establishment of Conservation and Protected Areas…*

have several small reserves (SLOSS problem), which will protect more species. This

Habitat loss and conversion are two major problems that can lead to the extinction of mangrove forest in the Niger Delta if not checked. This is because one or two stands of mangrove forest, which is made up of at least 5–10 trees are lost daily from this region as a result of deforestation for firewood (i.e., logging), sand dredging, urban development (e.g., roads, building of houses), etc. As the mangroves are brought down, their positions are quickly taken over by human structures such as roads, houses, industrial complexes and crude oil platforms. Areas that have not undergone infrastructural development, but have been disturbed by human actions contain scanty forests that become vulnerable to environmental pressures from invasive species, which had already completely taken over 60% of mangrove forest in the Niger Delta. Urgently, it is important to embark on deliberate protective measures, which can prevent the exploitation and plundering of the remaining

Department of Animal and Environmental Biology, University of Port Harcourt,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: aroloyen@yahoo.com

provided the original work is properly cited.

*DOI: http://dx.doi.org/10.5772/intechopen.89623*

mangroves resources in the zone.

**5. Conclusion**

is because isolation can stop the spread of diseases.

have several small reserves (SLOSS problem), which will protect more species. This is because isolation can stop the spread of diseases.
