DIVERSITY OF MANGROVE VEGETATION OF AKWA IBOM STATE COASTAL ECOSYSTEM.
This work shows a relative abundance of Mangrove in Eastern Obolo riverine areas which is carried out in two strategic locations (such as Okoroete, Iko estuary (Bella creek) all in Eastern Obolo L.G.A.).Iko riverine area and Okoroette riverine area is dominated by true mangrove such as the Red mangrove (28%), Black mangrove (72%) of the total abundance of the true mangrove and the Nypa palm (Nypafruitican). Mangrove forests are the world’s most productive ecosystems. They enrich coastal waters, yield commercial forest products, protect coastlines, and support coastal fisheries. True mangrove was seen to be in high density at Okoroette as the species richness (d) is high (6.523018) in Okoroette and less (4.519672) in Iko (Bella creek), but species abundance is slightly higher in Bella creek (0.544706) than in Okoroette (0.448609). This could be as a result of excessive cut down of mangrove tree at Bella creek for domestic and industrial use by the host community while Okoroette is experiencing growth and recruitment of new individual mangrove plant in the area which will and have contributed to the physical, chemical and biological stability of the area. Mangrove forests in the Niger Delta region of Nigeria have been deforested and degraded to a large extent due mainly to anthropogenic pressures. There is a need for mapping and strict protection of the remaining mangrove forests in the region. Massive regeneration of deforested and degraded mangrove areas should be carried out urgently, for enhanced ecological roles, socio-economic wellbeing of the people, and climate change adaptation/mitigation. Nypa palm threatened Nigeria's coastal extensive mangrove vegetation by displacing the mangrove stands and establishing itself in a mono-specific manner, the reduction of the potential for natural mechanisms for control of coastal soil erosion and causes general habitat conversion and biodiversity loss with the attendant reduction in biological production potentials of the ecosystem.
TABLE OF CONTENTS
Title page Pages
Certification - - - - - - - - - - i
Dedication - - - - - - - - - - ii
Acknowledgement - - - - - - - - - iii
Abstract - - - - - - - - - - iv
Table of Contents - - - - - - - - - v
1.0 Introduction - - - - - - - - - 1
1.1 Background of Study - - - - - - - 1
11 Justification of the Study - - - - - - - 3
1.2 Aim and Objectives - - - - - - - - 3
2.0 Literature review - - - - - - - - 4
2.1 Mangrove Assemblage in the Environment - - - - - 4
2.2 Adaptation of Mangrove to the Environment - - - - 5
2.3 Reproduction in mangrove - - - - - - - 6
2.4 Zonation of mangrove - - - - - - - - 6
2.5 Economic Importance of Mangrove - - - - - - 7
2.5.1 Ecological and environmental Important - - - - - 8
2.5.2 Maintenance of Water Quality - - - - - - 8
2.5.3 Control of Floods - - - - - - - - 9
2.5.4 Protection of Shorelines - - - - - - - 9
2.5.5 Contribution to coastal productivity - - - - - - 9
2.5.6 Contribution to carbon sequestration - - - - - - 9
2.5.7 Contribution to carbon sequestration - - - - - - 10
2.5.8 Contribution to air quality - - - - - - - 11
2.6.1 Educational Value - - - - - - - - 11
2.6.2 Heritage Value - - - - - - - - 11
2.6.3 Natural Beauty and Recreation - - - - - - - 12
2.7 Influence of Nypa Palm on Living Organism - - - - - 12
2.7.1 Influence of Nypa Palm on Coastal Aquatic Ecosystem - - - 12
2.8 Economic Importance of Nypa palm to the marine ecosystem and humanity 13
2.9 Prevention and Control of Nypa Palm in Iko - - - - - 14
3.0 Materials and Methods - - - - - - - 15
3.1 Study Area - - - - - - - - - 15
3.2 Sampling Design - - - - - - - - 16
3.3 Data Analysis - - - - - - - - 17
4.0 Results - - - - - - - - - 19
4.1 Physicochemical Parameters - - - - - - - 19
4.2 Mangrove distribution Analysis of Nigerian Coast Line - - - 20
5.0 Discussion - - - - - - - - - 22
5.1 Physicochemical Parameters - - - - - - 22
5.2 Distribution of Mangrove Vegetation - - - - - 23
5.3 Distribution of Nypafrutican - - - - - - 23
5.4 Distribution of True Mangrove - - - - - - 23
5.4 Conclusions - - - - - - - - - 24
5.5 Recommendation - - - - - - - - 25
References - - - - - - - - 27
1.1 Background of Study
Mangroves are defined as assemblages of salt-tolerant trees and shrubs that grow in the intertidal regions of the tropical and subtropical coastlines (Brandon 2012). Mangroves are survived with their roots submerged in water, mangrove trees thrive in hot, muddy, salty conditions that would quickly kill most plants. Mangrove forests are the world’s most productive ecosystems. They enrich coastal waters, yield commercial forest products, protect coastlines, and support coastal fisheries. However, mangroves exist under conditions of high salinity, extreme tides, strong winds, high temperatures, and muddy, anaerobic soils. There may be no other group of plants with such highly developed morphological, biological, ecological, and physiological adaptations to extreme conditions (Kathiresanet. al 2001).
Mangrove forests are found worldwide between latitude 300South and 300 north in the tropical and subtropical regions (Kathiresanet. al 2001).
They normally grow poorly in stagnant waters and have abundant growth in the alluvial soil substrates with fine‐textured loose mud or silt, rich in humus and sulphides. They can also be found in substrates other than muddy soil such as coastal reefs and oceanic islands. In such areas, the mangrove plants grow on peat, which is derived from decayed vegetation (Kathiresan 2000). They find it difficult to colonize the coastal zone with waves of high energy and hence they normally establish themselves in sheltered shorelines (Kathiresan and Bingham, 2001).
In Nigeria, mangrove covers an estimated area of 10,515km2; the estimate is based on the survey by Zabbey (Zabbey, 2008). Nigeria’s mangrove, in terms of area covered, is the largest in Africa and the fourth largest in the world; the largest being Indonesia, Brazil, Australia, Nigeria (Nandy and Mitra, 2004). The mangrove forests have been shown to sustain more than 70 direct human activities, ranging from fuel‐wood collection to fisheries (Dixon, 1989; Lucy, 2006). Also as recorded by Zabbeyet al, 2010 Mangroves provide various ecological goods and services directly for humankind, and indirectly through the supporting roles mangrove forests play in maintaining other productive systems in the seascape. The estimated economic value of mangrove forests to the local communities is in the range of $27,264 - $35,921 per hectare (Sathirathai and Barbiar, 2001). This estimate includes the value of direct use of wood and other resources collected from mangroves as well as additional external benefits in terms of off-shore fishery linkages and coastline protection. The mangrove forests are known to serve various socio-economic and ecological functions, especially in coastal communities. For instance, they provide breeding grounds for fish species and provide numerous non-wood products that contribute to rural livelihoods. Due to man’s need an explosion in the population, mangroves have suffered much pressure in the recent past with enormous losses through man’s activities directly or indirectly in the marine environment, mangrove swamps, and flood plain, which gives rise to The loss, destruction, and degradation of the mangrove forests have been attributed to many factors including urbanization, quarrying, salt, and sand extraction; pollution from industries, agro-industrial chemicals, petroleum and gas exploitation; absence of appropriate legislation; deforestation for fish smoking (Ajonina and Usongo, 2001; Ajoninaet al, 2005). Therefore, this research work is meant to access and determine the distribution of the survival of mangroves from the above-mentioned stressors and to suggest possible mitigation processes that can revive the exploited mangrove forest.
1.2 Significant of the study
The mangrove forests are known to serve various socio-economic and ecological functions, especially in coastal communities. For instance, they provide breeding grounds for fish species and provide numerous non-wood products that contribute to rural livelihoods through improving fishery resources added to the standing stock of the state’s fisheries and economy. This can only be certain if the distribution of mangrove is determined, of which this project work is aimed.
1.3 Scope of work
This project work is limited only to Iko coastal environment.
1.4 Aim and Objectives
This work is aimed at accessing the distribution of mangroves in the Iko coastal environment.
To determine the physicochemical parameters influencing the environment,
To determine the distribution pattern of mangrove species and their abundance in the Iko coastal environment,
To access the environmental effects of mangrove and the possible potential application of mangrove.