Biodiversity International Journal Review Article Open Access Review and assessment of environmental impacts of ecological disasters on biodiversity in Anambra state, Nigeria Abstract Volume 3 Issue 2 - 2019 Anambra State of Nigeria as well as other neighboring States and most of the other Boniface CE Egboka, Elizabeth I Okoyeh African countries suffer from major ecological disasters that pose much negative Department of Geological Sciences & sub-Department of environmental effects on Biodiversity; that have also resulted in terminal changes Applied Geophysics, Nnamdi Azikiwe University, Nigeria on the lives of plant and animal species in the total environment as glaringly- mirrored from Geological and Environmental Sciences field and laboratory studies Correspondence: Boniface CE Egboka, Department of and research. Climate change that results through natural and anthropogenic activities Geological Sciences & Sub Department of Applied Geophysics, into high temperatures, heat waves, wind/sand/dust storms, excessive aridity, heavy Nnamdi Azikiwe University, Awka, Anambra State, Nigeria, rainfall, flooding, soil and gully erosion and landslides; environmental pollution and Email contamination; desertification; deforestation and urbanization; hunger, poverty and disease; greed, ignorance, poor professional attitude, fraud and corruption are some Received: February 11, 2018 | Published: April 01, 2019 of the major environmentally-destructive factors that adversely-derail Biodiversity resources. Many varieties of plant and animal species and wildlife have been terminally-lost; by which all losses affecting parts of the Tropics of African countries are trending fast to an emerging regional biotic extinction within this Holocene (Recent) times. The present attitude by governments and people of all affected areas including Anambra State as a case example to Biodiversity losses is of a laissez-faire attitude and unscientific nature; officials do not seem to care. Also the public does not seem to care on the outcome. National governments, national and international aid agencies, institutional and corporate bodies, professionals and other individuals must change their attitude and acts to proffer better understanding to problems-solution and provide more moral and intellectual support and funding to experts and professionals for studies, research and effective local, national and regional control measures to check the massive terminal losses in Biodiversity in the environment. Introduction Biodiversity deals with components of “Bio or Life” and “Diverse” or varieties of environmental elements that affect life positively or negatively. Biodiversity issues require holistic and broad-based study/problem-solutions approach through the use of integrated, multitechnique and multiobjective measures in handling arising issues or solving the problems. As one writes on Biodiversity from the background and experience of field observations over the years Geology and Environmental Sciences, one realizes that professionals from different fields of endeavor should be encouraged to be part of problem-solutions. Anambra State is one of the fastest growing States out of the 36No. States in Nigeria (Figure 1). Anambra State is thickly-populated and compact with diverse socioeconomic and industrial activities (Figure 2). The State has lost a great deal vis-a-vis Biodiversity as a result of diverse negative impacts of many ecological disasters that hazard the environment; as many of the wildlife in form of plants and animals have gone out of existence. The high population density and crowded nature of the population of the State as well as the Map of Nigeria showing population density of different states of the nature of human settlements within urban, semi/peri-urban and rural Figure 1 federation (Source: Wikipedia). communities tend to defy proper classification of Demographic nature of Anambra State. The situation has adversely-affected Biodiversity The term, Biodiversity, must be well-understood and fully- of human beings, animal and plant lives. Wildlife and highly-needed appreciated on a wider scale so that one can articulate issues properly in plants, fruits and vegetables for food and medicinal purposes are order to possibly-solve the arising environmental/ecological problems terminally-lost as critically-observed for many years. from its negative global and high-level effects. Meaning of Biodiversity Submit Manuscript | http://medcraveonline.com Biodiversity Int J. 2019;3(2):53‒58. 53 © 2019 Egboka et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Copyright: Review and assessment of environmental impacts of ecological disasters on biodiversity in Anambra state, 54 Nigeria ©2019 Egboka et al. is a composite of ‘bio’ (life) and ‘diversity’, a state of being diverse through the area as a tributary of the River Niger (Figures 1 & Figure or having variety generally refers to the variety and variability of life 3). Water quality devaluation constitutes a major environmental and on Earth. Biodiversity measures variation at genetic level the species socioeconomic problem.1 and ecosystem level (UNEP). Terrestrial Biodiversity tends to be greater near the Equator which seems to be the result of warm climate high primary productivity. Biodiversity is not distributed evenly on Earth, and is richest in the Tropics. These tropical forest ecosystems cover less than 10 percent of earth’s surface and contain about 90 percent of the world’s species. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots and has been increasing through time but will likely slow down in the future. Rapid environmental changes cause mass extinction. More than 99.9% of all species that ever lived on Earth, amounting to over five billion species are estimated to be extinct. Estimates on the number of Earth’s current species range from 10 to 14 million of which about 1.2m has been documented and over 86 percent have not been described. More recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described. Since life began on Earth major mass extinction shave led to large and sudden drops in Biodiversity. Growth in Biodiversity via the Cambrian explosion in the last 540m years marked a rapid growth during which the majority of multicellular Phyla first appeared. The next 400m years included repeated losses in Biodiversity classified as mass extinction events. In Carboniferous period, rainforest collapse led to a great loss of plant and animal life. The Permian-Triassic extinction event, 251m years ago, was the worst; vertebrate recovery took 30m years. The most recent Cretaceous-Palaeogene extinction that occurred 65m years ago resulted in the extinction of the dinosaurs. The period since the emergence of humans has displayed an ongoing Biodiversity reduction named the Holocene or Recent extinction primarily caused by human impacts by habitat destruction. Figure 3 Drainage map of Anambra State (Source: Geohazards, Awka). The indigenous ethnic groups in Anambra State are the Igbo (98%) and a small population of Igala (2%). The stretch of more than 45km distance between the towns of Oba and Amorka contains numerous thickly populated villages and small towns, giving the area an estimated thick average density of 1,500–2,000 persons per sq. km. The State is rich in natural gas, crude oil, bauxite, lignite, quartz sands/ironstone and kaolinite for ceramics-making. It has an almost 100% rich arable lands of clayey soils inter-layered with silty and sandy materials with sometimes overlying red earth of lateritic soils. Anambra State is famous for its acidic soils of southeastern Nigeria with pH of about 5 that also occur in places as thick erodible layers of sandy soils sometimes as thick as 15-20m. Other economic resources include agro-based activities such as fisheries and farming. Anambra State is one of the thirty-six States of Nigeria with a thick population of over four million (4,182,032) people who are mainly of the hardworking, entrepreneurial and industrious Igbo ethnic group. The State is embedded in thick vegetation of Tropical Rainforest Belt. Figure 2 Map of Anambra State showing urban and Peri-Urban communities. Unfortunately over 80% of Rainforest Belt has been lost as result Impacts of demography, pedology, geography, geology of active deforestation, urbanization, floods, soil and gully erosion, landslides, other anthropogenic activities and adverse impacts of and hydrogeology climate change. Demography (population impacts), Pedology (soils effects), Geomorphologically, Anambra State has scarp slopes, rolling hills, Geography (surface features), Geology (rocky/subsurface soil/rock valleys and lowlands with patches of ancient forests dotted here and materials), Hydrogeology (water resources) etc. are fundamental there around ancient shrines as well as springs, lakes, streams and elements in Applied Sciences that drive the machineries and engines of rivers that cover parts of the landscape. The State is bounded in the Biodiversity changes; they are surface and subsurface features, human west by Delta State and Imo State; Rivers State to the south; Enugu beings, soils, solid and soft rocks and water elements that convey State to the east; and Kogi State to the north. Major urban centres data