Background

Environmental problem is a major threat to sustainable development (Ogamba et al., 2016). Environmental pollution has increased within the last few decades (Izah et al., 2015; Izah and Angaye, 2016; Izah et al., 2018a). These may have resulted from population growth (Iyorakpo, 2015), urbanization, industrialization, pressure on resources. According to Eludoyin et al. (2017), urbanization has impacted on vegetation and water quality and other resources at large. Several authors have reported that surface water pollution is resulting from mainly anthropogenic activities (Agedah et al., 2015; Izah and Srivastav, 2015; Ogamba et al., 2015a; 2015b; 2015c; Izah et al., 2016; Izah and Angaye, 2016; Ben-Eledo et al., 2017a; b; Seiyaboh and Izah, 2017a; b; Seiyaboh et al., 2017a; 2017b; 2017c; Aghoghovwia et al., 2018). In addition, environment degradation resulting from industrialization, urbanization, population growth, deforestation, emission of pollutant gases especially through gas flaring and vehicular movement are a major source of concern in many regions of the world. These has resulted to a decline in population dynamics, abundance, distribution and even species among biological diversity. Mmom and Chukwu-Okeah (2011) described environmental problems in the coastal region of Nigeria to be of serious concern that requires immediate attention. Globally action has been taken towards sustainable conservation of resources. To this effect Nigeria gazetted several biodiversity hotspots across selected regions. But due to poverty and hunger, its sustainability is poor in addition to inadequate enforcement and surveillance (Izah et al., 2018a).

In Nigeria, the Niger Delta region is home of many biodiversity of global significance (Spalding et al., 1997; Nwankwoala 2012; Izah et al., 2017a; Izah et al., 2018a). The biodiversity of the Niger Delta has many endemic flora and fauna probably due to the presence of rainforest and mangroves (Akani et al., 2004). According to Asimiea and Omokhua (2013), Mmom and Chukwu-Okeah (2011), the Niger Delta is a sensitive ecological zone since it contain several biodiversity that have major socio-economical values to people in and around the area. The area is classified into four main zones including coastal barrier islands, mangrove swamp, freshwater swamp and low land rainforests (Ubom, 2010; Asimiea and Omokhua, 2013). These zones are further sub divided into several distinct ecosystems including barrier islands, estuarine, mangroves, freshwater swamp, lowland rainforest and creeks (Ajao and Anurigwo, 2002; Ogbe, 2011; Izah et al., 2017a). The mangrove swamp of the Niger Delta is majorly dominated by dominated by Languncularia racemosa, Avaicennia nitidae, Rhizophora racemosa, Rhizophora harrisonii, Rhizophora mangle. Of these, red mangroves (Rhizophora racemosa) are the most predominant accounting for about 90% of the mangrove ecosystem (Mmom and Chukwu-Okeah, 2011). Ubom (2010) reported that freshwater swamp and low land rainforests are the most extensive ecological zones in the Niger Delta.

The Niger Delta wetland is one of the most important regions in Nigeria. The Niger Delta wetland is one of the hubs for biodiversity in Africa that inhabit several endemic species (Ogbe, 2011; Izah et al., 2017a). Typically, wetlands play an essential role in sustenance of several resources (Nwankwoala, 2012) including watersheds protection, climate stabilization and suitable ground for breeding processes (Izah et al., 2018a). Authors have variously reported that wetland are areas of fern, marsh peatland/water with static or flowing surface water (fresh or marine or brackish) which can either be natural or artificial, temporary or permanent with depth of ≤6 meters at low tide (Scott, 1989; Ohimain and Akinnibosun, 2007; Ramsar Convention Secretariat, 2007; Okonkwo et al., 2015; Izah et al., 2017a). Nearly half of the Nigerian shore/coastal lines are dominated by wetland especially in the Niger Delta region.

The Niger Delta wetland is under threat probably due to human and biogeophysical effects. Authors have variously reported that population growth, urbanization, industrialization, environmental degradation due to pollution resulting from industrialization, mining, oil and gas exploration, intensive agricultural practices such as unrestrained soil tilling, over-grazing, logging, uncontrolled land reclamation, dam construction, erosion, sea rising, alien invasion, desertification, droughts among others to be having an impact on the wetland (Uluocha and Okeke, 2004; Nwankwoala, 2012; Izah et al., 2017a). Probably due to these effects, ecological, economic, socio-cultural, scientific and recreational roles of the wetlands are under threats (Uluocha and Okeke, 2004; Nwankwoala, 2012; Izah et al., 2017a; 2018a).

The wetland of the Niger Delta are habitats to several species such as sea turtles, manatees, shoreline birds and other threatened marine species which have been previously identified within the coastal zone of Nigeria (Mmom and Chukwu-Okeah, 2011). Some of the wildlife such as Manatee also play essential role in the life of coastal communities (Mmom and Chukwu-Okeah, 2011), though the species is threatened in the marine ecosystem. The region is also an important source of plants with medicinal properties (Kigigha et al., 2015; 2016; Epidi et al., 2016a; b).

Anthropogenic activities such as logging of timber for construction works and fuel wood, cultivation, developmental projects are among the factors have led to decline in biodiversity of the Niger Delta region (Ubom, 2010). Bush burning, excessive exploitation/hunting practices is another impact factor leading to fast decline of biodiversity (Izah et al., 2017a). The human activities are now encroaching protected areas with little or no resistance by appropriate agencies in most areas in the Niger Delta region. This study reviews the changes on protected areas in Bayelsa state, Nigeria.

1 Protected Areas in Bayelsa State

Bayelsa state is among the state in the Niger Delta region. The state is within the sedimentary basin and fishing is a major occupation of the inhabitants of the area (Aghoghovwia et al., 2018; Kigigha et al., 2018). Bayelsa state has 8 local government area including Brass, Nembe and Ogbia (Bayelsa East), Southern Ijaw, Kolokuma/Opokuma and Yenagoa (Bayelsa Central), and Ekeremor and Sagbama (Bayelsa West) (Figure 1).

Like most other coastal regions of Nigeria, the frequency and severity of flooding events is quite high in the region (Ohimain et al., 2014). The state has experienced several flooding episodes which appear to be on the rise on yearly basis (Izah et al., 2015). Furthermore, the water level in the state is quite high (Agedah et al., 2015). Two predominant seasons viz: wet season (April to October) and dry season (November to March of the following year). The relative humidity (50-95%) and atmospheric temperature (28±8ºC) is nearly the same value previously reported in other Niger Delta region all year round (Izah et al., 2017b; 2017c; 2017d; 2018b). The major economic activities in region are mainly farming (i.e. fish farming and plant cultivation), civil servants and business men. Due to migration and urbanization the state can be described as a fast developing region (Izah et al., 2015).

The major ecological zones including lowland rainforest, freshwater swamps and mangrove area are also found in Bayelsa state. Generally, several protected areas in the Niger Delta region which Bayelsa state is part of is found in these zones. Ayanlade (2014) reported Okomu, Gillli-Gilli, Stubbs creek, Ukpe-Sobo, Ekenwan, Umon Ndealichi, Ebue, Ologbo, Obaretin, Sapoba, Sambrero, Upper and lower Imo river, Mamu river, Usonigbe, Isheagu, lower Enyong, Niocha, Oji river, Ute-Ukpu, Nsukwai, Ogwashi-Uku (low land forest reserve), Taylor creek, Apoi creek, Osomari, Nun river, Edumanon, upper and lower Orashi river, Ikibiri creek, Igbedi creek, (freshwater swamp forest reserve), Uwet Odot, Uremure Yokri and Olague (mangrove forest reserve) as the forest type in the Delta. This section of the paper focused on freshwater swamps protected area of Bayelsa state, Nigeria.

1.1 Edumanon forest reserve

The Edumanon Forest Reserve is the area the last chimpanzee was found in Niger Delta some decades ago (Erefitei, 2016). The forest covers part of old Nembe and Brass local government areas of Bayelsa State with an estimated area of about 9,324 hectares (Erefitei, 2016). The area has several oil and gas installations. Other activities in the area include road construction, hunting practices by hunters, and intensive agricultural practices including oil palm cultivation. Road linking Ogbia to Nembe cuts across the Edumanon forest (Erefitei, 2016). Some important wildlife species have been previously reported around the forest.

1.2 Apoi creek forest reserves

Apoi creek is one of the 2 Ramsar-listed coastal and freshwater wetlands found in the Niger Delta (Ayalande and Proske, 2015). The other Ramsar area in the Niger Delta is Upper Orashi (Ayalande and Proske, 2015). Typically, Nigeria hosts a total of 11 Ramsar-listed coastal and freshwater wetlands covering about 1,076,730 hectares (Ayalande and Proske, 2015). Apoi Creek was designated as a Ramsar site #1751 in 2008 (Ayalande, 2014; Erefitei, 2016). The Apoi creek reserve has other common features of the Niger Delta ecosystem including marshes, mangroves and freshwater swamps (Adelande, 2014; Ayalande and Proske, 2015; Okonkwo et al., 2015). Apoi Creek forest reserve is about 29,213 hectares of land (Niger Delta Forest Project, Undated; Ayalande and Proske, 2015) or approximately 190 km² (Wildlife Conservation Society, 2012). The creek was officially gazetted in 1975 (Wildlife Conservation Society, 2012). The reserve has considerable ecological significance and supports many rare, unique and/or threatened species as well as an important spawning and nursery ground for fisheries (Erefitei, 2016).

The Apoi forest is the stronghold for the endemic Niger Delta Red Colobus monkey (Procolobus epieni), Nigerian white-throated guenon (Cercopithecus erythrogaster pococki) (WCS, 2012; Ayalande, 2014) and other primates such as the olive colobus (Erefitei, 2016). Ikemeh (2015) reported the presence of Niger Delta Red Colobus, Putty-nosed monkey, Red-capped mangabey in Apoi creek especially around Gbanraun, Kokologbene, Ukubie. Procolobus epieni have been classified by International Union for Conservation of Nature as ‘Critically Endangered’ (Oates and Were, 2008) and is currently listed as one of the world’s 25 most endangered primates (Wildlife Conservation Society, 2012).

Several economic activities leading to shrinkage of the area including hunting and logging practices, installation of oil and gases facilities through canalization (Erefitei, 2016). The Apoi creek forest resources is a major source of livelihood to rural dwellers through provision of non-timber forest products, agricultural land and fisheries (Okonkwo et al., 2015)

1.3 Taylor creek forest reserve

Taylor creek is located within close proximity of the Bayelsa state National park reserve. Some authors have described the area as Taylor creek/Bayelsa state National park reserve (Ayanlade and Drake, 2016; Erefitei, 2016). Taylor Creek forest which is a lowland (<35 meters below the sea level) is surrounded by several communities including Biseni, Kaiama, Kalama, Odi, Zarama, Okordia, Odoni, and Ikarama (Akani et al., 2014). Taylor creek forest reserve has an area of nearly 220 km² with a seasonal inundated swamp forest shore of the Niger River that overlaps several communities in both Bayelsa and Rivers State (Niger Delta Forest Project, Undated). Several lakes and creeks (viz: Oluku lake, Esiribi lake, Oruma, Oyulo, Asa, Egbegidi, Azari, Egbe, Opuzuno, Puro, Akpidetoru, Isemu, and Abaniigina) exists along the drainage system of Taylor Creek (Akani et al., 2014). The region is prone to seasonal flooding probably due to its proximity to the River Niger. Akani et al. (2014) reported that three distinctive habitat are found in Taylor creek reserve including seasonally flooded freshwater swamp forests which are characterized by Raphia hookeri (Raphia palm), Mitragyna ciliata (Abura), Nauclea diderrichii (Opepe), Khaya ivorensis (Mahogany), Irvingia gabonensis (African bush mango), Eleais guineensis (Oil palm), Musanga cecropoides (Umbrella tree) among others such as ferns, epiphytes and macrophytes; riparian forests (which are characterized by thick and mature high canopy around Karama, Adibawa and Biseni, and derived savanna which are found along the right of way and cleared region meant for the proposed Yar’Adua International Airport at Nyambiri Zarama which is now a grazing ground for cattle’s and cultivated farmlands (which are evenly distributed). The area is home of several wildlife as well. Akani et al. (2014) through quantitative and qualitative study reported the presence of 27 species of mammals, 34 species of reptiles and 10 species of amphibians. The forest reserve is a major biodiversity hotspot that once contained viable populations of elephants, chimpanzees, West-African manatee and several important species of reptiles and fishes (Niger Delta Forest Project, Undated). Furthermore, Amadi et al. (2016) reported the presence of two-spotted civet (Nandinia binotata) in the Taylor creek Forest Reserve, Bayelsa State. But till date, the area is under intense pressure due to human activities including oil exploration, road construction, excessive logging and hunting. Furthermore, bushing burning is also having an effect on the forest resources of the area. Most of the trees of the area are of immense economic importance.

1.4 Nun river forest reserve

Nun river forest reserve is found in the tropical rainforest which is characterized by multi-layered or multi-storey vegetation, torrential rains and seasonal flooding (Hamadina et al., 2007). The Nun river forest covers approximately 97.15 km², and the area is widely called Wilberforce Island (Hamadina et al., 2007). Hamadina et al. (2007) reported the existence of 36, 67 and 18 species of mammals, avian fauna and reptiles, respectively which are distributed into 20, 25 and 12 families, respectively through interview and survey. Ohimain et al. (2014) reported the presence of 45 mammalian species belonging to 21 families, 78 avian fauna species belonging to 27 families, 56 plant species which were distributed into 39 families after the water flooding of 2012 by using questionnaire and survey assessment in Wilberforce Island. The Nun river forest used to be home to elephant (Loxondonta africana), African buffalos (Syncerus coffa) and Pygmy hippos (Hexaprotodon liberiensis) which have not been sighted in the area for over 3 decades (Hamadina, 2007). The authors further reported about 21 wildlife species found in the Nun river forest reserve to be animals which are tagged for trading prohibition or regulated under stipulated licencing Act 11 of 1985 of the Federal Republic of Nigeria in compliance with convention on international trade of endangered species of 1973.

Several local conservation of biodiversity of the area includes beliefs such as delineation of certain forest area as “sacred forest” or “evil forest” (Hamadina et al., 2007). As such, people are not allowed to enter the forest without first appeasing the “gods” except within some ritual ceremony period. Furthermore the practice of totem, a situation in which certain species are not killed for whatever reason and if inadvertently killed may require spiritual cleansing (Hamadina et al., 2007). In the Nun river forest some species have been implicated to totem includes Crocodylus niloticus (Nile crocodile), Varanus niloticus (Nile monitor lizard), Kinixys erosa (serrated hinge backed tortoise), Python sebae (Rock python), Python reguis (Royal python) and Naja nigricollis (black necked cobra), while species associated with taboos include Gypohierax angolensis (palm-nut vulture), Haliaetus vocifer (West African river eagle), Centropus leucogaster (black-throated coucal), Chrysococcyx klaas (Klaas’s cuckoo), Psittacus erithacus (Grey parrot), Tauraco persa (Green-crested turaco) (Hamadina et al., 2007).

The advent of Christianity has drastically reduced the practice of totem. Probably due to industrialization which mainly due to the establishment of Niger Delta University and Bayelsa state International airport, there have been on intense impact on the size and biodiversity status of the area. Typically, the forest is a source of biological diversity that plays several ecological roles to humanity. In addition, deforestation, bush burning and excessive exploitation/hunting and fishing practices are a major reason in the decline of wildlife status within the area. Authors have variously reported that the wildlife of the Nun forest is mostly exploited for bush meat (Hamadina et al., 2007; Ohimain et al., 2014). Hamadina et al. (2007) attributed this to changes in lifestyle, decline in economies leading to the use of the resources such as timber (used for construction) and land (for increased food production) to meet up with the quest for food due to population pressure.

1.5 Ikibiri creek forest reserve

Ikibiri Creek forest reserve is another important forest reserved in Bayelsa State. The area is known for its richness in important forest resources including timber products, medicinal plants, ornamentals plants, and wildlife. Like Apoi creek forest reserve, Ikibiri creek forest reserve depicts a shrinking trend but not as much as the other important forest reserves such as Nun River, Edumanon and Taylor Creek forest reserves. Ayalande (2014) reported a decline in Ikibiri forest reserve by 0.10%.

1.6 Igbedi creek forest reserve

Igbedi creek have been widely spelled as Igbedi creek (Abere and Ezenwaka, 2011; Seiyaboh et al., 2013; Erefitei, 2016), even though other authors have spelled it as Egbedi creek (Ayalande, 2014; Amadi et al., 2016). Igbedi creek is a tributary of the upper Nun River in the Niger Delta (Seiyaboh et al., 2013). Dredging has been a major anthropogenic activity along the creek between 2009-2011 (Seiyaboh et al., 2013). The region is one of the gazetted areas in Bayelsa state. The region is home of several wildlife and fisheries. Amadi et al. (2016) reported the presence of two-spotted civet (Nandinia binotata) in Igbedi forest reserve in Bayelsa State.

2 Trends in Protected Areas in Bayelsa State

Despite the numerous freshwater ecosystems, the Taylor creek, Apoi creek, Nun river, Edumanon, Ikibiri creek and Igbedi creek are the main forest reserves found in Bayelsa state (Table 1). Based on the percentage loss, Edumanon and Nun River forest reserve are majorly impacted leading to their shrinkage (Figure 2). Ikibiri and Igbedi creek are the least impacted. Furthermore, Ayalande (2014), Ayanlade and Drake (2016) reported variations in normalized difference vegetation index of major protected areas between 1987-2011 in Bayelsa state, Nigeria is presented in Figure 3.

From Table 1, the level of degradation of the protected area is low compared to some other fresh water swamps in the Niger Delta (Ayalande, 2014). According to Ayalande (2014), the degradation of protected area is higher among the ones close to major express ways. As a result, the shrinking of Apoi creek and Ikibiri creek is quite low probably due to their inaccessibility compared to Nun River forest reserve (with major road leading to Niger Delta University and Bayelsa international airport), Edumanon (major road linking Ogbia with Nembe) and Taylor Creek/Bayelsa state national park (previously close to former YarAdua International airport). The impacts on the protected area are mainly deforestation and degradation. However, Ayalande (2014) reported that Taylor creek tops the list of protected areas in Bayelsa state. Ayalande and Drake (2016) reported percentage of reserved forest of Taylor creek/Bayelsa state National park and Igbedi creek between 1987 to 2011 as -1.91% and -6.30% respectively. This could be due to high human interference compare to other forest reserves.

3 Impacts of Biodiversity of Protected Area

Typically, several species of wildlife and vegetation are found in the Niger Delta region of Nigeria. Akani et al. (2004) reported 28 species of amphibians which belongs to the family Bufonidae (genera Bufo and Nectophryne), Pipidae (Silurana and Hymenochirus), Ranidae (Hylarana, Ptychadena, Aubria, Conraua, Hoplobatrachus, and Phrynobatrachus), Arthroleptidae (Arthroleptis), Rhacophoridae (Chiromantis), Microhylidae (Phrynomantis), and Hyperoliidae (Hyperolius, Afrixalus, Leptopelis, Phlyctimantis, and Opisthothylax) from six locations in southern Nigeria. A total of 339 plant species belonging to 88 families have been reported in some Niger Delta states (Akwa-Ibom, Bayelsa, Cross River, Delta, Imo and Rivers) (Ubom, 2010). The authors further reported that Elaeis guineensis, Raphia hookeri, Cocos nucifera, Irvingia gabonensis, Hevea brasiliensis, Lonchocarpus cyanescens, Pterocarpus santalinoides and Dacryodes edulis has more uses compared to other plant species in the region.

In the Niger Delta region, the landscape is high in endemic and threatened primates species. Some of the common species found in these categories include endemic Sclater’s guenon (Cercopithecus sclateri), Nigerian white-throated guenon (Cercopithecus erythrogaster pococki), red-capped mangabey (Cercocebus torquatus) and the endangered Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) (Ikemeh, 2015). Probably due to ineffectiveness of the protected areas, conservation and management strategies of some important endemic mammals i.e. Heslop’s pygmy hippopotamus (Hexaprotodon liberiensisheslopi) have gone on extinction in the Niger Delta (Ikemeh, 2015). The author further reported that time and proactive measures will determine the fate of Niger Delta red colobus.

Using survey approach, Akani et al. (2015) reported that between 2010-2014, a total of 21 mammal species displayed for sales at popular Swali market in Yenagoa metropolis, Bayelsa state. The authors further reported that during the period a total of 897 mammal individuals were examined and some numbers of Cercopithecus mona, Cercopithecus sclateri, Cercopithecus nictitans, and pangolins were alive while several others was dead at the time of examination in the market. In a day, the landing rate of carcasses was about 37 mammal during the survey with Thryonomys swinderianus being the dominant species traded in the area in addition to Cricetomys cf. emini, Atherurus africanus, Crossarchus platycephalus, antelopes, and monkeys (Akani et al., 2015). Amadi et al. (2016) reported the presence of two-spotted civet (Nandinia binotata) meat in Edumanon forest reserve, Bayelsa State. Ohimain et al. (2014) reported the sales of some wildlife in some communities around Nun River forest reserve.

4 Challenges of Protected Area

Generally, biodiversity involves all species of living organisms (viz: plants, animals, microbes) that are found in the earth irrespective of the environment (arboreal, aquatic and terrestrial that is soil) (Izah et al., 2018a). The rate of environmental degradation is having a major impact on biodiversity resources. For instance, Oribhabor (2016) reported that pollution (organic and sediment), eutrophication, acidification, heavy metals and organochlorides, thermal pollution, nuclear pollution, oil and gas pollution, human introductions of pollutants are some of the contaminant pathways resulting to a decline in Nigerian biodiversity resources. The authors also reported that pollution results from anthropogenic activities from the large use of chemical fertilizers and pesticides in agricultural practices, industrialization, urbanization, population growth; mal-utilization and mismanagement of natural aquatic resources; construction of dam, road and bridge; irrigation activities; draining and filling of wetlands; exploration of petroleum resources (including exploration, drilling, refining, transportation and even marketing).

Typically, Niger Delta wetland provides several services to both local people and African continent at large. There has been intense environmental pressure due to quest of livelihood (Izah et al., 2018a). Some of the common cause of environmental degradation include oil and gas exploration, excessive logging (Ayalande and Proske, 2015), bush burning (Izah et al., 2017a). Traditionally, forest products such as fuel wood, timber, medicinal plants, wildlife, food are the major source of forest products and services (Erefitei, 2016) and excessive utilization could lead to degradation of the natural ecosystem (Izah et al., 2018).

Increasing rate of deforestation of forest reserves has many implications on biodiversity in the Niger Delta of Nigeria (Ayalande, 2014). Probably due to changes in the ecosystem, the biodiversity of the area is under threat while some have been in extinction. Furthermore, variation in land use (viz: construction works, urbanization, industrialization) and forest degradation (excessive exploitation of wildlife, illegal poaching, logging, bush burning, etc) are the major factors leading to a decline in protected area (Izah et al., 2018). Probably due to these factors, wildlife has been reportedly killed and displayed for sales within the vicinity of some of the reserves in Bayelsa state (Ohimain et al., 2014; Izah et al., 2018).

Bush burning is another major factor leading to a decline in protected areas. In recent times, the rate of bush burning has increased (Izah et al., 2017a; 2018a). Instances of bush burning have been observed around and within some protected areas in Bayelsa state especially in Nun River and Taylor creek reserve area.

Due to the effect of excessive degradation leading to loss of valuable forest products, there was the decision to establish reserve area so as to conserve the habitat (Abere and Ezenwaka, 2011). To this regard several wildlife species that have been officially protected by Nigerian federal, state and traditional laws but they are constantly being traded in many locations in Nigeria. In Nigeria, some existing laws and legislation on natural resources conservation include the national resources conservation act 1989 (which established conservation council empowered to address forestry, fisheries, wildlife, soil and water by formulating and implementing policies), Federal Environmental Protection Agency Act (Chapter 131, Laws of the Federation, 1990) (established to enhance conservation of natural resource through stringent environmental policies), the Environmental Impact Assessment Act (No. 86 of 1992) (aimed at carrying out environmental impacts assessment before any project that may impact on the various environmental components can be commence), Endangered species (control of international trade and traffic) Act 11 of 1985 (aimed to conserve the country wildlife and some rare and endangered species through prohibition of hunting, capture, or trading of any of the 91 animals species that are classified under endangered wildlife and listed in schedules 1 and 2), National Parks Decree (Decree No. 36 of 1991) (aimed to provide protective sanctuary for wildlife species and preserve the beauty and conservation of the natural vegetation); state laws like forestry act and traditional conservation practices through the dedication to certain deities that protects them from exploitation in the forest (Abere and Ezenwaka, 2011), practice of totem and ownership of scared forest (Hamadina et al., 2007).

But these law and legislations are not very effective in most forest reserves in the 21^st century. This is because the rate of exploitation of natural resources including protected areas and wildlife that are supposed to be conserved is still high (Izah et al., 2018a). Akani et al. (2015) reported that wildlife species that officially are protected by Nigerian federal law Act 11, Schedule I (such as Atherurus africanus, Tragelaphus spekei, Hyemoschus aquaticus, Neotragus batesi, Aonyx capensis, Manis tricuspis, Uromanis tetradactyla) and Schedule II (such as Genetta sp., Nandinia binotata, Viverra civetta, and different Cercopithecus species) are being widely traded in many bushmeat markets. The authors further reported that these legal impediment and local taboos are unlikely not influencing the trading of bushmeat. As such government policies on conservation of natural resources have not yielded desired result (Abere and Ezenwaka, 2011).

5 Conclusion and the Way Forward

The Niger Delta region is one of the hubs of biodiversity hotspots of global significance. The Niger Delta region is rich in fisheries, avian fauna, reptiles, amphibians, insects, mammals, among others. These resources are found in different environmental components depending on their life forms. The rate of degradation of natural resources is high especially during developmental projects (construction works, industrialization, urbanization) and quest for source of livelihood (agricultural proposes). In Bayelsa, the six major forest reserves include Taylor creek, Apoi creek, Nun river, Edumanon, Ikibiri creek and Igbedi creek which have been officially gazetted in on the shrinking trend. This study found that there are levels of shrinkage in size of the forest reserves especially in Taylor creek, Nun River and Edumanon forest reserve. It also appears that the reserve that are linked to major express ways (road) have the highest level of shrinkage. Several factors including developmental projects, excessive hunting, deforestation (lumbering, farming etc) and bush burning are some of the major factors leading to decline in size of the reserve area. Furthermore, the richness of species diversity has significantly decreased probably due to inadequate enforcement of law/legislation as well as surveillance. Hence, there is the urgent need to effectively implement environmental laws, biodiversity legislation, wildlife conservation acts at federal, state and traditional/local/customary settings in other to minimize biodiversity loss. Also, there is the need to enhance the political and legal frameworks for effective conservation strategy. Inclusion of biodiversity management and conservation at school curriculum could also boost conservation option. Only time can determine if the protected areas can achieved full conservation status that resulted to their establishment considering deforestation rate in the forest reserves.

Authors’ contributions

Authors SCI conceived the idea, managed literature search, wrote the initial draft and managed correspondence. Authors EIS proof read the manuscript and corrected tense. Both authors read and approved the final manuscript.

Reference

Abere S.A., and Ezenwaka J., 2011, Evaluation of forest resources conservation laws in Nigeria, Mediterranean Journal of Social Sciences, 2(5): 49-54

Agedah E.C., Ineyougha E.R., Izah S.C., and Orutugu L.A., 2015, Enumeration of total heterotrophic bacteria and some physico-chemical characteristics of surface water used for drinking sources in Wilberforce Island, Nigeria, Journal of Environmental Treatment Techniques, 3(1): 28-34

Aghoghovwia, O.A., Miri, F.A. and Izah, S.C., 2018. Impacts of Anthropogenic Activities on Heavy Metal Levels in Surface Water of Nun River around Gbarantoru and Tombia Towns, Bayelsa State, Nigeria. Annals of Ecology and Environmental Science, 2(2): 1-8

Ajao E.A., and Anurigwo S., 2002, Land-based sources of pollution in the Niger Delta, Nigeria, Ambio, 31(5): 442-445

https://doi.org/10.1579/0044-7447-31.5.442

Akani G.C., Aifesehi P.E.E., Petrozzi F., Amadi N., and Luiselli L., 2014, Diversity of terrestrial vertebrates in Taylor creek forest reserve, an area of high environmental value in the River Niger Delta (Bayelsa State, Nigeria), Vie et milieu-Life and environment, 64: 59-68

Akani G.C., Politano E., and Luiselli L., 2004, Amphibians recorded in forest swamp areas of the River Niger Delta (southeastern Nigeria), and the effects of habitat alteration from oil industry development on species richness and diversity, Applied Herpetology, 2(1): 1-22

https://doi.org/10.1163/1570754041231604

Akani, G.C., Amadi N., Eniang E.A., Luiselli L., and Petrozzi F., 2015, Are mammal communities occurring at a regional scale reliably represented in "hub" bushmeat markets? A case study with Bayelsa State (Niger Delta, Nigeria), Folia Zool, 64(1): 79-86

https://doi.org/10.25225/fozo.v64.i1.a9.2015

Amadi N., Akani G.C., Micheloni P., Eniang E.A., Luiselli L., and Petrozzi F., 2016, Distribution, habitat ecology and conservation status of the Two-spotted Palm Civet Nandinia binotata (Carnivora, Nandiniidae) in south-eastern Nigeria, Small Carnivore Conservation, 52 and 53: 24-38

Asimiea A., and Omokhua G., 2013, Environmental impact of illegal refineries on the vegetation of the Niger delta, Nigeria, Journal of Agriculture and Social Research, 13(2): 121-126

Ayanlade A., 2014, Remote Sensing of Environmental Change in the Niger Delta, Nigeria, PhD thesis submitted to Department of Geography, School of Social Sciences and Public Policy, King's College London, University of London

Ayanlade A., and Proske U., 2015, Assessing wetland degradation and loss of ecosystem services in the Niger Delta, Nigeria, Marine and Freshwater Research

http://dx.doi.org/10.1071/MF15066

Ayanlade A, and Drake N., 2016, Forest loss in different ecological zones of the Niger Delta, Nigeria: evidence from remote sensing, GeoJournal, 81: 717-735

https://doi.org/10.1007/s10708-015-9658-y

Ben-Eledo V.N., Kigigha L.T., Izah S.C., and Eledo B.O., 2017a, Water quality assessment of Epie creek in Yenagoa metropolis, Bayelsa state, Nigeria, Archives of Current Research International, 8(2): 1-24

https://doi.org/10.9734/ACRI/2017/34504

Ben-Eledo V.N., Kigigha L.T., Izah S.C., and Eledo B.O., 2017b, Bacteriological Quality Assessment of Epie Creek, Niger Delta Region of Nigeria, International Journal of Ecotoxicology and Ecobiology, 2 (3): 102-108

Eludoyin O.S., Obafemi A.A., and Hardy T., 2017, Effects of urbanization changes on landuse in Yenagoa Metropolis, Bayelsa State, Nigeria (1986-2013), International Journal of Development and Sustainability, 6(8), 728-745

Epidi J.O., Izah S.C., and Ohimain E.I., 2016a, Antibacterial and Synergistic Efficacy of Extracts of Alstonia boonei Tissues, British Journal of Applied Research, 1(1): 0021-0026

Epidi J.O., Izah S.C., Ohimain EI, and Epidi T.T., 2016b, Phytochemical, antibacterial and synergistic potency of tissues of Vitex grandifolia, Biotechnological Research, 2(2): 69-76

Erefitei A., 2016, Bayelsa State Forest Management

http://www.bodmasnewsblog.com/2016/05/bayelsa-state-forest-management.html

Hamadina M.K., Otobotekere D., and Anyanwu D.I., 2007, Impact assessment and biodiversity considerations in Nigeria: a case study of Niger Delta University campus project on wildlife in Nun River forest reserve, Management of Environmental Quality: An International Journal, 18(2): 179-197

https://doi.org/10.1108/14777830710725849

Ikemeh R.A., 2015, Assessing the Population Status of the Critically Endangered Niger Delta Red Colobus (Piliocolobus epieni), Primate Conservation, (29):87-96

Iyorakpo J., 2015, Impact of rapid urbanization on environmental quality in Yenagoa metropolis, Bayelsa state-Nigeria, European Scientific Journal, 11(23): 255-268

Izah S.C, Aigberua A.O., and Nduka J.O., 2018a, Factors affecting the population trend of biodiversity in the Niger Delta region of Nigeria, International Journal of Avian and Wildlife Biology, 3(3):206‒214

Izah S.C., Bassey S.E., and Ohimain E.I., 2018b, Ecological risk assessment of heavy metals in cassava mill effluents contaminated soil in a rural community in the Niger Delta Region of Nigeria, Molecular Soil Biology, 9(1): 1-11

https://doi.org/10.5376/msb.2018.09.0001

Izah S.C., Angaye C.N., Aigberua A.O., and Nduka J.O., 2017a, Uncontrolled bush burning in the Niger Delta region of Nigeria: potential causes and impacts on biodiversity, International Journal of Molecular Ecology and Conservation, 7(1): 1-15

https://doi.org/10.5376/ijmec.2017.07.0001

Izah S.C., Bassey S.E., and Ohimain E.I., 2017b. Geo-accumulation index, enrichment factor and quantification of contamination of heavy metals in soil receiving cassava mill effluents in a rural community in the Niger Delta region of Nigeria, Molecular Soil Biology, 8(2): 7-20

https://doi.org/10.5376/msb.2017.08.0002

Izah S.C., Bassey S.E., and Ohimain E.I., 2017c. Assessment of heavy metal in cassava mill effluent contaminated soil in a rural community in the Niger Delta region of Nigeria. EC Pharmacology and Toxicology, 4(5): 186-201

Izah S.C., Bassey S.E., and Ohimain E.I., 2017d. Assessment of pollution load indices of heavy metals in cassava mill effluents contaminated soil: a case study of small-scale cassava processing mills in a rural community of the Niger Delta region of Nigeria, Bioscience Methods, 8(1): 1-17

https://doi.org/10.5376/bm.2017.08.0001

Izah S.C., and Srivastav A.L., 2015, Level of arsenic in potable water sources in Nigeria and their potential health impacts: A review, Journal of Environmental Treatment Techniques, 3(1): 15-24

Izah S.C., Angaye T.C.N., and Ohimain E.I., 2015, Climate change: some meteorological indicators and perception of farmers in Yenagoa metropolis, Bayelsa state, Nigeria. International Journal of Geology, Agriculture and Environmental Sciences, 3(1): 56-60

Izah S.C., Chakrabarty N., and Srivastav A.L., 2016, A Review on Heavy Metal Concentration in Potable Water Sources in Nigeria: Human Health Effects and Mitigating Measures, Exposure and Health, 8(2): 285-304

https://doi.org/10.1007/s12403-016-0195-9

Izah S.C., and Angaye T.C.N., 2016, Heavy metal concentration in fishes from surface water in Nigeria: Potential sources of pollutants and mitigation measures, Sky Journal of Biochemistry Research, 5(4): 31-47

Kigigha, L.T., Seiyaboh, E.I., Obua, V.J. and Izah, S.C., 2018. Contamination of River Nun at Amassoma, Bayelsa State, Nigeria Due to Microbial Diversity in Sediments. Environmental Toxicology Studies Journal, 2(1): 2

Kigigha L.T., Biye S.E., and Izah S.C., 2016, Phytochemical and antibacterial activities of Musanga cecropioides tissues against Escherichia coli, Pseudomonas aeruginosa Staphylococcus aureus, Proteus and Bacillus species, International Journal of Applied Research and Technology, 5(1): 100-107

Kigigha L.T., Izah S.C., and Ehizibue M., 2015, Activities of Aframomum melegueta Seed Against Escherichia coli, S. aureus and Bacillus species, Point Journal of Botany and Microbiology Research, 1(2):23-29

Mmom P.C., and Chukwu-Okeah G.O., 2011, Factors and Processes of Coastal Zone Development in Nigeria: A Review. Research Journal of Environmental and Earth Sciences, 3(6): 625-632

Niger Delta Forest Project (Undated) Taylor Creek forest reserve

https://swnigerdeltaforestproject.org/project-sites/taylor-creek-forest-reserve

Nwankwoala H.O., 2012, Case Studies on Coastal Wetlands and Water Resources in Nigeria, European Journal of Sustainable Development, 1(2): 113-126

Oates J.F., and Were J.L., 2008, Niger Delta Red Colobus Monkey Procolobus epieni Grubb and Powell, 1999 Niger Delta, Nigeria

Ogamba E.N., Izah S.C., and Omonibo E., 2016, Bioaccumulation of hydrocarbon, heavy metals and minerals in Tympanotonus fuscatus from coastal region of Bayelsa state, Nigeria, International Journal of Hydrology Research, 1: 1-7

https://doi.org/10.18488/journal.108/2016.1.1/108.1.1.7

Ogamba E.N., Izah S.C., and Oribu T., 2015a, Water quality and proximate analysis of Eichhornia crassipes from River Nun, Amassoma Axis, Nigeria, Research Journal of Phytomedicine, 1(1): 43-48

Ogamba E.N., Izah S.C., and Toikumo B.P., 2015b, Water quality and levels of lead and mercury in Eichhornia crassipes from a tidal creek receiving abattoir effluent, in the Niger Delta, Nigeria, Continental Journal of Environmental Science, 9(1): 13-25

Ogamba E.N., Seiyaboh E.I., Izah S.C., Ogbugo I., and Demedongha F.K., 2015c, Water quality, phytochemistry and proximate constituents of Eichhornia crassipes from Kolo creek, Niger Delta, Nigeria, International Journal of Applied Research and Technology, 4(9): 77-84

Ogbe M.G., 2011, Managing the environmental challenges of the oil and gas industry in the Niger Delta, Nigeria Journal of Life Science, 1(1): 1-17

Ohimain E.I., Izah S.C., and Otobotekere D., 2014, Selective impacts of the 2012 water floods on the vegetation and wildlife of Wilberforce Island, Nigeria, International Journal of Environmental Monitoring Analysis, 2: 73-85

https://doi.org/10.11648/j.ijema.20140202.13

Ohimain E.I., and Akinnibosun H.A., 2007, Assessment of wetland hydrology, Hydrophytic vegetation and hydric soil as indicators for wetland determination, Tropical Journal of Environmental Science and Health, 10(1): 1-11

Okonkwo C.N.P., Kumar L., and Taylor S., 2015, The Niger Delta wetland ecosystem: What threatens it and why should we protect it? African Journal of Environmental Science and Technology, 9(5), 451-463

https://doi.org/10.5897/AJEST2014.1841

Oribhabor B.J., 2016, Impact of Human Activities on Biodiversity in Nigerian Aquatic Ecosystems, Science International, 4: 12-20

https://doi.org/10.17311/sciintl.2016.12.20

Ramsar Convention Secretariat, 2007, Information Sheet on Ramsar Wetlands (RIS): Apoi Creek

https://rsis.ramsar.org/ris/1751

Scott D.A., 1989, A directory of Asian wetlands, IUCN, Gland and Cambridge

Seiyaboh E.I., and Izah S.C., 2017a, Review of Impact of Anthropogenic Activities in Surface Water Resources in the Niger Delta region of Nigeria: A case of Bayelsa state, International Journal of Ecotoxicology and Ecobiology, 2(2): 61-73

Seiyaboh E.I., and Izah S.C., 2017b, Bacteriological assessment of a tidal creek receiving slaughterhouse wastes in Bayelsa state, Nigeria, Journal of Advances in Biology and Biotechnology, 14(1): 1-7

https://doi.org/10.9734/JABB/2017/34593

Seiyaboh E.I., Izah S.C., and Oweibi S., 2017a, Physico-chemical Characteristics of Sediment from Sagbama Creek, Nigeria, Biotechnological Research, 3(1): 25-28

Seiyaboh E.I., Izah, S.C., and Oweibi, S., 2017b, Assessment of Water quality from Sagbama Creek, Niger Delta, Nigeria, Biotechnological Research, 3(1): 20-24

Seiyaboh E.I., Izah S.C., and Bokolo J.E., 2017c, Bacteriological quality of water from river nun at Amassoma Axises, Niger Delta, Nigeria, ASIO Journal of Microbiology, Food Science and Biotechnological Innovations, 3(1): 22-26

Seiyaboh E.I., Ogamba E.N., and Utibe D.I., 2013, Impact of Dredging on the Water Quality of Igbedi Creek, Upper Nun River, Niger Delta, Nigeria, IOSR Journal of Environmental Science, Toxicology and Food Technology, 7(5): 51-56

Spalding M.F., Blasco F., and Field C., 1997, World mangrove ecosystem atlas, The international Society of mangrove ecosystem (ISME), Japan

Ubom R.M., 2010, Ethnobotany and Biodiversity Conservation in the Niger Delta, Nigeria, International Journal of Botany, 6: 310-322

https://doi.org/10.3923/ijb.2010.310.322

Uluocha N., and Okeke I., 2004, Implications of wetlands degradation for water resources management lessons from Nigeria, GeoJournal, 61: 151-154

https://doi.org/10.1007/s10708-004-2868-3

Wildlife conservation society, 2012, Saving the Niger Delta red colobus monkey from extinction: enlisting the support of local communities to help protect Apoi creek forest reserve, Stakeholder Workshop Report, Yenagoa, Nigeria