BIODEGRADATION POTENTIAL OF RHIZOSPHERIC MICROORGANISMS OF RHIZOPHORA RACEMOSA IN CRUDE OIL CONTAMINATED MANGROVE SWAMP IN THE NIGER DELTA

Rhizophora racemosa (red mangrove tree) belongs to the family Rhizophoraceae; it is an important constituent of the mangrove swamp in Niger Delta, an oil producing region in Nigeria. The remediation of soils containing organic pollutants is possible with the use of microbial communities when the ecology is understood for potentials maximization. This study investigated the biodegradation potential of rhizospheric microorganisms of Rhizophora racemosa in crude oil- contaminated mangrove swamp in the Niger Delta.The total microbial count was determined by the serial dilution method. The hydrocarbon-utilizing bacteria and fungi were enumerated using Mineral Salts Agar containing crude oil as the sole carbon source. The biodegradation potential of these rhizomicrobes was determined using screen test, shake flask degradation tests, Total Organic Gas (TOG) and Total Petroleum Hydrocarbon (TPH) InfraCal Analyzer (HATR-T2 and CH). The turbidity, total organic gas (TOG-N) and total petroleum hydrocarbon were measured weekly for twenty-eight days. Hydrocarbon-degrading microbes isolated from the rhizosphere were identified as Marinococcus sp., Azotobacter sp., Acinetobacter sp. Aspergillus niger, Aspergillus flavus and Candida albicans. The highest rate of TPH reduction was recorded in Acinetobacter sp. (from 150 mg/L on day 1 to ˂0.0031 mg/L on day 14). This was followed by Candida albicans (148mg/L on day 1 to 2.68mg/L on day 28) and Aspergillus flavus (150mg/L on day 1 to 4.21mg/L on day 28) In conclusion, it can be inferred that the some rhizospheric microbes of Rhizophora racemosa can efficienctly degrade hydrocarbon up to 100% rate over a period of 28 days.

Performance evaluation of polycrystalline photovoltaic modules in a Guinea Savanna and Mangrove swamp

This central idea of this research is to investigate how voltage, current, power output and efficiency of polycrystalline photovoltaic (PV) modules installed in a Guinea Savanna and Mangrove Swamp is affected by temperature, relative humidity and irradiance. The study locations are Calabar (mangrove swamp) and Ogoja (guinea savanna), in Cross River State, Nigeria. Two polycrystalline PV modules of exact specification mounted on a platform one-metre-high above the ground were used. A digital solar power meter (SM206) and a digital solar flux meter (MS 6616) was used to monitor and measure solar power and solar flux reaching the PV modules. A digital hygrometer and thermometer (KT-908) were used to monitor and measure the relative humidity and ambient temperature level at the height of installation and a digital multimeter (M880C+) accompanied with a temperature sensor was used to monitor voltage, current and panel temperature values from the modules. Analysis of the collected data reveals that the efficiency of the modules were not constant throughout the day. However, a higher voltage production and efficiency level was obtained for the PV module installed in Ogoja than that installed in Calabar under their respective levels of relative humidity, temperature and irradiance.

Incidence and relative abundance of rice stem borers in three selected rice fields in Lagos and Ogun States, Nigeria

This study was conducted to investigate the incidence of rice stem borer infestations and the species composition present in the selected rice fields. Data were collected between April 2017 and November 2018 across three locations, which include the upland rice field in Agbajege, Ogun state, rainfed lowland in Itoikin and Mangrove swamp in Igbogun, Lagos state, respectively. The incidence of rice stem borers was indicated by dead heart and white heads symptoms, while tillers were excised for rice stem borer identification and population. Results showed a high and low incidence of rice stem borers with no significant difference(p>0.05) at p= 0.29 and 0.37 between the early and late planting seasons in the rainfed lowland and upland rice fields respectively. Planting seasons were significant in the incidence of rice stem borers in mangrove swamp rice fields at p<0.05, p=0.01). This study showed that the predominant species of rice stem borers present in the three study sites were Chilo zacconius and Sesamia calamistis. C. zacconius was the most abundant species at 89% while S. calamistis was 11%. Rice stem borer populations were significantly higher at (p<0.05, p=0.000) in flooded zones while the highest rice stem borer populations were observed at the reproductive phase of the rice plants. Thisstudy showed that the planting seasons coincided with the peak period of the development of rice stem borers. Hence, conservation of natural enemies, monitoring and surveillance should be adopted in insect pest management in rice agroecosystems

Management of the Phanom-Surin Archaeological Site in Thailand: Concept, Policies and Practices

The Phanom-Surin (PNS) archaeological site contains the remains of a sewn-plank vessel that is dated to the 9th century CE and discovered in Thailand’s mangrove swamp. As the only accessible sewn-plank vessel archaeology in the world, it provides research opportunities and potential for collaboration between heritage stakeholders. Preservation of the site within its context is crucial. Throughout this article, I will explain the importance of the PNS site management and its context based on my experience. The fuller understanding of the PNS site relies much on the information to be extracted from the materials and contexts. This article therefore encourages the preservation and management of the site within the original context. There are several relevant international guidelines for heritage and environmental management, such as the World Heritage Operational Guidelines, the Annex of the UNESCO (United Nations Educational, Scientific and Cultural Organization) 2001 Convention and the technical Ramsar Convention, all of which can help develop domestic framework and practices. This article aims to draw public and government attention towards the PNS site, and discusses concepts, policies and practices relating to the site.

Bioaccumulated trace metal profiles of Tympanotonus fuscatus, Periophthalmus barbarous and Guinearma (Sesarma) alberti collected from a perturbed freshwater mangrove swamp in Warri, Nigeria

Bio –concentrated levels of trace metals; Fe, Zn, Cu, Cd and Pb in three (3) freshwater mangrove fauna; Tympanotonus fuscatus (periwinkle), Periophthalmus barbarous (mudskipper) and Guinearma (Sesarma) alberti (West African Sesarmid Crab) was investigated utilizng atomic absorbance spectrophotometery. Faunal sampling was conducted at five (5) sites in the Falcorp wetland area of Warri, Delta State, once monthly for an eighteen (18) month period. Maximal mean Fe and Zn values; 349.7 9 µg/g, dried wt ±15.64 and 16.92 µg/g, dried wt ±1.65 were recorded for the respective mudskipper and crab samples while minimal mean Fe and Zn values; 124.14 µg/g, dried wt ±7.85 and 7.71 µg/g, dried wt ± 0.96 were documented for the digested periwinkle tissues. The differences in the mean Fe, Zn, Cu and Cd values was siginificantly different at different levels (P<0.001, P <0.01 and P<0.05). The detection of significant bioconcentration of these metals especially Cd, is a possible indication of the wide reaching deletrious ecological effects of anthropogenic activities in the affected area. Keywords: Falcorp mangrove swamp, Bioaccumulation, Trace metal, benthic bio-indicator

Suku Phyllanthaceae pada Rawa Bakau dan Tambak di Telang Asri, Kabupaten Bangkalan, Pulau Madura

Madura island is known as a mixed deciduous forest area with dry seasons and limestone soil. The island has unique plant species compared to the mainland Java. However, most of the mangrove forest areas have been converted into ponds and housing. One of the remaining mangrove swamps is located at Telang Asri village, Kamal Subdistrict, Bangkalan Regency. Several species of mangroves have been reported here, along with other groups of plants from the Phyllanthaceae family, found numerously at the time of observation. In 1963, CA Backer and RC Bakhuizen van den Brink Jr. have already listed 16 species of Phyllanthaceae from Madura Island. Since then, the updated information on the Phyllanthaceae of Madura has not been available. Therefore, this study aimed to collect the members of Phyllanthaceae family in the mangrove swamp areas of Telang Asri village. The field study was carried out using the exploratory method, while specimen preparation was conducted in Herbarium Bandungense (FIPIA). In this study, seven species were collected from Telang Asri, namely Glochidion littorale Blume, G. zeylanicum (Gaertn.) A. Juss., Phyllanthus amarus Schumach. and Thonn., P. debilis Klein ex Willd., P. reticulatus Poir., P. urinaria L., and P. virgatus G. Forst.