Abstract： The majority of consumer products used today is composed of some form of plastic. Worldwide, almost 280 million tons of plastic materials are produced annually, much of which end up in landfill or the oceans. Plastics are produced by the conversion of natural products or by synthesis from primary chemicals, generally from oil, natural gas or coal. In contemporary society, plastic has attained a pivotal status, with extensive commercial, industrial, medicinal and municipal applications. It affects at least 267 species worldwide, including 86％ of all sea turtle species, 44％ of all seabird species, and 43％ of all marine mammal species. Marine animals are harmed mostly through ingestion, entanglement and subsequently strangulation. Ingested plastics debris has been found to reduce stomach capacity, hinder growth, cause internal injuries and create intestinal blockage. Plastics entanglement with nets or other materials can result in strangulation, reduction of feeding efficiency, and even drowning. Plastics pollution facilitates the transport of species to other regions, alien species hitchhike on floating debris and invade new ecosystem thereby causing a shift in species composition or even extinction of other species. Legislation, prohibiting the disposal of plastics in the sea, introducing of biodegradable plastics, recycling of plastics and public awareness campaigns to discourage littering are various ways in which this problem can be minimized. Other remedial measures include enforcing environmental laws, development of indigenous and homegrown knowledge for plastic waste management and development and implementation of quality standards for all plastic recycled products.

Abstract： This study assesses ornamental nursery operation and factors that influence gender composition variation among the operators in Akwa Ibom State, Nigeria. Data was collected using a structured administered to all the nursery operators in the study area being 42 operators. Descriptive statistics and ordinary least square regression were employed in analyzing the data collected. The findings revealed that majority of the respondents were male (66.67％), married (71.43％), literate (95.24％), between the age class of 25-54 years (85.77％), had been in operation for >6years (71.43％), acquired training in the operation (66.20％) and earned an annual income of ₦301,000-₦400,000 (47.62％). Also, majority of them obtain the seeds/cutting from mother trees (41.18％), preserved their seeds by drying (48.84％), used paid labor (68.89％), operated ornamental nursery size of <0.05ha (88.10) and operated all year round (100％). The result of regression analysis showed that the factors accounted for 67.9％ of the variation in gender composition in nursery operation and was significant at p<0.001. Age (-0.403, p<0.001), years in business (-0.209, p<0.05), income (2.751, p<0.05) and training in business (0.541, p<0.001) were the major determinants of gender variation. It is recommended that considering the annual income of the ornamental nursery operators, more people should be encouraged to venture into the business in other to expand the ornamental nursery sector in the state.

Abstract： Many studies have described the parasitic relationship between Opuntia ficus-indica and Dactylopius tomentosus in the light of biological control systems. This has been done with no or little concern on the direct cost the agent insect causes on the host plant and diversity of other organisms surrounding the plant’s existence. The aim of this study was to assess the percentage light interception variations on Opuntia fiscus-indica due to Dactylopius tomentosus insect infestation and its impact on phytomorphology around Masvingo City in Zimbabwe. The assessment was done by measuring changes in cladode/stem thickness, nymph density and PLI (Percentage Light Interception), the difference between the incoming (I0) solar irradiance and the outgoing (I1) solar radiation, of D. tomentosus infested plants over a period of 162 days. With increased infestation period, measurements on O. ficus-indica cladode/stem thickness and PLI were significantly lower than their initial states (p .000). These changes effected significantly on the structure of the host plant (O. ficus-indica), that is, lanceolated shape of the cladodes/stems collapsed, while at the same time the plant lost its green colouring. This allowed more light to pass through, hence reduced PLI. Pearson correlation between cladode/stem thickness and PLI over the same measurement period was significantly positive (p < .000). The correlation between nymph density and PLI over the same 4 time measurement period was significantly negative (p < .000). A relatively low but significant total dependence of PLI on nymph density was also shown (p < .000).Changes in the measurements of the three variables that is, cladode/stem thickness, nymph density and PLI over the study period affected the overall morphological structure of the host plant, predictive of total plant death and hence host plant local extinction beyond the study period.

Abstract： The study assessed the concentration of Zn, Fe, Pb, Cu, Mn and Cr in soils and contamination index found in residential, agricultural, market, institutional, mechanic workshop and filling station in Ojo area Lagos State. Random sampling technique was employed to collect 12 surface soil samples (2 soil samples for each land use) using a soil auger and analysed using standard laboratory procedures. The study found that the contents of Zn, Fe, Pb, Cu, Mn and Cr were far below WHO permissible level as the land uses generated very low quantities of heavy metals. The order of metal concentration was Fe>Cu>Zn>Mn>Cr>Pb; which implied that Fe and Cu had increased concentrations, while the order of land use with increased heavy metal contamination in the soil was mechanic workshop>agricultural>market>residential>institutional>filling station. Positive and significant associations between heavy metals were found between Fe and Zn, Mn and Zn, Mn and Cu, Cr and Zn, Cr and Cu and Cr and Mn. Results of contamination factor of heavy metal indicated low contamination factor. Also, the degree of contamination indicated low degree of metal contamination, while the pollution index revealed absence of pollution concern in spite of the numerous human activities in the area. Based on the results, the study suggested that though, the respective land uses had low heavy metal level, the soils around agricultural area and mechanic workshop should be monitored to control the gradual buildup of metals in the soil; because the activities carried out in these two land uses had the potential of increasing the content of heavy metal in the soil.