Anthropogenic and Biophysical Factors Influencing the Nesting Choice of the Green Turtle (Chelonia Mydas, Linnaeus, 1759) Along the Kenyan Coast

Abstract

The Green turtle Chelonia mydas Linnaeus, 1759 accounts for highest number of sea turtles that nest along Kenya’s coastline where there are varying biophysical and anthropogenic factors influencing nest sites that they select to lay their eggs. This study was conducted between February and November, 2016 and it was therefore, designed to establish the relationship between number of nests of C. mydas with biophysical and anthropogenic variables. A multiple regression model was employed to assess the factors that contribute to higher number of nest. The multiple regression model did not significantly predict the number of nest, F (8, 22) = 0.294, p > 0.05, R = 0.311. All the variables: vegetation cover, organic matter content, beach width, slope of the beach, number of people, debris weight, sea defence barrier and beach font lighting did not add statistically significantly to the prediction, p > 0.05. However, there was decrease in number of nests with increase of organic matter content, b = -8.312, sea defence height b = -3.155 and beach front lighting b = -2.154. Anthropogenic factors thus, had the greatest negative impact on number of nests. Nonetheless, nesting of C. mydas was observed to occur across different spectrum of human disturbance. Some of the uninhabited beaches in Lamu County had high number of annual nests despite high amount of debris per 100m-2 brought in by waves from other regions, for example, Kitangakikuu had 7kg, KSV had 3kg and Mwanabule had 3kg. The average debris weight was 1.90kg 100 m-2. It is therefore recommend that existing laws should be enforced to control beach development along the Kenyan coast to protect existing nesting areas and long term monitoring should to be put in place to evaluate the impact of human disturbance on the number of nests as a management tools in conservation efforts of C. mydas.