Assessing the relationships among coastal processes, beach and sediment dynamics and leatherback turtle nesting, at Grande Riviere, Trinidad

Keywords: Coastal geomorphology, sediment, leatherback turtle nesting, Grande Riviere, Trinidad
Abstract Type: Paper Abstract

Abstract

Coastal processes impact beaches which influence their sediment erosion and accretion cycles. An understanding of how these processes interface with the shoreline, beach morphology and beach sediment may determine leatherback turtle nesting behaviour at Grande Riviere. This paper analyzes nearshore processes and corresponding beach dynamics of an environmentally sensitive area critical to an environmentally sensitive species, the leatherback turtle (Dermochelys coriacea) using geomorphological and GIS approaches. Primary fieldwork at Grande Riviere investigated beach morphology using standard survey techniques and GPS mapping. Currents, wave and tide data were obtained with drogues and tide gauges. It was found that a small clockwise gyre exists in the south-eastern region of the bay on flood and ebb tides. The waves were larger toward the central to western regions of the bay. Beach profiling stations closest to the Grand Riviere River mouth showed greatest activity at the mid beach region of the profile. Topographic surveys indicated greater variability in elevation around the Grand Riviere river mouth when compared with the bay. Nesting behaviour progressively shifted to the west. Superficial sediment samples indicate possible linkages between the sediment Folk & Ward parameters and leatherback turtle nesting sites. These findings may have global application to environmentally sensitive coastal communities in light of sea level rise. Environmentally sensitive areas would benefit from relevant policies and improved management for leatherbacks.