The influence of fluvial dynamics and North Atlantic swells on the beach habitat of leatherback turtles at Grande Riviere Trinidad. (15th September 2016)

• Record Type: Journal Article
• Authors: Darsan, Junior; Jehu, Adam; Asmath, Hamish; Singh, Asha; Wilson, Matthew
• Is Part Of: Journal of environmental management. Volume 180(2016)
• Page Start: 111
• Page End: 122
• Publication Date: 2016-09-15
• Subjects: Beach erosion -- Episodic river flooding -- River shifting -- Coastal geomorphology -- Endangered species; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2016.05.014
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Grande Riviere beach, located on the north coast of Trinidad, West Indies, is internationally recognised as a critical habitat/nesting ground for the endangered leatherback turtles ( Dermochelys coriacea ). Episodic extreme flooding of the Grande Riviere River led to the shifting of the river mouth and resulted in backshore beach erosion, with the most recent recorded event occurring in 2012. Following this event, the construction of a sand dam to arrest further erosion which threatened coastal infrastructure, precipitated a host of new problems ranging from beach instability to public health threats. In January 2013, high energy swell waves naturally in-filled the erosion channel, and the beach recovery continued over the successive months, thereby rendering the intervention in the previous year questionable. This paper presents a geomorphological analysis of beach dynamics for Grande Riviere, within the context of this erosion event. Data on beach profiles, sediment and coastal processes were collected using standard geomorphological techniques. Beach topographic analysis and water quality tests on impounded water in the erosion channel were conducted. Results indicate that the event created an erosion channel of 4843.42 m 3 over a contiguous area of 2794.25 m 2 . While swell waves were able to naturally infill the channel, they also eroded 17, 762 m 3 of sand overall across the beach. Water quality tests revealed that the impounded water was classified as a pollutant, and created challenges for remediation. Hydrologic and coastal geomorphologic interplay is responsible for the existence and sustainability of this coastal system. It is also evident that the beach system is able to recover naturally following extreme events. Our results demonstrate that effective and integrated management of such critical habitats remains dependent upon continuous monitoring data which should be used to inform policy and decision making. Highlights: Riverine and beach erosion at Grande Riviere negatively impact leatherback turtles and their habitat. Anthropogenic intervention on beaches should be based on a proper understanding of the environmental processes at work. Multidimensional analysis should be considered for effective beach management.