An Investigation in-to the Possible Effects of Physical Features of Nesting Beaches on the Nest Site Beach Selection by Chelonia mydas (the green turtle) and Caretta caretta ( the loggerhead turtle)

<p>An investigation in to possible effects of physical beach parameters on the magnitude and success of nesting effort in the marine turtles Chelonia mydas, (green turtle), and Caretta caretta, (loggerhead turtle).The physical parameters measured were: beach length, beach width, beach slope, beach digability, beach waterlogging, sand grain size. Parameters describing marine turtle nesting were: number of activities, number of nests, nesting density, percentage emergence success and proportion of nests. It is known that marine turtles nest on a variety of sandy substrates but there have been very few investigations as to the factors responsible, (if any), for the selection of the nesting beaches. Data were collected during the 1997 nesting season and analysed by the use of multivariate statistics, (multiple regression). Results showed that some of the measures of beach selection significantly correlated, (both positive and negative), with some of the physical measurements, (nesting density correlated well with beach orientation in C caretta and with beach digability in C mydas). Results allowed conclusions to be drawn as to which factors had greatest effect on nesting beach selection and suggested areas of future possible research. Due to interseasonal nesting differences the actual predictions made from the regression analyses may vary from year to year. There may be other unmeasured physical parameters that exert an effect. There is scope for further study in to the effect that these and other physical parameters may be having in clutch viability and hatching success.