SEDIMENT CHARACTERISTICS OF CAPE MAY AND WILDWOOD BEACHES: IMPLICATIONS FOR COASTAL MANAGEMENT AND HABITAT RESTORATION

Grain size parameters of beach sediments are crucial for understanding sediment transport, depositional environments, and the composition of coastal sediments. These parameters elucidate the intricate dynamics of coastal processes and hydrodynamics, with significant implications for engineering practices. They also impact beach stability, morphology, habitat, and recreational quality. Despite the major recreational and ecological significance of Cape May and Wildwood, a recent cross-shore sediment analysis under high energy wave/stormy conditions has not been conducted. This study aims to fill this gap by examining the sediment characteristics of modern Cape May and Wildwood beaches during the stormy period.

Wildwood sampling locations are ocean-facing and Cape May is ocean and bay-facing. Sediment samples were collected in March 2024, encompassing transects from the berm crest to the high tide line. A total of 21 samples from Wildwood and 33 from Cape May were collected by excavating to a depth of 5-6 cm. 500 g of oven-dried (80°C for 24-48 h) samples were sieved using U.S. Standard sieve series. Statistical parameters were computed using GRADISTAT V8.0 software.

Results show that Wildwood Beach consists of sediments of very coarse silty fine sand to very fine sand, with a mean of 70-127 µm, and a median of 97-125 µm. They are symmetrically skewed and moderately sorted, displaying unimodal to bimodal distributions. The average mud content is ~10 - 27%. Cape May beach is composed of poorly sorted, very fine sand to very fine gravelly sand, with a mean of 160-275 µm and a median of 158-267 µm. Cape May Point to bayside shows sediment coarsening.

Results confirm that Wildwood and Cape May beaches show a low-energy depositional environment whereas Cape May bayside is a high-energy depositional environment. Bimodality and poor sorting indicate the fluctuation of wave energy and multiple sediment sources of these beaches (i.e., Cape May formation, glacial derived sediments, nourishment fill etc.). High-energy wave conditions, increasing intensity of storms and rising sea level can cause coastal erosion of fine sediment beaches in New Jersey. Thus, sustainable coastal management practices should be adopted to enhance the long-term resilience of the beach. This also increases the stability of the beach and provides recreational and ecological benefits to the surrounding areas.