Textural characteristics of foreshore sediments in Wildwood and Cape May beaches, New Jersey: implications for beach renourishment and habitat restoration

Abstract

Wildwood and Cape May beaches in New Jersey are vital for ecological, recreational, and economic reasons. These areas support critical habitats and endangered species that depend on the unique sediment characteristics of the beaches. Economically, Cape May County tourism contributed $7.7 billion in 2023 to the local economy. This study investigates the foreshore sediment textural characteristics and grain size distribution following a renourishment cycle. Sediment samples n = 54 were collected in March (winter) and n = 57 in August (summer) 2024 along cross-shore profiles from the berm crest to the high tide line. The samples were sieved and analyzed for grain size distribution, sorting, skewness, and kurtosis using sieve analysis and GRADISTAT V8.0 software. Results indicate that Wildwood beaches in the winter (pre-nourishment) were very well-sorted fine sand, and in the summer (post-nourishment), well-sorted fine to medium sand. Cape May oceanside was predominantly well-sorted medium sand, symmetrical to coarse skewed in winter and fine skewed in summer. In contrast, Bayside consisted of more poorly sorted coarse sand, including gravel. Results indicate that Wildwood and Cape May Oceanside are depositional environments during both seasons, whereas Cape May Bayside in winter is an erosive setting with sporadic high-energy events and multiple sources of sediments. Ultimately, the long-term nourishment has caused an increase in overall average grain sizes of the beaches, where coastal structures alter the natural sediment transport and wave energy reaching the nearshore, impacting the distribution of sediments. Under modern conditions with decades of future anthropogenic influence, these beaches could demonstrate a greater resilience to erosion, while being more stable. These findings are applicable to future coastal management and habitat restoration projects.