From the Editor’s Desk: Coastal times, they are a-changin’
Lesley C. Ewing
Determining depth of closure based on time-series beach profiles and empirical formulas: A case study along the Florida coast
Elizabeth Royer, Ping Wang, and Jun Cheng
Depth of closure (DOC) is defined as the most landward depth seaward of which there is no significant change in bed elevation and no significant net sediment exchange between the nearshore and the offshore over a certain period of time, such as 5 to 20 years. DOC is an essential parameter used in beach and shore protection, sediment management, and many other aspects of coastal studies. Taking advantage of advancements in wave hindcast and bathymetry measurement in the past 20 years (2000-2019), this study determined the DOC at 12 locations along the Florida coast, including three from the northwest Gulf coast, three from the west Gulf coast, and six from the east Atlantic coast. The 12 sites covered a wide range of coastal morphodynamic conditions, with considerable difference in tidal ranges, incident wave heights, as well as nearshore and offshore morphology. Hindcast wave data from WAVEWATCHIII, available since 2005, were analyzed and applied to calculate the closure depth using various empirical formulas. At all the 12 study sites, time-series profiles demonstrated an apparent convergence point indicating the presences of a DOC. The bed-level change at DOC, as quantified by the standard deviation of elevation variation, ranged from 0.05 m to 0.19 m. Along the studied northwest Florida Gulf coast the DOC ranged from 9.12 m to 9.76 m. The DOC along the studied west Florida Gulf coast ranged from 1.59 m to 4.06 m and is influenced by the shallow flat inner continental shelf. Along the studied east Florida Atlantic coast, the DOC ranged from 4.35 m to 8.20 m, with considerable alongshore variation. The Birkemeier formula yielded the closest predictions to the measured values. A linear relationship between the seaward slope of the outer bar and DOC was identified. Incorporating the seaward slope of the outer bar into the Birkemeier formula improved the accuracy of DOC prediction.
Case Study: Nearshore placement of dredged material for estuarine shoreline restoration in Berkeley Township, New Jersey
Daniel A. Barone, Robert Miskewitz, and W. Scott Douglas
Nearshore placement of sediments for beach nourishment has become a standard, cost-effective method for shore protection along ocean-facing shorelines but is not a widely adopted practice within tidal estuaries due to environmental concerns such as turbidity, burial of benthic and shore organisms, and pollution. This paper describes the monitoring and evaluation of nearshore placement of dredged materials at Goodluck Point, Berkeley Township, New Jersey. A total of approximately 4,500 cubic meters of dredged material was placed in the nearshore to create a parallel bar along a 0.5 km stretch of existing beach. The narrow beach is the front edge of a marsh system severely impacted by erosion due to lack of sediment supply compounded with local currents and waves that transport sediment out of the beach system offshore and alongshore. This beach erosion is exacerbated during coastal storms events. The Goodluck Point marsh is part of the Edwin B. Forsythe Wildlife Refuge managed by the U.S. Fish and Wildlife Service. Nearshore placement was determined to be part of an experimental project designed to evaluate methods of restoration for the marsh and reduce future impacts. The design for the nearshore placement called for sand to be placed in a temporary parallel bar just offshore of the existing beach, and over time it would weld to the beach. Analysis of pre- and post-placement surveys indicate that much of the dredged material placed in the project area remained there throughout the 18-month monitoring period. However, a combination of storms during and after placement, as well as ongoing longshore transport processes, resulted in the sand being washed south along the beach and accumulating in just the southern 200 meters of the project area. This paper introduces and suggests that the concept of “process-based design” will maximize resiliency benefits through more extensive pre-placement monitoring and modeling to identify optimal placement strategies. Process-based design is a beneficial use strategy that takes advantage of natural sediment transport processes to enhance or re-create nature-based shore protection features.
The impacts of climate change on surfing resources
Nick Sadrpour and Dan R. Reineman
Surfing has increased in cultural, social, and economic importance through the last century and is now globally significant. Predicated on the natural phenomenon of ocean waves interacting with coasts, surfing’s future is threatened by Earth’s changing climate. This paper provides a comprehensive review of physical processes, including swell generation, wave breaking, and coastal dynamics, relevant for the locations — surf breaks — where surfing occurs and the myriad mechanisms through which each can be affected by a changing climate. We propose an organizing framework for these impacts characterizing them based on their mode of action as direct versus indirect, as well as by their magnitude, and conclude that some impacts (such as sea level rise) may threaten some breaks but on more protracted timelines, whereas other impacts (such as coastal armoring implemented in response to climate change) may pose more immediate, existential threats. This framework underscores the importance of local environmental knowledge of a given surf break for understanding its susceptibility to climate change and informs a Surf Break Vulnerability–Climate Change Assessment Tool (SurfCAT), designed to enable improved wave stewardship by local resource managers and stakeholders in the face of a changing climate.
Supplemental Online Material: https://doi.org/10.34237/1009110
Surf Conservation Index: Mapping priority zones for surf protected areas in Mexico
Mara Arroyo, Georges Seingier, Gino Passalacqua Walter, and Diego Sancho Gallegos
A set of indicators was applied to 173 surf breaks in Mexico to help identify priority subregions for surf conservation. The surf conservation index developed consists of pressure, state, and response subindexes, with four scores ranging from very low priority to high priority. Priority surf breaks were defined as the surf breaks where high biodiversity overlaps with high-quality waves, reliance on tourism for income/ economic activity, and low environmental pressure. The highest priority surf breaks for conservation were found in the Gulf of California, followed by the Central-South Pacific coast. Pressure values show that a majority of surf breaks in Mexico are still in an area with low pressure or low population. Most surf breaks have relatively little coastal development and harbors or big cities. The biodiversity subindex, which considers both marine and adjacent terrestrial areas, shows that the highest biodiversity values are found in only 11% of all surf breaks, although 42% of surf breaks have at least half of their marine or terrestrial buffer in biodiversity conservation priority zones, showing a non-negligible presence in critical ecosystems. Overall, the surf break subindex values were generally high and stable, while a majority of surf breaks stand out for having a relatively important proportion of workers employed in tourism. Response analysis shows that only 3.5% of the total listed surf breaks in Mexico are already under a legal protected area framework. A strategy is needed to ensure that surfing, as a recreational activity, and surf breaks, as a natural resource, are considered in present and future management plans. Mexico finds itself at a crossroads as it aims to strengthen surf conservation efforts and preserve these unique coastal socio-ecosystems while also contributing to the sustainable development of local coastal communities.
Coastal Forum: Smoke-free beaches in Florida
John Michael Pierobon and Stephen P. Leatherman
Beach tourism is often the most important source of revenue for coastal communities, and surveys have shown that the foremost requirements for beachgoers are clean sand and clean water. Beach litter is harmful and costly in many ways, and the No. 1 form of litter on U.S. beaches is cigarette butts. Campaigns for smoke-free beaches have been based largely on environmental issues and aesthetics, but there are other important reasons. Hawaii was the first state to ban smoking on beaches. This paper presents the rationale for Florida cities and counties to adopt smoke-free policies for one of their most important natural resources and recreational destinations.
Coastal Observations: California coastal access damage from early winter 2022-2023 storms: A photo essay
Joseph Street, Claire Wilkens, Jeremy Smith, Angela Abshier, and Lesley Ewing
Atmospheric rivers, “bomb cyclones,” storm waves and high tides wreaked havoc along the central California coast from San Francisco to Monterey. From 26 December 2022 to 11 January 2023, more than 10 inches of rain fell in central California (Landers 2023). During this same time period, higher high tides were 6-ft or greater for 10 of these days and 35-ft high waves were noted. Beaches, beach accesses, and coastal trails were on the front lines for storm defenses and damage. In addition to the extensive new coverage, the National Oceanic and Atmospheric Administration’s National Geodetic Survey (NOAA/NGS) collected continuous post-storm(s) airborne photography along the west coast that will be invaluable in analyzing future long-term shoreline changes (NOAA/NGS 2023). The following photos, taken soon after the storms, show some of the coastal damage near and in Monterey Bay.
O’Brien Award Winners: An interview with Lee Weishar, Ph.D.
Dr. Lee Weishar won the Morrough P. O’Brien Award, ASBPA’s highest honor, in 2022. This interview presents his thoughts on his career and the future of coastal science and engineering.
In Memoriam: A tribute to Paul D. Komar (1939-2023)
It is with tremendous sadness that the international coastal community learned of the passing of Professor Paul D. Komar on Wednesday, 22 February 2023. Paul was the editor of Shore & Beach between 1996 to 1998 and over the years he published many articles in the journal. Paul was a faculty member at Oregon State University from 1970 until his retirement in 1998, after which he continued to contribute actively as an Emeritus Professor — particularly through memorable interactions with students.