Sandy beach social–ecological systems at risk: regime shifts, collapses, and governance challenges

Abstract

A ccounting for nearly one-half of the world's ice-free coastline, sandy beaches support various human uses, especially recreation and tourism -both of which are expanding globally as a result of increased leisure time (McLachlan and Defeo 2018). The economies of many coastal states are dependent on this beach recreation-tourism link (McLachlan et al. 2013). With more than one billion visitors annually, tourism is a major industry, and even when other ecosystems are the focus (eg coral reefs), beaches are central to all coastal recreation experiences. Moreover, the global human population, currently approaching 8 billion, is increasingly concentrated in coastal areas, generating inevitable pressures on beaches despite inequities of access. Indeed, nowhere is a beach free from the human footprint, such that the interaction between their ecology and human activity cannot be ignored. This emphasizes the "triple whammy" affecting coastlines (Elliott et al. 2019;Fanini et al. 2020): increased urbanization and industrialization, increased use of physical and biological resources, and reduced resilience and resistance to climate change and other exogenous natural and anthropogenic pressures. Therefore, maintaining the ecosystem functions of the world's sandy shores in the face of increasing human recreational and aesthetic demands requires adoption of a more holistic social-ecological system (SES) perspective (see WebPanel 1 for definitions of selected specialist terms).Sandy beaches are the dominant land-sea interface worldwide and are closely coupled to adjacent surf zones and foredunes (Figure 1). These three systems form the core of the "littoral active zone" (LAZ), the section of the coast characterized by wind-and wave-driven sand transport (McLachlan and Defeo 2018) that provides important ecosystem services, including (1) recreation; (2) food; (3) wave dissipation and associated buffering against storms and sea-level rise (SLR); (4) assimilation of organic materials and pollutants; (5) maintenance of biodiversity, as well as nursery and nesting sites for various taxa, such as fish, sea turtles, shorebirds, and marine mammals; (6) water storage in dune aquifers and groundwater discharge; and (7) water filtration and nutrient mineralization and recycling (Defeo et al. 2009;Barbier et al. 2011). These ecosystem services are increasingly impacted by perturbations Sandy beach social-ecological systems at risk: regime shifts, collapses, and governance challenges

Recovery of ghost crabs metapopulations on urban beaches during the Covid-19 “anthropause”

“…Sandy beaches are social-ecological systems, where physical, ecological, social and economic dimensions interact, providing several services for human well-being ( Defeo et al, 2021 ). Overuse of beaches as recreational assets to society has pervasive effects on animal assemblages and ecosystem services ( Defeo et al, 2021 ).…”

“…Sandy beaches are social-ecological systems, where physical, ecological, social and economic dimensions interact, providing several services for human well-being ( Defeo et al, 2021 ). Overuse of beaches as recreational assets to society has pervasive effects on animal assemblages and ecosystem services ( Defeo et al, 2021 ). While some sandy beaches experience chronic stressors that rarely cease, others are exposed to acute events causing sudden short-term changes such as tourism activities, including trampling, vehicle traffic and cleaning services ( Defeo et al, 2009 ; Costa et al, 2020a ).…”

Unravelling the role of local and large-scale factors in structuring sandy beach populations: the wedge clam Donax hanleyanus

“…Sandy beaches are one of the most extensive intertidal ecosystems worldwide (Luijendijk et al 2018, Defeo et al 2021. Their physical structure is determined by the interaction between sand, waves and tides, and the resident macrofauna is mainly controlled by these distinctive physical properties (McLachlan & Defeo 2018).…”

Long-term ecological trajectories of a disturbed Mediterranean coastal lagoon (Biguglia lagoon): Ecosystem-based approach and considering its resilience for conservation?

“…Coastal systems are particularly fragile, as the development of human activities and climate change are increasingly causing a "coastal squeeze" phenomenon, meaning the subtraction or loss of available space for the natural functioning of these systems (Chacón Abarca et al, 2021), aquatic ecosystem degradation (Perrow and Davy, 2002;Lloret et al, 2008), reduction of biodiversity, and consequent loss of ecosystem services (Elmqvist et al, 2003;Nyström et al, 2012) with, ultimately, reduced resilience and resistance to climate change and other pressures (Defeo et al, 2021). Coastal lagoons are transitional systems, strictly dependent on their connection to adjacent systems (Tagliapietra et al, 2009).…”