Nourished, Exposed Beaches Exhibit Altered Sediment Structure and Meiofaunal Communities

Abstract

To retain recreational uses and shoreline protection, a large proportion of ocean beaches have been, and continue to be, nourished. Adding sand from subtidal and terrestrial sources to nourish beaches rarely re-creates the original sediment structure of the beach. Numerous studies have demonstrated that meiofaunal communities are altered by changes in sediment composition in low-energy substrates, therefore, we have explored whether beach nourishment has affected exposed, ocean beach meiofaunal communities. Since the early 2000s, we have conducted a series of sampling and experimental studies on meiofauna and sediments on nourished beaches in coastal North Carolina USA that had been sampled previously in the early 1970s, prior to any beach nourishment. Most of our studies consider meiofauna at the level of major taxa only. However, a few studies examine free-living flatworm (turbellarian) species in detail because of the existence of historical studies examining this group. Comparison of contemporary results to historical data and of heavily nourished versus lightly nourished beaches reveals extensive changes to beach sediment structure and meiofaunal community composition, indicating that the beaches are a more heterogeneous habitat than in the past. The effects of these substantial physical and biological changes to the production of beach ecosystem services are unlikely to be inconsequential.

Effect of high temperature on the meiofauna composition, abundance, and biomass in a zone of geophysical anomalies

“…Sediment samples were washed and screened through a 0.5 mm mesh sieve (to separate macrofauna) and a 0.06 mm mesh sieve (to separate meiofauna). Recent deep sea meiofauna studies have recommended the use of smaller mesh sieves (0.032–0.04 mm), however, few shallow water meiofaunal studies still use a 0.06 mm mesh sieves (Fegley et al, 2020; Martínez et al, 2020). Caution is strongly recommended when drawing comparisons between different studies.…”

“…This smaller size corer is used in some meiofaunal studies (e.g. Fegley et al, 2020;Portnova et al, 2021), however, as it is more common to use a 10 cm 2 corer, this should be taken into consideration when reading, interpreting, and comparing the results. Sediment samples were fixed with 96% ethanol until samples could be processed extraction, this fixative was chosen because some meiofauna specimens will be described and sequence in further studies.…”

Soaring Building Collapses in Southern Mediterranean Coasts: Hydroclimatic Drivers & Adaptive Landscape Mitigations

“…It allows for a more dynamic coastal response (Van Rijn, 2011) and is considered an environmentally friendly option compared to hard protection. However, the costs of implementing sand nourishment can be prohibitive for large areas as it depends on the availability of specific types of sand reserves (Fegley et al, 2020). As such, this approach can only be applied in localized spots of a few hundred meters at most of Alexandria's seafront.…”

Designing Coastal Adaptation Strategies to Tackle Sea Level Rise

“…However, the literature points to negative physical and biological changes it can cause in beach ecosystem services (Fegley et al, 2020), as well as other ecological and socioeconomic impacts (de Schipper et al, 2020). An open question for the development of beach nourishment is the accessibility of beach-compatible sand.…”