Metagenomics Unveils Posidonia oceanica “Banquettes” as a Potential Source of Novel Bioactive Compounds and Carbohydrate Active Enzymes (CAZymes)

Posidonia oceanica is a long-living and very slow-growing marine seagrass endemic to the Mediterranean Sea that forms large amounts of leaf material and rhizomes, which can reach the shore and build important banks known as “banquettes.” These banquettes accumulate on the shore, where they can prevent erosion, although they also cause social concern due to their impact on beach use. Furthermore, Posidonia dry material has been considered a source of traditional remedies in several areas of the Mediterranean, and a few studies have been carried out to explore pharmacological activities of Posidonia extracts.

Social and Ecological Elements for a Perspective Approach to Citizen Science on the Beach

Sandy beaches are ecotonal environments connecting land and sea, hosting exclusive resident organisms and key life stages of (often charismatic) fauna. Humans also visit sandy beaches where tourism, in particular, moves billions of people every year. However, instead of representing a connection to nature, the attitude toward visiting the beach is biased concerning its recreational use. Such “sun, sea, and sand” target and its display seem to be deeply rooted in social systems. How could scientists engage the newest generations and facilitate an exit from this loop, fostering care (including participative beach science), and ultimately sustainable sandy beach use? To tackle this question, we applied the concept of social–ecological systems to the Littoral Active Zone (LAZ). The LAZ is a unit sustaining beach functionalities, though it includes relevant features making a beach attractive to the public. Out of the analysis of the system LAZ in its social and ecological templates, we extracted elements suitable to the planning of citizen science programs. The perspective of leverage points was integrated to the needs identified in the analysis, through reconnecting–restructuring–rethinking the components of the system. Two cross-cutting approaches were marked as important to social and ecological designs and break through the dominant perception of beaches as mere piles of sand: the physical dimension (LAZ) of the beach as a unit, and the use of communication through social media, suitable to both monitoring and scientific data collection, and to data communication and hedonistic display of a day on the beach.

Protecting local water quality has global benefits

Surface water is among Earth’s most important resources. Yet, benefit–cost studies often report that the costs of water quality protection exceed its benefits. One possible reason for this seeming paradox is that often only a narrow range of local water quality benefits are considered. In particular, the climate damages from water pollution have rarely been quantified. Recent advances in global water science allow the computation of the global methane emission from lakes caused by human nutrient enrichment (eutrophication). Here, we estimate the present value of the global social cost of eutrophication-driven methane emissions from lakes between 2015 and 2050 to be $7.5–$81 trillion (2015 $US), and in a case-study for one well-studied lake (Lake Erie) we find the global value of avoiding eutrophication exceeds local values of either beach use or sport fishing by 10-fold.

Microplastic abundance in beach sediments of the Kiel Fjord, Western Baltic Sea

We assessed the abundance of microplastics (0.2–5 mm) in drift line sediments from three sites in Kiel Fjord, Western Baltic Sea. The first site is intensively used by beach visitors, the second is in close proximity to a sewage plant and the third is polluted with large-sized plastic litter. Samples were split into three grain size classes (0.2–0.5, 0.5–1, 1–5 mm), washed with calcium chloride solution, and filtered at 0.2 mm. Filters were then visually inspected, and a total of 180 fragments was classified as microplastics, of which 39% were analyzed using Raman spectroscopy. At the site that is close to a sewage plant as well as at the site with intense beach use, 1.8 and 4.5 particles (fibers plus fragments) per kg of dry sediment were found, respectively, while particle abundances reached 30.2 per kg of dry sediment at the site with high litter loads. Our data suggest that the fragmentation of large plastic debris at site seems to be a relevant source for microplastics in Western Baltic Sea beach sediments.

SWRL Net: A Spectral, Residual Deep Learning Model for Improving Short-Term Wave Forecasts

Skillful nearshore wave forecasts are critical for providing timely alerts of hazardous wave events that impact navigation or recreational beach use. While typical forecasts provide bulk wave parameters (wave height and period), spectral details are needed to correctly predict wave and associated circulation dynamics in the nearshore region. Currently, global wave models, such as WAVEWATCH III (WW3), make spectral predictions, but do not assimilate regional buoy observations. Here, Spectral Wave Residual Learning Network (SWRL Net), a fully convolutional neural network, is trained to take recent WW3 forecasts and buoy observations, and produce corrections to frequency-directional WW3 spectra, transformed into directional buoy moments, for up to 24 h in the future. SWRL Net is trained with 10 years of collocated NOAA’s WW3 CFSR reanalysis predictions and buoy observations at three locations offshore of the U.S. western coast. At buoy locations SWRL Net residual corrections result in wave height root-mean-square error (RMSE) reductions of 23%–50% in the first 6 h and 10%–20% thereafter. Sea frequencies (5–10 s) show the most improvement compared to swell (12–20 s). SWRL Net reduces mean direction RMSE by 28%–54% and mean period RMSE by 20%–56% over 24 forecast hours. While each model is trained and tested at independent locations, SWRL Net exhibits generalization when introduced to data from other locations, suggesting future development may be composed of training sets from multiple locations.

Characterization of the Coastal Environment as a Baseline for Alternative Tourism Segments Development in Salinópolis, Pará

Salinópolis in Pará State, Brazil, is a coastal city with a highly seasonal tourism industry. Despite the potentiality of the region, tourism is mainly focused on beach use for recreation. The purpose of this study was to analyze environmental conditions to provide a baseline for development strategies of additional tourism activities, decreasing unwanted impacts, and improving the local economy. We combined wind and pluviosity data, remote sensing, and wave model results for the environmental characterization. Wave climate analysis shows higher waves in the first part of the year, favoring sports like water-surfing. Winds are more intense and parallel to the coast in the second part of the year when rain is low, defining ideal conditions for wind sports, like kitesurfing. Apart from sport activities, appropriately designed beach accesses through mangrove forest would allow a more even distribution of tourists on the beaches. Sustainable walkways projects could include multipurpose structures for beach access and development of ecotourism activities such as environmental education or bird watching. Gastronomic and cultural tourism could also reduce seasonality effects, attracting tourists also during the rainy season.

How Effective Were the Beach Nourishments at Cancun?

Beach nourishment is generally seen as the preferred means of rectifying coastal erosion, due to its low environmental impact and natural evolution. The largest beach nourishment project ever carried out in Mexico took place on Cancun beach in 2006, as a response to the most intense hurricane season ever registered in Mexico, in 2005. After Hurricane Dean, in 2009, a second nourishment was conducted, which evidenced flaws in the design and execution of the first project. Previous investigations report that the need for beach re-fills directly correlates with wave energy. However, following a thorough revision of the extreme climatic events that occurred between 1978 and 2018, it has been found that the amount of erosion also depends on the frequency and duration of high energy events. The findings also show that the apparent success of the second nourishment is mainly associated with a decline in the number of extreme wave power events impacting the beach. In the conclusion to this paper, we share the knowledge gained, but not yet applied, in Mexico or elsewhere, regarding beach use, urbanization, and protection in beach planning.