Beach Zone Research Articles

THE RELATIONSHIP BETWEEN MACROPLASTIC AND LARGE-MICROPLASTIC ABUNDANCE IN THE NORTHERN COASTAL REGION OF WEST PENINSULAR MALAYSIA

Several locations representing recreational area, tourist spots and fish landing grounds were selected in the northern coastal region of Peninsular Malaysia for L-Microplastic (L-MP) data collection. Marine litter samples were collected during HWS and LWN tidal regime. Quadrats of 50 cm x 50 cm were used to collect sediment from surface to 5 cm depth for microplastic analyses. A comparison between macroplastic and L-MP showed a significant relationship with R2 =0.9579 where linear regression computed resulted in y = 26.388x + 0.051, where y: microplastic (kg/m3) while x: macroplastic (kg/m3) for Perlis sampling region. The linear regression obtained for Penang island is y = 0.1248x + 0.0854 with R2=0.9036. Both results showed a significant difference where computed P-values were both <0.05. Findings from Penang island region demonstrated possibility of macroplastic and L-MP abundance relating to tidal condition, where during neap tides more plastics are settled on the beach zone as opposed to during spring tides mainly because of the difference in water volume and movement dynamics. Largest marine litter composition was plastic, followed by fabric and rubber. Although recent plastics used are of biodegradable grades meaning it breaks down into smaller sizes through exposure to sun, hydrolysis and microorganism reactions over time, these L-MP might further degrade to nanoplastic in size. The smallest microparticle reportedly detected in the oceans at the present is 1.6 µm in diameter. Further breakdown of microplastics is imminent and will be difficult to detect as these nano-sized plastics enter the food chain resulting in health risks. Based on this, the UN-SDGs directly affected will be SDGs 3, 6, 12, 14 and 15. KEYWORDS: microplastic, plastic, marine litter, marine debris, health risk, biodegradable

The extended concept of littoral active zone considering soft sediment shores as social-ecological systems, and an application to Brittany (North-Western France)

This paper applies and extends the concept of Littoral Active Zone (LAZ) of sandy beaches as a relevant dimension to observe and manage this socio ecological system. The LAZ is a dynamic zone where exchanges across land and sea occur, and this concept was initially proposed on a geomorphological background only. However, to achieve full relevance and timely address management choices tied to the functioning of soft sediment shores, it became appropriate to extend its consideration to both the ecological and social templates co-existing on the same physical unit. Current paradigms around the concept of LAZ were used as a background to organize information from different disciplines and extend the concept to different soft sediment shores (mostly sandy beaches and salt marshes), towards a global, integrated relevance of the concept.As a test for this approach, we 1) struabctured information on the biophysical and social templates around the concept of LAZ, 2) extended it to salt marshes and 3) applied it to the case of the Breton coast for a practical test on information organization. Such an exercise highlighted key characteristics of the LAZ using a multidisciplinary approach, but also gaps to be filled when targeting research, perception, communication, sustainable use and management of the LAZ as a functional unit.

Groundwater Flow and Moisture Dynamics in the Swash Zone: Effects of Heterogeneous Hydraulic Conductivity and Capillarity

AbstractA density‐dependent, variably saturated groundwater flow and solute transport model was used to investigate the influence of swash motions on subsurface flow and moisture dynamics in beach aquifers with heterogeneous distributions of hydraulic conductivity (K) and capillarity. The numerical simulations were performed within a Monte Carlo framework using field measurements conducted in the swash zone of a sandy beach. Our results show that heterogeneous capillarity causes spatially variable capillary rise above the groundwater table. In response to swash motions, heterogeneity creates capillary barriers that result in pockets of elevated moisture content beneath the swash zone. These moisture hotspots persist within the unsaturated zone even at ebb tide when the swash motions recede seaward. Heterogeneous capillarity also results in highly tortuous preferential flow paths and alters the flow rates from the sand surface to the water table. Heterogeneous K greatly enhances the seawater infiltration into the swash zone and modulates its spatial distribution along the beach surface. Due to heterogeneous K and capillarity, complex mixing patterns emerge. Both strain‐dominated and vorticity‐dominated flow regions develop and dissipate as tides and waves move across the beach surface. Complex mixing patterns of seawater percolating from the swash zone surface to the water table, with localized areas of high and low mixing intensities, are further demonstrated by analysis of dilution index. Our findings reveal the influence of geologic heterogeneity on swash zone moisture and flow dynamics, which may have important implications for sediment transport and chemical processing in beach aquifers.

The first occurrence of Cycloachelous granulatus (H. Milne Edwards, 1834) (Decapoda Portunidae) from Klah Island, Indonesia

NiThis article reported the first occurrance of Cycloachelous granulatus (H. Milne Edwards,1834) (Decapoda Portunidae) from Klah Island (close to Sabang Island), Aceh Province. Twospecimens were collected in intertidal zone of Klah beach, on June 2018. Our findings con-tribute to Indonesian Biodiversity Database and could be used as the basis to develop faunalknowledge such as study on taxonomic, biogeographic, evolutionary or conservation.

Ranking the ecological effects of coastal armoring on mobile macroinvertebrates across intertidal zones on sandy beaches

Coastal armoring is widely applied to coastal ecosystems, such as sandy beaches, in response to shoreline erosion and threats to infrastructure. Use of armoring is expected to increase due to coastal population growth and effects of climate change. An increased understanding of armoring effects on those ecosystems and the services they provide is needed for impact assessments and the design of these structures. We investigated the following hypotheses: 1) impacts of coastal armoring on beach macroinvertebrates increase from lower to upper intertidal zones and 2) location of an armoring structure on beach profiles affects the number of intertidal zones, using comparative surveys of armored and unarmored beach sections in Chile and California. The effects of armoring were greater for upper intertidal (talitrid amphipods) and mid-intertidal species (cirolanid isopods) than for lower shore fauna (hippid crabs). Our surveys of sections of armoring structures located higher and lower on the beach profile (with and without interactions with waves and tides), showed loss of upper zone talitrid amphipods and mid-zone isopods and a reduction of lower zone hippid crabs in sections where the structures were lower on the beach profile and interacted with waves, compared to non-interacting sections. Our results support the hypothesis that impacts of armoring on intertidal macroinvertebrates increase from the lower to the upper intertidal zones of sandy beaches and also suggest that the relative position of an armoring structure on the beach profile, determines the number of intertidal zones it affects. Our findings also imply that by altering the position of existing armoring structures on the shore profile and increasing the amount of interaction with waves and tides, sea level rise and regional factors, such as coseismic coastal subsidence, can be expected to exacerbate the impacts of these widely used coastal defense structures on sandy beach ecosystems.

Occurrence, Composition, and Relationships in Marine Plastic Debris on the First Long Beach Adjacent to the Land-Based Source, South China Sea

Land-based sources are the key sources of plastic debris, and mismanaged plastic debris can eventually enter the ocean via marine beaches. In this study, the spatial distribution and amount of plastic debris in the land-based source input zone of First Long Beach (FLB), China, which is a major tourist attraction, were first investigated. By using field investigation, sand samples were collected from two sections on FLB adjacent to land-based sources in December 2019, and the plastic debris in the sand samples was quantified and characterized in the laboratory. The amount of plastic debris ranged from 2 to 82 particles/m2 on this marine sand beach. There was a significant difference in plastic debris amount between the transects along the land-based source input zone (p < 0.05) due to the impacts of wind, ocean currents, and waves. The most abundant size of plastics was 0.5–2.5 cm (44.4%). Moreover, the most common color was white (60.9%). The most abundant shape of plastic debris fell into the fragment category (76.2%). The plastic debris amounts were significantly correlated with multiple sizes. Our results show that land-based wastewater discharge is a large plastic debris source on FLB under coastal water tide variation. Reduction strategies should be carried out by tracing the various land-based sources of plastic debris.

Beach Nourishment as an Adaptation to Future Sandy Beach Loss Owing to Sea-Level Rise in Thailand

A recent study suggested that significant beach loss may take place on the coasts of Thailand by the end of the 21st century as per projections of sea-level rise by the Intergovernmental Panel on Climate Change (IPCC). The present study adapts a framework and provides broad estimations for sand volumes and costs required to apply beach nourishment to each coastal zone in Thailand using a technique based on the Bruun rule assumption. Results indicate that a minimum of USD 2981 million (the best scenario) to a maximum of USD 11,409 million (the worst scenario) would be required to maintain all sandy beaches at their present width. Further, the effect of filling particle size on beach nourishment was analyzed in this study. The cost of beach nourishment ranges between USD 1983 and 14,208 million when considering filling particle size diameters of 0.5 and 0.2 mm. A zonal sand volume map for all 51 sandy beach zones in Thailand was created for use as an overview to help decision makers develop a more feasible adaptation plan to deal with the future sea-level rise for Thailand.

Characterization of plastic beach litter by Raman spectroscopy in South-western Spain

The characteristics and distribution of plastic litter were evaluated in October 2018 at 40 beaches along the coast of Cádiz Province, in Spain. A total of 14,261 plastic items, appertaining to 57 litter groups, were identified along the study area at different beach zones, i.e. at low tide water level (2%), along the foreshore (6%), at high tide water level (67%) and in the backshore area (25%). Plastic items have a great floatability, being this one of the main reasons for their proportional dominance among beach litter, especially in the wrack line. Hundreds of measurements were made of different items using Raman spectroscopy, an effective technique to determine the type of plastic. Cellulose acetate represented the most abundant material (79%) linked to cigarette butts, followed by polypropylene, 9% and polyethylene, 8%. The remaining were composed by polystyrene, polyethylene terephthalate and polyvinyl chloride. Smoke related items were the most common in the study area, followed by film and hard pieces, cotton bud sticks, fishing strings, food wrappers, caps/lids and single-use plastics. Beach litter can be related to beachgoers but some categories can be attributed to fishing activities or wastewater discharges. Plastics cause a multitude of damages to the coastal ecosystem, due to their toxic components and adsorbed substances and their facility of fragmentation and dispersion. Principal objective is the compositional characterization of plastic beach litter items and their spatial variability. It is therefore important to avoid unnecessary consumption, promote recycling and use other materials that are less harmful to the environment.

Flooding affects vertical displacement of intertidal macrofauna: A proxy for the potential impacts of environmental changes on sandy beaches

In the context of global environmental changes, sea level rise is expected to cause long-term floods in upper zones of sandy beaches, while increased rainfall may intensify freshwater floods with extreme salinity reductions. However, the effects of these changes on benthic macrofauna behavior, especially the species vertical displacement, remain largely overlooked in sandy beach ecology. Here, we used natural and manipulative experiments to evaluate whether the predicted effects of saltwater and freshwater floods would affect the distribution of beach macrofauna within the sediment column (i.e. vertical distribution). We first tested the effects of natural tidal flooding by analyzing the upper beach macrofauna at different depths within the sediment column during low and high tide periods. Then, we simulated saltwater and freshwater floods in manipulative experiments to examine their effects on the vertical distribution of the semiterrestrial crustacean Excirolana armata within the sediment. We observed that the macrofauna was concentrated closer to the sediment surface layer during low tide and in deeper areas during high tide. We also found that both saltwater and freshwater floods induced a movement of E. armata towards deeper layers of the sediment; yet this effect was dependent on salinity given that fewer individuals reached deeper sediment layers during freshwater floods. Overall, our results show that floods induce movements of sandy beach macrofauna within the sediment column, thereby changing the vertical distribution of benthic species. It is possible that these changes may affect ecological processes and services provided by sandy beach biodiversity such as bioturbation, biomass production and the flux of energy. In this regard, we suggest that future studies focus on the understanding of behavioral responses of macrofauna as a proxy for the impacts of global environmental changes, attempting to upscale their ecological consequences from the short to long-term effects.

Ingestion of microplastic by ontogenetic phases of Stellifer brasiliensis (Perciformes, Sciaenidae) from the surf zone of tropical beaches

Microplastics (<5 mm) are present in marine ecosystems worldwide where they can be ingested by a wide range of organisms from different trophic levels. In this study we analyzed the gastrointestinal tract of 443 specimens of Stellifer brasiliensis (124 juveniles, 254 subadults, and 65 adults) sampled in tropical beaches adjacent to the Paraíba River estuary. We found 1–3 microplastics in 42 fishes (9.48%), averaging 1.31 ± 0.52 microplastics per fish. The number of ingested microplastics by the different ontogenetic stages was statistically similar, but the adults had a higher ingestion frequency (13.8%). Among subadults, the condition factor of fishes that ingested microplastics was significantly smaller (p < 0.05) than those that had not ingested them. The ingestion of microplastics by the different ontogenetic stages of S. brasiliensis reflects the availability of this pollutant in the studied environment and highlights the vulnerability of fishes and other organisms through food webs.

FEMALE BEACH SPORT CENTER

This work proposes the development of a female beach sport center at Jeddah, Saudi Arabia. The concept of this sport center is to serve women with a healthy atmosphere that enables them to exercise and interact with their environment. In this work, three case studies were analysed. Based on the case studies, the estimated net area for the proposed sport center is 4761.7 m2. The sport center is comprised of seven zones, which are are admission zone, spa and fitness zone, restaurant and commercial zone, private beach zone, swimming center zone, scuba diving center zone, library and museum zone. This sport center will be constructed at Corniche Road, Jeddah, which is near to the Red Sea and beaches. The proposed sport center is designed with a centric flower structure based on an octagonal form. The design of this project focuses primarily on the privacy of the female users. This sport center is expected to help create interest between health and exercise among Saudi Arabia's female society and fulfill its goal of producing more female representatives in the sporting world.

Wave-driven Groundwater Flows in Sandy Beaches: A Richards Equation-based Model

Clément, J.-B.; Sous, D.; Golay, F. and Ersoy M., 2020. Wave-driven groundwater flows in sandy beaches: A Richards equation-based model. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1047–1051. Coconut Creek (Florida), ISSN0749-0208.A groundwater model is developed to simulate flows under the swash zone of sandy beach. Variably saturated beach is described by Richards equation, which is solved by the Rivage code thanks to a discontinuous Galerkin method. The SWASH code is used to simulate wave propagation in nearshore waters and compute suitable boundary conditions at the beachface to force Richards equation. An idealized case is considered to investigate the beach groundwater response to the action of swash cycles associated with long IG-like waves: infiltration/ exfiltration, water table, hydraulic head and pore velocities are outlined. A good qualitative agreement is found with observations from experimental studies in the literature.

From macro to micro, from patchy to uniform: Analyzing plastic contamination along and across a sandy tide-less coast

In search of an effective method to evaluate plastic contamination, macrolitter (>25 mm), mesolitter (5–25 mm), large microlitter (2–5 mm), large and small microplastics (2–5 mm and 0.5–2 mm) abundances in surface beach sands were simultaneously determined by two methods in four beach zones at six locations along the 100-km-long marine coast of the Curonian Spit National Park and the neighboring cities. Mean (median) content of plastic items per m2 is 0.85 (0.33) for macro-, 1.48 (0.40) for meso-, 3.35 (0.68) for large microlitter, and 3235 (1800) for microplastics (0.5–5 mm). The distribution of litter and microplastics (0.5–5 mm) is highly variable along and across the beach. The abundance of small-microplastics (0.5–2 mm) at the beach face is similar for all the locations and replicates. Swash-zone mixing, water percolation, importance of sediment pore size (rather than grain size), natural sorting of plastic particles at the beach face are considered.

Emerging crescentic patterns in modelled double sandbar systems under normally incident waves

Abstract. Double sandbar systems often characterize the surf zone of wave-dominated beaches and display a variety of poorly explained spatial configurations. Here, we explore the morphodynamic stability of double-barred beaches using a model based on linear stability analysis. Surf zone hydrodynamics are described by coupling depth and wave-averaged conservation of mass and momentum with the wave energy and phase equations, including roller dynamics. A simplified sediment transport formulation relates flow to seabed changes. Under normal wave incidence, an alongshore uniform coast with a cross-shore profile characterized by the presence of two sandbars can be unstable, thereby resulting in the development of crescentic and/or rip channel patterns. Our study demonstrates that sandbar coupling can be either in phase (highs and lows of both sandbars are at the same alongshore position) or out of phase (highs and lows of one sandbar correspond to lows and highs of the other sandbar). In line with observations, results of simulations show a large variability in the possible emerging bottom patterns. Our analysis indicates that modes of which the amplitude of the inner sandbar perturbation is larger than that of the outer sandbar are dominant for large height–depth differences between the two sandbar crests and small offshore wave heights. Patterns related to the outer sandbar dominate for small values of the difference in sandbar depth. For intermediate differences between the two sandbar depths, patterns on both longshore bars appear to be fully coupled (similar growth rates and strongly correlated pattern shapes). For relatively large waves and large depth over the outer sandbar, patterns can also develop close to the shoreline and/or inner surf zone together with patterns in the inner or outer sandbar.

Seascape connectivity exerts differing effects for fish assemblages in distinct habitats of the surf zones of ocean beaches

Abstract Animals move throughout coastal seascapes to disperse, feed, and spawn, including the surf zones of ocean beaches. Yet, the influences of seascape context on surf-zone fish are largely unquantified. We sampled surf-zone fish assemblages with baited remote underwater video deployments at 25 beaches across 50 km of coastline in eastern Australia to determine if variation in the spatial configuration of broader coastal seascapes shapes fish assemblages in different surf-zone habitats. We show that surf zones are not homogenous fish habitats, with offshore bars and nearshore troughs having distinct fish assemblages, shaped by different environmental variables. Fish assemblages of offshore bars were characterized by greater species richness and a higher abundance of indicator species (as identified by Dufrene–Legendre indicator species analysis) when close to rocky reefs and estuaries. In contrast, fish assemblages of nearshore troughs were characterized by greater species richness and a higher abundance of indicator species when far from estuaries, and off wider beaches. Our results highlight the importance of seascape connectivity in structuring surf-zone fish assemblages. Consequently, management approaches need to more thoroughly quantify the effects of seascape connectivity over smaller spatial scales and consider surf zones as key components of broader coastal habitat mosaics.

Seasonality of Organic Matter Degradation Regulates Nutrient and Metal Net Fluxes in a High Energy Sandy Beach

AbstractDuring seawater circulation in permeable intertidal sands, organic matter degradation alters the composition of percolating fluids and remineralization products discharge into surficial waters. Concurrently, coastal seawater nutrient and organic matter composition change seasonally due to variations in pelagic productivity. To assess seasonal changes in organic matter degradation in the intertidal zone of a high energy beach (Spiekeroog Island, southern North Sea, Germany), we analyzed shallow pore waters for major redox constituents (oxygen [O2], manganese [Mn], and iron [Fe]) and inorganic nitrogen species (nitrite [NO2−], nitrate [NO3−], and ammonium [NH4+]) in March, August, and October. Surface water samples from a local time series station were used to monitor seasonal changes in pelagic productivity. O2 and NO3− were the dominating pore water constituents in March and October. Dissolved Mn, Fe, and NH4+ were more widely distributed in August. Seasonal changes in seawater temperature as well as organic matter and nitrate supply by seawater were assumed to affect microbial rates and degradation pathways. Pore water and seawater variability led to seasonally changing constituent effluxes to surface waters. Mn, Fe, and NH4+ effluxes are minimal in March and reached their maximum in August. Furthermore, the intertidal sands switched from a net dissolved inorganic nitrogen sink in March to a net source in August. In conclusion, seasonal effects on intertidal pore water biogeochemistry affect constituent fluxes across the sediment‐water interface. The seasonality of the beach bioreactor must be considered when fluxes are extrapolated to annual timescales.

A New Species of Paraturbanella Remane, 1927 (Gastrotricha, Macrodasyida) from the Brazilian Coast, and the Molecular Phylogeny of Turbanellidae Remane, 1926

The family Turbanellidae includes Paraturbanella and five other genera. Despite the fact that the monophyly of these genera were not satisfactorily tested, species belonging to the genus Paraturbanella are distinguished from turbanellids by sharing a peculiar group of tubes on the ventrolateral side of the anterior pharyngeal region known as “dohrni” tubes. In this study, Paraturbanella tricaudata species nova (sp. nov.) from the intertidal zone of a sandy beach in Trindade (Rio de Janeiro State) and the sublittoral sand of Prumirim Island (São Paulo State), Brazil, is described. The new species can be distinguished from all other Paraturbanella species by the presence of three caudal cones (one medial and two laterals to it) and peculiar arrangement of the male system. This is the first description of a Paraturbanella species from Brazil and the third registered from the Southern Hemisphere (as opposed to 19 species in the Northern Hemisphere); thus, knowledge of marine gastrotrichs biodiversity in this region is far from satisfactory.

Benthic Filtering Reduces the Abundance of Primary Producers in the Bottom Water of an Open Sandy Beach System (Kashimanada Coast, Japan)

AbstractThe effect of benthic filtering by the upogebiid shrimp Austinogebia narutensis on the abundance of primary producers in the water column was investigated on a wave‐dominated nearshore zone in central Japan facing the Pacific Ocean. Chlorophyll a concentration in the bottom layer of the water column decreased significantly with increasing population density of A. narutensis, suggesting that shrimp feeding reduces the abundance of phototrophic microorganisms in the bottom layer. Because the upogebiid shrimp commonly occur in the nearshore zone of sandy beaches, similar effects of their benthic filtering as reported in this study can be expected in areas where the shrimp is as densely present.

Nucleus–Plasma Membrane Contact Sites Are Formed During Spermiogenesis in the Acoel Symsagittifera roscoffensis

Symsagittifera roscoffensis is a small marine worm found in the intertidal zone of sandy beaches around the European shores of the Atlantic. S. roscoffensis is a member of the Acoelomorpha, a group of flatworms formerly classified with the Platyhelminthes, but now recognized as Xenacoelomorpha, a separate phylum of disputed affinity. We have used electron microscopy to examine the process of spermiogenesis (the final stage of spermatogenesis) in S. roscoffensis, by which spermatids form highly elongated spermatozoa. Their nuclei are long and thread-like, running most of the cell’s length, and during the process, a pair of flagella are fully incorporated into the cell body. Two previously undescribed interorganelle contact sites form at different stages of spermiogenesis. Strikingly, there is an extensive nucleus–plasma membrane contact site. Golgi-derived granules containing electron-dense filaments line up along the spermatid plasma membrane, undergo a conformational change, and donate material that forms a perinuclear layer that cements this contact site. We also show in spermatids at an earlier stage that the same granules are associated with microtubules, presumably for traffic along the elongating cell. We identify a second spermiogenesis-specific contact site where sheaths engulfing each internalizing flagellum contact the nuclear envelope.

Triphorid snails in Thai Waters (Gastropoda: Triphoroidea: Triphoridae)

Eighteen genera and forty-four species in three subfamilies of triphorid snails have recorded from sand sediments in the intertidal zone of several beaches and rocky shores in Thai Waters, Thailand. In Andaman sea, 16 genera and 38 species were recorded while 12 genera 21 species found in the Gulf of Thailand and 10 genera and 14 species were recorded from the both Andaman sea and the Gulf of Thailand. All taxa are enlisted as a new record of Thai Waters.