Diversity and distribution of the Isopoda (Crustacea, Peracarida) of Kuwait, with an updated checklist

Thirty-eight species of Isopoda, belonging to 13 families and 29 genera, are listed from Kuwait based on previous literature records (of 17 species) and collections carried out along Kuwait’s coastal and subtidal zones during the present study. The majority of species belongs to the suborder Cymothoida (23), followed by Sphaeromatidea (9), Oniscidea (3), Valvifera (2), and Asellota (1). In total, 25 species were collected and identified from 12 families and 22 genera from Kuwaiti coastal and subtidal areas. These include eight families, 15 genera, and 21 species recorded for the first time from Kuwait. Isopod diversity was highest in the sandy rock areas, including southern Kuwait, particularly in Al-Khiran and Al-Nuwaiseeb, and in mixed habitat (muddy, rocky, and sandy) intertidal transects such as in Failaka Island. The species number increased from the subtidal and lowest zones into the high tidal zone. Isopods were found in sandy substrata, among shells, cobbles, rocks, dead corals, and algae.

Carbon and Nitrogen Contents Driven by Organic Matter Source within Pichavaram Wetland Sediments

Differences in grain size, total organic carbon (OC), total nitrogen (TN), OC/TN ratios, and stable isotope (δ13C and δ15N) were assessed in sediments from areas covered by mangrove and saltmarsh vegetation within Pichavaram estuary (Southeast India). The mean percentage contents of silt and clays (70 vs. 19%), OC (5.7 vs. 2.0%), and TN (0.39 vs. 0.14%) were consistently higher in the mangrove as compared to those observed in the saltmarsh tidal zone. These differences may obey the higher deposition and retention of fine particles in the presence of a mangrove root system that may facilitate the accumulation and preservation of organic matter within these sedimentary systems. Further, higher OC and TN contents were associated to higher terrestrial or mangrove-derived organic matter contribution with lighter δ13C signatures (−26.0‰) in both sedimentary tidal zones, whereas lower OC and TN contents were associated to heavier δ13C signatures. This study is in agreement with previous studies which indicate that the presence of wetland vegetation may increase the carbon and nutrient storage capacity within estuarine ecosystems, highly relevant information for the establishment of further conservation strategies for blue carbon ecosystems at global scales.

Cataclysmic Disturbances to an Intertidal Ecosystem: Loss of Ecological Infrastructure Slows Recovery of Biogenic Habitats and Diversity

Understanding the resilience and recovery processes of coastal marine ecosystems is of increasing importance in the face of increasing disturbances and stressors. Large-scale, catastrophic events can re-set the structure and functioning of ecosystems, and potentially lead to different stable states. Such an event occurred in south-eastern New Zealand when a Mw 7.8 earthquake lifted the coastline by up to 6 m. This caused widespread mortality of intertidal algal and invertebrate communities over 130 km of coast. This study involved structured and detailed sampling of three intertidal zones at 16 sites nested into four degree of uplift (none, 0.4–1, 1.5–2.5, and 4.5–6 m). Recovery of large brown algal assemblages, the canopy species of which were almost entirely fucoids, were devastated by the uplift, and recovery after 4 years was generally poor except at sites with < 1 m of uplift. The physical infrastructural changes to reefs were severe, with intertidal emersion temperatures frequently above 35°C and up to 50°C, which was lethal to remnant populations and recruiting algae. Erosion of the reefs composed of soft sedimentary rocks was severe. Shifting sand and gravel covered some lower reef areas during storms, and the nearshore light environment was frequently below compensation points for algal production, especially for the largest fucoid Durvillaea antarctica/poha. Low uplift sites recovered much of their pre-earthquake assemblages, but only in the low tidal zone. The mid and high tidal zones of all uplifted sites remained depauperate. Fucoids recruited well in the low zone of low uplift sites but then were affected by a severe heat wave a year after the earthquake that reduced their cover. This was followed by a great increase in fleshy red algae, which then precluded recruitment of large brown algae. The interactions of species’ life histories and the altered physical and ecological infrastructure on which they rely are instructive for attempts to lessen manageable stressors in coastal environments and help future-proof against the effects of compounded impacts.

Diversity and distribution of the brown macroalgae (Phaeophyceae Kjellman, 1891) in cham islands, Quang Nam province, Vietnam

The study investigated the Phaeophyceae during the year 2019 at sixteen sampling sites representative for Cham islands. Specimens were collected by scuba diving, snorkelling and walking at the upper tidal zone in both dry and rainy seasons. Twenty-five species of the Phaeophyceae identified for Cham islands from four orders, four families and eleven genera. The Sargassaceae family is the most abundant species composition, followed by Dictyotaceae, Scytosiphonaceae and Asteronemataceae family. In the six islands surveyed, Hon Lao has the highest diversity with 19 species recorded; Hon Dai, Hon Tai, Hon Kho and Hon Mo island recorded from 10 to 14 species, and the lowest diversity is at the Hon La island with 8 species. Ten species Canistrocarpus cervicornis, Dictyota spinulosa, Lobophora obscura, Lobophora variegata, Pandina minor, Sargassum bicorne, Sargassum herklotsii, Sargassum parvifolium, Turbinaria conoides, Asteronema breviarticulatum reported as new records for the marine flora of Cham islands.

Occurrences, Distribution and Composition of Microplastics in the Surface Seawater and Beach Sediments of the Southern Shandong Peninsula, China

The current work provides the detailed analysis about microplastics contamination of the beach sediments and surface seawater. Sediment samples were collected from the high tidal zone at 13 beaches, and surface seawaters of seven stations along the southern Shandong Peninsula. The presence of microplastics was recorded on both beaches and surface seawater. The mean quantity of microplastics was approximately 664±80 microplastics/kg of dry weight (dw) with 0.5~0.125 mm in beach sediments, and 5.62±0.4 microplastics/liter (L) of surface seawater. Predominant microplastics were fibers (>97%). While other plastic forms had lower percentage. Microplastics possessed different color with polymer composition including polypropylene, polyethylene, and polystyrene. The accumulation of microplastics on beaches is an alarming issue and provides better understanding about microplastics pollution along the coastal regions of the southern Shandong Peninsula. It would also help to establish better monitoring system for future and evaluate possible risks by microplastics due to rapid economic growth of China.

Tectonic Influence on Speleogenesis of Sea Caves on Biševo Island (UNESCO Global Geopark Vis Archipelago, Adriatic Sea, Croatia)

A geological and speleological investigation was conducted in the famous Blue Cave (Modra špilja) and the Monk Seal Cave (Medvidina špilja) on Biševo Island (Croatia) to promote the island’s geoheritage through the new Visitor Centre. The island is mainly composed of Cretaceous to Paleogene neritic carbonates, which form the bedrock, whereas parts of the island are covered with thin Quaternary sediments. The caves are of small dimensions and a simple layout, composed of the main channel and few shorter side channels, all positioned in the tidal zone. Thus, the caves are semi-submerged sea caves located along the coastline. The Blue Cave and the Monk Seal Cave developed within the bedrock limestones and dolostones, respectively, within a zone of left-lateral NNE–SSW striking strike-slip faults that belong to the Biševo fault system. Conjugated discontinuities within the carbonate bedrock indicate a specific strike-slip tectonic regime. Additionally, the host rocks were probably also deformed and fractured during the rise of salt diapirs that characterise this part of the Adriatic foreland. Tectonic and bedding discontinuities form the fragments of the host rock, that combined with the impacts of the strong southern waves, significantly influenced the genesis of the caves.

Mangrove diversity and community structure of Mimika District, Papua, Indonesia

Setyadi G, Pribadi R, Wijayanti DP, Sugianto DN. 2021. Mangrove diversity and community structure of Mimika District, Papua, Indonesia. Biodiversitas 22: 3562-3571. Despite being one the largest mangrove forest in the world, there are few studies on mangrove diversity and community structure in Mimika, Papua Province. The study collected data from 4 estuaries of Mimika Region, i.e. Kamora, Tipuka, Ajkwa and Minajerwi. Mangrove species, tree diameter at breast height and canopy height data were collected in 10 m x 10 m plot with three replicates for distance, specifically 0, 250, and 500m perpendicular to the riverbank. This study found 66 mangroves species consisting of 20 major, 10 minor, and 36 associate mangrove species. Their density ranged from 577-1,345 trees ha-1 with diversity Shannon-Weiner diversity indices (H’) ranging from 0.62-1.19 and Evenness Index (J’) ranging from 0.09-0.18. The canopy height of the mangrove trees was ranged from 9-42.5 m. The highest density species was Rhizophora apiculata (333 ha-1) followed by Avicennia marina, Bruguiera gymnorrhiza, and Camptostemon schultzii, while B. parviflora, S. alba, and X. granatum were the least dominant. Regarding basal area, R. apiculata and B. gymnorrhiza were the highest with medians of 7,853 cm2 ha-1 and 5,201 cm2 ha-1 respectively. In the low tidal zone area, mangrove was dominated by A. marina, Sonneratia alba and R. mucronata. Medium low to medium high tidal zones were dominated by B. gymnorrhiza, R. apiculata, and B. parviflora. The high tidal zone was more dominated by Nypa fruticans.

Utilization of Recycled Aggregate Concrete for Marine Site Based on 7-Year Field Monitoring

This research aimed to create value of construction and demolition waste to be able used as a recycled coarse aggregate (RCA) in durable concrete, based on 7-year field investigation in marine site. Fly ash was used to substitute Portland cement type I in RCA concrete varied from 0 to 50% by weight of binder with three W/B ratios and comparing to natural aggregate (NA) concrete. Cubical concrete specimens were cast having round steel bars embedded with various concrete coverings to evaluate the durability performances. After 28-day curing, the specimens were placed at a tidal zone in the gulf of Thailand and investigated both mechanical and durability performances at 7-year exposed period. Based on site monitoring, 15–25% fly ash RCA concrete with W/B ratio of 0.40 would be advantaged to resist destruction due to the marine attack when compared with NA concrete with the same water-to-binder ratio.

Permeation Characteristics and Surface Accumulation of Chloride in Different Zones of Concrete along Altitude in Marine Environments

The accumulation characteristics of surface chloride in concrete in different zones are different in the marine environment. A series of laboratory experiments were conducted to investigate the surface chloride and permeation characteristics of concrete in a simulated marine environment. The experimental results indicated that the surface chloride and chloride profiles of concrete in different zones of marine environment decreased in the following order: tidal zone > splash zone > submerged zone > atmospheric zone. The width of the ascent zone of Cl− concentration at tidal and splash zones was far less than that of the influential depth of moisture transport (IDMT), and the range of convection zone was dependent on the IDMT. Cl− at splash and tidal zones penetrated into concrete as a bulk liquid by non-saturated permeation driven by a humidity gradient. The change of chloride profiles in concrete along the altitudinal gradient was consistent with that of the cyclic water absorption amount (CWAA). The transport rate of chloride was the highest at the highest point of the tide.