Deeyagahage Sujeewa Mallika De Silva

Email-charukasadanruwan@gmail.comAbstractSeagrass leaves provide microhabitat for epiphytic organisms but knowledge on epiphytic fauna and associated bionts in seagrass are limited. In addition, seasonal changes in population structure of epiphytic communities have not been studied widely under Sri Lankan context. This abstract presents the diversity and abundance of filamentous epiphytic algal communities on the leaves of Oceana serrulata in Kayankerni Marine Sanctuary in Eastern coast of Sri Lanka. Leaves of Oceana serrulata were collected once a month from August 2024 to January 2025 and preserved with 5% formaldehyde. Leaves were measured and divided into three similar sections and labelled as tip, middle, basal parts. Ten randomly selected leaves per month were subjected to identify the filamentous epiphytes and their abundance. Epiphyte species were identified up to genus level using guide, key and published literature. Percentage epiphytic cover of each section of leaves was estimated using the microscopic field as the sample unit under 10*10 magnification. Shanon-Wiener diversity index, Pielou’s evenness index and Dominance index for each month calculated. Arcsine converted data of epiphytic cover on entire leaf-blades among different months were compared using ANOVA to identify the temporal variations. In addition, the percentage epiphytic cover of each species among sampling occasions were compared using ANOVA. Six genera of filamentous epiphytes were reported from leaf blades and were Ulva, Gayliella, Hydrolithon, Myrionema, Herposiphonia and Calaconema. Genus Ulva reported three (03) distinct species while others reporting single species each accounting the species richness of filamentous algae up to eight (08). Percentage epiphytic cover on the leaf blades was ranged from 11.25% to 1.18% reporting the highest epiphytic cover in August and lowest in January. Contribution of different genera to total epiphytic cover was reported as follows: Ulva spp. (27.87%), Gayliella sp. (26.63%), Hydrolithon sp. (22.04%), Myrionema sp. (12.03%), Herposiphonia sp. (11.04%), and Calaconema sp. (0.38%). The abundance of Gayliella sp., Herposiphonia sp., Ulva sp.1, and Ulva sp.2 have been reducing gradually from August to January, while Myrionema sp. and Ulva sp.3 were reported throughout the sampling period in low abundance. Calaconema sp.was reported varying levels in low abundance during the sampling period. Abundance of Gayliella sp. and Herposiphonia sp. was significantly higher (p

The prevalence and fate of microplastics in macrophytes are insufficiently understood, and data on the abundance of microplastic (MP) accumulation in macrophyte ecosystems are urgently needed to fill this knowledge gap. The main objectives of this study were to quantify and characterize the microplastics that accumulate in macrophytes, associated sediments, and water in Negombo Lagoon, Sri Lanka. The investigation was conducted with specialized sampling and extraction techniques. Microplastics were detected by the fluorescence tagging of polymers using Nile red, and polymer identification was conducted by ATR-µFTIR and ATR-FTIR. This study revealed variations in microplastic abundance across different macrophyte species. Gracilaria sp. had a higher abundance of 9 ± 3 items g⁻¹ wet weight, followed by Chaetomorpha sp. at 8 ± 3 items g⁻¹ wet weight and Halodule pinifolia at 6 ± 1 items g⁻¹ wet weight. The root surfaces of these species had slightly similar levels of abundance. Both blue and transparent microplastics were predominant. Fragments (>47%) were found at a higher percentage in macrophyte samples, but high fiber contents (>60%) were found in associated sediment and water samples. Nevertheless, macrophyte samples contained a higher percentage of fragments in the size range of 50–150 μm. This comprehensive study contributes to expanding our awareness regarding the influence of microplastic pollution on macrophyte ecosystems.

Plastics waste management is crucial in developing countries such as Sri Lanka. The mass of plastics waste has been increasing yearly due to the rise in plastics demand. Mismanagement of plastics waste is an alarming issue that creates critical environmental and health problems. Although plastics waste management methods, including recycling, pyrolysis and incineration, are available, sorting plastics waste is a challenging part of the process. This literature review mainly focuses on the available plastics waste separation techniques and the conceptual model for plastics waste management in developing countries. The results of the literature review show that plastics waste sorting techniques can be categorized as manual, dry, wet, and combined separation techniques. The conceptual model suggests inventing plastics waste parks in Pradeshiya Sabha areas and carrying out the separation of plastics from other waste and the separation of plastics according to the plastics type. Normally, manual and combined separation techniques can be used for this separation process. In addition, public awareness and legal framework are very important to build up a sustainable waste management system in a country. The proposed conceptual model can be applied to smaller administrative boundaries of the country with suitable separation techniques. To reduce usage of plastics, efforts must be made by citizens to study the usage of renewable raw materials to create innovative goods using current technological advancements. Additionally, daily usage of plastics should be minimised, which aids in the improvement of healthy environmental conditions.

Large plastic items in the environment are degraded into tiny pieces known as microplastics (MPs). MP contamination in tropical lagoon ecosystems poses a significant pollution threat. The mud crab, Scylla serrata, is an important crustacean in the tropical lagoon, valued as a key source of edible seafood in Asia and Europe. The potential MPs of one hundred samples were examined using the stereomicroscope for characterisation, and further analysis was conducted using µ-FTIR. A total of 1157 MPs were found in the gills and gastrointestinal tract. The mean abundance (±SD) of MP in mud crabs was 11.57 ± 6.29 items/individual. MPs were detected in both tissues, displaying a variety of colours. Transparent MPs dominated the gills at 43.9%, while blue microplastics were prevalent in the gastrointestinal tract at 32.8%. The filament (fibre) was the most prominent MP type found in the gills and gastrointestinal tract. The collected MPs from both tissues were categorised into four size ranges: 0.05–0.25 mm and 1.00–5.00 mm were the common size ranges in the gills and gastrointestinal tract, respectively. The prominent polymer type was rayon. These findings provide considerable proof of MP contamination in the mud crab species Scylla serrata and its implications for food security.

Microplastics have emerged as a significant global environmental concern in the recent decade. The aim of this study was to elucidate microplastic contamination of commercial fish species in a natural lagoon environment. Microplastic contamination was examined in the gastrointestinal tracts and gills of 157 commercial fish from 18 species with varying feeding habits in a vital and sensitive lagoon ecosystem, which connects to the Indian ocean. Microplastics were extracted using digestion, followed by stereomicroscopic inspection using Nile Red stain, and identified via μ-FTIR analysis. Over half of studied fishes ingested microplastics (54.14%). Filaments (50%) and blue items (43%) were the most commonly ingested. Of all the fish species, Eubleekeria splendens had the highest average concentration of microplastics in GIT (1.41 ± 2.52 items/g w.w. tissues), although no statistically significant difference in amount of ingested microplastics (items/g w.w. tissues) was observed among species. The highest concentrations of inhaled microplastics were recorded in Sillago vincenti (1.38 ± 1.30 items/g w.w. tissues). The majority of the extracted microplastics (33%) belonged in the size class 500–1500 μm with rayon, polyethylene terephthalate, and polypropylene as the primary polymers. This study found no correlation between microplastic ingestion and fish species and feeding habits, but a positive correlation with fish size was observed. These findings reveal widespread microplastic contamination in edible fish, posing potential risks to commercially important species due to increasing pollution in lagoon ecosystems.

Microplastic pollution (MP) in marine environments around the globe is severe and insufficient precautions have yet to be taken for its prevention. The focus of this study was on quantifying MPs from beach sediment and seawater samples and identifying their distributions and types along the western coast of Sri Lanka from the Kelani River estuary to the Mahaoya estuary. Nine sites along this 42 km stretch were selected, and random sampling was employed to collect a minimum of eight sediment samples from each site between October and December 2021. Water samples were also collected, parallel to the sediments, from the ocean surface. FTIR analysis revealed that most of the MPs found were polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), and phenol formaldehyde resin. The mean abundance of MPs varied from 2.0 ± 0.6 items/L to 161.0 ± 15.7 items/L in water samples and from 3.0 ± 0.3 items/m² to 656.0 ± 34.5 items/m² in sediment samples. The MPs found were identified in different shapes as fragments (80.2%), pellets (14.9%), fibers (2.7%), and foams (2.5%). Analysis revealed that the beach sediments were contaminated with PS, phenol formaldehyde resin, PET, PP, and PE, while the surface seawater was dominated by phenol formaldehyde resin, PS, PP, and PE.

Microplastic pollution (MP) in marine environments around the globe is severe and enough precautions have not been taken so far for its prevention. The focus of this study is to quantify MPs from beach sediment and seawater samples and to identify their distribution and types along the western coast of Sri Lanka from the Kelani River estuary to the Mahaoya estuary. Nine sites along this 42 km stretch were selected and random sampling was employed to collect a minimum of 8 sediment samples from each site between October and December 2021. Water samples were also collected, parallel to the sediments, from the ocean surface. FTIR analysis revealed that most of the MPs found were polyethylene(PE), polypropylene(PP), polystyrene(PS), polyethylene terephthalate(PET), and phenol formaldehyde resin. The mean abundance of MPs varied from 2.0 ± 0.6 items/L to 161.0 ± 15.7 items/L in water samples and, from 3.0 ± 0.3 items/m2 to 656.0 ± 34.5 items/m2 in sediment samples. The MPs found were identified in different shapes as fragments (80.2%), pellets (14.9%), fibers (2.7%) and foams (2.5%). Analysis revealed that the beach sediments were contaminated with PS, phenol formaldehyde resin, PET, PP and PE, while surface seawater is dominated by phenol formaldehyde resin, PS, PP and PE.

Microplastic (MP) pollution is a serious global issue affecting freshwater systems, coastal regions, and oceans. These non-biodegradable materials have a detrimental impact on marine species and ecosystems, disrupting their feeding, breathing, and reproduction. In this study, 120 samples of two species of shrimp, Penaus monodon and Penaus indicus, from ten locations in the Negombo lagoon in Sri Lanka were analyzed. MPs were extracted from gastrointestinal tracts (GI) and gills (GL) by alkali digestion followed by vacuum filtering. Stereomicroscopy coupled with advanced micro-imaging and analysis software was employed for analyzing the isolated MPs. A total of 415 items were identified as MPs with an average of 8.29 ± 4.63 items per gram of GI and GL in Penaus monodon and 5.52 ± 3.78 items per gram of GI and GL in Penaus indicus. The majority of MPs identified were fibers (93%), and the remaining ones were fragments. Most of the MPs were >1000 μm, and the most prevalent color was blue (61%), followed by red (15%), black (9%), and others, comprising polystyrene, polyamide, polyester, polypropylene, and rayon, as revealed by FTIR spectroscopy. This study highlights the prevalence of MPs in shrimps harvested from the Negombo lagoon and displays missing baseline data before the effects of fragmented nurdles from the X-Press Pearl incident.