Coastal deltas globally face increasing vulnerability to chronic erosion due to the synergistic effects of sea-level rise and diminished sediment supply, necessitating the development of optimized structural protection strategies for highly dynamic muddy environments. This study utilizes the MIKE 21/3 coupled numerical modeling system to evaluate the morphodynamic performance of two structural interventions under seasonal monsoonal forcing: shore-normal groynes (Option 1) and a detached breakwater system (Option 2). The results show that both interventions successfully transition the nearshore zone from an erosional state (natural retreat exceeding 10.0 cm) to a depositional regime. Option 1 is highly effective for sediment capture, yielding an average accretion of 1.0 cm and a 73% reduction in peak current velocities. In contrast, Option 2 exhibits superior wave attenuation, reducing significant wave heights by an average of 61.9% (approximately 54% more effectively than Option 1) while promoting a more uniform sedimentation pattern. However, both structures induce localized scouring at groyne tips and structural gaps, influenced by fluvial discharge. The study concludes that while detached breakwaters are optimal for wave energy dissipation and uniform morphological stability, groynes are preferable for maximizing total sediment accretion. These findings provide a science-based foundation for sustainable coastal management in climate-vulnerable deltaic regions.
Mediterranean coastal lagoons are increasingly threatened by biological invasions, yet impact assessments are critically constrained by the lack of pre-invasion biological baselines. This study establishes a biometric reference dataset for five autochthonous species of ecological and fisheries importance from El Mellah, Algeria's only coastal lagoon and a UNESCO Biosphere Reserve, using samples collected 5 years prior to the first observed occurrence of the invasive blue crab Callinectes sapidus. Length-weight relationships and condition indices were estimated for three fish (Anguilla anguilla, Mugil cephalus, Chelon auratus) and two bivalves (Cerastoderma glaucum and Ruditapes decussatus) from 1192 specimens. All regressions were highly significant (p < 0.0001, R2 = 0.828–0.966), with isometric growth observed in three species and negative allometry in the remaining two. Physiological conditions were broadly consistent with those reported from Mediterranean transitional ecosystems. By providing the earliest published biometric records for native species from El Mellah, this study establishes a valuable historical benchmark for future comparative assessments of biological change and long-term ecological monitoring following the establishment of C. sapidus and other ecological changes affecting this transitional ecosystem.
This study examined spatial and seasonal variation of benthic macroinvertebrate assemblages in Lake Sapanca, based on samples from five stations during spring, summer, and autumn 2020, and winter 2021. Physicochemical parameters, including pH, electrical conductivity (EC), dissolved oxygen (DO), depth, NO2-N, NO3-N, PO4-P, and total phosphorus, were measured to assess their influence on community structure. In total, 31 taxa from Ephemeroptera, Coleoptera, Isopoda, Gastropoda, Oligochaeta, and Chironomidae were identified, with an average density of 1422 individuals & centerdot; m(-2). The Nitrate Pollution Index indicated no nitrate-related pollution across stations or seasons. Bray-Curtis analysis showed the highest similarity (96.80%) between summer and autumn, reflecting stable communities during these periods. Spearman correlation revealed a positive relationship between temperature and EC, while NO3-N was negatively correlated with temperature and PO4-P. Canonical correspondence analysis (CCA) showed that macroinvertebrate distribution was influenced by temperature and nutrient gradients. Biological indices, including Biological Monitoring Working Party (BMWP; Spainsh version), Margalef diversity index, and ecological quality ratio (EQR), revealed spatial differences among stations. Station 1 had the highest ecological quality; Stations 3 and 4 were classified as "good," and the remaining stations as "moderate." Overall, Lake Sapanca shows conditions ranging from moderate to good, providing a baseline for long-term monitoring and sustainable management.
Otoliths from Boops boops and Nemipterus randalli were collected in Antalya Bay, T & uuml;rkiye, using bottom trawls (40-160 m depth). Scanning electron microscopy (SEM) revealed 21 morphological features, with 8 constants across life stages and 13 showing ontogenetic variation. Four variation types were identified: ontogenetic, interspecific, intraspecific, and sexual dimorphism. Comparison with otoliths from other regions showed notable intraspecific uniformity, confirming SEM-based analysis as a reliable tool for species identification. The study provides a SEM-based iconography for these species, supporting future taxonomic and ecological research. This work demonstrates SEM's value in advancing otolith morphology for fisheries science, palaeontology, and ecological monitoring.
Aquaculture, the fastest-growing food sector, has emerged as a vital contributor to nutritional sustainability and global food security. Rapid growth of the world population, coupled with rising nutritional requirements, has shifted focus from constrained land-based food production to sustainable aquatic-food production systems. In this context, nutrient-rich marine microalgae have gained considerable attention as sustainable plant-based ingredients for aquafeeds and as a valuable resource for high-value aquaculture production. A scientometric analysis was conducted to evaluate the research landscape and emerging trends in the field "marine microalgae in advancing sustainable aquaculture feeds and development." 1073 Scopus-based publications were identified, accounting for an h-index of 83, with yearly escalation in citations from 2008 onward. Visualization of country-based co-authorships illustrate Europe forming the primary collaboration landscape with maximal funded projects (83), while the US acts as a linkage node between Europe, Asia, and emerging regions. Norway is the leading country as per cumulative link strength with other regions, in terms of co-authorships. Keyword, title, abstract terms depict potential of microalgae, deemed as alternative source of aquaculture feeds and nutraceutical substances. Time trending semantic association depict promising role of microalgae food technologies in augmenting fish productivity, growth, value-added production, resource-use efficiency and sustainable aquaculture development contributing to circular blue economy.
