Aquatic Life Sciences

Ijeoma Patience OBOH, Nkonyeasua Kingsley EGUN, Ukpamufo Cyril OLOWO

Aquaculture contribution to human nutrition, consumers’ preferential bias towards capture fisheries and concerns on food safety has necessitated the need for information on the nutritional composition of fish species from diverse settings such as geographical locations and aquaculture rearing facilities. This study determined the nutritional profile and associated human health risk of adult size African catfish (Clarias gariepinus) cultured in plastic tanks with those harvested from the wild. Results showed the mean protein (18.04%) and lipid (8.71%) values of cultured C. gariepinus were significantly higher than reported values in C. gariepinus from the wild, which makes them of more nutritional value to consumers. Captured fishes reported higher ash, mineral and trace metal contents, which was attributed to the elevated levels of these elements in their habitat waters due to water pollution. Low metal pollution index (MPI) values in cultured and captured fishes indicated an insignificant bioaccumulation of trace metals, and the absence of non – carcinogenic (HI <1) and carcinogenic (ICR < 1 × 10^-6) risk associated with their consumption. Although the captured fishes at present poses no health risk to consumers; their recorded higher contents of trace metals, MPI, HI and CPI values is a cause for concern on the safe consumption of capture fishes. With increasing concerns on aquatic food safety, this study has shown that the consumption of cultured C. gariepinus provides more nutritional quality to consumers. The need for more monitoring studies on different culturing methods and settings on the nutritional composition and food safety is recommended.

Aquatic Life Sciences

Assifa Dina Aisyah

Giant clams (Tridacnidae) play an important ecological role in coral reef ecosystems; however, their populations continue to decline due to habitat degradation and overexploitation. Despite increasing conservation efforts, site-specific information on habitat preference, particularly related to substrate composition, remains limited in many Indonesian reef systems, including Bama Waters, Baluran National Park. This study aimed to assess the community structure and substrate habitat preferences of giant clams in this area. Field surveys were conducted at four stations using belt transect and quadrat methods, complemented by underwater photo transect analysis for substrate characterization and measurement of key environmental parameters. Community structure was analyzed using density and the Shannon Wiener diversity index, while habitat preference was evaluated using Ivlev’s electivity index. A total of three giant clam species were recorded with Tridacna crocea dominating with a density of 0.52 ind/ha. Diversity was categorized as low to moderate and varied spatially in relation to substrate composition. Stations with mixed substrates, particularly hard coral and rubble, supported higher diversity values. Electivity analysis revealed species-specific habitat preferences, with T. crocea favoring rocky substrates, T. maxima associated with hard coral and rubble, and T. squamosa showing weaker habitat specialization. This finding shows that substrate composition plays an important role. It also influences species distribution. This study provides site-specific ecological information that may support more effective conservation and management strategies for giant clams in coral reef ecosystems.

Aquatic Life Sciences

Vaishali Bhatt, Prasant Arya, Jaspal Singh Chauhan

Microplastic (MP) contamination in freshwater ecosystems is an emerging environmental concern, yet interactions between MPs and riparian macrophytes remain poorly understood, particularly in Himalayan river systems. This study provides a baseline assessment of MP surface entanglement across riparian macrophyte species, along with associated surface water and sediment, from River Alaknanda, Srinagar, Uttarakhand, India, sampled in June 2023. A total of 30 macrophyte, surface water, and sediment samples were collected and processed using extraction protocols integrating washing, oxidative digestion, density separation, stereomicroscopic analysis, and polymer characterization through ATR-FTIR spectroscopy. MPs were extensively detected on macrophyte surfaces, with species-specific normalized burdens ranging from 16.47 ± 2.59 to 273.86 ± 26.21 MPs/g dry weight. Kruskal-Wallis analysis revealed significant interspecific variation in normalized MP abundance (H = 25.73, p = 0.0023), with Chenopodium ambrosioides exhibiting significantly higher MP burdens than Conyza sp. and Equisetum sp. No MPs within the analytical detection range of 100 µm-5 mm were detected in digested plant tissues. Fibres were the dominant MP type in macrophytes and water, whereas fragments predominated in sediments, with white particles being most abundant across all matrices. Polymer analysis identified polyester, polyethylene, polypropylene, polyterephthalate, and polyethylene-vinyl acetate as dominant polymers. Strong compositional correlations among macrophytes, water, and sediment indicated similarities in MP characteristics across environmental matrices. These findings suggest riparian macrophytes as complementary matrices for freshwater MP monitoring. Despite methodological and spatial limitations, this study establishes a preliminary framework for incorporating riparian vegetation into freshwater MP monitoring and highlights the need for further investigations.

Aquatic Life Sciences

Karl Cirilson Ellema Angulo

Coastal ecosystems support high levels of marine biodiversity and provide essential services, including shoreline protection, carbon sequestration, and fisheries production. Silot Bay, Liloan, Cebu, Philippines, is an ecologically and socio-economically important embayment; however, biodiversity assessments in the area remain sparse and temporally fragmented. This study presents a narrative review with structured literature search elements to synthesize available ecological studies on major taxonomic groups, including mangroves, fish, meiofauna, and algae, and to evaluate methodological consistency among studies retrieved from Google Scholar, ScienceDirect, Philippine E-Journals, and institutional repositories from local universities. A total of nine studies met the inclusion criteria, the majority of which were conducted prior to 2000, with post-2000 research limited to a single study on algal communities. Substantial variation in sampling methods, effort, spatial coverage, and taxonomic resolution constrains direct comparison across studies and limits interpretation of temporal patterns. Differences in reported species richness and community composition are evident across taxa; however, these patterns cannot be confidently attributed to ecological change due to methodological inconsistencies and limited data availability. The small number of studies and reliance on partially inaccessible historical data further restrict the establishment of a reliable biodiversity baseline for Silot Bay. Overall, this review highlights significant knowledge gaps and emphasizes the need for standardized, multi-taxa biodiversity assessments to support long-term monitoring and evidence-based coastal management.

Aquatic Life Sciences

Nur Afidatul Himma

Parasitic infections in marine fish pose economic and public health risks, particularly when zoonotic species are involved. Ribbonfish (Trichiurus lepturus), a commercially important species in Indonesia, is highly susceptible to endoparasites that may reduce fish quality and threaten human consumers. This study aimed to identify the types, prevalence, and intensity of endoparasites infecting ribbonfish landed at Paciran (Lamongan) and Tamperan (Pacitan). A total of 56 fish samples were examined through necropsy and microscopic observation of internal organs. Two nematode species, Anisakis sp. and Camallanus sp., were detected in the intestine, stomach, and muscle tissues. Prevalence was 0.2% at Paciran and 0.4% at Tamperan, while intensity reached 1.3 and 1.9 ind/individual, respectively. Infected fish were typically larger, with body weights ranging from 100–400 g and lengths of 60–80 cm, and often contained undigested small fish and crustaceans that may serve as intermediate hosts. Although infection levels were classified as low, the detection of zoonotic Anisakis sp. underscores the need for continued monitoring to prevent potential health risks and safeguard fishery resources.

Aquatic Life Sciences