Journal of Fisheries and Environment

Seaweed Growth, Transcriptomics, and Defense Responses: Trends and Insights from Bibliometric Mapping

2025-11-09T14:31:22+07:00

Seaweeds (macroalgae) play a critical ecological role and hold growing promise for aquaculture, biotechnology, and the sustainable bioeconomy. Despite substantial advances in seaweed physiology, transcriptomics, and stress biology, current knowledge remains fragmented across physiological, molecular, and applied research domains. Here, we present a comprehensive bibliometric and critical synthesis of global seaweed research, integrating co-occurrence mapping with in-depth literature analysis. A dataset of 13,657 publications from Scopus and Web of Science (1970–2026) was analyzed using the Bibliometrix R-package (Biblioshiny) to identify research trends, thematic clusters, and knowledge gaps. Three dominant themes emerged: (i) growth and physiological regulation, (ii) stress responses and molecular adaptation, and (iii) cultivation and applied systems. Trend analysis indicates a clear shift from traditional ecological studies toward stress-related and application-driven research, including biostimulants and climate resilience. However, thematic mapping reveals a persistent disconnect between physiological and molecular approaches, alongside limited mechanistic insight in cultivation research. Our critical synthesis further uncovers inconsistencies in reported growth responses under environmental stress and a weak linkage between transcriptomic insights and practical aquaculture outcomes. These findings emphasize significant gaps in connecting gene expression with phenotypic performance and in translating laboratory-based molecular knowledge into field-scale cultivation systems. Collectively, the results suggest that interdisciplinary, multi-omics frameworks are essential for advancing seaweed growth and stress tolerance research, and that bridging fundamental and applied science is key to developing resilient, sustainable seaweed production systems.

Shore Height and Low-tide Exposure as Regulators of Intertidal Distribution Thresholds of Seagrass Enhalus acoroides in the Gulf of Thailand

2026-03-04T14:31:01+07:00

Understanding environmental controls on seagrass distribution is essential because inappropriate elevation selection can reduce restoration and transplantation success. This study investigated how shore height and low-tide exposure influence the distribution of Enhalus acoroides in the upper intertidal zone of the Gulf of Thailand. Shore height was measured at 261 stations across seven sites during 2022–2023 using a theodolite and a surveyors’ rod, and expressed as height above lowest low water (cm H_LLW) based on predicted tidal levels. Aboveground biomass was estimated using a modified Rapid Visual Estimation Technique. Across shore heights of 0‒120 cm H_LLW, the frequency of E. acoroides occurrence followed a normal distribution (D = 0.09, p = 0.35), with most observations between 40 and 80 cm H_LLW. Preferred shore-height ranges varied among sites, extending from 0 to 106 H_LLW. Percentage cover did not differ significantly among H_LLW intervals of 0‒40 cm, 40‒80 cm, 80‒120 cm. However, aboveground biomass differed significantly among groups, with the highest biomass at 0–20 cm H_LLW (17.77±6.75 g DW·m⁻²), where mean cover was 48.18±35.73%. The upper shore-height threshold of E. acoroides was lower in the eastern Gulf of Thailand (77 cm H_LLW) than in the southern coastal region (106 cm H_LLW) and was substantially lower than thresholds reported for the Andaman Sea. These regional and local differences were closely associated with tidal regime, low-tide level, desiccation duration, and sediment water-level drawdown. The findings provide practical guidance for restoring and transplantation intertidal E. acoroides meadows under changing coastal conditions associated with global warming.

Effect of Chestnut Wood Polyphenols on Growth, Survival, and Disease Resistance in Pacific White Shrimp (Litopenaeus vannamei Boone, 1931)

2026-03-29T06:09:18+07:00

Chestnut wood polyphenols (CWP) represent a natural feed additive with potential antibacterial and immunostimulant properties. This study evaluated the in vitro antibacterial activity of CWP against Photobacterium damselae subsp. damselae (PDD) and its effects on the growth performance, immune responses, and disease resistance of Pacific white shrimp (Litopenaeus vannamei Boone, 1931). The minimum inhibitory concentration and minimum bactericidal concentration of CWP against PDD were 10 µg·mL⁻¹ and 20 µg·mL⁻¹, respectively. In the feeding trial, shrimp (initial weight, 5.58±0.19 g) were given diets supplemented with CWP at 0 (control), 1, 3, or 5 g·kg feed⁻¹ for 30 days. The results indicate that dietary CWP significantly improved survival rates and feed conversion ratios in a dose-dependent manner, with the highest survival (92.00±4.00%) and lowest FCR (0.99±0.04) observed in the 5 g·kg feed⁻¹ group. In addition, CWP supplementation notably reduced intestinal Vibrio spp. counts and enhanced superoxide dismutase activity, while the immune parameters, including total hemocyte count, phagocytic activity, and phenoloxidase activity, remained unaffected. Following experimental challenge with PDD, shrimp fed 5 g·kg feed⁻¹ CWP exhibited higher survival (70.00%) compared to the control group (43.33%). On day 7 post-challenge, attenuation of PDD-associated lesions in the hepatopancreas and muscle by dietary CWP was revealed by histopathological examination. These findings thus demonstrate that dietary supplementation with CWP, particularly at 5 g·kg feed⁻¹, enhances growth performance and immune responses, while reducing pathogenic bacterial loads and improving disease resistance in Pacific white shrimp.

Microplastic Distribution in Khlong Wong, Songkhla Lake, Thailand: Implications for Household and Fishing-Related Sources

2026-04-16T09:54:20+07:00

Microplastic pollution has emerged as a global environmental concern affecting aquatic ecosystems. Khlong Wong, a major canal draining into Songkhla Lake in southern Thailand, may serve as an important transport pathway for land-based microplastics into the lake system. This study aimed to investigate the spatial and temporal distribution of microplastics in the water column of Khlong Wong and examine their relationships with environmental factors. Water samples were collected bimonthly for one year from seven sampling stations along the canal, together with measurements of key water quality parameters. Five types of microplastics were identified: polyester, cotton, nylon, alkyd, and polypropylene (PP). Polyester fibers were the dominant type, accounting for 53.94% of total microplastics, suggesting inputs from household activities and fishing practices. Spatial analysis showed high similarity in microplastic composition along the canal (79.52%–94.88%), with the greatest observed accumulation at the canal mouth, indicating its possible role as a convergence zone before discharge into Songkhla Lake. Temporal analysis showed descriptive seasonal variation, with the greatest observed microplastic abundance recorded during the northeast monsoon in December (36.14±7.69 items∙100 L⁻¹), dominated by polyester fibers likely transported by increased runoff. In contrast, PP and nylon were more prevalent during the hot season (February–April), possibly associated with degradation of fishing gear under prolonged sunlight exposure. Overall, the results suggest that Khlong Wong may function as an important transport pathway conveying microplastics from terrestrial sources and fishing practices into Songkhla Lake. This study provides baseline information to support water quality management and strategies to mitigate microplastic contamination.

Assessment of Coral Reef Conditions and Resilience in Eastern and Northern Bali, Indonesia

2026-05-06T08:40:36+07:00

Across the Indo-Pacific, coral reef condition is increasingly affected by human pressures, land-based pollution, and climate-related stressors, including bleaching events. These challenges threaten biodiversity and the ecological services provided by coral reefs. This study aimed to assess coral health and recovery potential in East and North Bali and provide baseline data for conservation and management strategies. The research was conducted from June to November 2023 at seven reef sites, consisting of three sites in East Bali and four sites in North Bali. Benthic composition and live coral cover were assessed using the Underwater Photo Transect method, while reef fish abundance and biomass were evaluated using the Underwater Visual Census method. Site-level values were used to calculate coral cover, reef fish parameters, and Coral Health Index scores. Live coral cover ranged from 13.14% to 38.77% with regional means of 19.40% in East and 25.94% in North Bali; however, the difference was not statistically significant (p = 0.9998). A total of 380 reef fish representing 30 species and six families were recorded, comprising 85 individuals in East Bali and 295 in North Bali. Reef fish abundance also did not differ significantly between regions (p = 0.4277). Acanthuridae was the dominant family. Coral Health Index scores ranged from 3 to 6, while reef fish biomass was classified as low at all sites. These findings provide baseline information to support long-term monitoring, site-specific management, and conservation prioritization for Bali’s coral reef ecosystems.

Effects of Dietary Cucumber Tree Leaf Extract (Averrhoa bilimbi) Supplementation on Survival and Growth Performance of Bilih Fish (Rasbora maninjau)

2026-04-02T16:39:17+07:00

This study investigated the effect of dietary supplementation with cucumber tree leaf extract (Averrhoa bilimbi) as a natural feed additive on the survival and growth performance of bilih fish (Rasbora maninjau). Leaves of A. bilimbi were dried, ground, and macerated in 96% ethanol (1:10 w/v) for 72 h. The solvent was evaporated, and the viscous extract was stored at 4°C prior to feed incorporation. A completely randomized design (CRD) was applied, comprising four dietary treatments with three replicates each: P0 (control, no extract), P1 (1% extract), P2 (3% extract), and P3 (5% extract) per kilogram of feed. Juvenile bilih fish measuring 2–3 cm in length were stocked at a density of one fish per liter and reared for 40 days. Feed was administered at 3% of biomass daily in two equal meals. Key response variables included survival rate and growth performance. Analysis of variance (ANOVA) revealed that dietary supplementation with cucumber tree leaf extract had a significant effect on growth performance (p<0.05) but exerted no significant influence on survival rate (p≥0.05). The optimal supplementation dose was approximately 3% (P2), with lower or higher doses resulting in reduced growth performance. A. bilimbi may be effective as a natural feed supplement for improving the growth of R. maninjau, possibly because of its bioactive compound content and the slight increase in the dietary protein level.