1Department of Aquatic Resources Management, Faculty of Fisheries and Marine Science, Universitas Diponegoro, Indonesia
2Department of Aquaculture, Faculty of Fishery, University of 45 Mataram, Indonesia
BibTex Citation Data :
@article{JKT34364, author = {Naning Sulystyaningsih and Agus Hartoko and Tita Elfitasari and Eko Susanto}, title = {Biomass Loss and Carrageenan Content of Longline-Cultivated Kappaphycus alvarezii in Ekas Bay, Lombok: A Single-Season Case Study}, journal = {Jurnal Kelautan Tropis}, volume = {29}, number = {3}, year = {2026}, keywords = {Biomass Loss and Carrageenan Content of Longline-Cultivated Kappaphycus alvarezii (N.D. Sulystyaningsih1}, abstract = { Seaweed cultivation performance varies with local conditions, changing biomass production and the chemical characteristics of harvested thalli. This study evaluated the growth performance, seawater elemental dynamics, thallus elemental composition, phytochemical profile, and carrageenan content of Kappaphycus alvarezii cultivated using the longline method in Ekas Bay, East Lombok, West Nusa Tenggara, Indonesia. The study ran for 45 days, from 21 May to 5 July 2025. We evaluated growth performance from four field replicates, each with three nested subsamples, based on final wet biomass, daily growth rate (DGR), absolute growth, and biomass retention. We measured seawater elemental composition at planting and harvest without independent analytical replication. Thallus elemental composition, qualitative phytochemical profile, and carrageenan content were assessed using three independently analyzed thallus samples. Mean final wet biomass was 19.34 ± 10.62 g from an initial biomass of 100 g, with a DGR of −4.10 ± 1.41% day⁻¹, absolute growth of −80.66 ± 10.62 g, and biomass retention of 19.34 ± 10.62%. Potassium and chlorine were the dominant measured elements in the thalli, with concentrations of 10.34 ± 0.50 and 10.09 ± 0.85 mass%, respectively. Seawater concentrations of S, Cl, K, Ca, and Br were higher at harvest than at planting, with increases of 52.74%, 34.84%, 14.35%, 73.73%, and 11.85%, respectively; these observations were descriptive because seawater samples were not independently replicated. Phytochemical screening showed strong positive reactions for flavonoids and alkaloids (+++), weak positive reactions for saponins (+), and variable responses for tannins, terpenoids, phenol/hydroquinones, and steroids. Carrageenan content averaged 40.77 ± 1.58%. The results demonstrate substantial biomass loss during the cultivation period, while the remaining thalli showed measurable elemental, phytochemical, and carrageenan characteristics. The study is limited by the single-site, single-period design, unreplicated seawater elemental sampling, and the use of three independently analyzed thallus samples for chemical characterization, which restricts broader inference regarding seasonal patterns and the causes of biomass loss. }, issn = {2528-3111}, pages = {427--440} doi = {10.14710/jkt.v29i3.34364}, url = {https://ejournal2.undip.ac.id/index.php/jkt/article/view/34364} }
Refworks Citation Data :
Seaweed cultivation performance varies with local conditions, changing biomass production and the chemical characteristics of harvested thalli. This study evaluated the growth performance, seawater elemental dynamics, thallus elemental composition, phytochemical profile, and carrageenan content of Kappaphycus alvarezii cultivated using the longline method in Ekas Bay, East Lombok, West Nusa Tenggara, Indonesia. The study ran for 45 days, from 21 May to 5 July 2025. We evaluated growth performance from four field replicates, each with three nested subsamples, based on final wet biomass, daily growth rate (DGR), absolute growth, and biomass retention. We measured seawater elemental composition at planting and harvest without independent analytical replication. Thallus elemental composition, qualitative phytochemical profile, and carrageenan content were assessed using three independently analyzed thallus samples. Mean final wet biomass was 19.34 ± 10.62 g from an initial biomass of 100 g, with a DGR of −4.10 ± 1.41% day⁻¹, absolute growth of −80.66 ± 10.62 g, and biomass retention of 19.34 ± 10.62%. Potassium and chlorine were the dominant measured elements in the thalli, with concentrations of 10.34 ± 0.50 and 10.09 ± 0.85 mass%, respectively. Seawater concentrations of S, Cl, K, Ca, and Br were higher at harvest than at planting, with increases of 52.74%, 34.84%, 14.35%, 73.73%, and 11.85%, respectively; these observations were descriptive because seawater samples were not independently replicated. Phytochemical screening showed strong positive reactions for flavonoids and alkaloids (+++), weak positive reactions for saponins (+), and variable responses for tannins, terpenoids, phenol/hydroquinones, and steroids. Carrageenan content averaged 40.77 ± 1.58%. The results demonstrate substantial biomass loss during the cultivation period, while the remaining thalli showed measurable elemental, phytochemical, and carrageenan characteristics. The study is limited by the single-site, single-period design, unreplicated seawater elemental sampling, and the use of three independently analyzed thallus samples for chemical characterization, which restricts broader inference regarding seasonal patterns and the causes of biomass loss.
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