Jornal de Biologia Marinha e Oceanografia

Assessment Carbon Sequestration Rate of Different Cultivable Seaweeds of Cox’s Bazar Coast, Bangladesh

Mazharul Islam Sajeeb

Seaweed has the ability to use carbon from the environment through photosynthesis to produce biomass. This study aims to estimate the carbon sequestration rate by different cultivable seaweeds as a strategy to mitigate the impact of ocean acidification and global climate change. This study also determines the influence of carbon sequestration on different environmental factors. The study was undertaken at Cox’s Bazar coast. Locally available five seaweed species namely Gracilaria tenuistipitata, Ulva compressa, U. intestinalis, U. lactuca and polysiphonia sp. were cultured with the longline and net method for three cultivation periods, starting from October to March, 2020-2021. Each cultivation period was taken about 45 days. Seaweed samples were collected every 15 days from day 0 (initial), 15,30 to 45 (replanting) for every cultivation period to assess the carbon content of seaweeds. The results show that the sequestration rate of U. intestinalis is significantly higher than the others in the longline and net method. Highest concentration found in the day-45 and lowest concentration is in the day-15. Descending order of the Carbon sequestration in the cultivated seaweeds U. intestanalis>U. compressa>G. tenuistipitata>U. lactuca>Polysiphonia sp. Trends of carbon sequestration rate were influenced by different seaweed variants. Generally, U. intestinalis has higher sequestration rate than other four seaweed variants. Highest concentration found in the day 45 and lowest concentration is in the day 15. Two way-ANOVA results showed the comparisons of the rate of the carbon sequestration among the different cultivated seaweeds at Cox’s Bazar coast among different stations and seasons. Correlation matrix and multiple regression analysis showed the influence of different environmental factors. If the cultures of seaweed increases worldwide in a large scale it will be a powerful tool in controlling ocean acidification and economically benefitted.