Dynamics of Chlorophyll-a Concentration in Ternate Island Waters and Its Effect on Yellowfin Tuna Production

Abstract

This research was conducted from May to August 2023, with the aim of assessing the distribution of chlorophyll-a concentration and its effect on yellowfin tuna production in Ternate Island waters. The use of experimental fishing methods in collecting research data and data analysis in the form of abundance analysis, exponential regression, cross correlation, and General Aditive Models is expected to answer the research objectives. The results showed that the fluctuation of yellowfin tuna fish catch was similar to the abundance of fish stocks with the highest catch in June (14 229 kg) followed by July (11 142 kg), August (10 764 kg) and May (8 001 kg). The catch of yellowfin tuna fish is spread over a range of chlorophyll-a concentrations between 0.06 mg m-3 to 0.32 mg m-3, with an average monthly chlorophyll-a concentration of 0.22 mg m-3. Chlorophyll-a conditions in Ternate Island waters are quite fluctuating and significantly affect the catch of yellowfin tuna fish with a very strong correlation coefficient of 0.87. The results of General Aditive Models analysis found that the chlorophyll-a concentration value for potential yellowfin tuna fishing areas is > 0.01 mg m-3 with a correlation distance or time leg is in week 15.