Current status of environmental water quality of Kappaphycus alvarezii seaweed cultivation in the Seribu Islands, Indonesia and the concept of sustainable development by using a System Dynamic Model approach

The aim of this research is to analyze the current status of water quality in seaweed cultivation environments related to the decline in seaweed production. Field research was conducted in the Seribu Islands Regency, DKI Jakarta, during April and May 2023. The analysis of environmental factors encompassed physical, chemical, and biological parameters at 12 designated sampling points. The results of the analysis of water quality parameters generally meet the requirements, except for oil and grease at 7-51 mg/L and nitrate at 1.60-6.3 mg/L, both of which exceed the quality standards for biota. Plankton analysis shows the total abundance of plankton reaches 36 to 9,070 ind/L. Evaluation of the suitability class shows that the waters are in class S (Suitable). The Pollution Index value ranges from 6.51 to 8.05, indicating a fairly polluted status. The high levels of oil and grease, nitrate, and the presence of index pollutants have a significant influence on the decline in seaweed production in the Seribu Islands Regency. The preparation of improvement strategies can be conducted using a System Dynamics Model approach, involving the creation of comprehensive Causal Loop Diagrams. This process considers four key factors: environmental water quality, human resources, technology, and seaweed.