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The real-time monitoring of ocean wave data is a crucial element in marine environmental monitoring and the development of marine resources. It is unfortunate that the majority of wave measurement devices remain challenging, relatively high-priced, and require sophisticated technology. This study investigates the validation of a new type of ocean wave measurement, designed based on the mini wave gauge (MWG), using low-cost materials. The study utilizes an accelerometer sensor, specifically the ADXL335, which is converted to measure wave height, and the GY-271 designed to measure wave direction. This research addresses the validation of MWG by comparing measurements from the acoustic doppler current profiler (ADCP) and HOBO. The validation of wave height demonstrates high accuracy, with a MAPE percentage of 0.46% between MWG and ADCP, and 23.30% between MWG and HOBO. In contrast, the validation of MWG for wave direction by ADCP still requires improvement, with a MAPE of 36.75%. This is due to the sensor's sensitivity to the earth's magnetic field, which requires further improvement of the buoy design to accommodate the direction of incoming waves. Additionally, the MWG's sampling rate in milliseconds allows for analyzing wave characteristics based on wave periods using the fast Fourier transform (FFT) method. [ABSTRACT FROM AUTHOR]

Karimunjawa National Park (KNP) has increasing tourist visits and shipping traffic as its main tourist destination. These conditions have the potential to the degradation of coral reef ecosystems. Hence, the objective of this study was to investigate the biological effects of anchorage on disease prevalence, % coral cover, abundance, and diversity of corals. The six islands with high, medium, and low anchoring intensities were selected. The survey method was carried out by scuba diving on each selected island at depths of 3 and 8m by establishing a 2x25m line and belt transects with three replications. The statistical results indicated that there were significant differences among anchoring levels in disease prevalence. Even the coral abundance and diversity tend to be lower on the island with high anchoring activity. However, there were no significant differences in species richness, diversity index, or relative abundance among anchoring levels. Moreover, the different levels of anchoring also made no difference in the percentage of coral cover (p 0.087 >0.05). This study revealed that anchoring damage might be indirectly responsible for the dispersal and elevated levels of disease. Further study is needed to identify anchoring activity and coral disease in wider areas to conserve the coral reefs of KNP. [ABSTRACT FROM AUTHOR]