The Karimunjawa Marine National Park, situated in the Java Sea, Indonesia, is renowned for its rich biodiversity and lively coral reefs. However, amidst the backdrop of this natural beauty, concerns have been raised regarding the potential impacts of shipping activities on the health and diversity of these fragile ecosystems.The increase in maritime traffic, including commercial vessels, tourist boats, and fishing vessels, traversing through the Karimunjawa Marine National Park raises significant environmental concerns. The movement of these vessels, especially along specific shipping routes, has the potential to disturb and damage coral reefs through various mechanisms. Hence, the aim of this study was to investigate the possible impacts of shipping routes on the coral abundance and diversity and the coral health in the Karimunjawa Islands, Java Sea, Indonesia.

In this study, the ship routes were grouped into 3 categories (west, east, and non-routes). The West Route, East Route, and Non-Route including a total of 15 islands were investigated for their % prevalence of coral disease, % coral cover, diversity index, species richness, relative abundance, and evenness. At each island, a 15x2 m belt transect was established at 3 and 8 m in depth with 3 repetitions. The statistical analyses showed that there were significant differences in coral abundance and species richness among the ship-route groups. Nonetheless, there were no significant differences in all parameters observed between 3 m and 8 m in depths. These findings suggest that while certain aspects of coral health and diversity are not influenced by shipping routes, other factors or mechanisms may play a more dominant role in determining disease prevalence, coral cover, and overall diversity in the Karimunjawa coral reefs.