Hambantota Port emerges as marine biodiversity hotspot with over 8 unique fish species

A new baseline study by the Department of Fisheries and Marine Sciences, at Ocean University of Sri Lanka has revealed a thriving ecological marvel beneath the waters of Hambantota International Port (HIP).

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Despite being an artificial breakwater, the reef at HIP now supports the highest diversity of reef-associated fish in Southern Sri Lanka, outperforming natural sites like Weligama, Polhena, and Thalaramba.

Using a standardised swim-timed transect method, covering areas of 5 by 20 meters at depths between 0.5 and 5 meters, researchers catalogued observed visual counts of fish by family and feeding behaviour. While Weligama and Polhena showed respectable biodiversity (with Shannon-Weiner Diversity Index scores of 1.8 and 1.6, respectively), they lagged behind HIP in both species richness and ecological balance. Thalaramba, once a promising site, recorded the lowest diversity (1.1).

HIP’s remarkable fish diversity at 2.3 on the SWD index isn't accidental, it’s sustained by a natural ecological balance rarely seen in similar coastal areas. A healthy population of herbivorous fish, such as surgeonfish and damselfish, play a vital role in this balance by feeding on fast-growing algae that can otherwise smother corals. Their presence allows coral species to thrive and recover naturally.