The increase in fish population along the 3.1-km breakwater that is under construction for the Vizhinjam International Seaport works has come as a surprise for many. Popular notion is that the construction work will drive away shoals of fish and other marine species from the region due to fluctuations in temperature, salinity and the accumulation of silt and pollutants.
But the underwater cameras mounted on divers employed to check the line and level of breakwater construction, especially for the placement of accropodes, captured images of a thriving marine ecosystem with portions of the breakwater under the water acting as artificial reefs offering suitable habitats for many marine species, including ornamental fishes.
According to experts engaged in the construction of the port, once the dredging works started, the seabed got agitated and the nutrients from the seabed got mixed in the water, attracting fishes. Further, the boulders and accropodes of the breakwater are acting as safe breeding ground for fish. Most of the fishes spotted along the breakwater are ornamental, than edible ones.
M.K. Anil, Principal Scientist, Central Marine Fisheries Research Institute (CMFRI), told The Hindu that “the structure had been acting like artificial reefs, which are relatively less in our sandy coast compared to the coastal areas from Rameswaram to Kanyakumari. These hard structures attract lobsters and mussels since the structure can offer breeding grounds for several such species, including ornamental fishes, in addition to providing habitat for corals and other invertebrates.”
“Though the port work may create some turbidity in the region, it will be for short period. Considering the level of monsoon turbidity along the coast of Kerala, this will not create any major issue for the marine ecosystem. If there would be any issues in the future, it would be from any possible oil spillage from ships. But considering that big ships are expected to called in at the port, the level of oil spillage will be less,” added Mr. Anil.
Fisherfolk have been alleging that dredging, reclamation and so on have been polluting the marine ecosystem, leading to a fall in marine biodiversity and decline in fish catch. Meanwhile, the work on 1.6 km of the 3.1-km breakwater has been completed. Also, reclamation of 35 hectares of sea out of the 53 ha required and work on 5.4 ha of container yard out of the total 30 ha have been completed.