GREEN Alert Environmental Network (Gaen) warned that the dredging activities in E.B. Magalona could threaten the town's blue crab industry.
In a post made on social media, the group said dredging is not a total solution to the recent flooding, which devastated the area.
They pointed out that such activities could be a "double jeopardy" as it could worsen the floods in the area and could bring hunger.
"There is no assurance from the government officials as to who will pay for their livelihood loss," the group said.
The extraction of black sand will release harmful substances and increase water turbidity and liters of toxic metals that negatively affect marine biodiversity, and slow land subsidence may occur, the group added.
It also said that black sand mining can cause much economic damage aside from flooding, although spread out over a longer period.
The group said the sustainable backbone economy of E.B. Magalona is the blue swimming crab industry. Negros Occidental has produced about five tons of blue swimming crabs per day, amounting to an P8-billion
industry, the fourth largest in the country based on a data released in 2016.
Gaen said the nine out of 23 barangays of the town depend on the coastal resources, and black sand mining would not be beneficial to the town's populace.
It said sand bars that have formed in the area also serve as natural protection from high waves and typhoons.
"Once gone, then prepare for the worst nightmare," the group warned.