Natural causes led to the fish kill in Manila Bay near Baseco last Sept. 17, results of the water quality test released by the Department of Environment and Natural Resources (DENR) showed.

Undersecretary for Solid Waste Management and Local Government Units Concerns Benny Antiporda said the water quality analysis conducted by the DENR's Environmental Management Bureau (EMB) revealed Friday afternoon that the fish kill was a result of low concentrations of dissolved oxygen in the water.

“Our test results are now out. The dissolved oxygen is only 3 mg/L (milligrams per liter), which caused the death of fish in Manila Bay. DENR's standard dissolved oxygen is 6 mg/L,” Antiporda said.

The EMB and the Bureau of Fisheries and Aquatic Resources (BFAR) have conducted separate water sampling analysis from different locations but both tests came out with the same results.

BFAR conducted water quality testing and fish sample collection at four sampling sites namely, Baseco Beach, mouth of Pasig River, barge docking area, and aplaya.

Its test results released last Sept. 17 found “very low” level of dissolved oxygen at 0.11 mg/L. BFAR's acceptable level of dissolved oxygen for marine waters is 5 mg/L.

Antiporda previously denied claims by some groups that the artificial white sand filling activity using dolomite sediments along the Manila Bay baywalk had caused the fish kill in Baseco.

“Nothing to worry about because the (beach) nourishment area is too far from the area were the dead fishes were. There is no connection between the ongoing nourishment project and the recent fish kill,” he said.

The “insinuations” of some groups connecting the fish kill with the DENR's beach nourishment project had Antiporda looking into the possibility of “sabotage.”

“We are not insinuating na may kriminal dito, but we are (also) not discounting na may ganoong moves na ngayon kasi these are desperate moves, desperate times. Ito na lang 'yung paraan nila para i-discredit ang beach nourishment project. (We are not insinuating that there are criminals here, but we are also not discounting that such moves can happen now because these are desperate moves, desperate times. This is just their critics way to discredit the beach nourishment project),” he earlier said.

Fisherfolk group Pamalakaya said the fish kill is an indication that Manila Bay is degraded as it is.

It reiterated that the Manila Bay's environmental degradation should be the main concern that the DENR must address, and not through beach nourishment that is only aesthetics but irrelevant to rehabilitation.

The group called on the BFAR to get to conduct water sampling and laboratory analysis for possible water pollution.