Tracking systems fail to show extent of Filipino fishers' reliance on West Philippine Sea

MANILA, Philippines — Despite being a crucial fishing ground for scores of Filipino fishers, the West Philippine Sea (WPS) remains largely unmonitored, with global tracking systems in the dark about the true scale of Filipinos' fishing activities in the area.

Filipino fishers, who mostly use small fishing boats, are invisible or outnumbered by foreign vessels in the resource-rich WPS based on spatial and satellite trackers, according to a study by fisheries analyst Rollan Geronimo of the United States-based University of Hawaii.

This means the Philippines is "not able to demonstrate to the world how it is utilizing fishery resources in the area," Geromino wrote.

Geronimo's study is one of 13 articles included in the "West Philippine Sea: State of the Coasts" report by the University of the Philippines Marine Science Institute, which was released on Tuesday.

The research highlights the dominance of foreign fishing vessels in the WPS as shown by data from two main vessel tracking systems: the Automatic Identification System (AIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS).

The AIS relies on transponders installed on ships to broadcast identifying information about vessels. The system mostly tracks large industrial boats as smaller fishing vessels may not always carry AIS transponders. Some boats also turn off their AIS transponders, known as going dark at sea, to conceal their location and identity.

Meanwhile, the VIIRS is a sattelite-based sensor that detects lights emitted by fishing vessels at night. Unlike the AIS, VIIRS cannot identify the vessels' flag or size, making it difficult to ascertain the flag of the vessels entering Philippine waters.

Both systems show that Filipino vessels are outnumbered by foreign vessels entering the Philippines' exclusive economic zone.

"Both AIS and VIIRS indicate what appear to be foreign fishing vessels operating in the WPS, some of which had even been observed approaching the Babuyan Islands in the past," the study said. 

"More surprising, however, is that we do not detect Philippine-flagged fishing vessels on AIS," Geronimo wrote.

Too, tracking by the VIIRS shows that "there is greater movement of vessels