The Asia Maritime Transparency Initiative (AMTI), which provides tracking data, noted a huge increase in activity. Thirteen military or law enforcement ships from the Philippines sailed through waters surrounding the Spratly Islands and Scarborough Shoal at least 57 times in the period between March 1 to May 25.
It read: “This was a substantial increase over the previous 10 months.
“When three vessels were tracked making seven total visits to contested features.”
The note also highlighted the drastic boost in patrols was “beyond anything seen in recent years” from the country.
Earlier this month, China imposed a three-month fishing ban in the northern part of the South China Sea.
It was viewed by observers as Beijing’s latest attempt to assert power over its neighbours.
The Philippines, in turn, rejected the annual summer fishing veto and urged its vessels to continue fishing in the territorial waters.
The fishing moratorium imposed by China since 1999 runs from May 1 to August 16.
It covers areas of the South China Sea as well as other waters off China.
Greg Poling, director of the Asia Maritime Transparency Initiative at CSIS, said Beijing is now “more capable” of imposing the fishing prohibition than in previous years.