The Fishery Zoning and Management Plan (ZOMAP) for Laguna de Bay was developed in 1983. It was designed to rationalize the management and regulate the utilization of the lake’s fishery resources as well as to resolve equity problems among large-scale fishpen operators and small-scale fishermen dependent upon open water catch.

Revised ZOMAP , an improvement on the initial ZOMAP was approved by the LLDA Board of Directors on October 1995 as a fundamental component of the Master Plan.

In 1999, the fishpen belt as laid out in 1996 revised ZOMAP was further modified and duly approved per LLDA Board Resolution No. 95, s. 1999. Its implementation was then placed under LLDA Lake Management Division.

Areas were allotted for fishpens, fishcages, fish sanctuaries and open fishing. Navigational lanes and barangay access lanes were also identified to facilitate the movement of people, goods and services within the lake.