Laguna (province) producing of fish. Carp and tilapia fingerlings are also being grown in inland ponds and freshwater fish pens. There are a total of 457 operators utilizing an area of for fish pens and fish cages. Aside from the Laguna de Bay, approximately 12% of the area in the Seven Lakes of San Pablo is being used for aquaculture. Laguna is home to twenty-one economic zones as registered under the Philippine Economic Zone Authority. Most of these economic zones are located in Santa Rosa, Biñan, and Calamba. The largest economic zone in Laguna is the Laguna Technopark, located in Santa Rosa
Arroyo de la Laguna Lake. With development of the valley starting in the 19th century, drainage alterations in this watershed reduced the lake to a watercourse now called the Arroyo de la Laguna. In the northern portion of the Arroyo de la Laguna catchment basin, the Tassajara Formation underlies Quaternary valley fill material. Contacts of these two formations are often indistinguishable due to similarities of physical characteristics. The prism of sediments identified as valley fill materials contains from eight to ten separate zones of sand and gravel separated by zones of silt and clay. Rapid development and other historic changes in the upper watershed