The Philippine Archipelago, being surrounded by bodies of water of different depths, has been the object of visits by several foreign research vessels since 1846. All the studies made of Philippine waters were mostly aimed to investigate the extent of the Philippine Deep.
The U. S. Fish and Wildlife Service through the Philippine Fishery Program, with the use of the S. F. Baird, focused its investigations on coastal and inshore areas from 1947 to 1950, forming the basis of future oceanographic research in the islands. Upon the termination of the Program and with the turn-over of the David Starr Jordan to the Philippine Bureau of Fisheries, a well-planned investigation of bays and gulfs was carried out in Manila Bay and Lingayen Gulf.
In November, 1956, the Section of Hydrology and Fisheries Biology started the marine fishery biological research programme with the help of the FAO technical assistance officer on marine, biology. The programme was divided into two phases—fishery biology and oceanography. Again the oceanographic activities were confined to Manila Bay and approaches which, however, were later on extended to San Miguel Bay in Southern Luzon.
Oceanographic investigations include studies on hydrology, plankton, benthos and primary productivity. From the different hydrographic stations that were occupied, temperature, salinity, oxygen, pH, phosphate and transparency data were collected.
The study on the distribution of plankton was made to show its relation to fish stock abundance in the bay.