[3] His fields of interest in fisheries science are genetics, resource assessment, aquatic biodiversity, biotechnology, climate change adaptation, and policy.

[2][8] He pursued his Master's and Ph.D. degrees in biosciences at the Tokyo University of Marine Science and Technology (TUMSAT), Japan, as a Japanese Government (Monbukagakusho) scholar.

[1][2][9] Santos' research interests are in fisheries science, specifically in the areas of genetics, resource assessment, aquatic biodiversity, biotechnology, climate change adaptation, and policy.

[13] He co-authored the discovery of new fish species such as the Whitechin surgeonfish, Acanthurus albimento [14] and the Arafura lanternbelly, Acropoma arafurensis.

[15] He also helped determine a number of first records of marine species in the Philippines including the Bali sardine, Sardinella lemuru,[16] Tawian sardinella, S. hualiensis,[17] Blacknape Large-Eye Bream, Gymnocranius satoi,[18] Bohol lanternbelly, Acropoma boholensis,[19] Pacific bluefin tuna, Thunnus orientalis,[20] Deranayigala’s beaked whale, Mesoplodon hotaula[21] and Noah’s giant clam, Tridacna noae [22] He became an academician of the National Academy of Science and Technology last 2018.

The Pogi perchlet, Chelidoperca santosi, was discovered in Iloilo's public fish market which was captured in the province of Palawan.

[27] He is recognized as one of United Nations Division for Ocean Affairs and Law of the Sea Pool of Experts under the Asia-Pacific States Region with expertise on fish biology and ecology.

[28] Santos is into science communication via social media to promote his advocacy on fisheries sustainability and marine biodiversity conservation.