A troubled top of the marine food chain: Ecotoxicological relevance and consideration to stranded cetaceans in Philippine waters

Anthropogenic contaminants such as polychlorinated biphenyls (PCBs), dichlorodiphenyltricloethanes (DDTs), heavy metals, and polycyclic hydrocarbons (PAHs) are continually being detected in various tissues of marine mammals in other parts of the world. Data correlating pollutant residues with altered reproductive and development states, liver disease, endocrine system damage, and alarming growth in cancer cases are reported for these marine top-level predators. If exposure has already been long-term, this may be more deterrent to a population’s continued success than a single, high-impact event. In the Philippines, there are data reporting the presence of these xenobiotics in almost all environmental media (sediments, soils, waters, mussels, fish, squids, and shrimps). Through the process of biomagnification, cetaceans found stranded in Philippine waters are greatly at risk. Moreover, reports show that these stranded cetaceans are used for human consumption in the country. Given these data, the high frequency of stranding events in the country are currently being maximized in an ecotoxicological, biomarker and histopathological research targeting at least 30 cetaceans found stranded (live and dead) in our waters. Findings of this pioneering study will be used to (1) provide knowledge & understanding of current contamination levels in these cetaceans, which are at the top of the food web, found stranded in Philippine waters, (2) educate our locals of possible human health impacts of cetacean consumption, and (3) present scientific data which will initialize development of ecotoxicological protocols in the Philippines using not just stranded cetaceans but also other marine mammal species or other marine species in general