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Whales Suffer from Renal Failure, Mystery of Cetaceans Inhabiting Taiwan’s Coast Unveils
Meng-Hsien Chen
Department of Oceanology, National Sun Yat-sen University
Specialty: Heavy metal pollution, aquatic exotoxicoloty, fish biology, and zooplanktonology

Each year, sightings of cetaceans typically take place from March until November, with May being the peak season for whalewatching in Taiwan. As whales and dolphins are the apex consumers of marine ecology, hence investigating the metal bioaccumulation in their bodies will give insights to their individual health conditions, leading to understand the pollution status in the entire marine ecological environment all over the world. Deeply aware of the importance of this matter, NSYSU’s Professor Meng-Hsien Chen of the Department of Oceanology joined the Taiwan Cetacean Society without any funding support 20 years ago, and cooperated long-termly with the Cetacean Research Laboratory leading by Professor L.S. Chou, Department of Zoology of National Taiwan University, into cetacean researches. He analyzed 7 species samples collected over 10 years, and unlocked the mystery behind the cetaceans inhabiting the coastal water in the eastern region of Taiwan.

As the ocean off East Coast is the corridor of the Black Current rich in marine resources, large migratory fish and cetacean species including Pantropical Spotted Dolphin (Stenella attenuate) and Dwarf Sperm Whale (Kogia simu) are often sighted swimming in this water. However in spite of a prosperous whalewatching industry, humans know very little about food sources and habitats of these marine mammals.

In the 10 years from 2001 to 2011, Professor Chen sampled 7 cetacean species accidentally caught and stranded around Taiwan, investigating the accumulation of carbon and nitrogen isotope as well as Arsenic and cadmium concentration in their muscles, liver and kidney. She noted that adult Fraser’s Dolphins (Lagenodelphis hosei) are capable of diving up to 2000 feet to feed on deep sea mesopelagic fish and cephalopods, but calves tend to stay in costal waters and are only capable of diving up to 200 feet feeding on squids and hatchetfish.
Risso’s Dolphins (Grampus griseus) have similar behaviors and diet as the Fraser’s Dolphins, with the exception that they prefer squids. Both species occur to areas of upwelling.

Also occurring to the same upper continental slope are young Pantropical Spotted Dolphins (Stenella attenuate) and Dwarf Sperm Whales (Kogia simu). The gregarious Pantropical Spotted Dolphins’ habit of feeding in groups near the coastline makes them the star of cetacean watchers.

Long-term ingesting squids with heavy metal concentration expose both Risso’s and Fraser’s dolphins to high doses of arsenic and cadmium, leading to health risks such as liver and renal failures. The source of these heavy metal pollutants is from land. Professor Chen calls for man not to undermine the health risks of these apex consumers, as industrial development has caused environmental pollution leading to worsening marine ecology issues.
Publish date : 2015-05-04
  • Distribution map of Taiwan Cetacea
    Distribution map of Taiwan Cetacea
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