Taiwan’s west coast and the Penghu Islands beyond are home to a special species of fiddler crab known for building chimney-like structures from mud after breeding. But that may not be the case for long, if a new survey of their numbers is correct.
The Taiwanese fiddler crab is a master of survival among the shifting tides of the Taiwan Strait. But it is no match for human development and invasive species that have taken over much of its habitat.
All along Taiwan’s west coast and the outlying Penghu Islands—the crabs’ natural range—fish farms and invasive mangrove species have moved in, leading to a dramatic drop in the crabs’ numbers.
Professor Shih Hsi-Te of National Chung Hsing University’s Department of Life Sciences is among those most concerned about the future of this crab species. He says the invasive mangrove species make the environment far too muddy for the fiddler crabs’ survival. Shih says that the added pressure from human activity and invasive species has left the crabs unable to cope with their natural competitors, the bowed fiddler crab.
A recent survey of crab numbers found only 500,000 Taiwanese fiddler crabs, an alarming drop. And in much of its natural range, this crab has already disappeared—in some areas, surveyors failed to find a single individual. Conservationists are calling for better protection of the crabs’ habitat and an investigation into the negative impact on their survival caused by the expansion of mangrove species.