More than 80 tonnes of rubbish are washed ashore on Penghu's four southern islands every year, bad news for the marine ecosystem, though improvements in how it is cleared have brought some progress.

• Last year more than 80 tonnes of marine debris were removed from the four islands, mainly discarded fishing gear, polystyrene and PET bottles.
• The rubbish entangles marine life or is swallowed by it, directly threatening the animals' lives.
• Winter currents and the northeast monsoon push large volumes of rubbish onto the basalt coastline, cliffs and narrow sea-eroded gullies.
• The terrain is too treacherous for heavy machinery, so clearance relies on workers abseiling down and on canoes to carry the rubbish by sea to Dongji Island.
• This year a "mobile rubbish truck" has also begun operating on land across the four islands, collecting waste and food scraps on fixed routes and schedules to reduce the amount of rubbish flowing into the sea.

Outlook: Clearance capacity has improved, but as long as the monsoon and ocean currents follow their usual pattern, rubbish will pile up on the shore again next winter, and the National Park Service is urging visitors to take away the rubbish they generate.