TAIPEI (Taiwan News) — Greenpeace has warned that Taiwan’s coastal fisheries are catching more fish before they can reproduce, raising concerns over smaller stocks and weaker future catches.
A Greenpeace survey found that immature fish made up 77.7% of sampled catches in Taiwan’s coastal and offshore waters in 2023, rising to 93.3% in 2025, per CNA.
The group said more than 80% of individuals in 30 sampled species were below that maturity benchmark, known as Lm50. Ho Hsuan-ching (何宣慶), an associate professor at National Kaohsiung University of Science and Technology, said three years of findings point to severe overfishing, according to the report.
Ho warned that continued pressure could make future catches smaller and less abundant, with possible genetic bottleneck effects if management does not improve.
The report also highlighted trawling in nearshore waters, where fishing vessels are barred from operating within 3 nautical miles (5.6 km) of land. Greenpeace listed Yilan, Penghu, and Pingtung among areas with the highest average trawling hours from 2023 to 2025, with Yilan topping 30,000 hours and the other two each exceeding 10,000, CNA reported.
Greenpeace ocean project director Huang Hsin-tung (黃昕彤) said the 3-nautical-mile zone is a key nursery area for marine life but remains under heavy fishing pressure. She said the Fisheries Agency issued 24 trawling penalties in 2025, while Yilan, Penghu, and Pingtung recorded no local penalties from 2023 to 2025.
The Fisheries Agency said it has set length rules for crabs and mahi-mahi, while local governments use size limits, closed seasons, and no-fishing zones.
The agency said coastal and offshore catches have held at around 170,000 tonnes over the past five years. It said 64 illegal trawling violations within 3 nautical miles were penalized from 2023 to 2025 after Coast Guard referrals.
