HISTORICAL COLONY HARVESTING, AT-SEA HUNTING, AND LOCAL FISHING BYCATCH OF THE JAPANESE MURRELET AT BIROJIMA, MIYAZAKI-KEN, JAPAN

摘要

Information on colony harvesting, at-sea hunting, and local fishing bycatch of Japanese Murrelets (Synthli- bo-ramphus wumizusume) in the Birojima area, Miyazaki-ken, Japan, was obtained through interviews with 13 local resi- dents of Kadogawa town. Egg harvesting occurred between 1912 (or possibly earlier) and 1992, but was heaviest in 1940 to 1959 during and after World War II at roughly 1,100–2,080 eggs per year. Between 1912 and 1992, about 47,740–111,880 eggs were harvested. Extensive adult harvesting (180–320 adults per year) occurred between 1944 and 1959, with much lower levels between 1960 and 1970 (16–30 adults per year). Between 1944 and 1970, about 3,056–5,450 adults were har- vested. At-sea hunting of small numbers of murrelets (4–12 per year) occurred between 1951 and 1983, with lower num- bers (5 per year) in 1940–1950. Between 1940 and 1983, about 187–451 murrelets were shot at sea. Local fishing bycatch of small numbers of murrelets (2–9 adults per year) since 1940 resulted in about 148–666 murrelets killed in fishing nets by 2013. Harvesting and hunting of Japanese Murrelets became illegal in 1918, but people did not follow these regulations until they were partly enforced after 1973. These activities finally stopped when seabird biologists were present on Biro- jima during the breeding season in 1993–1996 and the Kadogawa government began educating fishermen and the public in 1992. The population of Japanese Murrelets at Birojima likely declined between the 1940s and 1960s, due mainly to heavy adult and egg harvesting. Partial or complete recovery apparently had occurred by 1994, when 3,000 Japanese Murrelets (about 1,000–1,500 breeding pairs) were estimated and this colony was recognized as the largest in the world for this species..