Abstract
High diversity of coastal fishes is found in Western Pacific, East
Asian, Australasian, Southern African and Caribbean waters, while the
greatest diversity of tunas and bill-fishes is found in Tasman Sea,
Equatorial Pacific and Southern African waters. I used publicly
available Global Fishing Watch data to map industrial fishing activity
during 2018 in six broadly defined High Diversity Regions (HDRs):
Western Pacific, Eastern Pacific, Southern Africa, Australasia, Tasman
Sea and Central America. Automatic Identification System (AIS) metadata
for vessels identified as fishing by Global Fishing Watch were used to
partition fishing hours by vessel class and flag state. Drifting
long-lines, tuna purse seines, squid jigging and trawling dominated
AIS-inferred effort (vessel power X fishing hours) in different HDRs.
Large numbers of fishing vessels are operating in High Diversity
Regions. Based on AIS reporting, a minimum total of 2,276 registered
drift longliners, 475 tuna purse seiners, 693 trawlers, and 340 squid
jiggers were fishing in the six HDRs during 2018. The top three flagged
countries account for 56 − 75% of drift longline activity, 89 − 99% of
trawling, and 99% of squid jigging. There is a wide range of flagged
countries fishing purse seines, with the top three accounting for only
33 − 56% of activity in the HDRs. East Asian fleets account for 99% of
squid jigging, and 25 − 75% of drift longlining, but only 0 − 31% of
purse seine and 0 − 12% of trawl fishing in High Diversity Regions. The
Western Pacific and Southern African HDRs are subject to more fishing
activity than other HDRs, and the most common fishing gear used is drift
longlining. China and Taiwan have the largest number of registered drift
longline vessels in these regions. Longline and purse seiner fleets had
surrounded large Marine Protected Areas by 2018, indicating both
successful exclusion, and the potential for encroachment of protected
areas by industrial fleets. Real-time monitoring guiding targeted
enforcement provides hope for protecting the High Diversity Regions of
the world ocean from distant water fleets, which admittedly is only one
of the threats that they face in a changing climate.