Comment are off
Critical Habitat for Asian ISRAs (Important Shark and Ray Areas) largely unprotected
Abstract
The Asia region harbors exceptional chondrichthyan (shark, ray, and chimaera) diversity
but faces intense fishing pressure. The Important Shark and Ray Area (ISRA) process
provides a collaborative, evidence-based framework to identify critical habitats and inform
spatial management. We assessed ISRAs across the Bay of Bengal, Southeast Asia, and
the Northwest Pacific to characterize their extent, ecological significance, and conservation
relevance. We delineated 122 ISRAs spanning ~ 1 million km2 (~ 3% of the region)
across 12 jurisdictions and international waters, encompassing habitats for 121 species
(~ 30% of Asia’s chondrichthyans), 76% of which are threatened. Depleted taxa (e.g., giant
guitarfishes, Glaucostegidae) were represented, but charismatic megafauna (e.g., Whale
Shark Rhincodon typus) were overrepresented. In contrast, deepwater and freshwater species
were underrepresented. Reproductive Areas were the most common ISRA sub-criterion
applied (52% of ISRAs), largely in nearshore zones, while areas for range-restricted
species were less frequently (18%) identified. Twelve ISRAs overlapped with biodiversity
hotspots, including seven in areas of high overall chondrichthyan species richness and five
in areas of high range-restricted species richness. Citizen science was the predominant
research method used to delineate ISRAs, while fisheries data were underused despite the
region’s major fisheries footprint. Geographic coverage was uneven: Indonesia held the
most ISRAs (n = 40; 71.7% of ISRA coverage) while eight jurisdictions (e.g., Viet Nam,
China, Republic of Korea) lacked ISRAs due to data gaps. Protection shortfalls are stark:
MPAs cover < 5% of national waters in 16 jurisdictions (eight with < 1%); 5.4% of ISRA
area lies within MPAs; and only 2.8% of ISRA spatial extent overlaps with no-take zones.
These results provide a regional foundation to guide spatial planning, prioritize management,
close data gaps, and support recovery of Asia’s diverse and imperiled chondrichthyan
assemblages.
The Asia region harbors exceptional chondrichthyan (shark, ray, and chimaera) diversity
but faces intense fishing pressure. The Important Shark and Ray Area (ISRA) process
provides a collaborative, evidence-based framework to identify critical habitats and inform
spatial management. We assessed ISRAs across the Bay of Bengal, Southeast Asia, and
the Northwest Pacific to characterize their extent, ecological significance, and conservation
relevance. We delineated 122 ISRAs spanning ~ 1 million km2 (~ 3% of the region)
across 12 jurisdictions and international waters, encompassing habitats for 121 species
(~ 30% of Asia’s chondrichthyans), 76% of which are threatened. Depleted taxa (e.g., giant
guitarfishes, Glaucostegidae) were represented, but charismatic megafauna (e.g., Whale
Shark Rhincodon typus) were overrepresented. In contrast, deepwater and freshwater species
were underrepresented. Reproductive Areas were the most common ISRA sub-criterion
applied (52% of ISRAs), largely in nearshore zones, while areas for range-restricted
species were less frequently (18%) identified. Twelve ISRAs overlapped with biodiversity
hotspots, including seven in areas of high overall chondrichthyan species richness and five
in areas of high range-restricted species richness. Citizen science was the predominant
research method used to delineate ISRAs, while fisheries data were underused despite the
region’s major fisheries footprint. Geographic coverage was uneven: Indonesia held the
most ISRAs (n = 40; 71.7% of ISRA coverage) while eight jurisdictions (e.g., Viet Nam,
China, Republic of Korea) lacked ISRAs due to data gaps. Protection shortfalls are stark:
MPAs cover < 5% of national waters in 16 jurisdictions (eight with < 1%); 5.4% of ISRA
area lies within MPAs; and only 2.8% of ISRA spatial extent overlaps with no-take zones.
These results provide a regional foundation to guide spatial planning, prioritize management,
close data gaps, and support recovery of Asia’s diverse and imperiled chondrichthyan
assemblages.
