| Abstract | Effective and comprehensive regional-scale
marine conservation requires fine-grained data on the spatial
patterns of threats and their overlap. To address this
need for the Papaha¯naumokua¯kea Marine National Monument
(Monument) in Hawaii, USA, spatial data on 14 recent
anthropogenic threats specific to this region were gathered
or created, including alien species, bottom fishing, lobster
trap fishing, ship-based pollution, ship strike risks, marine
debris, research diving, research equipment installation,
research wildlife sacrifice, and several anthropogenic climate
change threats i.e., increase in ultraviolet (UV)
radiation, seawater acidification, the number of warm ocean
temperature anomalies relevant to disease outbreaks and
coral bleaching, and sea level rise. These data were combined
with habitat maps and expert judgment on the
vulnerability of different habitat types in the Monument to
estimate spatial patterns of current cumulative impact at
1 ha (0.01 km2) resolution. Cumulative impact was greatest
for shallow reef areas and peaked at Maro Reef, where 13 of
the 14 threats overlapped in places. Ocean temperature
variation associated with disease outbreaks was found to
have the highest predicted impact overall, followed closely
by other climate-related threats, none of which have easily
tractable management solutions at the regional scale. High
impact threats most tractable to regional management relate
to ship traffic. Sensitivity analyses show that the results are
robust to both data availability and quality. Managers can
use these maps to (1) inform management and surveillance
priorities based on the ranking of threats and their distributions,
(2) guide permitting decisions based on cumulative
impacts, and (3) choose areas to monitor for climate change
effects. Furthermore, this regional analysis can serve as a
case study for managers elsewhere interested in assessing
and mapping region-specific cumulative human impacts.
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