Future sea level rise in northwest Mexico is projected to decrease the distribution and habitat quality of the endangered Calidris canutus roselaari (Red Knot)

Sea level rise (SLR) is one of the most unequivocal consequences of
climate change, yet the implications for shorebirds and their coastal
habitats is not well understood, especially outside of the north temperate
zone. Here, we show that by the year 2050, SLR has the potential to cause
significant habitat loss and reduce the quality of the remaining coastal
wetlands in Northwest Mexico—one of the most important regions for
Nearctic breeding migratory shorebirds. Specifically, we used species
distribution modelling and a moderate SLR static inundation scenario to
assess the effects of future SLR on coastal wetlands in Northwest Mexico
and the potential distribution of Calidris canutus roselaari (Red Knot), a
threatened long-distance migratory shorebird. Our results suggest that
under a moderate SLR scenario, 55% of the current coastal wetland extent
in northwest Mexico will be at risk of permanent submergence by 2050, and
the high-quality habitat areas that remain will be 20% less suitable for
C. c. roselaari. What is more, 8 out of the 10 wetlands currently
supporting the largest numbers of C. c. roselaari are predicted to lose —
on average — 17.8% of their highly suitable habitat areas, with two sites
completely losing all their highly suitable habitat. In combination with
increasing levels of coastal development and anthropogenic disturbance in
Northwest Mexico, these predicted changes suggest that the potential
future distribution of C. c. roselaari (and other shorebirds) will likely
contract, exacerbating their ongoing population declines. Our results also
make clear that SLR will likely have profound effects on ecosystems
outside the north temperate zones, providing a clarion call to natural
resource managers. Urgent action is required to begin securing sufficient
space to accommodate the natural capacity of wetlands to migrate inland
and implement local-scale solutions that strengthen the resilience of
wetlands and human populations to SLR.