The Ocean and Us

Such ecosystems can act in a similar manner to breakwaters or shallow coasts. In this way, coastal ecosystems play a role in reducing the impacts of climate change (SDG13 take urgent action tocombat climatechangeand its impacts ), particularly the increased frequency of storms and sea level rise. Importantly, recent studies have also found that salt marshes can adjust to sea-level rise and can reduce coastal erosion and increase accretion, depending on a range of site-specific variables, as a part of adaptation to climate change (Fagherazzi et al., 2013; Shepard et al., 2011).

reducing vulnerability, possibly in hybrid solutions combining ‘grey’, engineered infrastructure with ‘green’ natural coastal protection (Spalding et al. 2013), and including key local stakeholders (Barbier, 2015). Coastal ecosystems can play a role in making cities and human settlements safe even in the case of coastal megacities. A recent study for New York City (Aerts et al., 2014) shows that wetland restoration and beach nourishment can be used in a hybrid approach to reducing vulnerability to flooding. In terms of providing protection from extreme events, coral reefs, seagrasses, mangroves and dunes, can also, in certain circumstances, provide protection against storm surges by forming barriers along coastlines.

Pacific Ocean

Atlantic Ocean

Pacific Ocean

Indian Ocean

Number of people who may receive risk reduction benefits from reefs by country 10 000 - 50 000 670 000 - 2 150 000 120 000 - 330 000

Source:Ferrario& etal , Theeffectivenessofcoral reefs for coastal hazard risk reduction and adaptation ,2013

330 000 - 670 000

Coral reefs

50 000 - 120 000

more than 2 150 000

Coastal communities across the globe are increasingly at risk from storms and flooding as a side effect of climate change paired with rapid human-led coastal development. Nature- based solutions like coral reefs offer a low-cost opportunity to reduce risk and also can be paired with other ecosystems services such as tourism and fish production. The map above shows the number of people by country that may derive a risk reduction benefit from reefs. The countries are grouped by the number of people living below 10m elevation and within 50 km of a coral reef to demonstrate the capacity for coral reefs to protect coastal communities.

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