Cath Lovelock<\/a> from the University of Queensland, Australia, combined high and low-tech methods to show the effect of dams on mangrove forests. From satellite images, Lovelock and her team measured the color and muddiness of coastal waters around the Indian and Pacific Oceans. The researchers also got well and truly muddy. Tromping out to 27 sites in Vietnam and southern Australia, they whacked metal poles into the ground and fixed them to bedrock. From the late 1990s onwards, and for up to 16.5 years, they trudged back through the mud to gauge changes in soil levels.<\/p>\n\u201cYou measure these things with a ruler,\u201d\u00a0says Lovelock.<\/p>\n
They found that the muddier the water, the faster mangrove soils build up vertically: no great surprise. The problem, says Lovelock, is that 69 percent of the sites studied receive insufficient mud to uplift soils fast enough to outpace sea level rise. Unless the soil is continuously replenished, mangrove roots spend too much time submerged in the water. There, they become oxygen-deprived and eventually die.<\/p>\n
\u201cWe then asked, does this really matter?\u201d says Lovelock. The team wanted to know how long it would be before the mangrove forests they studied completely drowned. Their data suggest that across the Indo-Pacific large mangrove areas will be lost to rising seas by 2070. Based on a computer model combining their data with various factors including projections of future sea level rise, they found vulnerable sites with low sediment supplies in Indonesia, the Philippines, Sri Lanka, and the Solomon Islands.<\/p>\n
Emily Pidgeon, with the nonprofit Conservation International, knows well how important mangroves are to many people. She works with a community in an Indonesian province, West Papua, which she says \u201cbases its entire livelihood, economy, and much of its culture around mangroves.\u201d People eat and sell mangrove crabs, and build homes from mangrove wood. The loss of these trees would upend an entire way of life.<\/p>\n
Mud-starved mangroves, however, are not just threatened by rising sea levels. A complex mix of anthropogenic forces is already affecting some mangrove forests. At the mouth of Thailand\u2019s Chao Phraya River, dams have reduced sediment outflow by 80 percent; groundwater extraction is causing subsidence; and human developments are blocking the way for mangroves to naturally shift inland. The result is the loss of mangroves along kilometers of coast.<\/p>\n
The problem is complex and extends far beyond the mangroves themselves.<\/p>\n
\u201cWe have to look at the whole system rather than just the pieces,\u201d Pidgeon says. And while sediments play their part, the situation is further muddied when politics come into view. \u201cHelping governments understand this is probably one of the greatest challenges.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
Dams are leaving mangroves dangerously short on dirt.\u00a0<\/p>\n","protected":false},"featured_media":12627,"menu_order":0,"template":"","format":"standard","meta":{"_acf_changed":false,"om_disable_all_campaigns":false,"footnotes":""},"categories":[],"tags":[],"acf":{"hero_video_url":null,"hero_video_caption":"","deck":"Dams are leaving mangroves dangerously short on dirt.","authors_group":[{"by_group":"by","contributors_group":[15555]}],"word_count_override":"","podbean1":"","podbean2":"","redirect":"","geolocation":null,"related":[16079,16868],"twitterimage":13542,"facebookimage":13542,"twitterdescription":"","edited":"","factchecked":"","code":"","no_old_story_flag":[]},"_links":{"self":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/16939"}],"collection":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/types\/custom_news"}],"version-history":[{"count":2,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/16939\/revisions"}],"predecessor-version":[{"id":18891,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/16939\/revisions\/18891"}],"acf:post":[{"embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/news\/16868"},{"embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/features\/16079"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/media\/12627"}],"wp:attachment":[{"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/media?parent=16939"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/categories?post=16939"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hakaimagazine.com\/wp-json\/wp\/v2\/tags?post=16939"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}