Globally, coastal areas are being squeezed between rising seas on one side and human development on the other. The average distance from the high waterline to the first built-up area with human structures or paved roads is less than 400 yards around the world. The narrower a coast, the sooner rising sea levels cause problems.
Narrow coasts have reduced ability to defend against storm surges and other weather events. Construction close to the sea makes coastal areas extra vulnerable. Narrow coasts are also bad news for biodiversity. A study by the Royal Netherlands Institute for Sea Research investigated plant diversity in both the Netherlands and the United States. They found that the wider the coast was, the greater the plant diversity.
In Florida and Georgia, whenever coastal zones reached a couple of kilometers in width, diversity increased rapidly. In the Netherlands, only coastal areas at least 3.8 kilometers wide reached their maximum plant diversity, but such areas are rare. Dutch sand dune areas are typically no more than a kilometer wide, leaving plant diversity at no more than half the possible level.
Limited biodiversity in narrow coastal strips can be somewhat boosted by nature management but would benefit much more by spatial planning. In the Netherlands, a spot called The Sand Motor is where a gigantic amount of sand was deposited off the coast in 2011. Since then, natural forces have spread it along the coast. Such coastal expansion could increase biodiversity. Biodiversity is not a luxury. It makes for a better future for coastal defense, a healthy drinking water supply, and a better human food supply.
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Coastal squeeze is bad for biodiversity, and for us!
Photo, posted June 21, 2017, courtesy of Mark Bias via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio
