Worldwide, coastal areas are squeezed between a rising sea level on one end and human structures on the other.
Worldwide, coastal areas are squeezed between a rising sea level on one end and human structures on the other. The distance between a sandy coastline and the first human structures averages less than 400 meters around the world. And the narrower a coastline is, the lower its biodiversity as well. That is shown by the thesis that coastal ecologist Eva Lansu will defend at the University of Groningen on May 20th. “This coastal squeeze is not only a problem for biodiversity, it also affects our defense against flooding and our drinking water supply”, Lansu says.
Vulnerable to Sea Level Rise
Constructions close to the sea make coastal areas extra vulnerable, Lansu emphasizes in her dissertation. “The narrower a coast, the sooner you will run into problems with rising sea levels.” In addition to those weaker defenses, narrower coasts are also bad news for biodiversity, Lansu found in a comparative study in both the Netherlands and the United States. In the Netherlands, together with colleagues, Lansu visited 35 dune areas. In each of these areas, they walked a transect perpendicular to the coastline and determined plant diversity every hundred meters. She did the same along 12 transects in the states of Florida and Georgia. Lansu: "It was clear that the wider the coast was, the greater the plant diversity. Especially the first two kilometers, that diversity increased rapidly."
In the Netherlands, only coastal areas of at least 3.8 kilometers wide reached their maximum plant diversity. "But unfortunately, such wide zones are rare. Dutch dune areas are on average no more than one kilometer wide, leaving plant diversity stuck at half the possible level," Lansu said.
Read more at Royal Netherlands Institute for Sea Research
Image: Florida beach erosion - photo by Paul Brennan (Credit: Photo by Paul Brennan)
