Walker R. Rayburn Jr.: Sea-level rise affecting swamps

In response to the June 23 letter “Sea-level rise”: Any inch of sea-level rise may not seem important. However this last inch is. A threshold was crossed that completely changed the swamps on the north side of Albemarle Sound.

I have been studying wetlands in North Carolina for 50 years. I retired as a biologist monitoring mosquitoes for the counties north of the sound.

In 2009 the water rose high enough to change the swamp from having temporary pools to those permanently flooded if only by a fraction of an inch. That year the dominant mosquito species changed from those reproducing in temporary pools to species that can reproduce only in permanent pools. The new relative abundance condition has persisted to this year.

Not only have the mosquito species changed, but the lack of oxygen in the soil has caused several of the tree species in the swamp to die. Dying from the roots up takes several years, but we can see it progressing. Within 10 years our beautiful swamp forests will be grassy marshes.

Salt water intrusion into canals and onto cropland south of the sound has been a problem for several decades.

This story was originally published June 29, 2015 at 6:01 PM with the headline "Walker R. Rayburn Jr.: Sea-level rise affecting swamps."