warning: date(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone. in /home/drupal/drupal/sites/udel.edu.environmentalportal/themes/enviro-theme/ud-footer.php on line 7.

Return of the native

April 10, 2014--Delaware’s native mud crabs were on the verge of being completely edged out by invasive Asian shore crabs 10 years ago.

Today, new research shows that the tables have unexpectedly turned.

“I was shocked,” said Charles Epifanio, a scientist in the University of Delaware’s College of Earth, Ocean, and Environment whose lab started researching Asian shore crabs with support from Delaware Sea Grant a few years after they first appeared in Delaware Bay in 1988. “When this crab arrived here and took over the rocky intertidal habitat, it was remarkable. It wasn’t gradual. It exploded.”

By 2001, two of the three native species of mud crabs in that habitat were gone, replaced by Asian shore crabs. The invaders established such a stronghold that researchers assumed the trend would continue and did not resume population counts until a follow-up project by a summer intern in 2011 to see whether there were any changes.