When I returned to this particular breakwater this year, I found a whole slew of Cladophora algae piled at the catwalk.
Here’s a BEFORE (last year) and AFTER (this year):

BEFORE

AFTER
and another BEFORE and AFTER:

BEFORE

AFTER
Whoa.
Before: Photographed July 23, 2013
After: Photographed September 17, 2014