Global Scholars Student-Faculty Research Team on Ocean Acidification
Dr. Tom Arnold (Biology) pioneered Dickinson's inaugural Global
Scholars Honors Program at the Dickinson Brisbane Center, leading an
interdisciplinary team of student-researchers in their
investigation of the causes and effects of ocean
acidification. Students were not only engaged in the field
research and data collection, but they continue to work under
Professor Arnold's direction back on campus in Carlisle, preparing
their findings for publication.
Ocean acidification (OA) has been called "the evil twin" of climate
change. Ignored or unappreciated for decades, this phenomenon
begins with the absorption of atmospheric CO2 by the oceans which
results in changes in ocean chemistry, including a reduction in the
pH of seawater.
The good news is that approximately one-third of CO2 emissions
have been soaked up by the oceans, which has slowed global
warming.
The
bad new is that this CO2 triggers the formation of carbonic
acid, the reduction of seawater pH, the destruction of carbonate
ions required to produce the calcium carbonate skeletons of hard
corals, the shells of oysters, clams, and scallops, and the
coverings of critical species of oxygen-producing
phytoplankton.
A high CO2 / low pH world can cause dramatic reductions in the
growth of corals and certain seaweeds. Some have predicted
that within this century the combination of acidification and
higher sea temperatures will trigger the loss of reefs worldwide.
The growth of certain shellfish species may be affected as
well. For example, the Chesapeake Bay oyster suffers reduced growth
and a thinning of shells at low pH. On the West Coast of the
U.S., several aquaculture facilities struggle to grow shellfish
where once they had been plentiful. Unfortunately, the
effects of OA have been examined for only a few marine species, so
it is difficult to predict how marine communities are likely to
respond to acidification.
The only way to study the potential impacts of OA on marine
species in situ is by using a Free-Ocean-Carbon-Enrichment
(F.O.C.E.) system. Only three operational systems exist--one was
designed at UQ and another was developed in Dr. Arnold's lab here
at Dickinson. F.O.C.E. systems mimic the conditions of climate
change--and in particular the high CO2 /low pH conditions of ocean
acidification--under otherwise natural conditions. The Dickinson
F.O.C.E. system was designed as a portable, near-shore system and
was tested in 2009-2011 in Florida and Maryland (USA). Student
teams use the F.O.C.E. system to investigate further the
impact of OA and to help address what was deemed a high-priority,
critical need by no fewer than five international panels on ocean
acidification.