|
|
|
 |
 |
 |
 |
 |
Hydrodynamic Influence on the Productivity of Reef Ecosystems
Stephen
Monismith , Civil
& Env. Eng.
G. Shellenbarger, Civil & Env. Eng.
A.
Paytan, Geologic and Env. Sciences
This research project focuses on the role played
by physical forcing, i.e., currents and turbulent
mixing, in determining the way in which coral
reefs maintain high biological productivity despite
the fact that they are generally found in oceanic
regions that are otherwise remarkably unproductive.
The key to this paradox, originally posed by Darwin,
is that reefs may be remarkably efficient at extracting
materials from the adjacent ocean. However, if
this is the case, then the flow of food (nutrients
and plankton) may be limited by the rate at which
food-depleted water in contact with the reef can
be replaced by water with higher concentrations
of food.
To test this hypothesis, simultaneous measurements
of currents, and of phytoplankton (algae) and
nutrient distributions in space and time were
made over the fringing coral reef found at Eilat,
Israel. However, quantifying offshore-onshore
exchanges of fluid is critical yet difficult to
do accurately.
A novel aspect of the work is the use of naturally
occurring radium isotopes derived from groundwater
sources to identify terrestrial nutrient sources
entering from submarine groundwater flows and
as natural markers that the researchers can compute
the rate of exchange of waters over the reef with
the waters of the adjacent Gulf of Aqaba, a branch
of the Red Sea. |
 |
|
 |
|
|
