A diagram of the Rutgers University Marine
Field Station and the LEO-15 Observatory near Tuckerton, New
The Rutgers LEO-15 Observatory off Tuckerton, NJ,
is one of the first coastal observing systems in the world. Ocean
observatories or "observing-systems" are facilities with numerous
instruments for making automated measurements of oceanographic properties.
NOAA's Undersea Research Program's Mid-Atlantic Bight Center (MAB)
at Rutgers University, one of six regional NURP Centers, established
a Long-Term Ecosystem Observatory site (LEO-15) on the continental
shelf in the mid-1990s with the engineering support of Woods Hole
Oceanographic Institution (WHOI). LEO-15 is located on a sandy bottom
in about 50 feet (15 meters) of water offshore from the Rutgers
University Marine Field Station near Tuckerton, New Jersey. LEO-15
is a very dynamic area with periodic upward movement of deep water
(or "upwelling") to the surface driven by southwesterly winds. Such
"upwelling" is a common feature of the Mid-Atlantic coast and is
partly responsible the high abundance of plankton.
A photo of a LEO-15 Node out of the water
on the dock showing "guest ports" and other connections.
LEO-15 has become a major center for coastal research
and has also provided important public and educational outreach
to an increasingly large community (http://www.thecoolroom.org/).
LEO-15 utilizes two "nodes" anchored to the bottom that are connected
to the shore-based control center by cables providing power and
communication. These nodes have "guest ports" for plugging in additional
instruments. The observation network provides information on the
temperature, salinity, and other properties of the seawater on command.
During special experiments, sampling at LEO-15 uses real-time data
from these nodes and an array of satellites, meteorological sensors,
underwater vehicles, and other instruments.
One of the most exciting instruments to use the LEO-15
guest ports is the FlowCytobot, an instrument for observing the
smallest components of the "phytoplankton" or plant plankton that
are the "grass" of the sea and the basis of the marine food chain.
This instrument was developed by plankton biologists Robert Olson
and Heidi Sosik at the Woods Hole Oceanographic Institution. Using
a laser, this instrument measures light scattering and fluorescence
of microscopic plankton cells that are less than 1/10,000 of an
inch in diameter.
A photo of the FlowCytobot
and a diagram showing how it is anchored to the bottom and
connected to the LEO-15 node. Seawater is sampled through
the sample inlet at about 16 feet (5 meters) depth.
An example of measurements
from the FlowCytobot at LEO-15 during a 3-day period in late
October 2000. Samples from a depth of 16 feet (5 meters) were
analyzed by the instrument every 5 minutes. The red and green
lines show the results for two different types of phytoplankton.
Panels B and C show phytoplankton properties that vary regularly
from day to night.
The FlowCytobot is connected to the LEO-15 observatory
through a guest port, which supplies power and allows the instrument
to communicate with the laboratory on shore. The instrument is anchored
to the bottom by divers and samples seawater through a hose that
is suspended at a depth of about 16 feet (5 meters).
The FlowCytobot can be controlled using the internet,
and the results can be observed the same way. It can make continuous
measurements for weeks at a time without operator attention. It
is very sensitive and can detect even the smallest phytoplankton
in coastal waters.
In the future, instruments like this may help us to
find "red tides" or determine the effects of coastal runoff or pollution
on the plankton. The information will be useful to coastal ocean
managers as well as scientists. This instrument offers a new perspective
on marine ecosystem monitoring, with the potential for high-resolution,
continuous measurements over long time periods.