This new method of sampling was developed for the St. Johns River
in northeast Florida. The Monitoring and Event Response for Harmful
Algal Blooms (MERHAB) program began in 1999 and was a 3-year,
comprehensive study of the lower St. Johns River estuary.
One of the problems with many sampling programs,
including those for harmful algal blooms, is obtaining
representative samples from the area of interest. Often, few data
points are used to represent long time periods or a large
geographic area. The limiting factors are usually resources (time
and personnel) and logistics. Therefore, this type of
"spot-sampling" misses most of the high-frequency variability in
aquatic ecosystems. Many programs are now using continuously
recording instrumentation in the field. These remote sensors allows
specific variables to be measured at short intervals for an
extended period.
We have contracted AMJ
Equipment Corp of Lakeland, Florida, to design and build a platform
with continuously recording instrumentation aboard. The platform is
mounted on a pontoon boat deck, which permits safe and convenient
maintenance and portability among sites. This autonomous platform
will be deployed in the St. Johns River in northeast Florida. A
datalogger controls the sampling intervals of the sensors and
stores the data. A volumetric sampler can collect whole water
samples for analysis in the laboratory. Various sensors are
connected to a flow-through sample system that can draw water from
three depths. Onboard sensors will measure several water column
variables including relative fluorescence, nitrate, phosphate,
water temperature, dissolved oxygen, pH, salinity, and turbidity.
The platform will also have a meteorological package, light sensors
(ambient and underwater), a current meter, and a tide gauge. Data
can be transmitted to a home base via a GOES-satellite or cell
phone.
We are excited about obtaining this type of high-frequency water
quality data that will help us understand the complex interactions
of water quality, harmful algal blooms, and, possibly, fish-disease
events. Also, this is currently the most extensive sensor array on
a remote platform in Florida. The platform is currently in the
water and in the testing stage.
This project is made possible by the National
Aeronautics and Space Administration (NASA) and the Florida Fish and Wildlife Conservation
Commission (FWC).
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