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The SiteA buoy mounted nutrient analyzer
measuring seawater nutrient
concentrations near aquaculture farms
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Deployment Technique Matters MostMultiple intakes are used at multiple depths, exposed to
the rapidly growing tropical seawater conditions, while
the instrument is protected from fouling in the buoy
The proof is in the data
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Using the same instrument for multiple depths gives greater detail than using separate instruments at each depth*
* Applies regardless of the brand or manufacturer of the instrument
Instrument Accuracy
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If separate instruments were used, it is impossible to resolve differences to anything smaller than the instrument accuracy
Instrument accuracy on NO2 with full
scale range of 1mg/L, specified to be
±5%, or 50 parts per billion (ppb).
Instrument Repeatability
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When using the same instrument, clear and repeatable differences become obvious
Clear and repeatable differences between
the three depths, resolvable to around
3ppb between middle & deep and a
further 5ppm between middle and shallow
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50ppbResolve differences to the instrument repeatability rather than the absolute accuracy of the instrument
Understand why
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When being able to trust small differences, more complicated processes can be understood
What appears to be
“noise” is actually
related to tidal cycles
As the tide
goes down,
nutrients
go up
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Learn the complete picture
• The nearby aquaculture feeding practices were causing
elevated nutrient levels near the sea floor*
• The outgoing tide was flushing nutrients past the site
* Outcome that could not be understood unless a profiling sampling system was used instead of in-situ instruments
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Coastal Water QualityThere are many other advantages in the way we deploy
coastal instruments. Email today to start the
conversation.
