Our Backyard WaterwaysOur Backyard Waterways::Predicting a Predicting a

Phytoplankton BloomPhytoplankton Bloom

When is Dinner Served?When is Dinner Served?

Predicting the Spring Predicting the Spring Phytoplankton Bloom in the Phytoplankton Bloom in the

Gulf of MexicoGulf of Mexico

University of New Hampshire Coastal Observing Center

Institute for the Study of Earth, Oceans, and Space

When is Dinner Served?When is Dinner Served?

Users will produce and analyze graphs showing water temperature, salinity, density, and chlorophyll concentration for 2004 at four buoy locations in the Gulf of Maine.

Time required:

About three 45 minute classes

GoalsGoals Explain the ecological importance of phytoplanktonExplain the ecological importance of phytoplankton Describe the components that influence a phytoplankton Describe the components that influence a phytoplankton

bloombloom Interpret satellite images in order to correlate buoy dataInterpret satellite images in order to correlate buoy data Use the scientific process to predict the onset of the Use the scientific process to predict the onset of the

spring bloom based on background dataspring bloom based on background data Download and analyze graphs of oceanographic buoy Download and analyze graphs of oceanographic buoy

datadata Identify geographic features in the Gulf of MaineIdentify geographic features in the Gulf of Maine

Case StudyCase Study

Phytoplankton are a Phytoplankton are a main food source in the main food source in the ocean.ocean.

Sustain almost all life in Sustain almost all life in the ocean.the ocean.

Microscopic plantsMicroscopic plants Produce more than half Produce more than half

of Earth’s Oxygen of Earth’s Oxygen supply!supply!

Case StudyCase Study

All plants need sunlight, All plants need sunlight, carbon dioxide, water, carbon dioxide, water, and nutrients to grow.and nutrients to grow.

Sunlight most available Sunlight most available at the water surface.at the water surface.

Chlorophyll-a makes Chlorophyll-a makes them green.them green.

Green blooms can be Green blooms can be detected in satellite detected in satellite images.images.

Case StudyCase Study

Blooms attract the attention of scientists and Blooms attract the attention of scientists and fisheries.fisheries.

Global Carbon CycleGlobal Carbon Cycle: large consumer of : large consumer of carbon dioxide, therefore if reduced it could carbon dioxide, therefore if reduced it could affect our global climate.affect our global climate.

Limiting growth factors: amount of sunlight Limiting growth factors: amount of sunlight and nutrients (nitrate, phosphate, and silicate)and nutrients (nitrate, phosphate, and silicate)

Nutrients found in deeper cold waters are Nutrients found in deeper cold waters are brought to the surface in brought to the surface in upwellingsupwellings in the in the spring.spring.

What causes a bloom?What causes a bloom?

Blooms occur when sunlight and nutrients are readily available to the plants, and they grow and reproduce to a point where they are so dense that their presence changes the color of the water in which they live.

North Atlantic bloomNorth Atlantic bloom

Movie

What causes a bloom?What causes a bloom?

May last a few days to several weeks May be small or cover hundreds of square

kilometers. Scientists have not yet been able to predict the

exact date and location of a phytoplankton bloom before it occurs, but through the use of satellites, long term moored buoys and monthly oceanographic research cruises we are able to make better educated guesses.

Gulf of MaineGulf of Maine

Scientists study phytoplankton using research vessels, long term moored buoys, and satellite instruments

Depth and Shape of the ocean floor determines upwellings

Gulf of MaineGulf of Maine

Georges Bank and Browns Bank are just two of the large underwater ledges that create a barrier between waters off shore and the inner Gulf of Maine.

Gulf of MaineGulf of Maine Water generally flows in a counterclockwise

direction.

Gulf of MaineGulf of Maine

Cold water from the north, known as the Labrador Current, and warm water from the south, known as the Gulf Stream, are mixed outside the Gulf before entering.

The combination of these consistent currents, the direction of flow, the bathymetry and much more, makes the physical structure of the water column very different at each buoy location.

StratificationStratification

Temperature, salinity, and Temperature, salinity, and density affect the water density affect the water column.column.

As salinity increases, As salinity increases, density also increases.density also increases.

At temperature increases, At temperature increases, density decreases.density decreases.

Salinity Temp.

StratificationStratification

When ocean water becomes separated into layers of similar densities, it is said to be stratified.

The black line also represents the temperature within the layer.

NutrientsNutrients

Concentrations of nutrients in the water column vary depending on the time of year, density of water, how they entered the ocean, and how much mixing has taken place during that season.

Nutrient data is collected from water samples gathered on research vessels

NutrientsNutrients Change with the seasons In general, when nutrients are found near the surface,

they are not plentiful at deeper levels and vice versa. Winter mixing brings nutrients up from below,

concentrating them near the surface. Spring warming creates a surface layer that floats on

top, halting the supply of nutrients brought to the surface.

As spring turns to summer, nutrients in the surface layer are consumed by phytoplankton, reducing nutrient availability at the surface.

NutrientsNutrients

As summer sets in, phytoplankton die and drift to the bottom, taking the nutrients they ingested with them. Surface waters are now left with few nutrients available.

Once autumn sets in with cooler days, a limited amount of vertical mixing brings nutrients up from below.

In winter, heavy winds and plummeting temperatures cause strong mixing again.

BloomsBlooms

Spring brings warmer temperatures and increased sunlight, creating a thermocline that traps nutrients at the ocean surface.

This allows phytoplankton to absorb energy and take in the nutrients they need to photosynthesize and multiply.

As the phytoplankton use up the available nutrients however, they begin to die and drift to the bottom.

Norway Bloom 2003Norway Bloom 2003

GoMOOS BuoysGoMOOS Buoys

Gulf of Maine Ocean Observing SystemGulf of Maine Ocean Observing System 10 buoys in the Gulf of Maine with real-time 10 buoys in the Gulf of Maine with real-time

data availabledata available Maintains 11 more buoysMaintains 11 more buoys

http://www.gomoos.org/

http://www.gomoos.org/

Compare Buoy DataCompare Buoy Data

Graphing & Data Downloads

GraphsGraphs

Create a graph of the following data:Create a graph of the following data:

• Density

• Daily Avg.

• 1/1/04 – 12/31/04

• Buoy B

• Salinity

• Daily Avg.

• 1/1/04 – 12/31/04

• Buoy B

Predicting a BloomPredicting a Bloom

Create Graphs for Buoy E, I, MCreate Graphs for Buoy E, I, M Water TemperatureWater Temperature SalinitySalinity DensityDensity

Buoy M only select these locationsBuoy M only select these locations 1 m, 2 m, 20 m, and 50 m1 m, 2 m, 20 m, and 50 m

12 graphs total12 graphs total

Predicting a BloomPredicting a Bloom

Step 1:Step 1:

Group graphs by Buoy locationGroup graphs by Buoy location

Step 2: Analyze graphs to predict Spring BloomStep 2: Analyze graphs to predict Spring Bloom

How does depth affect the water temperature, How does depth affect the water temperature, density, and salinity?density, and salinity?

What do your density graphs look like during times that the water column is mixed? How do the lines on the density graph change as the water becomes stratified?

Predicting a BloomPredicting a Bloom

Predicting a BloomPredicting a Bloom Knowing that blooms occur when

phytoplankton have ready access to sunlight and nutrients in a floating surface layer, make a prediction of the month or week that a bloom might occur for each buoy location.

Does your predicted bloom date vary by buoy location? Consider where each buoy is located in the Gulf.

Can you explain any difference in predicted bloom dates based on the buoy locations?

Chlorophyll DataChlorophyll Data

Step 3: Checking your predictionStep 3: Checking your prediction Use GoMoos to graph data from Buoy B, E, I, Use GoMoos to graph data from Buoy B, E, I,

and Mand M Chlorophyll / Daily Avg.Chlorophyll / Daily Avg. 1/01/2004 – 12/31/20041/01/2004 – 12/31/2004

How can you use this data to predict a bloom?How can you use this data to predict a bloom? Spikes in the graph indicate high levels of Spikes in the graph indicate high levels of

chlorophyll, and are good indicators of high levels chlorophyll, and are good indicators of high levels of phytoplankton.of phytoplankton.

Chlorophyll DataChlorophyll Data How do the levels of chlorophyll compare at How do the levels of chlorophyll compare at

each Buoy location?each Buoy location?

Buoy M appears to have about 15 times as Buoy M appears to have about 15 times as much chlorophyll as the other locations.much chlorophyll as the other locations.

Ocean buoys are subject to many factors that Ocean buoys are subject to many factors that can alter data collection: boats accidentally can alter data collection: boats accidentally running into buoy, storms, whales…running into buoy, storms, whales…

Also notice that after May 15 the buoy stopped Also notice that after May 15 the buoy stopped recording all data, which may suggest it was recording all data, which may suggest it was taken off-line for repairs!taken off-line for repairs!

Therefore, we should disregard data from this Therefore, we should disregard data from this buoy.buoy.

Chlorophyll DataChlorophyll Data

Using Satellite ImagesUsing Satellite Images

March 22, 2003 April 23, 2003

WebCoast ImagesWebCoast Images

University of New Hampshire: Center for University of New Hampshire: Center for Excellence in Coastal Ocean Observations and Excellence in Coastal Ocean Observations and AnalysisAnalysis http://www.cooa.unh.edu/index.jsphttp://www.cooa.unh.edu/index.jsp

Look in the middle column under Satellite Look in the middle column under Satellite Images: Search and Retrieval ToolImages: Search and Retrieval Tool

When is the bloom?When is the bloom?

April 22,

2004

What about Buoy M?What about Buoy M?

Evidence shown here suggest that Buoy M only reads 2-5 mg chlor-a per cubic meter, and is not at the highest location of phytoplankton density.