What is This Green Bloom?

NGSS Phenomena: From a satellite, the ocean is seen with swirls of light colors.

NASA Satellite image of the Barents Sea during an algal bloom.

NASA

There are almost always a few species of algae in almost every part of the ocean. After rainfalls in areas where there is a lot of farming, fertilizer that was meant for agriculture is washed into rivers, lakes, and oceans. These extra nutrients and the perfect weather can give microscopic algae exactly what they need to reproduce and take over. They use photosynthesis to create food and one cell is able to divide into two so rapidly, that they can quickly deprive all the water below them of oxygen. In addition, the algae grows on or near the top of the water, blocking light from the lower parts of the water.

NGSS Phenomena: In the shape of a ball, tiny little bony plates are stuck onto each other.

A Coccolithophore - one of the organisms responsible for the green bloom in the images above and below.

Richard Lampitt, Jeremy Young, The Natural History Museum, London

Without oxygen or light, many living things below the surface of the water die and this releases additional nutrients into the water to help the algae grow even more. Algae cannot live for long in this environment, so they’ll soon die and sink to the bottom of the sea. Bacteria break them down and use up any oxygen that was stored in the algae’s bodies in the process, which leaves very little for other living things. The next year, if everything is just right, the cycle starts again.

NGSS Phenomena: hundreds of dead fish float to the top of the water.

Fish floating dead in the water, showing the results of lack of oxygen in the Chesapeake Bay in 1973.

This happens all over the world every year in many places, where water flows away from agriculture, but let’s look at one particularly big example. Just north of the boundary between Canada and the U.S. is a body of water called the Strait of Georgia that leads out into the Pacific Ocean. In 2016, a NASA satellite caught a time-lapse of a green haze that covered hundreds of miles of water in a matter of days.

NGSS Phenomena: A time-lapse of a large body of water with swirls of lighter colors appearing and moving around over time to cover a very large area.

Timelapse of the Strait of Georgia from Aug 15 to Aug 24 in 2016

NASA Worldview

1. Two genetic factors that influence this phenomenon are that reproduce and require in water than many other living things.

Drag the answers below into the grey placeholders above

sexually

algae

a smaller amount of oxygen

larger amounts of oxygen

on the surface of the water

with agricultural runoff

asexually

small amounts of nutrients

blooms

all over the world

2. What statement shows the best evidence that environmental factors contribute to this phenomenon?

Algal blooms are commonly found in waters where there has been runoff from agricultural lands.
Algae blooms occur every year in many parts of the world and can bee seen from space.
Deprived of light and oxygen, many living things below the surface of the water die.
Scientists are still debating the function of Coccolithophores hard exterior scales.

3. What environmental and genetic factors influence the growth of algae in this phenomenon?

4. Choose the reasoning that best supports the following statement:

“Algal blooms are the result of both environmental and genetic factors and this leads to the death of many living things in the sea.”

There is evidence that shows a link between algal blooms and low levels of oxygen in the water, which can lead to an environment that is difficult for other organisms to survive.
Bacteria break down dead algae and use up all remaining oxygen in the ocean, which deprives living things the oxygen they need to survive and leads to algal blooms.
Human pollution can drive growth in algae, which have the ability to reproduce very quickly and deprive the water of oxygen and this leads to the death of many living things in the ocean.
Every year, human pollution is washed down into the ocean with the rains and this is toxic to the living things in the ocean, which causes many of them to die.

5. What scientific explanation can be given for this phenomenon?

6. One of your classmates makes the following statement about the growth of algal blooms:

“There are a lot of environmental factors that contribute to the growth of algal blooms, but no genetic factors.”

Evaluate their statement and use evidence to support your evaluation.

7. Based on the information described here, does it seem reasonable to conclude that all algal blooms are as large as the one in the Strait of Georgia in 2016? Use evidence from the article or your experience to support your claim.

8. Create a CER statement that scientifically answers this question:

What genetic and environmental factors caused algae to grow this fast?

9. Using the resources provided, explain one environmental and one genetic factor that influences the growth of algae in this phenomenon? In this scenario, is “rapid algae growth” considered a cause or an effect and why?

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This matching question aligns to the following standards

LS1.B: Growth and Development of Organisms
MS-LS1-5
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