Thursday, February 26, 2015

Algal Blooms and Fertilizers

Red tides in local beaches has always been a seasonal hindrance to fishing and tourism in any coastal state.  The technical term for "red tide" is harmful algal bloom, or HAB (NOAA).  The blooms are caused by a rapid proliferation of bacteria in water that is rich in nutrients; HABs occur when the algae in the water releases toxins.
Fertilization and red tides have been correlated through many studies going back a decade. Excess fertilizer is lost in runoff, which enter the waterways into the ocean.  The nutrient rich water creates the perfect environment for HABs which have the potential to exhaust the nutrients and deplete the oxygen levels of the surrounding water.  The lack of oxygenated water and toxins released by HABs create "dead zones" in the coastal marine environment.

McGill University researchers have documented a dramatic increase in the spread of cyanobacteria in ponds and lakes across Europe and North America.  Commonly referred to as blue-green algae, the bacteria poses a threat to drinking water; certain species release toxins into their freshwater habitat.  The researchers believe the increase in the cyanobacteria is caused by fertilizer runoff from local agriculture.  The threat posed by this fresh water toxins is more serious than the salt water because HAB contaminations are more readily contained through warnings and recalls, while contaminated drinking water is a more complex issue to deal with.

Posted by Daniel Bonkowski (Group A)

12 comments:

  1. Very interesting and very scary, especially when you realize that this blue-green algae could be potentially dangerous to our drinking water. Have these algae blooms caused dead zones in fresh water habitats?

    David Rains,

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    1. The article did not mention the occurrence of dead zones like those that occur in salt water, but from the limited amount I know about this algae I'd assume that it has similar negative affects on fresh water.
      Posted by Daniel Bonkowski

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  2. Very interesting to see that fertilizer run-off could have such a large-scale effect. Have scientists developed a way to eliminate the algae in the ocean in order to restore the water back to normal, or must it simply run its course?
    -Meghan Harrington

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  3. I've heard of red tides, but never of the blue-green algae in fresh water sources. Are the freshwater algae a problem in many places, or are they more isolated incidents? Also, referring to the algae in oceans, have they found a way to fix this problem? Is there any way to kill the algae without harming essential organisms also present?

    -Carolyn McDonagh

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    1. I looked into solution, and the only thing I could find was spreading clay on the algae. The clay is spread over the surface, then clumps together and drags the algae to the bottom, where it is smothered and dies. I don't think its very common.
      Posted by Daniel Bonkowski

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  4. Going off of Megahns post I'm curious as well as to how red tides are treated. I've always been under the impression that the ocean sort of corrects itself after the algae stop blooming. I'm also curious as to how many ocean sides get HAB.
    The blue green algae issue is something I've never heard of before, but if we have ways of solving the red algae bloom then perhaps we can keep the blue algae in control.

    ~ Mitchel Logan

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  5. Do you know if there are any preventative measures to decrease HAB? I am also curious too if or how they fix the red algae problem. This is interesting I have never heard of blue green algae buts it scary that it can contaminate our drinking water. I wonder too if the fresh water causes the blue green color and salt water causes the red color of the alga.

    -Jazmin Granadeno

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  6. Interesting post! Is fertilizer the only source of the red tides? Also, what steps are being taken to reverse red tides?

    -Amanda Okpoebo

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    1. Atmospheric deposition and naturally occurring nutrient cycles can also cause algal blooms, red tides can be suffocated by spreading clay, but usually they are allowed to run their course.
      Posted by Daniel Bonkowski

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  7. In my experience building aquariums, algae is a nuisance. It was a clear sign that the ecology of your fish tank was off, because an excess of nitrates are in the water. Your description of excess fertilizer is one way to make that happen, but in an aquarium, its often because the waste of fish has no place to go once it's converted into nitrates by bacteria. One solution was to frequently change water to remove excess nitrates, or establish aquatic plants that consume nitrates just like algae does, but is more easily controlled.
    -Patrick O'Loughlin

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  8. I just recently read an article about the bloom of algae and according to them, there are five main causes of the bloom of algae in water bodies, including the ponds. The stable conditions in the water are preferred by blue-green algae and when the water begins to move slower or turns into a pond, the growth of algae is encouraged. Other than that, the light, temperature, nutrients and turbidity are also factors that causes an algae bloom. However, for those pond owners, you can still prevent the growth of algae in your pond by using pond dye for algae control as this type of pond colorant effectively shades the water from UV rays, so that the amount of sunlight that passes through is not significant enough for algae to proliferate.

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