Sea Nettles, Estuaries, and Riparian Buffers

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Sea Nettles, Estuaries, and Riparian Buffers

• By the MATES QuickSCience Team

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Estuaries

• Estuaries are a habitat where saltwater and
  freshwater mix, creating a habitat that is ideal
  for life.
• Estuaries are also where many problems occur,
  including the presence of sea nettles
• Can you name the estuary closest to us?

http//www.davenewbould.co.uk/posters-gallery/imag
es/Sunlight20on20the20Mawddach20Estuary.jpg
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What Are Sea Nettles?

• Sea Nettles are jellyfish about 10 cm in diameter
  and 1 meter in length.
• They prefer waters with lower salinities, which
  means that they love brackish estuaries.
• They are white in color, but in salty waters turn
  a reddish color.
• Have you ever seen a sea nettle?

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Problems Sea Nettles Pose

• Sea Nettles are considered annoying to many
  people because they are a species of jellyfish
  that sting.
• They sting by using stinging cells called
  cnidocytes. Each cell has a trigger and barb,
  which is called a nematocyst.
• When something comes into contact with a
  cnidocyte, it releases its nematocyst. The
  nematocyst imbeds itself into its target and
  releases venom.
• To the small creatures it feeds on, the sting is
  often lethal, but to humans, it is more of a
  painful annoyance.

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Food Chain

• Nutrient runoff from non-point source pollution
  adds nitrogen and phosphorus to the water.
• Bacteria feed off of the nutrients.
• Zooplankton, like copepods, eat the bacteria.
• Comb jellies eat the zooplankton.
• The sea nettles consume both the zooplankton and
  comb jellies.
• Thus, non-point source pollution leads to an
  increase in sea nettle populations

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But how do we fix it?

• The most effective way to control sea nettle
  populations is to prohibit excess nutrients from
  entering the system.
• This prevention can be done through riparian
  buffers.

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Riparian Buffers

• Riparian buffers are plants and shrubs planted
  along the edge of a body of water.
• The plants remove the nutrients from the runoff
  before they infiltrate the water.
• Thus, without the starting nutrients, the
  conditions of the water wont be as favorable to
  support sea nettle life.

http//www.dof.virginia.gov/rfb/images/rfb-riparia
n-buffer-classic-photo.jpg
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Human Impacts

• Agricultural and residential fertilizer,
  livestock, and sewerage systems add many
  nutrients into water via runoff.
• The runoff causes eutrophication.
• Aside from attracting sea nettles, the
  eutrophication process has other negative effects.

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Death

• During eutrophication, algal blooms are common.
• The blooms cut off light from reaching SAV
  (submerged aquatic vegetation)
• Thus, the SAV dies.

http//www.underwater.com.au/content/5203/sea_gras
s.jpg
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Bacteria

• The dead plants cause bacteria to multiply in
  order to carry out decomposition.
• The bacteria consumes oxygen, and diminishes the
  supply required by other species to respirate.
• The other species die off.

http//www.flmnh.ufl.edu/fish/southflorida/evergla
des/marshes/images/brooksilverside2.JPG
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After Death

• When eutrophication is in the later stages, the
  water system that was an estuary now becomes
  swamp-like and boggy.
• Less people visit the area, naturally decreasing
  tourism.
• The lack of tourism causes a decreased economy.
• This situation is easily preventable with the
  utilization of riparian buffers.

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References

• http//www.mdsg.umd.edu/MarineNotes/Jul-Aug94/side
  1.html
• http//www.seakayak.ws/kayak/kayak.nsf/NavigationL
  ist/NT00010632
• http//www.cblad.state.va.us/Shorelands/ripfor.htm