Jug  Bay  Wetlands  Sanctuary 

Teen Adventure: SAV Monitoring

… so what's the problem?

SAV has been disappearing from the Bay.

  • Historically, up to 600,000 acres of SAV grew along the shoreline of Chesapeake Bay. But by 1978, only 41,000 acres remained.
  • SAV has declined all over the world in densely populated coastal areas.

    Many factors have contributed to the single biggest problem for SAV: a reduction in the amount of light penetrating to the submerged plants.

  • SAV needs at least 15-20% of surface sunlight.

    What's blocking the light?

    Poor Water Clarity:

  • Sediment and other particles in the water
  • Algae in the water
  • Algae on the leaves (epiphytic algae)
  • A very low percentage of sunlight reaching the leaves, so SAV grows poorly or dies.

    What causes too much sediment?

  • Construction
  • Agriculture
  • Dredging operations
  • Natural processes

    What causes too much algae?

  • Nutrients such as nitrogen and phosphorus are needed by all plants to survive and grow.
  • But when excess amounts of these nutrients are introduced into a waterway, algae can experience explosive growth, literally choking off other life forms.
  • This introduction of excess nutrients into waterways, which causes algal "blooms", is called eutrophication.

    Some sources of this nutrient pollution are

  • Sewage and septic runoff
  • Direct land runoff (stormwater drain system)
  • Livestock waste
  • Fertilizer runoff
  • Detergents
  • Industrial wastes
  • Because we are focusing on SAV, we have emphasized that excess nutrient input causes too much algae, which blocks the light, which kills the SAV.

    But eutrophication is even worse than that.

  • As the algae die, the bacteria which feed on them can deplete oxygen levels in the water to the point where it cannot support other life forms which need oxygen, such as fish.
  • Water which is hypoxic (low O2) or anoxic (no O2)

    How We Did It.

    What Did We Find?

    What is SAV?

    Why is SAV important?

    What habitat conditions influence SAV distribution?

    … so what's the problem?

    Why Should I Care About SAV?

    What Can I Do?

    Who Are We?

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