1. CHARACTERISTICS OF AN
ESTUARY
BY: JANET C. BESAGAS

3. Three main characteristics of San
Miguel Bay
1. High sediment
output resulting in
soft, muddy
substrates.
Beach on San Miguel
Island

4. 2. High nutrient inputs
resulting in high
primary, secondary,
and tertiary
productivity. The
watershed of San
Miguel Bay measures
3,320 sq. km.
Bicol river watershed

5. 3. Highly variable salinity
gradients resulting in
floral and faunal
assemblages which are
tolerant of wide
fluctuations in salinity.

6. OTHER CHARACTERISTICS
OF AN ESTUARY

7. Estuarine Circulation

8. In Alabama, 85 species of fish
are considered to be marine or
estuarine

9. • Estuaries and coastal waters provide
essential habitat for over 75% of the
commercial fish catch and 80-90% of the
recreational catch of fish.
• Estuaries are among the most productive
natural systems on Earth due to the mixing of
nutrients from land and sea.

10. Estuaries are becoming
more and more polluted.
Now there is a project going
on trying to save our
estuaries to keep them
cleaner and healthier.