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HUMAN IMPACT on NATURAL FLUIDS SYSTEMS. WHAT IS BALLAST?. BALLAST. Ballast: added weight placed in a ship’s hull to give it buoyancy and stability when it is empty. What can function as ballast?. BALLAST.
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BALLAST • Ballast: added weight placed in a ship’s hull to give it buoyancy and stability when it is empty. • What can function as ballast?
BALLAST • Ballast: added weight placed in a ship’s hull to give it buoyancy and stability when it is empty. • What can function as ballast? Many things! Ex: water or sand
BUT...BALLAST PROBLEMS EXIST! • When water is used and transported around the world, it can pose a variety of environmental risks, including the introduction of exotic species. • HOW?
ZEBRA MUSSELS TAKEOVER! • Zebra mussels are an exotic species that quickly multiplied in the Great Lakes. The two main reasons: • 1) They have few natural predators • 2) They found conditions in the Great Lakes favourable • This takeover is considered both a curse & a blessing
Queen’s Anne’s Lace TAKEOVER! • Came across the ocean in sack of grain • Pastures, hay fields, grass fields, xmas tree fams • Can survive drought • mildly toxic
Purple Loosestrife TAKEOVER • Aggressive invader that was brought in North America with the settlers in early 1800s
Moose TAKEOVER! • Moose population in Newfoundland: • 1904: 4
Moose TAKEOVER! • Moose population in Newfoundland: • 1904: 4 (introduced in NB) • 2010: 150 000
VIDEO (Michigan U) • http://www.youtube.com/watch?v=MyfedJYPJ4Y
BALLAST: DEBATE • ZEBRA MUSSELS - Beneficial or harmful?