Ocean Dead Zones
Strategies to prevent ocean dead zones
1. Nutrient Management 2. Water drainage management 3. Livestock waste management 4. Cover crops 5. Buffers
Gulf supplies
72% of US harvested shrimp 66% of oysters 16% of commercial fish
Gulf of Mexico
Has one of the largest dead zones in the world
Fish that cannot swim out of dead zones
Worms, mollusks and anemones, and microscopic organisms - bottom dweller fish move up to surface
Algae blooms
a sudden growth in algae that can turn the surface of a lake or pond green
Ocean Dead Zones are created by human
activity but primary nutrient pollution
Hypoxic waters
are a dead zone area in the gulf of Mexico at the mouth of the Mississippi River
Ocean Dead Zones
are areas in various bodies of water with extremely low oxygen concentrations where life suffocates and dies - Can be permanent or return seasonally - Can occur naturally
Oil Spill Aftermath
cleaned up using: 1. Floating blooms 2. Skimmers 3. Chemical dispersants
Eutrophication results in
excessive plant growth and decay causing a severe reduction in species diversity and water quality
Fish and shellfish die
from rapid growth and decay consuming oxygen, especially at lower depths
Mississippi River
goes through 32 US states and two Canadian provinces - Ranks as fourth-longest - 15th largest river by discharge in the world
Restoration riparian wetlands
implication will reduce time
Oil Spill
in the Golf of Mexico caused by BP deepwater horizons ruptured rig - largest offshore oil spill in US history - Released 134 million gallons of oil into the Gulf of Mexico over a period of 87 days
Nutrient enrichment
in the Gulf of Mexico from Miss River
Eutrophication
is an Aquatic system response to addition of artificial natural nutrients.
Nitrates and Phosphates
nutrients linked to eutrophication caused naturally or by humans Example: Untreated sewage and fertilizers from agricultural run-off
Eutrophication and hypoxia
occurs in Canada: 1. Lower St. Lawrence Estuary 2. Lake Winnipeg
Van Meter
reported if nutrient drainage stopped completely it will take 30 yrs to decrease the Gulf of Mexico eutrophication
Largest Dead Zone
was in the Gulf of Mexico measuring 8,776 miles
Black sea area
was revived and recovered due to decrease in agriculture activities and animal farm closures - Nutrient concentration decrease led to drop in dead zone volume
Lakes turn green, yellow, brown or red
when the water becomes cloudy