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