A.   An area of hypoxia or where there is too little oxygen in the water causing organisms to die

B.   An area where all the fish have been caught

C.   A burial ground for dead animals no longer useful on a farm

A.   10,000 square kilometers

B.   20,000 square kilometers

C.   1,000 square kilometers

D.   100,000 square kilometers

E.   40,000 square kilometers

A.   The spill of chemicals that block plant growth.

B.   The over enrichment of the sea by nutrients that allow plants to grow.

C.   A drop in the salinity of the ocean.

D.   A rapid rise in the pH of water.

A.   Rising fossil fuel use, bykill, and the construction of sewage systems drive excess nitrogen into coastal waters.

B.   Nuclear energy use, mass breeding of food animals and intensive farming, and the construction of sewage systems drive excess nitrogen into coastal waters.

C.   Rising fossil fuel use, mass breeding of food animals and intensive farming, and bykill.

D.   Overfishing, bykill, and thermo luminescience.

E.   Rising fossil fuel use, mass breeding of food animals and intensive farming, and the construction of sewage systems drive excess nitrogen into coastal waters.

A.   No

B.   Not yet but models predict it will be in 50-100 years

C.   Yes

A.   Diatoms are toxic and they destroy all food webs

B.   Its causing the diatoms to outnumbered other ocean creatures

C.   This is a problem because diatoms become outnumbered by small or less digestible types of species and gelatinous organism reduce the efficiency of the food chain causing fish stocks to drop.

D.   Gelatinous organisms eat all the diatoms

A.   It occurs when plankton die and thus all who need them die

B.   It occurs when fishing vessels catch all members of one species and then catch all members of another.

C.   An imbalance of the food chain worsened by immense fishing. The hunting of a top predator results in rising numbers of smaller fish eating more zooplankton and leading to more phytoplankton.

D.   An imbalance of the food chain worsened by immense fishing. The hunting of a top predator results in rising numbers of zooplankton and less phytoplankton.

A.   3 days

B.   40 days

C.   20 days

D.   7 days

E.   Its entire life

A.   Nothing can be done to restore the area

B.   Dead zones can be restored by adding nutrients from the land to the water.

C.   Dead zones can be restored by reducing the nutrient delivery from nearby lands

A.   All of these

B.   River catchments that store high amounts of nutrients dissolved  ingroundwater or trapped in soils

C.   Eutrophication

D.   Dearth of nearby healthy populations of marine plants & animals that can provide the seed stock

A.   Governments have to reduce the intensity of commercial fishing activities.

B.   Landmark iniatives to maintain runoff nutrients also need to be put into effect. 

C.   Comprehensive plans must be in place in order to prevent nitrogen and phosphorus from getting into the water. 

D.   Governments must make sure economic development does not lead to resurgence of nutrients into the sea. 

E.   All of these

A.   Mussels filter water but bacterial decomposition consumes as large amount of oxygen. The end result is the mussels collapse from low oxygen.

B.   Mussels eliminate all other animals that can live there.

C.   Mussels use so little oxygen that once the nutrients fall other animals out compete them and cause the mussels to collapse.

D.   Mussels release too many nutrients.

A.   Yes

B.   No