Reviving Dead Zone Quiz Black Sea

A  Yes

B  No

A  Mussels eliminate all other animals that can live there.

B  Mussels release too many nutrients.

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

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

A  All of these

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

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

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

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

A  Eutrophication

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

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

D  All of these

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  3 days

B  40 days

C  20 days

D  7 days

E  Its entire life

A  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.

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

A  Its causing the diatoms to outnumbered other ocean creatures

B  Gelatinous organisms eat all the diatoms

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  Diatoms are toxic and they destroy all food webs

A  No

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

C  Yes

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

D  Overfishing, bykill, and thermo luminescience.

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

A  A rapid rise in the pH of water.

B  A drop in the salinity of the ocean.

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

D  The spill of chemicals that block plant growth.

A  10,000 square kilometers

B  40,000 square kilometers

C  1,000 square kilometers

D  100,000 square kilometers

E  20,000 square kilometers

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