Background: Increased solar ultraviolet radiation resulting from the Antarctic ozone hole has reduced marine primary productivity (phytoplankton) by as much as 15% and has started damaging the DNA of some fish. Illegal, unreported, and unregulated fishing, especially the landing of an estimated five to six times more Patagonian toothfish than the regulated fishery, likely affects the sustainability of the stock. Long-line fishing for toothfish causes a high incidence of seabird mortality.

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: Which time would see more phytoplankton, time A or time B?
Answer: time A

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: Which time would see less phytoplankton, time A or time B?
Answer: time B

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: Would time A see less or more phytoplankton than time B?
Answer: more

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: Would time B see less or more phytoplankton than time A?
Answer: less

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: In which time more fish DNA would be damaged, time A or time B?
Answer: time B

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: In which time less fish DNA would be damaged, time A or time B?
Answer: time A

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: In time A would less or more fish DNA be damaged than in time B?
Answer: less

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: In time B would less or more fish DNA be damaged than in time A?
Answer: more

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: Which time would more likely see reduced marine primary productivity, time A or time B?
Answer: time B

Situation: Bob was studying about Earth's atmosphere. He found that increased depletion of Earth's ozone layer is a relatively new phenomenon. Most scientists would blame the CFC gases for the depletion of ozone layer. In the early twentieth century ozone layer was relatively stable. Bob labeled that time as time A. But in the late twentieth century situation changed with seasonal depletion of ozone layer. He labeled that time as time B.

Question: Which time would less likely see reduced marine primary productivity, time A or time B?
Answer: time A