Living in the Environment 18th Edition by Tyler Miller,Scott Spoolman

تمرين 12

A fishprint provides a measure of a country's fish harvest in terms of area. The unit of area used in fishprint analysis is the global hectare (gha), a unit weighted to reflect the relative ecological productivity of the area fished. When compared with the fishing area's sustainable biocapacity (its ability to provide a stable supply of fish year after year, expressed in terms of yield per area), its fishprint indicates whether the country's annual fishing harvest is sustainable. The fishprint and biocapacity are calculated using the following formulas:
Fishprint in (gha) = metric tons of fish harvested per year/productivity in metric tons per hectare × weighting factor
Biocapacity in (gha) = sustained yield of fish in metric tons per year/productivity in metric tons per hectare × weighting factor

Based on the graph,
a. What is the current status of the global fisheries with respect to sustainability
b. In what year did the global fishprint begin to exceed the biological capacity of the world's oceans
c. By how much did the global fishprint exceed the biological capacity of the world's oceans in 2000