Global warming has started to erode coral reefs, churn up more storms and drive salt water into fresh water sources - such as this threat to the Ganges in India.

Now a new study shows that while fisheries in the northern hemisphere may bear the brunt of the impact environmentally, people in the poorest countries will suffer the most hardship as fish populations decline. Worldwide, more than 2.6 billion people rely on fish for at least 20 percent of their protein intake. 

Two-thirds of the 33 most vulnerable nations are in Africa, where fish accounts for half of all protein intake in many countries. Angola and the Democratic Republic of Congo were most at risk, though Russia stood out ranking third. Peru and Colombia in South America; and Bangladesh, Pakistan and Vietnam in Asia also made the list.

Add this report to the pressures from overfishing - from the hungry demand of Asian and European nations -- and Africa may well be at the leading edge of unsustainable fisheries.

For another perspective check out this video of a lecture by researcher Daniel Pauly, a fisheries biologist who studies populations trends. 

- Samuel Fromartz