One of Portugal's prize industries, sardine fishing, is reportedly under threat because of climate change.

As world leaders in Paris debate the effect global warming is having on the Earth and what to do about it, footage has emerged from Porto in northwest Portugal illustrating the very real impact climate change can have on certain industries.

According to reports, prized fish catches in the region have dropped by more than 150 million tonnes since the 1980s and scientists say declines in sardine stocks in Portuguese waters is mainly down to climate change and problems with phytoplankton.

This video shows fisherman unloading sardines from their trawler at Matosinhos near Porto.

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Since the early 1980s, when they landed just over 200 million tonnes (metric) of the prized fish, the annual catch is now well under 50 million tonnes and the graph shows a steady decline since times 80s. Scientists here say that the massive decline in sardine stocks in Portuguese waters is due to problems connected with phytoplankton and climate change. Here fishermen unload sardines from their trawler at Matosinhos near Porto in Portugal. One of several clips for a news feature.