Climate change impact on commercial fisheries may increase int'l tensions

International tensions will likely increase as global marine biodiversity ranges shift as a result of climate change, sending commercially important fisheries outside of a country's own, or into neighboring, exclusive economic zones.

Wide-ranging international climate assessments have confirmed global biodiversity is changing in response to shifts in regional climate conditions, with the most impacted species to date occurring solely in the most sensitive environmental systems -- the poles and high altitude regions.

But, when those species are commercially important, such as the Scottish Mackerel which is now starting to turn up in Atlantic waters, those small shifts in ranges can cause some degree of international friction, Scottish Association of Marine Studies Professor Mike Burrows told Xinhua in an online media briefing from Hobart on Wednesday.

"It emphasises the need to manage those sorts of resources at larger scales than in simple country exclusive economic zones," Burrows said.

International law allows rival flagged vessels to commercially fish outside a country's exclusive economic zone, which has marine ecologists concerned a lack of fisheries management will lead to a depletion of fish stocks.

Areas of friction are likely to be around the Equator, the North Sea and the northern Pacific where a high degree of velocity - or a high degree of species range change - will occur if sea temperatures continue to rise from human-induced climate change.

However it should also be noted there are also commercially relevant areas that will still see a big temperature change yet will not experience a high degree of velocity due to a sharp temperature differentials where the warm water meets the cold.

The impact would only require species to a short distance to match their temperature needs, keeping them within, potentially, the country's exclusive economic zone and thereby stay where they can be managed, Burrows said.

Australian scientists have previously proposed the worlds oceans be closed to commercial fishing, limiting fishing only to the EEZ's that extend up to 200 nautical miles from a country's coastline.

The controversial move would protect current commercial fish stocks and drastically reduce over-fishing in open waters, while being more equitable and economically and environmentally sensible. Endit