Thought Shrapnel

If scientists have indeed got this correct, it’s an incredible finding.

Prof Duarte led a seven-month circumnavigation of the globe in the Spanish research vessel Hesperides, with a team of scientists collecting echo-soundings of mesopelagic fish.

He says most mesopelagic species tend to feed near the surface at night, and move to deeper layers in the daytime to avoid birds.

They have large eyes to see in the dim light, and also enhanced pressure-sensitivity."

They are able to detect nets from at least five metres and avoid them," he says."

Because the fish are very skilled at avoiding nets, every previous attempt to quantify them in terms of biomass that fishing nets have delivered are very low estimates."

So instead of different nets what we used were acoustics … sonar and echo sounders."