Scottish-based scientists have been involved in a study of how light adversely affects the behaviour of deep sea animals.
Oban's Scottish Association for Marine Science (Sams) were part of a team of Norwegian and UK researchers who carried out the research in the Barents Sea in the Arctic Ocean.
Part of the study involved the scientists switching off all the lights on their ship.
They then used a "super sensitive light sensor" developed at Sams and echo sounders to detect the presence of organisms, including tiny zooplankton to fish.
These creatures reacted to even the smallest detection of light, often moving away from the source.
Light dictates how marine organisms behave, acting as a prompt for when to move through different depths of water to find food and avoid predators.
Sams said it hoped the research would allow scientists to better predict how an increase in light penetrating the Arctic Ocean - a result of climate change affecting sea ice - will impact on marine life.
Prof Finlo Cottier, a Sams scientist, said: "During the polar night, marine organisms respond to the faintest of natural light during months of darkness.
"We therefore believed that introducing artificial light from a ship or even a head torch might not give an accurate sample of what is happening down there.
"Switching off the lights gave us a much clearer picture of natural behaviours in the ocean."
The team recorded creatures 200 metres (656ft) down reacting to artificial light.
Dr Phil Anderson, another Sams scientist, said: "Even the smallest detection of light was enough to make these marine organisms react."
Prof Jorgen Berge, from UiT The Arctic University of Norway, has been investigating the ecology of the polar night for nearly a decade.
He said: "This is another discovery about the responsiveness of organisms to light, in one of the darkest places on the surface of the planet.
"We're slowly understanding how the black box of the polar night functions."
Images are the copyright of Michael O Snyder.