Mohammed Allie, BBC News:
“I had the privilege of visiting this incredible animal for almost a year. It totally trusted me, lost all fear, it would take me on hunting expeditions and let me into its secret world.
“Octopuses have different personalities, some are quite bold, others very shy, she was in between,” Mr Foster told the BBC, describing how she would come over and greet him when she became accustomed to his visits.
“It is a great privilege to step into that world to learn - not like a mammal - but like a fellow spineless creature in her invertebrate world,” he said.
Mr Foster, an award-winning film-maker of natural history, managed to adapt to the underwater world the tracking techniques he learnt in the Kalahari desert from the San people, widely regarded as being the best trackers in the world.
“It involves a number of things like looking at subtle changes in sand and sand texture to see what animals have been around, looking to see if, for example, there’s been a kill, if a worm has been digging, slime trails, egg casings - there are a multitude of signs underwater.
“Initially I thought it would be impossible to try and track underwater but I was desperate to try and break into this very cryptic world,” he said.
“This crazy idea was in my mind for a long time and then eventually I started seeing the first underwater tracks, that’s when I first thought it could work but I had no idea that I could develop it into such a detailed way understanding of animals underwater.”
It was this understanding that led to Mr Foster uncovering eight new species of shrimp, one of which - Heteromysis Fosteri - has been named after him.
“The whole way I’ve been taught by other humans to live on this planet is completely unsustainable and I’ve also realised that these animals, particularly the phytoplankton, provide the oxygen for every breath I take. They provide the basis for every meal I have.
“They have taught me that all the financial, political and other issues we hear about in the news are inconsequential compared to that natural foundation that holds everything up and we’re chipping away at it,” Mr Foster said.
“We need to nurture it rather than doing the opposite.”