in polar bear fat, DHA content is among the highest among mammals

polar bears live in extreme cold with barely any UV for months.

the DHA in their fat acts as a semiconductor antenna collecting whatever photons are available and converting them to DC current

Natural selection solved the low-light problem with a better semiconductor, not a bigger one

this is why marine mammals thrive in cold dark environments.

DHA compensates for low light by being a better collector

and you live at the 45th parallel, never eat seafood and wonder why winter destroys you