Fog and ice often come together, unfortunately. When the sun is shining and/or southerly winds bring warmer air to the pack ice, the air gets cooled down by the ice. And as colder air can hold less water vapour as warm air. The water condensates and fog appears. This fog is often very thin, from the top deck you can see the blue sky overhead, but it does decrease visibility at ground level and with that the chance of finding wildlife.
This thin fog sometimes does show a nice atmospheric phenomenon: the fog bow. This colourless rainbow is can be seen when the water droplets are too small to refract the light to create the colours in the rainbow but the bow is still made. Nice for us to see, but hopefully not too long as we would like to see other things as well.