What is the meaning of dreams of being in the ocean and/or fear of possible sharks?

I had a dream last night where I was swimming/wading in the ocean with several other people. It was dark and gloomy and foggy outside (but not necessarily night time) and my sister was close by too. We were a little apprehensive about the possible sharks looming around, plus at one point we saw seals in the water. Any suggestions what this means?