If you have seen images of the fjords you may have noticed that sometimes the water seems to have a green or light blue color This mostly happens during the spring and summer but also in late winter when the freshwater from the mountains fill up the fjord and when all the life in the water wakes up after a long winter. The green color comes from algae named Emiliana Huxleyi. This algae thrives in waters with poor levels of oxygen. It usually blooms up when the water contains a good mix of salt and freshwater and there has been calm weather and little circulation in the water.
The light blue comes from sediments in the freshwater that ends up in the fjords. In some fjords the meltwater mainly comes from glaciers . Glaciers are dirty ice, they contain high levels of dirt, sediments and minerals. When it melts and runs down the mountain the water brings the dirt with it and ends up in the fjord.