There is large interannual and geographical variation in the distribution and abundance of phytoplankton species with in the area. However, the main pattern in the annual succession pattern is rather stabile despite variability in abiotic factors (e.g. temperature) between the years. The starting point of the spring bloom will vary between years, a variation that in large degree is controlled by the onset of necessary stability of the water column for bloom formation. Large blooms, with exception of the spring and autumn situation, might occur some years along the coast or in the open waters of the Barents Sea.