As a result there can be a lag between the time the organism was alive and when it was finally transported to the lake and deposited with lake sediment.
Storage on land, prior to transport and later deposition, may not cause an error in the age of the fossil, but there will be a potential mismatch or lag between the age of the fossil and the younger varve in which the fossil was eventually deposited.
During the winter, ice melting is very slow, melt-water streams do not contain much water, and they flow slowly, carrying little material.
During the summer, melting accelerates, melt-water streams flow faster and carry more material.
Varve dating has a greater significance than just for local dating, since frequently there is enough organic material to allow radiocarbon dates to be calculated.