What is an average number of dead seabirds and marine mammals?
This is the main objective of the Beach COMBERS project, to document the average trend in deposition rate (number per kilometer surveyed). The deposition rate is dependent upon many factors including wind, swell, tide, the orientation the beach, beach width, and time of year. The time of year has a big influence on the number of birds and mammals washing in on beaches. During the winter, November – February, deposition of seabirds is low (1-2 per km) due to beach scour and lower densities of birds found nearshore. The number of beached birds (3-6 birds per km) increases during spring and summer with increased numbers of migrating birds and less scour of the beaches. Fewer marine mammals than seabirds wash up on beaches; an average of less than 1 mammal per km comes in each month. When we have recorded an increase in the deposition rate of marine mammals, we have found it to be associated with a harmful algal bloom (a.k.a. red tide, domoic acid) or starvation due to the El Niño phenomen
