Dr. John Pearse has been tracking the number of Harbor Seals on the western beach at the Hopkins Marine Station (HMS) since Fall 2003. HMS recently posted 30-day averages of his nearly daily counts at: https://seaside.stanford.edu/
Dr. Pearse notes some interesting trends, such as, “The consistent dip in the fall of harbor seals and the downward trend after about 2010. Can’t help but wonder where the seals go in the fall.”
He also collected information about Elephant Seals and Southern Sea Otters, which also use the western beach at HMS.
Dr. Pearse also said, “I also have notes on time of day, tide height, sea conditions, and weather and visibility, as well as the number of people on the fence and kayaks in the water. However, it will take a lot of work to sort those out with respect to the fluctuations in animal numbers. The only pattern that I think I detect is that the heavier the surge the higher the numbers — and that is not a strong relationship if it occurs at all.”
Pearse is Professor Emeritus, Department of Ecology and Evolutionary Biology at the University of California, Santa Cruz. He is world-renowned for his knowledge of invertebrates and has published over 120 peer-reviewed articles and books since 1962.