Counting Gray Whales: Why Different Results?
Michael H. Smith, Project
Director of Gray Whales Count
Mr. Smith with his binoculars at Coal Oil Point ("Counter Point")

Q. What can't the counts tell us? What can they tell us?

A. Neither Gray Whales Count nor the ACS-LA Census are capable of estimating the size of the overall migration. Both are capable only of estimating the number of whales that use the respective "corridors" by each of our survey stations. As such, the data from Gray Whales Count in Goleta, California, reflect what is happening locally. Since, however, we are all sampling, and we are in a sense connected as a network, we (along with other stations such as Piedras Blancas) can together provide a bigger picture of what is going on for the greater migration.

Q. Why are numbers so different at the California counting sites?

A. The numbers at all the counting sites will be different. Some reasons are: the hours and days in the survey, the weather and sea conditions, the ability of the observers, and most importantly, the number of whales going by the survey area that could potentially be counted. (Whales travel around the clock and in all types of weather, so not all whales are seen!)

Q. Why don't you count the southbound migration from Coal Oil Point?

A. Most of the southbound migration does not go by Coal Oil Point. Most of the whales go from Point Conception out through the Channel Islands. The whales are riding the very strong California Current in a more direct line to Mexico. Any whales that do go by Coal Oil Point are mostly juveniles who are, perhaps, following the route taught to them by their mothers. T
he ACS-LA site (#6 on the globe showing Journey North's observation posts)) is a much better place for seeing the southbound migration.


1. census station at Coal Point
2. Point Conception

Q. What makes Coal Oil Point a good place for counting northbound whales?

A. We do have many mature whales coming through the nearshore of the Channel. As they head north, they are riding a small gyre-current created by the passing California Current. The large majority of mothers and calves choose the nearshore corridor through the Santa Barbara Channel.

Q. How do counts from different places help scientists find answers?

A. Our location in the Channel puts us in a good position to provide a check for Wayne Perryman's counting station at Piedras Blancas (#8 on the globe showing Journey North's observation posts). Mr. Perryman's count estimates successful calf production for NOAA. Mr. Perryman sees more mothers and babies than we do because of his location. He also spends more hours per day counting. However, our sampled numbers should graph in a similar manner. for example, in 2007, we all graphed similar pictures of the decline in calves; and so, with our combined samples, we were able to state with confidence that there was, indeed, a problem with low calf numbers. We look forward to seeing what each year's counts will reveal!