Gray Whales: Why Different Results?
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.
Why are numbers so different at the California counting sites?
Why don't you count the southbound migration from Coal Oil Point?
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!