December 2, 2020

Hi Everyone,

Hope the holiday season is treating you well! I just wanted to give a quick update on our white shark count for this season. So far, we have identified 29 individuals at the Southeast Farallon Island over 8 trips! Fortunately, this is an above average year for the number of sharks seen per trip. Alternatively, we have made 10 trips out off Point Reyes National Seashore and have only seen 2 individuals. At this location, we didn't see any sharks during the 'peak' of the season (mid-October to mid-November) and only saw our first shark there on November 28th! Usually by this time of the year at this location, we have identified 35-45 individual white sharks, so this lack of sharks is extremely atypical. We do not know the specific reason for this inactivity, but it could be something to do with Orcas, which we have shown can displace white sharks at their seasonal aggregation sites (link to scientific publications at bottom of page). There could be plenty of other possibilities (e.g. La Nina effects, reduced prey availability) but it is difficult to pin-point a specific driver. Hopefully, this is just a 2020 blip in normalcy and things return to a more typical pattern in 2021!

While we have only seen 2 white sharks off Point Reyes, one of those sharks is the most notorious white shark off the west coast of the US. A 16ft male white shark we call "Mr. Burns" has been seen off Point Reyes every single year dating back to 2006, a 15 year record! We have gotten to 'know' this shark as we have interacted with him 61 times over the years! He is readily identified by not only his dorsal fin, but his caudal fin (tail) is unique with a rounded tip on the upper lobe along with a big bite taken out of it (see photo). Additionally, his behavior is familiar to us as he usually investigates the decoy from a more vertical approach, inevitably surprising all of us on the boat and leaving a bite mark or two on the decoy. It is a relief to see him again and at the very least see something 'normal' going on at this location.

Thank you so much for your contribution to this project! This wouldn't have been possible without your generous support!

Paul

Here are the article titles and the links to the publications:

"Killer whales redistribute white shark foraging pressure on seals"
www.nature.com/articles/s41598-019-39356-2

"Predation on a white shark by a killer whale and a possible case of competitive displacement"
https://doi.org/10.1111/j.1748-7692.1999.tb00822.x