The full moon rises June 18 at 10:30 am with the summer solstice soon to follow on June 21st. The moon makes it lowest arc across the sky for this summer 'Moon of Good Fishing' for the Tlingit people.
Summer is just around the corner with the return of brown pelicans to the Lighthouse and Drakes Bay; the gopher hunting heron afield at Bear Valley and brush bunnies along roadways.
Scraps of scarlet along roadsides are 'twinberry', a native shrub - "the bracts, as the fruit ripens, turn a rosy red and set off the bug-eyed pair of shining black fruits to perfection' (Roxana Ferris - Flowers of Point Reyes). The pink flowering stage of this plant draws hummingbirds, the fruits are not edible to humans but enjoyed by birds. Plenty of elderberry flowering along roadsides, light yellow clumps of flowers that will become berries by late summer.
Tule elk are calving now; typically the calves may be left resting by themselves while the mother is nearby nourishing herself on fresh grasses and shrubs. Males have their antlers in velvet. In order to remove the velvet, they'll begin scratching and honing the antlers against brush and power poles in the reserve, preparing for late summer battles.
Marin County Parks and Open Space staff host a tidepooling expedition on Friday, June 6th at Agate Beach County Park from 9:00 am to 12 noon. Meet at the end of Overlook and Elm Road in Bolinas for one of the best daylight low tides of the year.
A permit has been issued for a wedding at Limantour Beach (60+ people) on Saturday June 7 from 2:00 pm to 4:00 pm; Expect some congestion in the parking lot in the afternoon.
New artwork on display at the Bear Valley Visitor Center is by Judith Corning, paintings of various scenes around the park.
Expect road closures this Sunday, June 7 in the town of Point Reyes Station; Highway 1 will be closed from approximately 12 noon through 1:00 pm for a local parade; traffic will be diverted onto side streets.
PORE Ocean Update 1.6
White Sharks at Point Reyes National Seashore
Have you ever seen a white shark at Point Reyes? How about one feeding on seal carcasses near the headlands? Would you like to know where and how often white sharks are seen, and what they are usually seen doing? This may be useful information if you dive or surf in open water at PRNS!
Scot Anderson, Ben Becker and Sarah Allen published an article in the January 2008 edition of California Fish and Game on observational sightings of white sharks at Point Reyes National Seashore over 23 years and decoy surveys over 11 years.
A white shark is seen here feeding on a seal just off shore. Photo credit: S. Anderson, 2007.
Where are they seen? Most observations were clustered in three areas: Point Reyes Headlands, McClures Rock, and Tomales Point. White sharks are mostly seen close to shore, in water depths from 5m to 30m. This is likely because they need to keep sight of the surface where they capture their prey.
When are they seen? White sharks are observed at PRNS most frequently in the late summer and fall (August, September, October), which coincides with the seasonal peaks of pinnipeds: California sea lions congregate in the area when males migrate north in the fall, and northern elephant seals juveniles haul out in the fall. When Scot Anderson used decoys to track the frequency of white shark appearances, he found that they were seen approximately once every 6 hours at PRNS! However, this frequency is still less than the frequency in which they are sighted at the Southern Farallon Island: once every 1.9 hours.
What do they eat? At Point Reyes National Seashore, white sharks prey on pinnipeds that congregate onshore and they also scavenge on marine mammal carcasses (especially whales). At the Farallones and Año Nuevo, the pinniped population that white sharks primarily feed on are the northern elephant seals. However, this is not what Scot Anderson found at Point Reyes—the white sharks here seem to be feeding mostly on harbor seals and California sea lions.
White sharks also scavenge off of marine mammal carcasses. Large dead marine mammals such as sperm whales, baleen whales, and northern elephant seas can leave an odor trail that can be carried for many kilometers. White sharks can track these “odor corridors” and follow them to the source. In 2004, when a dead sperm whale drifted to PRNS, as many as four white sharks came to feed on the carcass at one time. A large white shark (~943 kg) can survive up to 45 days after feeding on 30 kg of blubber from a dead cetacean!
Should I be concerned about attacks on humans? There were five human attacks by white sharks at PRNS over 23 years, all of which occurred in the fall season close to shore in water <10 m deep. All the victims survived. Those highest at risk appear to be people who dive for abalone, spearfish, or surf in open water in or near areas where sharks have been sighted, or near seal colonies. Please be careful, and report any white shark attacks to Law Enforcement (464-5170).
If you would like more information, Scot Anderson is currently working as a seasonal with the Trails crew. Contact Bill Michaels at ext. 5157. For electronic copies of the article, contact ben_becker@nps.gov.
__________________
Jessica Luo
Ocean Education and Outreach Coordinator
Pacific Coast Science and Learning Center
Point Reyes National Seashore
Point Reyes Station, CA 94956
jessica_luo@partner.nps.gov
office: (415) 464-5132