September 2015 Field Report
This weekend we visited the Gulf of the Farallones twice, with each day providing unique and memorable experiences. Saturday we lead a University of San Francisco ecosystems class out into the Gulf of the Farallones National Marine Sanctuary.
These field courses introduce students to marine ecosystems, marine life and management challenges for both. Starting with estuarine ecosystems we move out into the open ocean or the pelagic ecosystem. With the new App Spotter Pro, developed by Conserve iO, we record the vessel’s track in real time and add observations of marine mammals, providing data for resource managers and scientists.
Saturday we had clear sunny skies with a residual swell and winds building behind the passing cold front. After seeing harbor seals and harbor porpoises, we discussed plate tectonics and the unique geology of this juncture between the Pacific, North American and the former Farallon Plate. We were fortunate to have two members of The Marine Mammal Center in Marin who informed us of issues facing the pinnipeds (seals and sea lions) including starvation and domoic acid poisoning.
Heading north up the coast we observed two Bottlenose dolphins and a Humpback whale, surrounded by shearwaters and murres all feasting on the anchovies. We conducted oceanographic measurements, comparing salinity, dissolved oxygen, pH, turbidity and other parameters for comparison inside and outside the Bay, as well as plankton tows to identify the base of the food chain.
Being on the water in the National Marine Sanctuary, and our California Marine Protected Areas helps the students understand the importance of marine ecosystems as well as management issues. We also learned the fisherman’s perspective on marine management and marine protection regulations from Captain James Robertson, and that protection comes at a cost to humans making a livelihood on the ocean. Scores of salmon boats fished among the feeding whales with several close encounters observed. We spotted the same humpback whales we have been observing over the past month, both with significant scarring from a ship strike or propellor damage. The locations we record will help determine threats to these whales from the busy shipping lane nearby. While collecting data and eating lunch in the warm calm of Drakes bay, we experienced the highlight of the trip with a rare sighting of a N. Pacific Minke Whale Balaenoptera acutorostrata. The second smallest of the rorqual or baleen whales at 24 feet long, the whale furtively surfaced a few times before swimming off. Looking much like a shrunken down version of their cousin the Blue Whale, Minke’s are still hunted by the Japanese in the Antarctic for “scientific ” purposes, despite outcry and protest against this violation of the Marine Mammal Protection Act.
Sunday the fog resumed and the winds were light with only a residual swell, making the trip across the Gulf quick and relatively smooth. Fisherman’s Bay was loaded with sea lions (California and the larger golden Stellar’s) as well as Northern Fur Seals. The water measured at a record high of 65 degrees F which the brown sea nettles appear to thrive in, but not the krill so important to many forms of marine life from the tiny Cassin’s Auklet to the mighty Blue Whale. Cruising by the shark cage-diving boat we were informed that two predation events (not shark attacks!) had occurred last week near the island.
Biologists with Point Blue (formerly Point Reyes Bird Observatory) keep watch from the old lighthouse, recording the bird and pinniped population, as well as people who enter the Sanctuary waters near the island. They have also resumed the white shark observation program, recording predations.
The Sanctuary regulations require mariners to stay 100 yards away from the islands and outlying rocks to avoid disturbing nesting and breeding seabirds. State regulations ban fishing south of SE Farallon Island, middle rock and North Farallon Islands. We headed uphill in the light wind and visited Point Reyes and Drakes Bay where another haul out of elephant seals exists. The exterior edge of Point Reyes is also a state marine protected areas with a 1000 foot exclusion. The protected Drakes Bay, part of the Point Reyes National Seashore, waters swarmed with cormorants, pelicans and shearwaters.
It is always an adventure on these trips out to the island and Gulf, and these trips leave our guests amazed at the diversity and abundance of marine life so close to the city of San Francisco, and gives us a better appreciation of the continued challenges to restore and protect wildlife and ecosystems.
We call the return of the sharks Sharktober, and instead of maligning the white sharks like Shark Week, we are celebrating the shark with a series of education, talks and film events. We will be leading several marine education trips out into the Sanctuary, taking observations, collecting data and learning about sharks, as well as watching for whales and other marine life.
California Harbor Seal
California Sea Lion
Stellar’s Sea Lion
Northern Fur Seal
Northern Elephant Seal
Bottle Nosed Dolphins
Double Crested Cormorrant
Pink Footed Shearwater
Red Necked Phallarope
Ocean Sun Fish (Mola mola)
Brown Sea Nettle