July 28, 2020 • Field Notes, Ocean Facts
We are pleased to share with you a recording of our most recent Field Notes webinar, ‘The Ecological Importance of the Greater Farallones National Marine Sanctuary: A Virtual Tour of the Farallon Islands and Beyond’ with Oceanic Society naturalist and education specialist Peter Winch, hosted by Chris Biertuempfel, Oceanic Society’s California Programs Manager. Below you can also find a written version of the excellent Q&A that followed Peter’s presentation, as well as travel opportunities, and ways to stay engaged with ocean conservation during this time.
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Questions have been organized beneath subheadings for convenience. Written responses are included below. For questions that were answered live, we have provided the timecode to watch the answer in the webinar recording.
Q: How often do you offer trips?
A: Our trips to the Farallon Islands run (with new COVID-safety protocols) on weekends April-November. Details and dates are here: Farallon Islands Whale Watching
Q: I am lucky enough to have been out to the Farallones with the Oceanic Society three times. I wondered, what is the animal you were most surprised to see?
A: Answered live, see 54:26. Additional answer: Leatherbacks and orcas are always a nice surprise. There are also species of beaked whale, Cuviers, that can be seen out there. It’s quite a rush to see whales and always good to be slower and diligent when identifying them. Sperm whales and pilot whales have also been seen on Oceanic Society trips. So getting a rare species is always a surprise.
Q: When is the peak time for the bird migration?
A: Answered live 51:31. Between May and the beginning of August is the peak time for birds at the islands. The nesting colony disperses pretty quickly after the first of August. But you can still see many birds on the water and around the islands after August 1 too.
Q: When is the best time to see blue whales on a Farallones trip?
A: Historically, blue whales are most abundant in the Greater Farallones National Marine Sanctuary from mid-July through mid-November.
Q: What are the fifteen species of sharks?
A: The following shark species occur within the Greater Farallones National Marine Sanctuary:
1. Common Thresher Shark (Alopias vulpinas) 2. White Shark (Carcharodon carcharias) 3. Bigeye Thresher Shark (Alopias superciliosus) 4. Shortfin Mako Shark (Isurus oxyrinchus) 5. Basking Shark (Cetorhinus maximus) 6. Blue Shark (Prionace glauca) 7. Leopard Shark (Triakis semifasciata) 8. Broadnose Sevengill Shark (Notorynchus cepedianus) 9. Bluntnose Sixgill Shark (Hexanchus griseus) 10. Pacific Spiny Dogfish (Squalus suckleyi) 11. Prickly Shark (Echinorhinus cookei) 12. Pacific Sleeper Shark (Somniosus pacificus) 13. Pacific Angel Shark (Squatina californica) 14. Salmon Shark – (Lamna ditropis) 15. Brown Catshark – (Apristurus brunneus) 16. Swell Shark – (Cephaloscyllium ventriosum) 17. Filetail Catshark – (Parmaturus xaniurus) 18. Brown Smoothhound Shark – (Mustelus henlei) 19. Gray Smoothhound Shark – (Mustelus californicus) 20. Soupfin Shark – (Galeorhinus zyopterus) 21. Oceanic Whitetip Shark – (Carcharhinus longimanus) and 2 years ago a hammerhead shark was recorded in Monterey Bay – none up at the Farallones yet!
Q: How long does it take a turtle to swim from Indonesia to the islands?
A: It takes about a year and a half for a leatherback turtle to travel from Papua, Indonesia to the west coast of the U.S. The longest sea turtle migration ever recorded was a leatherback that swam 12,774 miles (20,558 km) from Indonesia to Oregon over 647 days. Pacific Leatherback Sets Long-Distance Record
Q: Do the leatherback sea turtles only go to that area to feed? That’s a really far distance to go to eat!
A: Answered live, see 55:53.
Q: Does the baby murre have to be able to fly before he can join the father on the water?
A: Not exactly, but they do need to know how to glide and take an incredible leap of faith. The process of fledging for Common Murre chicks requires that they first cross the entire nesting colony to reach the cliff, where they make a sometimes enormous leap (up to 150 feet) into the water (you can see a video of this behavior here). Read more about the process here.
Q: Is a right whale dolphin the same as the right whale?
A: Nope! There are two species of right whale dolphins (northern and southern) that are named after right whales because they are similarly colored and, like the whales, they also lack a dorsal fin. The species we see in the Greater Farallones is the northern right whale dolphin. Learn more here.
Q: How long does it take the black-footed albatross to fly from Northwest Hawaii to the Farallones?
A: This is a bit challenging to answer, because Black-Footed Albatrosses (BFAL) do not regularly fly directly from the Northwest Hawaiian Islands to the Farallon Islands. That said, we do know that BFAL are able to fly a 2,400-mile round-trip journey in about two weeks, to get food for their young. So we can infer from that, that they can cover about 1,200 miles in about a week. (10 days to 2 weeks round trip is usually my answer PW)
Q: Do y’all ever see whale sharks in that area due to all of the krill?
A: No, whale sharks prefer warmer waters (above 70F). Water temperatures in the Farallones are only in the mid to upper 50s (54-57F). Basking sharks are also filter feeding sharks, and they are found in the area. Whale Sharks have been seen as far north as Monterey Bay, but never at the Farallones.
Q: Are the Farallones considered the main mating grounds for the Great White, or is this an unknown?
A: No, great white sharks come to the Farallones to feed (on seals and sea lions), not to mate. It is unknown where the east Pacific population of white sharks mate, however some evidence suggests that they may mate far offshore in an area of the open ocean between California and Hawaii. More information here.
Q: How do you tell a male from a female whale?
A: The only sure way to distinguish between male and female whales is by looking at the genital slits on their underside; in some instances it is also possible to determine gender based on their behavior, most notably when observing mother-calf pairs. A whale that is easy to tell by sight is the killer whale (orca). Mature killer whale males have a large upright dorsal fin, up to 5 ft high! While females have a more modest curved fin.
Q: Are all the different species of shark feeding on the same food sources or do they feed on different things?
A: There is some overlap in prey, but in general the different sharks feed on different prey for which they are highly specialized. White sharks feed on seals and sea lions, dolphins and porpoises, and other fish like tuna, sharks and more; basking sharks feed on plankton; thresher sharks feed on schooling fish and squid; mako sharks feed on tuna, swordfish, and other sharks; leopard sharks are bottom feeders that eat crustaceans, octopus, small fish, etc.
Q: What do pelagic birds do when there are hurricane level winds?
A: Birds are masterful navigators and are deeply attuned to wind and weather patterns. They use a variety of strategies to avoid getting caught in high winds, to correct course when blown astray, and even to use strong winds to their advantage. They can of course be caught in or impacted by severe storms, and they may fly high to get out of the weather, hunker down, or fly straight through a storm. You can read more on this topic here.
Q: What is the status of the white shark population around the islands?
A: Answered live, see 48:30.
Q: There was a report about a year ago of an abundance of mice, what’s happened to the mice and other random mammals of the past? Q: What is your opinion on the planned pesticide drop to remove rodents from the Farallones? Q: I was reading about the mouse problem on the islands and was wondering if this is still an issue and/or what has been done about it.
A: Yes, there is currently an overabundance of introduced house mice on the islands, described as being at “plague-like levels,” one of the highest mouse population densities observed in the world. The mice are the last remaining invasive vertebrate species on the islands and they are known to negatively impact native species including seabirds, salamanders, crickets, and vegetation. Oceanic Society supports the mouse eradication efforts proposed by our partners at Point Blue Conservation Science and U.S. Fish and Wildlife Service. Their experience and insight about issues on the islands is unparalleled, and they have a 50+ year track record of successful work there. We recommend you visit their websites for comprehensive analyses of the issue; see more here and here.
Q: Would you consider the Farallones something of an early warning system of issues that can inform our coastal policies in California?
A: Answered live, see 57:27.
Q: Are there climate change indicators affecting the food chain for whales/pinnipeds/sea birds around the Farallones?
A: Climate change is influencing the waters of the GFNMS in a number of ways. Firstly, a handful of warm water species from Southern California have relocated up here successfully (bottlenose dolphins, Humboldt squid, some species of nudibranch, and California spiny lobster). More frequent “King Tides” (really high tides) exacerbated by higher sea levels have eroded the beaches on the Farallones, making it more difficult for elephant seals to haul out, and for the females to wean their young, resulting in a decrease in the elephant seal population at the Farallones. This will have an effect on the white shark population as 65% of their prey are elephant seals. Climate change related impacts to whales are also being observed all along the California coast, including increases in gray whale strandings and humpback whale entanglements in crab fishing gear.
Q: Does a lot of plastic drift along with the (cold water) currents that were mentioned and is that an issue on the Farallon Islands?
A: We are not aware of any comprehensive studies of plastic pollution in the Greater Farallones National Marine Sanctuary. However, plastic pollution is found throughout our oceans and is especially concentrated near human population centers. We do not encounter a lot of surface plastic pollution during our trips (and when we do, we pick it up), but that does not mean plastic pollution is not present. Our partners at 5 Gyres recently completed a study of microplastic pollution in SF Bay and the adjacent marine sanctuaries (including the Greater Farallones), which you can read more about here.
Q: I didn’t know there were so many different wildlife species at the Farallon Islands. I know it’s a protected national wildlife refuge, but still, are you seeing any differences in the wildlife population numbers and behavior given there have been months of reduced tourism and commercial fishing in the area due to COVID-19?
A: Answered live, see 52:55.
Q: Can the ship speed be regulated to go slowly so that the whales don’t die if they are hit by a ship…or the ship navigator can see the whale and avoid it?
A: Yes, slowing down large ships (to under 10 knots) is one of the methods that has been shown to reduce the likelihood of ship strikes because it gives the whales more time to evade the vessels. Learn more here.
Q: Are basking sharks endangered?
A: Yes, basking sharks are classified as Endangered by the IUCN Red List of Threatened Species, and are considered a species of concern by NOAA.
Q: Do boats rely fully on technology to avoid the islands or is there some form of light on the hill that signifies the islands to help with navigation?
A: There used to be a regular lighthouse at the Farallones, but nowadays technology has taken over and all boats rely on satellite navigation systems to safely sail the waters of the GFNMS. There is still a light on a pole on top of the base of the old lighthouse on Southeast Farallon Island (Farallon Island Light), which has been operational, in one way or another, since 1855.
Q: Where can we purchase Peter’s coloring book
A: The Giant Ocean Coloring Book
Q: There is a whale carcass at the lost coast trail. I wonder what kind?
A: I did do some research on this but couldn’t find a recent reference to whale carcasses being washed ashore on the Lost Coast (Mendocino I assume). When dead whales wash ashore it isn’t always a cause for concern. A few years ago several humpback whales were washed ashore in San Mateo and Marin—researchers attributed this to the fact that many were feeding along the coast on anchovies, so it would be expected that more would wash ashore due to being close to the land. I heard a fact that on the ocean floor along this coast there is probably a dead whale in some sort of state of decay every 5 miles! I found this astonishing, but it goes to show that this is a popular place for whales because of the upwelling.
Q: The Lightkeepers is a fiction book by Abby Geni that takes place on the Farallon Islands and in the book, one of the researchers is fatally attacked by birds on the island during their mating season. Is this actually realistic/possible?
A: There have been researchers stationed continuously on the Farallon Islands since April 1968, led by our partners at Point Blue Conservation Science, and none have been killed by the birds! However, the birds can indeed attack researchers during the breeding season, so the biologists wear hard hats and rain gear in summer for protection. Here is a comical report from a NPR reporter who visited the islands.
If you are interested in joining us to look for whales and other wildlife in the Greater Farallones National Marine Sanctuary, please find details and dates are here. Trips have been redesigned with new COVID-safety protocols including social distancing, reduced capacity, and other measures. Learn more at the link above.
For more ways to stay engaged virtually, consider joining Oceanic Society’s new membership program! For as little as $5/month, you will join this growing community of ocean-lovers and receive exclusive updates about our work (see a sample of our June member’s only newsletter, The Tide, here). Members provide needed, consistent support that makes a real difference to our work!
Humpback whales, seabirds, and California sea lions feed near the Farallon Islands. ©Chris Biertuempfel