Dumpy Little Seabird Celebrates World Ocean Day
By Mary Jane Schramm
In the thin light of dawn the caffeine-charged (but still sleepy) scientists headed out from Sausalito aboard the 67-foot NOAA research vessel Fulmar into Greater Farallones National Marine Sanctuary and adjacent waters. Today they were surveying across and just beyond the Continental Shelf for seabirds, and for marine mammals such as whales, dolphins, and sea lions. These are indicator species that would reflect ocean productivity during this spring upwelling season. Periodic stops for plankton net tows would reveal what lay beneath the surface in the water column, and sea water sampling would document its chemistry. Following a lengthy COVID-mandated interruption of field work, and with good sea conditions, all were agreed: it was good to be back at sea.
Past the offshore Continental Shelf Break where deep nutrient-laden water surges up to the surface, they approached the end of a long, straight-line transect - one of a series of tracks that ensures a consistent, methodical profile of sea life. Perched on the flying bridge, a researcher peered through powerful binoculars and called out, “Cassin’s Auklets, 300, feeding” as a colleague entered the data into a computer. The flotilla of Cassin’s auklets (Ptychoramphus aleuticus), a small, chunky seabird and prime sentinel of ocean productivity, signaled the presence of krill: tiny shrimplike creatures that form their main diet, and for that matter, that of giant blue whales, too, and many species in between. Abundant krill meant every creature in the marine food web would feast well this season.
Flying Tennis Balls: The Cassin’s Auklet is easy to identify. Mostly dark gray, on the wing it resembles a flying tennis ball, and its white “eyebrows” give it a quizzical expression. Its tiny beak limits its prey to plankton, small fish, and squid seized in shallow dives, or picked from the surface.
They breed on islands from Alaska’s Aleutian chain to Baja California, Mexico. The Farallon Islands off San Francisco host a spring-summer population of around 50,000 breeding pairs, but it can fluctuate wildly from year to year, depending on food availability. Little is known of their winter non-breeding range or offshore diet.
Baby Boom, or Bust? These auklets nest deep inside burrows made comfy with native vegetation. They typically lay only one egg, but may “double-clutch” - nest again later in the season - in highly food-productive years. However, if upwelling fails due to warming seas–an increasingly frequent occurrence with climate change–these small birds are among the first to experience nesting failure and massive at-sea mortality. The marine sanctuaries document this through research cruises and the mostly volunteer Farallones Beach Watch shore survey program. They share this information with other agencies and conservation groups to enlarge and enhance ecosystem monitoring, and so coordinate actions to protect our ocean’s health.
World Oceans Day: On June 8 we (and the auklets) celebrate United Nations World Oceans Day to appreciate the beauty, wealth and promise of the ocean, and to work toward making ours a sustainably managed Blue Planet. Its 2022 theme is “Revitalization: Collective Action for the Ocean.” If you can, head out to the coast, but also take time to learn about our national marine sanctuaries and their work to protect our waters from oil drilling, habitat destruction, and pollution. That knowledge may lead you to become part of the “collective action” through one of the sanctuaries’ volunteer programs.
To find out more about Greater Farallones and Cordell Bank national marine sanctuaries, go to https://farallones.noaa.gov and cordellbank.noaa.gov For more on World Ocean Day, see https://worldoceanday.org/
Top: Flying tennis balls, or Cassin's Auklets? Photo: NOAA.
Middle: Tiny seabird in burrow sitting one huge egg. Photo: NOAA.
Bottom: Nondescript, but sentinels of the sea. Photo: CINP-NPS.
