Saturday, August 2, 2014

July 21st-July 27th 2014

Daily Low Tides

Monday, July 21st
Low tide: 2.4' @ 2:41 PM

Tuesday, July 22nd
Low tide: 2.6' @ 3:52 PM

Wednesday, July 23rd
Low tide: -0.3' at 5:12 AM
Low tide: 2.6' @ 4:49 PM

Thursday, July 24th
Low tide: -0.5' @ 5:59AM
Low tide: 2.5 @ 5:40 PM

Friday, July 25th
Low tide: -0.6@ 6:40 AM
Low tide: 2.4' @ 6:26 PM

Saturday
Low tide: -0.6@ 7:17 AM
Low tide: 2.3' @ 7:10 PM

Sunday
Low tide: -0.5@ 7:52 AM
Low tide: 2.2'@ 7:50 PM

Notes from the Week

HRAP staff and volunteers worked extra hard this week covering double daily low tides. For tide pool enthusiasts like us, one of the joys of summer is good low tides and long daylight hours to take advantage of them. Another joy of summer is beautiful weather, which we've had in spades lately-- except for Wednesday, when multiple squalls, complete with bursts of torrential rain, interrupted one of our beach shifts. Kudos to our visitors for braving the bouts of bad weather with good humor and enthusiasm.

The day before, we also suffered a setback when the HRAP truck wouldn't start. This is the truck that carries our signs, binoculars, spotting scopes, field guides, and other equipment that helps us successfully educate visitors about the wildlife of Haystack Rock. We're currently fundraising for a new truck, one suited for life on the beach that will last us a decade or more. Visit http://friendsofhaystackrock.org/contribute.html if you're able to donate!

On Thursday, HRAP staff chose to close the intertidal to Homo sapiens visitors so that black turnstones could feed there uninterrupted. Black turnstones are a staple of the intertidal bird community, and as their name suggests, they forage by turning over stones to eat the crabs, barnacles, and limpets underneath.

The Needles hosted some great wildlife this week, including a purple sea urchin (see below) and Brown Pelicans diving for fish. While most pelicans sieve fish from the surface of the water, Brown Pelicans "plunge-dive," using the force of their impact to stun fish before scooping them into their stretchy throat pouches. Their dives are so forceful that they create a splash that is often mistaken for whale spouts.

Brown Pelicans tuck their heads in and rotate their body left as they dive. It's thought that this position protects their trachea and esophagus as they collide into the water. Photo by Susan Glarum.

As common as Brown Pelicans are today-- coastal residents may think of V-shaped flocks of pelicans as an emblem of everyday life here-- this is a species that faced extinction as a result of the pesticide DDT. Made famous by Rachel Carson's Silent Spring, DDT disrupts the birds' calcium metabolism so that they lay thin-shelled eggs which can't bear the weight of their parents' feet. Pelicans have made a spectacular recovery following the ban of DDT but still face threats from oil spills and habitat degradation.

Speaking of happily nesting birds, eight tufted puffins were spotted constructing new burrows on the north side of the rock on Sunday. Staff interpreter and regular blog contributor Susan Glarum provided us with this fantastic shot of a puffin landing on the rock.

  A tufted puffin touches down. Photo by Susan Glarum

Creature Highlights

Sure, you've seen your fill of aggregating and green sea anemones-- but have you ever heard of a rose anemone? How about a moon glow anemone?

Rose anemone in the sand. 

Rose anemones have pink columns and white or pink tentacles and oral discs. Moonglow anemones are also called burrowing anemones. They tend to look like blobs in the sand, but in actuality they are often living in the holes excavated by boring bivalves. (Don't let the name fool you. Some of us find these to be among the most exciting of the clam species.) Moonglow anemones are characterized by white horizontal stripes on their tentacles, and can appear a bright green if colonized by algae.

As hinted above, we were lucky enough to spot a purple sea urchin at the needles this week. Smaller, more purple, and shorter-lived than its big red cousin the red sea urchin, these echinoderms (a member of the sea star family) are a common inhabitant of the rocky shore, but are hard to find without a good low tide exposing them.

Purple sea urchins like this one rely on the crashing waves of the low intertidal to bring them snacks in the form of algae, like this sea lettuce (Ulva sp).

Birds

  • Brown Pelican (Pelicanus occidentalis)
  • Black Turnstones (Arenaria melanocephala)
  • Black Oystercatcher (Haematopus bachmani)
  • Peregrine Falcon (Falco peregrinus)
  • Bald Eagle (Haliaeetus leucocephalus)
  • Pigeon Guillemot (Cepphus columba)
Intertidal

  • Purple sails (Vellela vellela)
  • Dungeness crabs (Cancer magister)
  • Aggregate anemone (Anthopleura elegantissima)
  • olive snails (Olivella sp.)
  • rock louse (Ligia sp.)
  • tube worms [Polychaete (a class of Annelid, or segmented) worms]
  • Ochre star (Pisaster ochraceous)
  • tube snout/needle fish (Aulorhynchus flavidus) 
  • Leopard sea slug (Diaulula sandiegensis)
  • Lemon sea slug (Anisodoris nobilis)
  • Opalescent nudibranch (Hermissenda crassicornis)
  • Shaggy mouse nudibrach (Aelid papillosa)

References

Lamb, A. and Hanby, B. Marine Life of the Pacific Northwest: A Photographic Encyclopeida of Invertebrates, Seaweeds and Selected Fishes. Maderia Park B.C. Harbour Publishing, 2005.

http://www.allaboutbirds.org/guide/brown_pelican/lifehistory. Accessed 8/2/2014

http://www.nytimes.com/2012/09/23/magazine/how-silent-spring-ignited-the-environmental-movement.html?pagewanted=all&_r=0. Accessed 8/2/2014


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