Friday, August 15, 2014

August 4th - August 10th 2014

Daily Low Tides

Monday, August 4th
Low tide: 2.3' @ 12:34 PM

Tuesday, August 5th
Low tide: 2.7' @ 1:43 PM

Wednesday, August 6th
Low tide: 2.8' @ 2:58 PM

Thursday, August 7th
Low tide: 2.6' @ 4:08 PM

Friday, August 8th
Low tide: -0.8' @ 5:22 AM
Low tide: 2.2' @ 5:10 PM

Saturday, August 9th
Low tide: -1.2' @ 6:13 AM
Low tide: 1.7' @ 6:08 PM

Sunday, August 10th
Low tide: -1.4' @ 6:59 AM
Low tide: 1.2' @ 7:03 PM

Notes from the week

Another busy week here at Haystack Rock, both for the humans and for the birds! Tufted puffins can still be seen guarding their burrows, and the black oystercatcher pair continues incubating their precious eggs, which should be hatching any day now. Oystercatcher hatchlings are precocious and able to leave the nest as soon as their downy feathers dry-- usually within about 24 hours of hatching; tufted puffin hatchlings aren't quite as mobile and must stay in the nest longer. Both species stick by their parents' side until they are close to adult size.

We had a couple of unusual animal sightings on Sunday. In the morning, we spotted a salmon trapped in one of the tidepools!


A salmon found its way into a Haystack Rock tide pool this weekend. 

On Sunday afternoon, we glimpsed a six-rayed star tucked between a couple aggregating anemones on a tidepool rock. These stars are different from the ochre star (the purple and orange stars more commonly found at Haystack Rock) in a number of ways. First, as their name implies, they have six arms instead of five; second, they reach adult size at just 9 cm instead of 25 cm, and third, their parenting style is much more hands-on (rays-on?) The mother star will brood her babies for over a month, clinging to the rock by the tips of her rays and holding her babies beneath her. When the tiny stars have developed tube feet capable of clinging to the rock, the mother star can finally release them, flatten against the rock, and resume eating.



Many six-rayed stars are a drab gray or olive green-- not this one!

Creature Highlights

A common question HRAP interpreters are asked is, "What are all those green blobs?" In fact, many visitors to Haystack Rock don't even think about the "green blobs" at all-- that's why we have to step in to make sure visitors don't scramble over the rocks and crush them. They don't look alive, and they certainly don't look active.

But the common aggregating sea anemone-- which does indeed look like a green blob when it is out of water-- is more active than you might think. These animals are capable of cloning themselves, typically by splitting in two, and in fact can create large, tight groups of genetically identical individuals. When one such group encroaches on another group's territory, war ensues-- clone wars! And the anemones are well-equipped to do battle.


Aggregating sea anemones always bear these club-shaped stinging tentacles in a crown below their oral disc, but they usually only extend them when they feel threatened by invading unrelated anemones. These clubs are called "acrorhagi."

The next time you visit the tide pools, take a look at the blankets of "green blobs" on the rocks. You may notice a break between clusters of anemones. It may not look it, but that's an active battle ground. Check out a great video of this here

Birds
  • Black Oystercatcher (Haematopus bachmani)
  • Western Gull (Larus occidentalis)
  • Tufted Puffin (Fratercula cirrhata)
  • Bald Eagle (Haliaeetus leucocephalus)
  • Brown Pelican (Pelecanus occidentalis)
  • Pigeon Guillemot (Cepphus columba)
  • Black Turnstone (Arenaria melanocephala)
Intertidal
  • Purple sails (Velella velella)
  • Sea urchin (Strongylocentrotus purpuratus)
  • Lion's mane jellyfish (Cyanea capillata)
  • Red rock crab (Cancer productus)
  • Ochre star (Pisaster ochraceus)
  • Surf perch 
  • Shore crabs
  • Sand dollar (Dendraster excentricus)
  • Sea lemons (Anisodoris nobilis)
  • Leopard nudibranchs (Diaulula sandiegensis)
  • flatworm
  • Salmon
  • Six-rayed star (Leptasterias hexactis)
References

Ruppert, E. and Barnes, R. Invertebrate Zoology. 6th ed. Thomson Learning. 1994. 

Elphick, C., Dunning, J., Sibley, D. (eds) The Sibley Guide to Bird Life and Behavior, 2nd ed. New York: Alfred A. Knopf, 2002.

Kozloff, E. Seashore Life of the Northern Pacific Coast: An Illustrated Guide to Northern California, Oregon, Washington, and British Columbia. Seattle and London: University of Washington Press. 1993.

http://www.allaboutbirds.org/guide/Black_Oystercatcher/id. Accessed: 8/15/14

http://www.allaboutbirds.org/guide/Tufted_Puffin/id. Accessed: 8/15/14





No comments :

Post a Comment