Friday, May 30, 2014

May 19th to May 25 2014

Daily Low Tides

Monday, May 19th
-0.5' @ 11:01 AM

Tuesday, May 20th
0.0' @ 11:56 AM

Wednesday, May 21st
0.4' @ 12:55P M

Thursday, May 22nd; shift extended due to exposure and visitors
0.9' @ 1:57 PM

Friday, May 23rd; shift ended early due to bad weather
1.2' @ 2:57 PM

Saturday, May 24th
1.5' @ 3:53 PM

Sunday, May 25th
1.7' @ 4:45 PM

Notes from the week

Black Oystercatchers took center stage this week; establishing a nest is the saddle and were observed sitting on their nest. Now that the nest is established one of the biggest tasks is to limit the disturbance to the nesting birds by the hundreds of people visiting the intertidal. A volunteer or two is being stationed in front of the saddle to limit interference with the oystercatchers. They are particularly vulnerable to human disturbance; even speaking too loudly can cause them to flush, leaving their nest and chicks vulnerable or causing them to abandon the nest site.

Check out this article on the American Bird Conservancy's website to learn more guidelines for protecting nesting birds.  It is important to be aware of birds in any place you visit, and watch for signs that you may be distressing or disturbing a nest. Education is the key to ensure healthy bird populations and to protect important habitat.


Black Oystercatchers on Nest; Photo from 2013 by Susan Glarum


Black Oystercatcher and Chick; Photo from 2013 by Susan Glarum 


Black Oystercatchers and Chick; Photo from 2013 by Susan Glarum 

Piddock clams (Family Pholadidae) were spotted spawning on the south side. The piddock clams are unique in that each side of their shells is divided into 2 or 3 separate sections; one of the piddock's shells has a set of ridges or "teeth" which they use to grind away at clay or soft rock and create tubular burrows. The shape of these burrows is due to the rotating motion of the piddock as it grinds the rock to make its home. The piddock stays in the burrow it digs for the entirety of its eight-year lifespan, with only its siphon exposed to take in water that it filters for food. When the piddock dies and leaves an empty tubular burrow, other marine life such as sea anemone, crabs and other molluscs may use the burrow. They are typically white in coloration though through consumption of red tide algae some may develop a pink coloration.

Clams are broadcast spawners; the pink piles  in the photos are the eggs and the water is cloudy with the sperm. The tidepools temperature were the spawning occurred was very warm; likely leading to the spawning.


Piddock Clams Spawning; Photo by Alix Lee


Piddock Clams Spawning; Photo by Alix Lee

There were visits from eight school groups this week bringing a total of 457 students to the intertidal. One group was high schoolers and the remaining groups were grade school students. Monday, with the highest school group number of 4, featured an Aquaria station.  School visits will be winding down in the next two weeks as the school year comes to a close.

The highest visitor count in the intertidal was 291 on Saturday, with three consecutive hourly counts over 200. Memorial Day on Monday also brought many visitors to the beach with a high count of 199 in the late morning.

Creature Highlights

Birds

  • Bald Eagle (Haliaeetus leucocephalus) - Bald eagles again made multiple appearances this week. There were several successful hunts during the week taking murres and raiding pelagic cormorant nests for eggs.
  • Black Oystercatchers (Haematopus bachmani) - An Oystercatcher nest has been established in the saddle.
  • Common Murre (Uria aalge) - Spotted nesting on ledges by puffin burrows in the grass
  • Brown Pelicans (Pelecanus occidentalis) - The pelicans were in close; seen at the needles and diving offshore. 
  • Pelagic Cormorant (Phalacrocovax pelagicus)
Invertebrates
  • Piddock clams (Family Pholadidae)  - These boring clams were spawning on the south side. 
  • Sea Lemon (Anisodoris nobilis) - Usually growing to around 4 inches, the sea lemon is found in the low intertidal to depths of 750 feet. It is flat, bright yellow to orange. It has pointed rhinospores at the head region and a pair of frilly gills at the rear.




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