May 13, 2012

Location: Saltwater State Park (25621 Marine View Dr S, Des Moines, Washington).

Coordinates: 47.3724022229, -122.3245609739

Weather: It was a sunny day with about 20% cloud cover. The wind was blowing quite hard along the beach, but not anywhere else. The lighting was good and the water was surprisingly tolerable to walk in even though it was only 65 degrees Fahrenheit.

Habitat: The habitat of this area was very similar to the area I explored on April 28, 2012 since they are technically the same beach. The Saltwater State Park beach is just a mile or so walk down a stretch of beach from the beach I visited on April 28. The main difference is that the beach at Saltwater State Park is considerably less rocky and much more sandy than the other beach. There were areas that were heavily rocky, but they were present in a thin belt between two large sandy belts, one of which was close to the cliff face and the entrance to the park and the other of which was closest to the water, that extended down the length of the beach for as far as I could see. The sandy beach with the thin rock belt made it possible for new and interesting species to be present alongside species present in rocky beaches, so this area was a mix of habitats. The crabs, mussels, limpets, and other similar creatures were confined to the rocky patches along with all of the seaweed present on the beach. The sand fleas and geoducks, however, are creatures one will only find on sandy beaches. The aggregating anemones and sand dollars can be found both in rocky and sandy areas, as I observed on this excursion. I'm glad I was able to go to a beach with this kind of diversity in habitat and, by extension, species. I observed all kinds of interesting behaviors that I will detail in the general comments section.

Vegetation: The vegetation on the beach was limited to the seaweed species growing solely on rocks in the rocky belt. There were obviously no trees or other plants present. I was not able to identify most of the seaweed species, though it was clear there was one dominant species present in an even distribution and a few less dominant species present in only some patches here and there. Rockweed is an example of a less dominant species I saw.

General Comments: I learned a lot of new things thanks to this visit. Firstly, I had never even seen a geoduck before and, though I only got to see some geoduck siphons poking through the sand, it was still exciting. Geoducks suck in water and eat the detritus out of it, which is what they were doing when I happened upon them. When touched, the siphons would retract into the sand and would poke back out again after a minute or so. There were obviously three or four geoducks in one small area since each geoduck only has one siphon, so I wonder how deeply I would have had to dig in order to unearth them. Second, I was not aware that anemones would anchor themselves in the sand. I had only ever seen them on rocks up to that point but, that day, there were huge groups of them sitting in the sand at the edge of the rocky belt. They would squirt water up into the air from time to time and a couple of them even had their little tentacles out since those were partly submerged in small amounts of water. They seemed to be doing quite well even though many of them were exposed to the sun and not covered in water. Third, I saw at least a hundred live sand dollars at that beach, which was amazing. I had never even seen a live one until a few weeks before that and then I was suddenly finding huge groups of them. I wonder why there were so many of them out that day? Most were buried in the sand to avoid drying out, but a few were in the slow process of dying when I got to them. I tried moving the exposed ones into water and burying them a little since I felt bad for them, but I don't know if that actually helped. Finally, I observed a small sand flea hopping all by itself on the sand. I thought that was odd since I'd only ever seen them moving in large groups. I wonder why that one in particular was on its own? It seemed pretty weak so I wonder if something had attacked it or if it was dying for some other reason. I have no doubt that the gulls and crows that had been dotting the beach would have loved to eat that little guy.

Species List:
Unidentified, small, white crab (Possibly a baby)
Blue Mussel (Mytilus edulis)
Shield limpet (Collisella pelta)
Aggregating Anemone (Anthopleura elegantissima)
Geoducks (Panopea generosa)
Sand flea species (Megalorchestia corniculata)

Posted on June 1, 2012 09:17 AM by tessaf tessaf

Observations

Photos / Sounds

What

Yellow Shore Crab (Hemigrapsus oregonensis)

Observer

tessaf

Date

May 13, 2012 05:12 PM PDT

Photos / Sounds

What

Black Mussels (Genus Mytilus)

Observer

tessaf

Date

May 13, 2012 05:13 PM PDT

Description

For more information on the habitat, vegetation, and weather of this beach, please see the journal entry for May 13, 2012 here on iNaturalist. These blue mussels can be distinguished from the more common California mussel by their size. Blue mussels are much smaller in comparison. These blue mussels were covering a few of the rocks in the tide pools and were much less common than the larger California mussels. This little guy had fallen off his rock, so I picked it up for a picture. It was only about an inch long and two centimeters wide and its shell was a dark blue with no markings.

Photos / Sounds

What

Shield Limpet (Lottia pelta)

Observer

tessaf

Date

May 13, 2012 05:16 PM PDT

Description

The striped shell is the shield limpet. For more information on the habitat, vegetation, and weather of this beach, please see the journal entry for May 13, 2012 here on iNaturalist. I only saw a few of these limpets of this same coloration on the rocks in the tide pools at this beach. There were others, but they were of different species or had different coloration. This limpet caught my eye because of its odd black stripes. Limpets are a species of sea snail that have very simple, flat shells. They stick themselves to rocks, just like this one in particular was.

Photos / Sounds

What

Aggregating Anemone (Anthopleura elegantissima)

Observer

tessaf

Date

May 13, 2012 05:22 PM PDT

Description

For more information on the habitat, vegetation, and weather of this beach, please see the journal entry for May 13, 2012 here on iNaturalist. These little anemones were in groups buried in the sand all over the beach. It was odd to me because I had only ever seen them living on rocks, not in the sand. A few of them, like the one in the second picture, had their tentacles out, which were light green with pink tips. Each anemone was about an inch across and the one in the picture was one of only a few that was on its own, the rest were in large groups. Occasionally, they would squirt water at me from surprisingly great distances.

Photos / Sounds

What

Pacific Geoduck (Panopea generosa)

Observer

tessaf

Date

May 13, 2012 05:33 PM PDT

Description

For more information on the habitat, vegetation, and weather of this beach, please see the journal entry for May 13, 2012 here on iNaturalist. This observation was a surprising and exciting find for me. I have never seen a live geoduck before, and these geoduck siphons are the closest I've ever come. There were about six of them in a small group poking above the surface in the soft sand. They were visibly sucking in water, which is because the geoducks are trying to eat the plankton in the water. When poked, these little siphons would bury themselves in the sand and come back up after a few seconds. Geoducks are the largest bivalves in the Puget Sound, the largest burrowing clam in the world, and one of the longest living animals on earth (they can live up to 146 years).

Photos / Sounds

Observer

tessaf

Date

May 13, 2012 05:43 PM PDT

Description

For more information on the habitat, vegetation, and weather of this beach, please see the journal entry for May 13, 2012 here on iNaturalist. These little sand fleas (also called beach hoppers) are a common sight on the higher parts of the intertidal zone. They like to burrow under dried up and rotting seaweed to hide from the hot sun during the day. Tiny fleas like this one bite surprisingly hard and can cause all kinds of dangerous infections. They will often travel in large groups, though this one was on its own. This flea was only about a centimeter long but could jump fairly high despite its size.

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