Tuesday, February 14, 2017

Watch Out Prey - They Sting!

Alan Quimby was the lead interpreter on the beach on May 16, 2016 and spied an Aggregating Anemone (Anthopleura elegantissima) and a Shore Crab in close proximity in the tidepools.

The aggregating anemone is an invertebrates that looks likes a flower, with a tube shaped body capped by tentacles. Colored anemones have algae living in their tissue in a symbiotic relationship. The anemone bends away or toward the light to facilitate the light level needed for photosynthesis in the algae; it return, the algae provides food to the anemone.

Aggregating Anemone

Anemones eat a wide variety of food, using stinging cells on their tentacles (called nematocysts) to paralyze their prey. They can even ingest small crabs and discard the shells. Perhaps that is what happened to the shore crab on this day as the crab must have gotten a little too close and appeared to have been paralyzed  by a small aggregating anemone.

Paralyzed Shore Crab

The anemone is abundant on the rocky shore and can almost always be seen in the tidepools at Haystack Rock. If you have visited Haystack Rock multiple times, you have probably noticed that the sand can drift from week to week and even from day to day. The anemone can easily be buried by the drifting sand but can survive up to 3 months under the sand.

Anemones retract their tentacles when they are exposed to the air. Sand and bits of shell cling to sticky bumps on their body which provide both camouflage and protection from drying out. The anemone is less apparent in this state, frequently blending into the rocks to which they are adhered.

Aggregating Anemone

Next time you are at the rock, take an opportunity to admire the 'flowers' of the tidepool. The beach season at Haystack Rock has now started and we look forward to seeing you on the beach!

Sunday, January 29, 2017

Haystack Rock Field Trips

Haystack Rock is a great destination for field trips. The Haystack Rock Awareness Program provides educational field trip programs that integrate observation, investigation, and exploration. In 2016, HRAP hosted fifty-two educational programs on the beach for students of all ages, reaching over 2100 students.

On June 10th, 2016, HRAP hosted a group of grade-school students. That day was rainy, windy, sunny - everything the Rock can be - but most importantly - educational! The students had a great time exploring the tidepools and learning about its inhabitants guided by HRAP interpreters.

If you are interested in scheduling an educational group visit to Haystack Rock, visit http://www.ci.cannon-beach.or.us/hrap/page/teachers-planning-field-trip for details on scheduling a visit. The beach season will begin on February 13th and planning is already underway. We hope to see your group on the beach this season!

Thursday, December 8, 2016

What is That Scurrying On the Sand?

August 8th was a cloudy day with a few sprinkles in the morning at Haystack Rock. Katie Corliss, lead interpreter, along with three additional interpreters were on the beach for the 1.5 ft low tide at 11:13 am. Over five hundred visitors experienced the Marine Garden during the five hours the interpreters were on the beach.

Katie captured a great video of mole crab activity in the sand. In the genus Emerita they are crustaceans commonly known as mole crabs, sand crabs or sand fleas. Related to hermit crabs and stone crabs, the mole crab spends much of its time buried in the sand. It is well camouflaged by its gray shell, burrowing quickly and frequently into the sand. The crab lives in the area of breaking waves, moving up and down the beach with the tides. It feeds by filtering tiny plankton from receding waves using a sweeping motion of an antenna. Check out the video of the crabs scurrying in the sand and burrowing in.


Mole crabs are less that 2 inches in length and can be found along the entire west coast of the US from Alaska to Baja California. Their life span is rarely more than 2 to 3 years and they can reproduce in their first year producing bright orange eggs. Next time you are at the beach, look closely down at the sand near the tide line for these scurrying crabs.

Friday, December 2, 2016

Opalescent Nudibranch In The Sand

Today we look back to August 3rd on the beach. Gina Palmer was the lead interpreter on the beach for the 1.4 ft low tide at 7:46pm. It was a sunny afternoon with a NNW winds between 15 and 25 knots. The opalescent nudibranches, typically found under the boulders in the central pools of Haystack Rock, were today out in the sand.

Opalescent Nudibranch 

The opalescent nudibranch (Hermissenda crassicornis) is an invertebrate that resides in the intertidal rocky shores from Baja California to Alaska. They grow to about 3 inches, subsisting on a diet mainly of hydroids, but will also eat small sea anemones and bryozoans.  A nudibranch lives for a maximum of one year and is hermaphroditic. It's eggs are laid in narrow, coiled strings attached to eelgrass or algae. 

The opalescents are a colorful species of nudibranch, having bright orange areas on their back with a blue line on each side. Next time you're in the intertidal zone at low tide - anywhere on the west coast -take a look in the sand or under boulders for these colorful invertebrates!

Friday, October 28, 2016

That's A Wrap on the 2016 Beach Season

On October 27th we officially wrapped up our 2016 season on the beach. We're still working on our final counts, but as of September 30th, we've interacted with 98,500 people this season both on and off the beach and hosted 52 educational programs on the beach. Now that's an epic season!

HRAP Staff and Volunteers finished the season with an 'End of Season Cleaning and Storage Party' on the 28th. The HRAP trailer was emptied and the equipment cleaned and stowed for the winter.

Planning for the 2017 Beach Season is already underway and we'll be back on the beach in February.

We'll be revisiting the 2016 season on the blog this winter. Check back in with us to learn about the season from the perspective of the HRAP Interpreters.

Saturday, September 24, 2016

Red Ascidian Tunicate - Aplidium solidum.

Red Ascidians are tunicates, a marine invertebrate with a hard exterior layer, or tunic, where it get's it's name. The first known species of tunicate dates back to 485.4 millions years ago to the early Cambrian period, when most modern phyla first appeared.


The red ascidians have two siphons which move water in and out of it's body, much like a heart. They grow in colonies up to 20 centimeters long and can be a favorite food of the opalescent nudibranch.

Have you seen a red ascidian at Haystack Rock? Let us know! Happy Tide-pooling!

Wednesday, September 14, 2016

Dendronotus Density Dispatch

Tidepools on the north side of Haystack boasted a startling abundance of nudibranchs in the genus Dendronotus. "Dendrites" is Greek for "treelike." Upon close examination, these creatures with branching bodies did appear treelike.

Individual dendrontid against a background bryozoan.
From a distance, however, the dendrontids looked like a dense growth of algae carpeting the floor of the pool. 

The "blob" in the left-hand corner is a nudibranch "walking" upside down by moving its foot across the surface tension of the water. The mossy growths covering the sand are clusters of dendrontids in uncountable hundreds.

Courtesy of Stephen Grace