Where to tidepool
The intertidal marine life of the Olympic Peninsula is diverse and can be seen most easily “in the wild” along rocky shorelines at minus tides during daylight hours. Local staff favorites are Freshwater Bay (public tidelands only on the left side out to Bachelor Rock), Crescent Beach at the Salt Creek Recreation Area (a marine reserve) and Clallam Bay. On the Pacific coast, check out the intersection of Olympic National Park and the NOAA Olympic Coast National Marine Sanctuary, and including the coastal treaty Indian tribes of the Hoh, Makah, and Quileute, and the Quinault Indian Nation.
When to tidepool
Before you visit a local beach or park, check the tide chart and try be there at least an hour before the low tide time. Following the tide as it goes out is a safe way to be sure you are finished with your explorations and to see marine creatures as they become uncovered by the water, before they have found good hiding places for the next several hours.
How to tidepool
Don’t forget to use good tidepool manners – although these creatures have developed adaptations that help keep them safe from non-human predators, you are much larger than they are and can easily damage or destroy intertidal life.
If you can’t make the low tide times, or you aren’t able to venture out on rocky unstable ground, Feiro provides a way to easily enjoy the marine life of the Olympic Peninsula. Another way to enjoy the diverse marine life in the region is by getting out on or into the water through kayaking, stand up paddle boarding (SUP) or diving. There are many local guides and rental companies!
Feiro Marine Life Center is also a stop on the Whale Trail; which provides interpretive signage for sighting marine mammals from popular shore-based destinations.
While most people don’t bring a microscope with them to the beach, the ocean is teeming with tiny plants and animals. Some of these plants and animals spend their entire lives just beyond our unaided vision, others only partially so, as they grow from a young larval stage into the adult fish, crabs and marine invertebrates we find so easily.
The Pacific and Strait of Juan de Fuca coastal regions are populated by a variety of marine invertebrates. Invertebrate creatures, meaning without backbones, make up more than 97% of all species found on earth. We present a selection of Olympic Peninsula marine invertebrates below.
Some of these groups have served as food sources for native peoples who have lived in this region for thousands of years. These marine resources remain vital as economic drivers for tribes on the Olympic Peninsula to this day. See the Jamestown S’Klallam Tribe Natural Resources Department web page, as one example.
If you look closely at a rocky surface in the intertidal zone, you might see an oblong shape flattened into the rock. Chitons are marine molluscs, some with eight overlapping plates making up a dorsal “shell” protecting the soft-bodied animal underneath. Most chitons are algae eaters, and make their way across the rocky surface using their tongue-like radula, with 17 sharp teeth containing magnetite to scrape the algae from the rock. Their foot is able to hold them to the rocky surface during tidal changes and wave action.
You only have to glance at some photos of the variety of sea slugs called nudibranchs to understand why they capture so many people’s attention. Despite their small size, these invertebrates have remarkable colors and body features that often bring to mind fantastical and imaginary creatures. Rather than a shell, like many gastropods (think snails & limpets), nudibranch defense relies on camouflage and/or the consumption of sea anemone stinging cells, toxins from sponges or other chemical deterrents, which it is able to store in its own body to be used for defense.
The primary sea cucumbers found along the Olympic Peninsula include California sea cucumbers and burrowing sea cucumbers.
California sea cucumbers can grow to be almost two feet long! They play an important role in keeping the ecosystem clean by scavenging for food along the bottom. Its primary predators are certain kinds of sea stars and occasionally sea otters, but humans also consume them. When disturbed California sea cucumbers have the ability to eject their internal organs out of their anus in order to confuse or trap predators in a sticky mucus. They can later regrow the organs!
Burrowing sea cucumbers are often thought by visitors to be the same as anemones. This is because of their fringed tentacles used to gather plankton from the water for feeding. They are a bit smaller than the California sea cucumber, reaching a maximum of 10 inches, and spending most of their time burrowed into the sand. They can retract their tentacles inside their bodies, which makes them appear as only a slender tube with five rows of tube feet running from one end of the animal to the other.
Why not call them “starfish?” Fish are a very specific type of animal. Sea stars do not have gills, fins or scales. They pump sea water, not blood, through their bodies.
There are 30 different species of sea stars you can encounter in the Pacific Northwest! Unfortunately the sea star population has been hard hit by a virus that causes sea star wasting disease, meaning there are certain kinds of sea stars that are difficult, if not impossible to see, along the coast. One example of this is the ochre star, which is a well-known iconic creature, with large purple, orange or pink stars draped over one another along rocky shores.
Feiro has been conducting citizen science surveys of sea stars at Freshwater Bay. We are currently searching for evidence of juvenile sea stars, which would indicate that populations of ochre stars and others, like sunflower stars, would return.
Sea stars, like other echinoderms, use a water vascular system to control the thousands of tube feet along their undersides not only for locomotion, but to also conduct gas exchange (respiration) feeding, sensory reception and to attach to rocky surfaces.
Sea stars also sense by means of “eye spots” at the tip of each arm. While some sea stars have five arms, others can have six, 10 or even 20 arms.
For sea stars that consume mussels, they are able to use those tube feet to pry open the mussel shells and exude their stomachs inside the shell, releasing digestive enzymes that are able to start to break the soft body of the mussel down inside its own shell.
When most people think of a sand dollar, they think of the white “shell,” called its test, that can be found washed ashore on the beach. Living sand dollars are actually covered in tiny purple spines. These spines are used for locomotion and, on the back, serve as gills. Sand dollars live in shallow waters and often stand on one end of their shell when the water is calm so any food particles being carried in the water will easily reach their mouths (found on their undersides, like their relatives sea stars and sea urchins) with the aid of tiny hairs called cilia among the spines that move food along the body. When the water is rough they will bury themselves in the sand or grow heavier skeletons. Young ones may swallow sand to help weigh them down.
Sea anemones are among the most colorful creatures in the ocean with colors ranging from purple to red to green to white. Their bodies consist of a stalk that ends in a flattened disk with a central mouth surrounded by tentacles.
Anemones are carnivores and will eat fish, crabs, and anything else that swims within reach. Their tentacles, like their close relatives the jellyfish, contain nematocysts or stinging cells. When a fish gets too close the nematocysts release a paralyzing neurotoxin into the prey which is then guided into the mouth.
For the most part, anemones are stationary. They attach themselves to a hard substrate and lie in wait for food to swim by. However they can detach themselves and roll along with the currents when they are threatened or if the water chemistry has changed, finding a new place to attach themselves.
Some anemones, like the Giant Green Anemone, have symbiotic relationships with algae. The algae live inside the anemone and are given protection from the grazing animals that would feast it, and the anemone benefits from an increase in nutrients directly from the algae.