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Every year, as early as Memorial Day or as late as Father's Day, there's about a week of really lovely low tides. This midsummer tide series usually includes the lowest low tides of the year, and we intertidal ecologists plan our field activities around them. Incidentally, there's a corresponding low tide series in the midwinter, too. However, at that time of year the lows are in the afternoon, and because the low occurs about 50 minutes later each day you're fighting darkness as you work the series. But in the summer, even if the first day of the tide series has a low tide before sunrise, that 50-minutes-later-each-day thing is really nice and you never have to worry about running out of daylight.

This year, the California Academy of Sciences sponsored several citizen science excursions called Bioblitzes to various locations on the California coast. The goal of these Bioblitzes was to document biodiversity in the intertidal in protected and non-protected areas of the coastline. Back in May I volunteered to lead a Bioblitz at one of the sites close to me, and planned to participate in a few others as well. In addition to actual organized Bioblitzes, citizens were invited to submit their own independent observations to the project.

Today is the three-week anniversary of the car accident that left me bruised and concussed. The bruises are pretty much healed at this point, and the soreness in my ribcage is also much improved. The medical advice I got for dealing with the concussion was, "Protect your brain from stimulation. Let it heal. And REST." So for the past three weeks I haven't been doing much of anything. I was worried that I wouldn't be able to go out on any of the midsummer low tides, as it didn't take much to overtax my injured brain and I didn't want to risk overextending myself. I did end up skipping the first Bioblitz of the week and modified my original plans for the rest of the tide series to play it safe and stay closer to home.

I'm still trying not to spend too much time on the computer (electronic screens are very bad for injured brains) so I'm going to summarize my week's activities in a single post. I'll keep the stories short. But I did want to share some of the things I saw.

Day 1 - Natural Bridges, Monday 6 June 2016, low tide -1.6 ft at 06:25

My first venture out by myself was to Natural Bridges. It's very close to my house and I figured that if I needed to bail I could walk out and be home within 15 minutes. It was cold and foggy and I felt energized just to be out there again.

Natural Bridges State Beach 6 June 2016 © Allison J. Gong
Natural Bridges State Beach
6 June 2016
© Allison J. Gong
Open ends of tubes of the polychaete worm Phragmatopoma californica. 6 June 2016 © Allison J. Gong
Open ends of tubes of the polychaete worm Phragmatopoma californica.
6 June 2016
© Allison J. Gong
Anthopleura sola in a tidepool at Natural Bridges. 6 June 2016 © Allison J. Gong
Anthopleura sola in a tidepool at Natural Bridges.
6 June 2016
© Allison J. Gong
One of many healthy Pisaster ochraceus stars I saw at Natural Bridges. 6 June 2016 © Allison J. Gong
One of many healthy Pisaster ochraceus stars I saw at Natural Bridges.
6 June 2016
© Allison J. Gong
Intertidal life at Natural Bridges. 6 June 2016 © Allison J. Gong
Intertidal life at Natural Bridges.
6 June 2016
© Allison J. Gong
A woolly sculpin (Clinocottus analis) in a tidepool at Natural Bridges. 6 June 2016 © Allison J. Gong
A woolly sculpin (Clinocottus analis) in a tidepool at Natural Bridges.
6 June 2016
© Allison J. Gong
Shore crab (Pachygrapsus crassipes) playing peek-a-boo at Natural Bridges. 6 June 2016 © Allison J. Gong
Shore crab (Pachygrapsus crassipes) playing peek-a-boo at Natural Bridges.
6 June 2016
© Allison J. Gong

Turns out this trip was about all my brain could cope with that early in the week. I skipped a Bioblitz up at Pigeon Point on Tuesday so I could stay home and rest, which ended up being a good call. A whole day of doing nothing was exactly what my concussed brain needed.


Day 2 - Mitchell's Cove, Wednesday 8 June 2016, low tide -1.1 ft at 08:02

The day of rest was enough to get me back out there on Wednesday. My friend Brenna met me at Mitchell's Cove for a morning of tidepooling. Mitchell's Cove is a popular, dog-friendly beach in Santa Cruz, particularly busy in the mornings and evenings. Last September it was visited by a juvenile humpback whale, which came right into the Cove and hung out there for several days. I didn't see any whales this week, but there was a surprising diversity of life in a relatively small area of rocky intertidal.

Rocky intertidal on the west end of Mitchell's Cove. 8 June 2016 © Allison J. Gong
Rocky intertidal on the west end of Mitchell's Cove.
8 June 2016
© Allison J. Gong
Pisaster ochraceus regenerating an arm, at Mitchell's Cove. 8 June 2016 © Allison J. Gong
Pisaster ochraceus regenerating an arm, at Mitchell's Cove.
8 June 2016
© Allison J. Gong
A small (~2 cm long) chiton, Mopalia muscosa, nicely camouflaged on a rock at Mitchell's Cove. 8 June 2016 © Allison J. Gong
A small (~3 cm long) mossy chiton, Mopalia muscosa, nicely camouflaged on a rock at Mitchell's Cove.
8 June 2016
© Allison J. Gong

We have two species of surfgrass in northern California. At this time of year they are very lush and conspicuously green.

Two species of surfgrass at Mitchell's Cove. Phyllospadix torreyi (front) and P. scouleri (rear). 8 June 2016 © Allison J. Gong
Two species of surfgrass at Mitchell's Cove. Phyllospadix torreyi (front) and P. scouleri (rear).
8 June 2016
© Allison J. Gong

Phyllospadix scouleri, the species that has flatter, more ribbon-like leaves, was blooming. Its congener, P. torreyi, growing in almost exactly the same place, has narrow leaves that are more cylindrical in cross-section, and was not in bloom. Phyllospadix is a true marine plant; the flowers are inconspicuous swellings near the bottom of the leaves and the pollen is carried by water, rather than wind, to nearby plants.

Surfgrass (Phyllospadix scouleri) in bloom at Mitchell's Cove. 8 June 2016 © Allison J. Gong
Surfgrass (Phyllospadix scouleri) in bloom at Mitchell's Cove.
8 June 2016
© Allison J. Gong
Flower of surfgrass Phyllospadix scouleri at Mitchell's Cove. 8 June 2016 © Allison J. Gong
Flower of surfgrass Phyllospadix scouleri at Mitchell's Cove.
8 June 2016
© Allison J. Gong

And I saw two species of hydroids! This one is easy to ID to the genus Aglaophenia, but I would need to examine it under a microscope to determine the species. I wasn't collecting anything on Wednesday so I don't know which species it is.

Hydroid (Aglaophenia sp.) at Mitchell's Cove. 8 June 2016 © Allison J. Gong
Hydroid (Aglaophenia sp.) at Mitchell's Cove.
8 June 2016
© Allison J. Gong

This second hydroid is, I think, a species of Abietinaria. The hydroid colony is the pale orange stuff; the pink stuff is coralline alga.

Small clump of the hydroid Abietinaria sp. at Mitchell's Cove. 8 June 2016 © Allison J. Gong
Small clump of the hydroid Abietinaria sp. at Mitchell's Cove.
8 June 2016
© Allison J. Gong

And I saw an octopus! We know that they're in the intertidal, but they are so cryptic and clever at hiding that we don't see them very frequently. This one was definitely smarter than I was. Instead of scooping it out and placing it on dry ground so I could photograph it more easily, I chased it around a tidepool with my camera. Thus, this is the best picture I could get:

Small octopus (Octopus rubescens) in a tidepool at Mitchell's Cove. 8 June 2016 © Allison J. Gong
Small octopus (Octopus rubescens) in a tidepool at Mitchell's Cove.
8 June 2016
© Allison J. Gong

Okay, you'll just have to take my word for it.


Day 3 - Davenport Landing, Thursday 9 June 2016, low tide -0.7 ft at 08:52

This was the day of my "official" Bioblitz. I had four participants--Brenna, Alice, Martha, and Andy. As of right now (Brenna hasn't yet uploaded her observations) the other four of us have made 120 observations, documenting 50 species. Here are some of mine:

Nudibranch (Hermissenda opalescens) at Davenport Landing. 9 June 2016 © Allison J. Gong
Nudibranch (Hermissenda opalescens) at Davenport Landing.
9 June 2016
© Allison J. Gong
Can you see Pisaster ochraceus hiding in this clump of mussels (Mytilus californianus)? 9 June 2016 © Allison J. Gong
Can you see Pisaster ochraceus hiding in this clump of mussels (Mytilus californianus)?
9 June 2016
© Allison J. Gong
Looking north towards Davenport Landing beach. 9 June 2016 © Allison J. Gong
Looking north towards Davenport Landing beach.
9 June 2016
© Allison J. Gong

There are kelps, such as Egregia menziesii (feather boa kelp) whose habitat is the rocky intertidal. Most kelps, though, live subtidally, often in kelp forests. Nereocystis luetkeana, the bullwhip kelp, is one of the subtidal canopy-forming kelps. This one recruited to the intertidal. It is quite small and extremely cute; the float is only 2 cm in diameter.

A baby bullwhip kelp (Nereocystis luetkeana) at Davenport Landing. 9 June 2016 © Allison J. Gong
A baby bullwhip kelp (Nereocystis luetkeana) at Davenport Landing.
9 June 2016
© Allison J. Gong
A small moonglow anemone (Anthopleura artemisia) at Davenport Landing. 9 June 2016 © Allison J. Gong
A small moonglow anemone (Anthopleura artemisia) at Davenport Landing.
9 June 2016
© Allison J. Gong

Algae look their best when immersed. Out of the water they usually collapse into stringy or gooey masses, making it difficult to appreciate their structural beauty. This piece of Microcladia borealis was submerged in a tidepool, and fortunately there was enough light that I could take this picture.

The beautifully delicate red alga, Microcladia borealis, at Davenport Landing. 9 June 2016 © Allison J. Gong
The beautifully delicate red alga, Microcladia borealis, immersed in a tidepool at Davenport Landing.
9 June 2016
© Allison J. Gong

Day 4 - Natural Bridges, Friday 10 June 2016, low tide -0.2 ft at 09:42

Yesterday I returned with a former student, Daniel, to Natural Bridges. It was sunny and warm, completely different from how it had been on Monday. There were many boaters out on the bay, taking advantage of the glassy flat sea.

View of Monterey Bay from Natural Bridges. 10 June 2016 © Allison J. Gong
View of Monterey Bay from Natural Bridges.
10 June 2016
© Allison J. Gong

I've seen a lot of shore crabs running around on the rocks this year. On cool, damp days they just scurry about, but on warm sunny days they often sit still and literally foam at the mouth. The bubbles they produce keep their gills moist so they can still breathe even while emersed. This biggish shore crab was working up quite a froth.

Shore crab (Pachygrapsus crassipes) at Natural Bridges. 10 June 2016 © Allison J. Gong
Shore crab (Pachygrapsus crassipes) at Natural Bridges.
10 June 2016
© Allison J. Gong

Hermit crabs don't usually end up out of the water. This one was immersed in a tidepool, wearing the shell of the snail Olivella biplicata.

Hermit crab (Pagurus sp.) in shell of the snail Olivella biplicata, at Natural Bridges. 10 June 2016 © Allison J. Gong
Hermit crab (Pagurus sp.) in a tidepool at Natural Bridges.
10 June 2016
© Allison J. Gong

Nuttallina californica is one of the most common chitons seen around here. They often hunker down into small crevices where water will collect even at low tide. This individual was nestled among a clump of Phragmatopoma tubes; being closely surrounded by other animals will help keep its own body moist.

Nuttallina californica, one of the most common chitons at Natural Bridges. 10 June 2016 © Allison J. Gong
The chiton Nuttallina californica at Natural Bridges.
10 June 2016
© Allison J. Gong

Unlike the hard granite that you'd find at the southern end of Monterey Bay, the rock at Natural Bridges is a soft, easily eroded mudstone. You can scratch it with your fingernail. Limpets take advantage of this soft rock by digging themselves little home scars, which conform perfectly to the contours of their shells and make a snug, water-tight fit. The limpet leaves its home scar to forage when the tide is in and returns to it as the tide recedes. The owner/occupant of this scar has likely died, as it wouldn't have abandoned its home scar when we were there at low tide.

Home scar of a limpet (Lottia sp.) at Natural Bridges. 10 June 2016 © Allison J. Gong
Home scar of a limpet (Lottia sp.) at Natural Bridges.
10 June 2016
© Allison J. Gong

And speaking of limpets, Daniel and I spent a lot of time observing the owl limpet, Lottia gigantea. This limpet is noteworthy not only for its large size, but for its territorial behaviors. They are indeed large--the biggest ones I've ever seen are about the size of the palm of my hand--and the big ones are all females. Lottia gigantea is a protandrous hermaphrodite: individuals begin sexual maturity first as males, and then the lucky few turn into females.

Owl limpet (Lottia gigantea) at Natural Bridges. 10 June 2016 © Allison J. Gong
Owl limpet (Lottia gigantea) wearing a smaller limpet (Lottia sp.) at Natural Bridges.
10 June 2016
© Allison J. Gong

The truly remarkable thing about L. gigantea is its ability to modify the environment. The large females maintain an area called a farm, from which they diligently remove interlopers. They will scrape off settling larvae of barnacles and mussels, and will push off other limpets. Lottia farms are very common at Natural Bridges; if you are here and see a suspiciously empty patch of rock amid the mussel bed, look for a big limpet hanging out on the edge of the empty spot.

Farm of an owl limpet (Lottia gigantea) at Natural Bridges. 10 June 2016 © Allison J. Gong
Farm of an owl limpet (Lottia gigantea) at Natural Bridges.
10 June 2016
© Allison J. Gong

The owl limpet has a good reason for keeping other animals off her territory. It provides her food. This animal is indeed a farmer. See the pale zig-zag markings in the Lottia farm? Those are marks made by the limpet's radula as she grazes over the rock. All limpets are grazers, but L. gigantea actively manages her farm so that she feeds on one area while allowing the algal film to grow on other areas, then rotates to a new feeding spot as the old one becomes depleted. Pretty clever for a snail, isn't it?

It felt really good to spend some quality time with Mother Nature again. I'm still taking it very easy, careful not to get overtired and to continue letting my brain heal. Getting outside for even short periods definitely seems to help.

In recent years, citizen science has become a very important provider of biological data. This movement relies on the participation of people who have an interest in science but may not themselves be scientists. There is some training involved, as data must be collected in consistent ways if they are to be useful, but generally no scientific expertise is required. The beauty of citizen science is that it allows scientists and science educators to share the experience of discovery with people who might not otherwise know what it's like to really examine the world around them. I think it is a great step towards creating a less science-phobic society, one in which science informs policy on scientific matters.

LiMPETS stands for "Long-term Monitoring Program and Experiential Training for Students." The program seeks both to give students experience doing real science and to establish baseline and long-term ecological data for California's sandy shores and rocky intertidal areas. As an intertidal ecologist myself, I naturally wanted my students to participate in the rocky intertidal monitoring.

The LiMPETS coordinator for Santa Cruz and Monterey Counties is a woman named Emily Gottlieb. She and I decided to have my class monitor the site at Davenport Landing. Emily came to class two weeks ago to train the students in identifying the relevant organisms and recording the data.

Practice tidepooling, training for real-life monitoring in the intertidal. 15 April 2016 © Allison J. Gong
Practice tidepooling, training for real-life monitoring in the intertidal.
15 April 2016
© Allison J. Gong

Tidepooling is easy and comfortable when you do it inside a classroom seated at a table. But today was all about the real thing. It was overcast and breezy when we met up with Emily at 09:30 and headed out to the site. At first the students seemed to be a little skeptical about the whole thing.

Students get their first look at their morning workplace. 29 April 2016 © Allison J. Gong
Students get their first look at their morning workplace.
29 April 2016
© Allison J. Gong

We were extremely fortunate to be joined this morning by Dr. John Pearse, Professor Emeritus of Biology at UC Santa Cruz, one of my graduate advisors, and the founder of LiMPETS. Dr. Pearse has been monitoring some sites, including this one at Davenport Landing, since the 1970s. He is THE person to talk to about intertidal changes in California over the past 40 years.

Years ago John set up permanent transect lines and plots at Davenport Landing, marking the origin of each transect with a bolt. The first thing we had to do when we got to the site was find the bolt. Then John ran out the transect line to the lowest point that students could work safely, given the conditions of tide and swell; this happened to be about 15 meters.

Dr. John Pearse runs out the vertical transect line. 29 April 2016 © Allison J. Gong
Dr. John Pearse runs out the vertical transect line.
29 April 2016
© Allison J. Gong

For the vertical transect, 1/2-meter square quadrats were placed at each meter. Some organisms were counted as individuals and others were marked as either present or absent in each of the 25 small squares within each quadrat. Emily gave the students their assignments and data sheets, and they spread out along the transect line.

Students working the vertical transect. 29 April 2016 © Allison J. Gong
Students working the vertical transect.
29 April 2016
© Allison J. Gong
LiMPETS sampling 29 April 2016 © Allison J. Gong
LiMPETS sampling
29 April 2016
© Allison J. Gong
LiMPETS sampling 29 April 2016 © Allison J. Gong
LiMPETS sampling
29 April 2016
© Allison J. Gong
LiMPETS sampling 29 April 2016 © Allison J. Gong
LiMPETS sampling
29 April 2016
© Allison J. Gong

Aside from the experience of learning how to do this kind of data collection, I hope the students understand what a privilege it is to have been in the field with John Pearse. He has such a thorough understanding of the intertidal that he is a treasure vault of knowledge. Here he is explaining what owl limpets are all about:

Dr. John Pearse explains what owl limpets are and how to find them. 29 April 2016 © Allison J. Gong
Dr. John Pearse explains what owl limpets are and how to find them.
29 April 2016
© Allison J. Gong

Interestingly, we didn't find many owl limpets. And certainly not any of the big ones that I see all the time at Natural Bridges. John said that this is one of the differences between a protected area (Natural Bridges) and an unprotected one (Davenport Landing). Collecting is not allowed at Natural Bridges, and the owl limpets are left unmolested--by humans, at least--to grow large (10+ cm long is not uncommon). On the other hand, people do collect at Davenport and I've heard it said that owl limpets are good to eat; today we saw fewer than a dozen owl limpets and they were all small, none larger than 3 cm long.

The sun came out after a while, but the wind also picked up. The tide came up as well, and some of the students got more than a little wet. Overall they were real troopers, though, and I didn't hear much complaining. Next week is the last lab of the semester, and we'll be participating in another citizen science project. But that's a tale for another day.

I did take advantage of the beautiful setting to have one of Emily's LiMPETS volunteers (and a former student of mine!) take our class photo. Here we are, the Bio 11C class of 2016!

Class photo, taken at Davenport Landing. 29 April 2016 © Allison J. Gong
Class photo, taken at Davenport Landing.
29 April 2016
© Allison J. Gong

This morning I drove up the coast to Pigeon Point. It was cold and very windy, and I was grateful to have decided to wear all of my layers. I don't remember any cold mornings from last year's low tides, which made me think that perhaps we're returning to a more normal non-El Niño weather pattern. The wind was screaming down the coast from the north, and if it keeps up we should get some upwelling in a few days. Fingers crossed!

Even the pelicans, which can fly through strong winter storms, were having a bit of trouble with the wind:

Pelicans in flight over turbulent seas at Pigeon Point. 24 April 2016 © Allison J. Gong
Pelicans in flight over turbulent seas at Pigeon Point.
24 April 2016
© Allison J. Gong

My favorite kelp grows in the intertidal, and it wasn't having any difficulty at all with the strong surf. It's not large and doesn't form the magestic kelp forests that divers flock to, but it is very charming in its own way. The sea palm Postelsia palmaeformis is a small  (1/3-1/2 meter tall) kelp that lives only on exposed rocks sticking out into the brunt of the waves. It requires the full force of the crashing waves, where other algae would get broken off. They have a thick flexible stipe that bends with the waves and then pops back up. Postelsia is a protected organism and I can't collect it even with my scientific collecting permit, which is fine with me.

Postelsia palmaeformis on exposed outer coast at Pigeon Point 24 April 2016 © Allison J. Gong
Postelsia palmaeformis on exposed outer coast at Pigeon Point
24 April 2016
© Allison J. Gong

This is the kind of environment in which Postelsia thrives:

You can tell how windy it was by the sound of the wind and my inability to hold the camera steady. As the tide comes in the pounding from the waves will only get worse. These little algae are pretty damn impressive!

Pigeon Point has always been a good place to see the 6-armed stars of the genus Leptasterias. Unlike the five arms that most of the local asteroids have, Leptasterias has six. And unfortunately for us naturalists, the taxonomy of the genus is incompletely understood. All that is agreed upon is that there are several species in the genus. This is referred to as a species complex, acknowledging that the genus contains more than one species but that the species have yet to be definitively described.

Leptasterias sp. at Pigeon Point. 24 April 2016 © Allison J. Gong
Leptasterias sp. at Pigeon Point.
24 April 2016
© Allison J. Gong
Leptasterias sp. at Pigeon Point. 24 April 2016 © Allison J. Gong
Leptasterias sp. at Pigeon Point.
24 April 2016
© Allison J. Gong
Leptasterias sp. at Pigeon Point. 24 April 2016 © Allison J. Gong
Leptasterias sp. at Pigeon Point.
24 April 2016
© Allison J. Gong
Leptasterias sp. at Pigeon Point. 24 April 2016 © Allison J. Gong
Leptasterias sp. at Pigeon Point.
24 April 2016
© Allison J. Gong

As you can see, these stars vary quite a bit in terms of arm thickness and color pattern. Most of the time they are blotchy but the blotches can be pink, gray, orange, or cream-colored. Some of the stars have slender arms with very little taper, while others have thicker arms that taper strongly to the tips. For the time being, until the sea star systematists come to consensus about the species in this genus, I'll refer to all of them as Leptasterias sp.

Most of the Leptasterias that I see in the field are in the size range of 1-4 cm in diameter, usually no longer than my thumb. Today I saw a big one, which would have been about the size of the palm of my hand.

Leptasterias sp. at Pigeon Point. 24 April 2016 © Allison J. Gong
Leptasterias sp. at Pigeon Point.
24 April 2016
© Allison J. Gong

The reason this star doesn't look quite as big as that in the above photo is that it was eating when I disturbed it. The star was humped up over its breakfast!

Leptasterias sp. at Pigeon Point 24 April 2016 © Allison J. Gong
Leptasterias sp. at Pigeon Point
24 April 2016
© Allison J. Gong

The unfortunate breakfast item, the turban snail Tegula funebralis, was about 2 cm in diameter. It seems like a very large and well-protected prey item for a star this size, doesn't it? And yet, there it is. The animal is always right, and Leptasterias certainly knows what it should be eating.

And lastly, because they were just so beautiful and I can't help myself, I'm going to close with photos of anemones.

Anthopleura sola at Pigeon Point 24 April 2016 © Allison J. Gong
Anthopleura sola at Pigeon Point, surrounded by encrusting and upright coralline algae
24 April 2016
© Allison J. Gong
Anthopleura xanthogrammica at Pigeon Point 24 April 2016 © Allison J. Gong
Anthopleura xanthogrammica at Pigeon Point
24 April 2016
© Allison J. Gong
Anthopleura sola at Pigeon Point 24 April 2016 © Allison J. Gong
Anthopleura sola at Pigeon Point
24 April 2016
© Allison J. Gong

Take that, charismatic megafauna!

After pretty much neglecting us in February, El Niño has returned with a bang in March. Late yesterday and last night a weather station near me, more or less at sea level, recorded 4.67 inches of rain and wind speeds of 15 mph. Stations in the Santa Cruz mountains recorded close to 6 inches of rain yesterday, and there were patchy power outages throughout the county. This morning I woke to sunny, clear skies. Beautifully clear, with white puffy clouds. The forecast calls for another storm to head in this evening, giving me a window of opportunity to run up the coast and grab some mussels.

I have to say, El Niño's timing could be better. We have alternating weeks of spring and neap tides, and this winter the storms seem to be arriving during the spring tides. More than one tide series has been washed out because of storm surge and majorly big swell. I had figured that this would be the case today, so I didn't expect to get very far down in the intertidal. However the only thing I absolutely had to collect was mussels and I don't need a very low tide for those. It was very unlikely that I'd be unable to collect them, and at the very least I'd be able to take some photos.

Walking across the beach to the rocks, I noticed my first Velella of the season. As usual for these strangely wonderful animals they were gathered into windrows at the high tide level. Many of them were very small, less than 1 cm long, and the largest I saw was about the length of my thumb.

Velella velella stranded on the beach at Davenport Landing. 6 March 2016 © Allison J. Gong
Velella velella stranded on the beach at Davenport Landing.
6 March 2016
© Allison J. Gong

While it is not at all unusual to find Velella washed up on the beach, I did find some in a place that I didn't expect. More on that in a bit.

Conditions in and on the water were pretty rough. There were no surfable waves, therefore no surfers. They'd have been beat up by the waves crashing in all directions.

Rough water at Davenport Landing Beach. 6 March 2016 © Allison J. Gong
Rough water at Davenport Landing Beach.
6 March 2016
© Allison J. Gong

On a calmer day, the water at this beach can be glassy smooth with very gently breaking waves. Not so today:

Easily accessible beaches such as this one are typically crowded for these afternoon low tides. Most of the people there are just hanging out with their friends, family, and dogs. Every once in a while, however, I run into people who might not be entirely on the up and up. Much of the coast in California is designated as a marine protected area (MPA), and while allowed activities vary from MPA to MPA, in general I don't have permission to collect at any of them with my current state-issued scientific collecting permit. This means that collecting, both scientific and recreational, is concentrated into the few places where it is allowed.

Today I arrived at the parking area at the same time as a family of three adults and about five kids. The men were wearing wellies and carrying 5-gallon buckets. It was clear that they were going to be collecting something. I can't really say that I looked any different, in my hip boots and with my own bucket, so I just smiled a greeting to them and headed out on my way. Given that there was so little exposed rock, we were bound to keep running onto each other. At one such meeting I asked what they were doing, and they said they were collecting mussels to eat. I said I was, too, to use as food for animals at the marine lab. They asked what the limit was. I told them that I didn't know what the limit was for taking with a marine fishing license (assuming that they had one), but the limit for my collecting permit is 35. We nodded and went our separate ways.

Now, I'm not a game warden and it's not my job to enforce the state's rules about collecting, or even to see if other citizens have the appropriate permits or licenses. I generally feel that the better part of valor is to mind my own business. These guys today were friendly enough and completely non-threatening, but my gut instinct tells me that they didn't have a fishing license. Is that any of my business? I don't think so; yet as a citizen of this state I have a vested interest in protecting our wildlife from unlawful take. I know there aren't enough wardens to patrol all beaches all the time, and now that I think about it I don't know that I've ever been stopped by a warden on an afternoon low tide. The enforcement strategy seems to be to let citizens patrol each other, in the sense that skullduggery is less likely on a crowded beach in the broad daylight of afternoon than at the crack of dawn on a morning low tide.

Anyway, on to the matter at hand. I've noticed that recently my eye has been drawn to patterns that occur among whatever objects happen to be around. Scrambling down a little cliff and continuing up the coast I noticed these smears of algae growing on the vertical sandstone face. It's not that I hadn't seen them before, but because of the recent rain there was water running down the cliff face, which added a sheen to the green algae that they don't have when they're dry.

Streaks of green algae on sandstone cliff face at Davenport Landing. 6 March 2016 © Allison J. Gong
Streaks of green algae on sandstone cliff face at Davenport Landing.
6 March 2016
© Allison J. Gong

At this site there are some little caves that you can get to at low tide. The tide wasn't low enough to reach the caves that go back any appreciable distance, but I did get to a small one. It was more of deep fissure than a cave, really, large enough to duck into but only a couple of meters deep. The really cool thing about it was the waterfall cascading over the opening. Again, without the runoff from yesterday's rain this little waterfall wouldn't even exist.

Also, there is quite a bit of stuff living inside the cavelet. Not much in the way of algae, of course, with the exception of both encrusting and upright corallines, but in terms of animals there was more or less the same fauna that I'd expect in the high-mid intertidal.

Cavelet at Davenport Landing Beach. 6 March 2016 © Allison J. Gong
Cavelet at Davenport Landing Beach.
6 March 2016
© Allison J. Gong

The biggest surprise in this little cave was Velella! A bunch of them had apparently gotten washed up into the fissure by the last high tide. I found them stuck amongst barnacles and algae.

Velella velella stuck to coralline alga inside cave at Davenport Landing. 6 March 2016 © Allison J. Gong
Velella velella stuck to coralline algae inside cave at Davenport Landing.
6 March 2016
© Allison J. Gong

This one was maybe half the length of my thumb. On the opposite side of the cave a crab was taking advantage of this unusual bounty.

Small shore crab (Pachygrapsus crassipes) dining on a mangled Velella velella in a cave at Davenport Landing Beach. 6 March 2016 © Allison J. Gong
Small shore crab (Pachygrapsus crassipes) snacking on a mangled Velella velella in a cave at Davenport Landing Beach.
6 March 2016
© Allison J. Gong

I can't imagine there's much nutrition in a Velella for a crab, but the animal is always right even (especially?) when it doesn't make sense to us. The crab knows what it's doing.

All told, it was a short but very satisfying little jaunt to the intertidal. The clouds had spent the afternoon talking about whether or not to build to anything, and by the time I left they'd come to consensus. The wind is picking up now, the rain should start soon, and the National Weather Service says we may be in for thunderstorms tonight. I'm tucked up at home, warm and dry. Have a good evening, everybody!

Davenport Beach

While much of America was glued to the television watching a football game, I went out to the intertidal at Davenport Landing to do some collecting and escape from Super Bowl mania. The Seymour Center and I have a standing agreement that some animals--small hermit crabs and certain turban snails, for example--are always welcome, which gave me an excuse to look for them. I also needed to pick up some algae for labs that I'm teaching later this week, so it was an easy decision to be alone in nature for a couple of hours.

As usual, I was easily distracted by the animals, especially the anemones. They are simply the most photogenic animals in the rocky intertidal. And we have an abundance of beautiful anemones in our region; I feel very lucky to photograph them where they live. I would like to share them with you.

First up, Anthopleura sola:

Anthopleura sola 7 February 2016 © Allison J. Gong
Anthopleura sola specimen #1
7 February 2016
© Allison J. Gong
Anthopleura sola 7 February 2016 © Allison J. Gong
Anthopleura sola specimen #2
7 February 2016
© Allison J. Gong

Second species, Anthopleura xanthogrammica:

Anthopleura xanthogrammica 7 February 2016 © Allison J. Gong
Anthopleura xanthogrammica
7 February 2016
© Allison J. Gong
One large and one small Anthopleura xanthogrammica 7 February 2016 © Allison J. Gong
One large and one small Anthopleura xanthogrammica
7 February 2016
© Allison J. Gong

Along the central California coast we have four species of anemones in the genus Anthopleura. Two of them, A. xanthogrammica and A. sola, are large and solitary; in other words, they do not clone. The geographic ranges of these two species overlap in central California. Anthopleura xanthogrammica has a more northern distribution, from Alaska down to southern California, while A. sola typically lives from central California into Mexico.

I've seen these congeneric anemones living side-by-side in tidepools at Natural Bridges and at Davenport. Here is a photograph from yesterday. The animals are almost exactly the same size, and are separated by about 30 cm. Can you tell which is which?

So, which is which? 7 February 2016 © Allison J. Gong
So, which is which?
7 February 2016
© Allison J. Gong

The pièce de résistance yesterday was a treasure trove of Anthopleura artemisia anemones. I'd seen and photographed them several times before, and always appreciated the variety of colors they come in. For some reason, though, yesterday they really caught my eye. I had a number of "Wow!" moments.

Anthopleura artemisia specimen #1. 7 February 2016 © Allison J. Gong
Anthopleura artemisia specimen #1.
7 February 2016
© Allison J. Gong
Anthopleura artemisia specimen #2 7 February 2016 © Allison J. Gong
Anthopleura artemisia specimen #2
7 February 2016
© Allison J. Gong
Anthopleura artemisia specimen #3 7 February 2016 © Allison J. Gong
Anthopleura artemisia specimen #3
7 February 2016
© Allison J. Gong

Sometimes two colors are combined:

Anthopleura artemisia specimen #4 7 February 2016 © Allison J. Gong
Anthopleura artemisia specimen #4
7 February 2016
© Allison J. Gong

Stunning, isn't it?

But this next anemone is unlike any I've ever seen before. Get a load of this:

Anthopleura artemisia specimen #5 7 February 2016 © Allison J. Gong
Anthopleura artemisia specimen #5
7 February 2016
© Allison J. Gong

These stark white tentacles are new to me. The anemone measured about 4 cm across. In every other aspect it looks like A. artemisia, and I'm almost entirely certain that's what it is. It does feel special to me. I will hopefully be able to keep an eye on this individual and see if its colorless tentacles are a temporary or long-term condition. And now that my eye has been primed to see the colors that A. artemisia comes in, I may notice more unusual color morphs.

One of the best things about teaching is the opportunity to keep learning. Case in point: yesterday I attended an all-day teacher training session for the LiMPETS program, so that I can have my Ecology students participate in a big citizen science project in the rocky intertidal later this spring. In the Monterey Bay region LiMPETS is organized and run out of the Pacific Grove Museum of Natural History, where yesterday's training took place. LiMPETS has two ongoing citizen science projects, one looking at populations of mole crabs (Emerita analoga) on sandy beaches and the other monitoring population of several invertebrate and algal species on rocky shores. Of course, my interests being what they are I signed up for the rocky intertidal monitoring project.

We spent the morning learning about the history of the program and how to identify the organisms that are monitored, then after lunch went out to Point Pinos to collect some data and work through the process that we need to teach to our students. The day before we'd had a high surf advisory on the coast, and yesterday the swell was still big. We hiked out to the study site and set up the transect line, which runs from the top of a rock through the entire range of tidal heights to the low intertidal.

LiMPETS study site at Point Pinos. 6 February 2016 © Allison J. Gong
LiMPETS study site at Point Pinos.
6 February 2016
© Allison J. Gong
One of our instructors, the intrepid Emily, sets the transect line. 6 February 2016 © Allison J. Gong
One of our instructors, the intrepid Emily, sets the transect line.
6 February 2016
© Allison J. Gong

Where Emily is standing is about 10 meters along the transect line. The monitoring protocol calls for sampling at every meter on the transect. One of the other teachers, Phaedra, and I were the only ones wearing hip boots, so we volunteered to work at the lowest spot. We thought we'd start with the 10-meter quadrat and hopefully get down to the 11-meter quadrat once the tide receded a bit more. Then we got hit by a few big waves and decided that discretion is the better part of valor and gave up. It was a pretty easy decision to make, especially after the quadrat got washed away and we had to go fetch it when the waves brought it back.

Field gear. 6 February 2016 © Allison J. Gong
Field gear.
6 February 2016
© Allison J. Gong

All told the group collected eight quadrats of data. We had a little time to poke around (i.e., take pictures) before heading back to the museum for data entry.

A gorgeous chiton! 6 February 2016 © Allison J. Gong
A gorgeous chiton! I don't know which species it is.
6 February 2016
© Allison J. Gong
Codium fragile, a filamentous green alga. 6 February 2016 © Allison J. Gong
Codium fragile, a filamentous green alga.
6 February 2016
© Allison J. Gong

Codium is an interesting alga. These cylindrical structures are composed of many filaments, which in turn contain multi-nucleate cells. Yes, the cells contain multiple nuclei. Codium fragile has the common name "dead man's fingers," I suppose because. . . well, I actually have no idea. As far as I can tell they don't feel anything like a dead man's fingers, or the way I imagine a dead man's fingers would feel.

There were quite a few empty abalone shells scattered among the rocks. As we were hiking out I found this shell. When I tried to pick it up I found that it was still alive, and well stuck to the rock. This is a very good sign, as the black abs have been suffering from withering syndrome, in which the animal gradually loses its ability to hang on.

Haliotis cracherodii, the black abalone, wearing a few barnacle friends. 6 February 2016 © Allison J. Gong
Haliotis cracherodii, the black abalone, wearing a few barnacle friends.
6 February 2016
© Allison J. Gong

All in all, this workshop was a lot of fun. If I have to give up an entire Saturday to do training, it couldn't get much better than spending at least part of it in the intertidal. And Point Pinos is such a fabulous intertidal site that I certainly wouldn't turn down an opportunity to explore there again.

2

The new moon is tonight, which of course means that we are in spring tides. Yesterday afternoon my friend and colleague Scott joined me for my first visit to the intertidal in 2016. And where to go for this inaugural field excursion of the new year, but to Franklin Point? Low tide was at 15:53 yesterday, so we met up at 14:00, stopped to fill up the gas tank, and headed up the coast. Expecting it to be crazy windy as afternoons tend to be on the coast, I had dressed in extra layers. Scott and I were surprised to emerge from the car and find it wasn't windy at all, so even though the air temperature was cool at least we didn't have to deal with any significant amount of windchill factor.

Hiking over the dunes we saw Unusual Thing #1--a bridal photo shoot. A couple of stretches of the trail are covered by a boardwalk, and on the first of these we encountered a bride decked out in full regalia--wedding dress, flowers, hair, make-up--and two photographers. They were very nice and let us pass through in our decidedly inelegant boots and field gear. I didn't think it would be very nice to take their picture. However, I did think that they'd lucked out and gotten a great day for photography: the aforementioned lack of wind meant that the bride wasn't freezing in her slip of a wedding dress, and the afternoon light was flat so there were no shadows or harsh glare.

Descending onto the beach we came across Unusual Thing #2--an elephant seal.

Male elephant seal (Mirounga angustirostris) hauled out on the beach at Franklin Point. 8 January 2016 © Allison J. Gong
Male northern elephant seal (Mirounga angustirostris) hauled out on the beach at Franklin Point.
8 January 2016
© Allison J. Gong

It is e-seal haul-out time at Año Nuevo State Park a few miles down the road from Franklin Point, and I've seen them on the beach a few times before. This was the first time I'd seen an adult male, though, and he was HUGE! Without being stupid and going over to stand next to this animal it's hard to depict how large he is, and unfortunately there wasn't anything in the vicinity to give a sense of scale. So trust me, or look it up for yourself, male elephant seals are ginormous. This big guy was taking a siesta, and we could hear him snoring. He did wake up and lift his head to look at us, but we gave him plenty of room as we walked past and he returned to his nap.

One of the reasons I wanted to see Franklin Point after the El Niño storms of the past week was to see how much sand had been washed away from the beach. Sand typically accumulates on California coastal beaches during the dry storm-less months of summer and autumn, only to be flushed away by storms the following winter. After a particularly violent storm or a series of storms occurring in a short time, very large amounts of sand can be removed from a beach. For the past four years we haven't had much of a winter storm season (hence the awful drought) and the beach at Franklin Point has been tall and gently sloped. I'd grown accustomed to this state of affairs, which makes what we saw yesterday qualify as Unusual Thing #3--rocks that had been covered with sand for years and are now exposed.

To set the stage, here's a picture that I took on an afternoon low tide last year on 17 March 2015:

Franklin Point beach on 17 March 2015. © Allison J. Gong
Franklin Point beach on 17 March 2015.
© Allison J. Gong

And here's yesterday's photo from the same general area:

Franklin Point beach on 8 January 2016. © Allison J. Gong
Franklin Point beach on 8 January 2016.
© Allison J. Gong

Can you see how much steeper the beach is in yesterday's photo? And those rocks on the left side? They are not visible in the photo from last spring because they were under sand!

Here's a closer look at the newly exposed rocks:

Newly exposed rocks at Franklin Point. 9 January 2016 © Allison J. Gong
Bare rocks at Franklin Point.
9 January 2016
© Allison J. Gong

You can see exactly how high the sand was last summer. What's really exciting is that these rocks represent pristine habitat that has yet to be exploited. I can look at primary ecological succession this spring! Well, at least until the sand returns and buries the rocks again.

As we meandered among the rocks in the intertidal, Scott and I both noticed an abundance of abalone shells. Fairly early on we spotted this black ab shell lying emersed above the water line:

Black abalone (Haliotis cracherodii) at Franklin Point. 8 January 2016 © Allison J. Gong
Black abalone (Haliotis cracherodii) at Franklin Point.
8 January 2016
© Allison J. Gong

Turning the shell over we saw Unusual Thing #4--an abalone showing signs of withering syndrome:

Ventral view of a black abalone (Haliotis cracherodii) at Franklin Point. 8 January 2016 © Allison J. Gong
Ventral view of a black abalone (Haliotis cracherodii) at Franklin Point.
8 January 2016
© Allison J. Gong

We were actually surprised to see that the animal was alive. Healthy living abalone are firmly attached to rocks, tucked into crevices. This one wasn't attached to anything, just lying on the sand. We picked it up, turned it over, and found the body of the animal shriveled up and filling up only about half of the space it should have occupied. It didn't respond to gentle pokes but wasn't dead yet, or at least not dead enough to pass the stink test for deadness.

Withering syndrome is a bacterial disease that inhibits digestive function in abalone. To stave off starvation the infected animal begins to digest its own body tissues. As a result the entire body shrinks and eventually the foot can no longer stick to rocks. In California it affects black abs and red abs (H. rufescens). Until the recent years of warmer-than-usual water black abs (H. cracherodii) had been most common in southern California, but I've been seeing more of them in the past few years. Now it looks like the disease that plagues them has accompanied them up the coast. It's not surprising, given the current El Niño conditions.

This gives me another thing to keep an eye out for in my intertidal excursions. I'll start keeping track of abalone and see if withering syndrome becomes more prevalent. Might as well start with this afternoon's low tide!

In defiance of post-nasal drip and an ominous tickle at the back of my throat, I got up early again this morning and went out on the low tide. I skipped yesterday's low tide in favor of getting a little more sleep, thinking that it would help me fight off this incipient summer cold, but I didn't want to miss two of the three intertidal trips I had planned for this weekend. So I made the quick drive up to Davenport Landing, where low tide was at 06:4o.

The first thing I noticed when I got down to the beach was that the algae have started piling up. There were drifts that I sank into almost knee-deep. Fortunately they hadn't really started decomposing yet, so the smell wasn't too bad. That will change if it stays warm and the high tides don't wash any of the algal detritus back out to sea.

Looking back at Davenport Landing beach, from the north. 2 August 2015. © Allison J. Gong
Looking over piles of algal detritus towards Davenport Landing beach, from the north. 2 August 2015.
© Allison J. Gong

It's treacherous stuff, that algal duff. It covers up deep holes and slippery rocks, so each footstep becomes an adventure. Because it has been so warm I had considered going out in shorts and surf booties, but more than once this morning I was glad to be wearing my hip boots.

It was a busy day for nemertean worms. Nemerteans are unsegmented, slimy, predatory worms that feed by shooting out a proboscis and wrapping it around prey. In some nemerteans the proboscis is armed with a stylet that injects toxins to help immobilize prey, which are often small polychaete (segmented) worms. Nemerteans are not uncommon, but are often inconspicuous and easily overlooked. None of the ones that I saw today were actively hunting.

Nemertean worm (Paranemertes peregrina) at Davenport Landing, 2 August 2015. © Allison J. Gong
Nemertean worm (Paranemertes peregrina) at Davenport Landing, 2 August 2015.
© Allison J. Gong

As you can see, the body of this worm is not segmented. However, it has the same body wall musculature that you'd find in the polychaetes, which are the segmented marine worms. It uses the muscles to alternately contract and elongate the body and move forward. In most nemerteans neither the head nor the tail end is particularly distinguishable, but in worms you can usually tell the anterior (head) end by the direction of locomotion. Here's a video:

Continuing to play with the 'microscope' setting on my camera, I took this picture of a chiton (Mopalia muscosa):

Mopalia muscosa at Davenport Landing, 2 August 2015. © Allison J. Gong
Mopalia muscosa at Davenport Landing, 2 August 2015.
© Allison J. Gong

I'm still learning how to make that compromise between super-macro and depth of field on this setting. The chiton in the above photo is about 4 cm long so I wasn't zoomed in terribly far, and I like how it is in focus but some of the other critters are as well.

On the reef to the north of Davenport Landing beach there's a large pool that gets to a bit more than knee deep on me, and is cut off from the ocean during low tide. This pool has proven to be a great place to practice my underwater picture taking. The past couple of times I've come out here I've seen schools of surfperches swimming in this pool. The school contains large individuals (about as long as my hand) and smaller ones that I think are the babies of the big ones. I haven't been able to catch one--for some reason I've never included a dipnet in my collecting gear, preferring to catch sculpins with my hands--but I think they are shiner surfperches (Cymatogaster aggregata).

Before trying to photograph the fishes underwater, I shot some video from above:

It turns out that photographing fish underwater isn't as easy as I thought it might be. Surfperches are pretty skittish and I couldn't get as close to them as I wanted. However if I stood still for a minute or so they forgot about me and would resume their normal behavior. In the meantime I did sort-of-accidentally take some cool pictures of the pool from below the surface.

Large tidepool at Davenport Landing, 2 August 2015. © Allison J. Gong
Large tidepool at Davenport Landing, 2 August 2015.
© Allison J. Gong
Large tidepool at Davenport Landing, 2 August 2015. © Allison J. Gong
Large tidepool at Davenport Landing, 2 August 2015.
© Allison J. Gong

And finally, fish!

Shiner surfperches in large tidepool at Davenport Landing, 2 August 2015. © Allison J. Gong
Shiner surfperches (Cymatogaster aggregata) in large tidepool at Davenport Landing, 2 August 2015.
© Allison J. Gong

Last, but certainly not least, in this same large pool I found several anemones. The most brightly colored are the Anthopleura artemisia. I love how their tentacles can be such a vibrant translucent orange or purple, or the oral disc can have that deep saturated red color.

Anthopleura artemisia at Davenport Landing, 2 August 2015. © Allison J. Gong
Anthopleura artemisia at Davenport Landing, 2 August 2015.
© Allison J. Gong
Anthopleura artemisia at Davenport Landing, 2 August 2015. © Allison J. Gong
Anthopleura artemisia at Davenport Landing, 2 August 2015.
© Allison J. Gong

Hard to believe that these animals are the same species, isn't it? Then again, to an alien scientist studying humans it might be hard to believe that a Viking, an Australian aboriginal and I (an Asian-American) are the same species. It's all simply a matter of perspective.

3

This morning I went on a solo trip to one of my favorite intertidal sites up the coast a bit. I've been busy with stuff at the marine lab and my house is a construction zone this summer so it was really nice being alone in nature for a couple of hours before most people had gotten out of bed.

I didn't find what I was looking for but did see some great stuff that I wasn't looking for, which is just as rewarding.

The approach to the beach over the dunes is always spectacular even on a gloomy morning. I find this color palette very soothing.

The hike over the dunes, 5 June 2015. © Allison J. Gong
The hike over the dunes, 5 June 2015.
© Allison J. Gong

The site itself is rocky with a sandy bottom. Depending on the severity of recent storm action there can be more or less sand. Winter storms wash sand away, while in the summer the sand tends to accumulate and can bury the rocks to surprising depths.

Surfgrass bed (Phyllospadix sp.) and rocks at Franklin Point, 5 June 2015. © Allison J. Gong
Surfgrass bed (Phyllospadix sp.) and rocks at Franklin Point, 5 June 2015.
© Allison J. Gong

It may be an optical illusion, but when I'm scrunched down in amongst the rocks it appears that the waves are breaking at heights quite a bit above my head. Most of the water's force is dissipated as the waves wash over the rocks, and unless I've wandered out too far, by the time it gets to me all I need to worry about is whether the surge will overtop my boots. Which has indeed happened and makes for a cold squelchy morning.


And now for some happy snaps!

A small mid-intertidal pool at Franklin Point, 5 June 2015. © Allison J. Gong
An example of intertidal biodiversity at Franklin Point. The most conspicuous organisms are Ulva (sea lettuce), coralline algae (the pink stuff), small acorn barnacles, the tube-dwelling worm Phragmatopoma californica, and small anemones in the genus Anthopleura. 5 June 2015.
© Allison J. Gong
I love my hip boots!  © Allison J. Gong
I love my hip boots!
© Allison J. Gong
Pagurus hirsutiusculus hermit crab in shell of the snail Olivella biplicata, 5 June 2015. © Allison J. Gong
Pagurus hirsutiusculus hermit crab in shell of the snail Olivella biplicata, 5 June 2015.
© Allison J. Gong
A beautifully camouflaged kelp crab (Pugettia producta) hiding in plain sight, 5 June 2015. © Allison J. Gong
A beautifully camouflaged kelp crab (Pugettia producta) hiding in plain sight, 5 June 2015.
© Allison J. Gong

Because, really, doesn't everybody have a favorite red alga? This is mine. It presses gorgeously and is so damn beautiful!

Erythrophyllum delesserioides, 5 June 2015. © Allison J. Gong
Erythrophyllum delesserioides, 5 June 2015.
© Allison J. Gong

At one point I saw a worm-like thing thrashing around in a shallow pool. Turns out it was a polychaete worm, probably in the genus Nereis, doing epic battle with a predatory nemertean worm (Paranemertes peregrina). By the time I figured out what was going on and stuck my camera in the water the interaction had more of less come to an end. The polychaete did get away without apparent damage, but it was moving pretty slowly afterward. In this video Nereis is the segmented worm that's doing all the wiggling, and Paranemertes is the purple and beige unsegmented worm that you can sort of make out in the top of the frame. I wish I had been swifter on the uptake with the camera.


And the pièce de résistance for this trip:  A little sea hare! This guy was so small (about 2.5 cm long) that at first I thought it was a clump of red algae. Then I saw the little rhinophores (those ear-like projections that give them their common name) and recognized it as a sea hare. Amazingly cute!

A little sea hare (Aplysia sp.), 5 June 2015. © Allison J. Gong
A little sea hare (Aplysia sp.), 5 June 2015.
© Allison J. Gong

I was lucky enough to capture some video of this critter crawling around.

Aside from the rhinophores it doesn't look hare-like at all, does it? I wonder about common names sometimes.

All in all, it was a great morning. An early morning low tide is the best reason I can think of to crawl out of bed at 04:30!

4

Answer:  When it's a snail! Yes, there are snails that secrete and live in white calcareous tubes that look very similar to those of serpulid polychaete worms. Here, see for yourself:

Serpula columbiana, a serpulid polychaete worm, at Point Piños, 9 May 2015. © Allison J. Gong
Serpula columbiana, a serpulid polychaete worm, at Point Pinos, 9 May 2015.
© Allison J. Gong

The worms secrete calcareous tubes that snake over whatever surface they're attached to. When the worm is relaxed, it extends its delicate pinnate feeding tentacles and uses them to capture small particles to eat; they are what we call suspension feeders.

Serpula columbiana polychaete worms, Seymour Marine Discovery Center, 11 May 2015. © Allison J. Gong
Serpula columbiana polychaete worms, Seymour Marine Discovery Center, 11 May 2015.
© Allison J. Gong

But there are gastropods that secrete calcareous tubes, too. They are the vermetid snails, the local species of which is Thylacodes squamigerus. This is one of my favorite animals in the low intertidal, probably because it is so delightfully un-snail-like.

There are three individuals of T. squamigerus in this photo:

The vermetid snail Serpulorbis squamigerus at Point Piños, 9 May 2015. © Allison J. Gong
The vermetid snail Thylacodes squamigerus at Point Pinos, 9 May 2015.
© Allison J. Gong
Serpulorbis squamigerus at Point Piños, 9 May 2015. © Allison J. Gong
Thylacodes squamigerus at Point Pinos, 9 May 2015.
© Allison J. Gong

Thylacodes is also a suspension feeder, but it gathers food in a very different way. When submerged, it spins out some sticky mucus threads that catch suspended particles, then reels in the threads and eats them.

So how would you tell these animals apart if you see them? Here's a hint:  Look at the tubes themselves.

I invite you to use the comments section to tell me how you'd distinguish between Serpula and Thylacodes.

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