Saturday, June 11, 2016

An Intertidal Exploration: Gulf of California (Baja Sur and Sonora)

In 1940, Biologist Ed Ricketts and writer John Steinbeck spent 6 weeks exploring the intertidal zone of the Gulf of California. They came equipped with crew, supplies, and extensive biological knowledge, and they returned to Monterey with thousands of specimens in jars, plus extensive notes that would become The Log from the Sea of Cortez. We spent 9 weeks exploring about 125 miles of the Gulf Coast of Baja California Sur with a point-and-shoot camera and a minimum of invertebrate knowledge, returning with thousands of photographs and more questions than answers.

Steinbeck compares his and Ricketts' collecting expedition to that of Charles Darwin on the Beagle:
He was called a "naturalist." He wanted to see everything, rocks and flora and fauna; marine and terrestrial. We came to envy Darwin on his sailing ship. He had so much room and so much time. He could capture his animals and keep them alive and watch them. He had years instead of weeks, and he saw so many things. Often we envied the inadequate transportation of his time—the Beagle couldn't get about rapidly. She moved slowly along under sail. And we can imagine that young Darwin, probably in a bos'n's chair hung over the side, with a dip-net in his hands, scooping up jellyfish. When he went inland, he rode a horse or walked. This is the proper pace for a naturalist. Faced with all things he cannot hurry. We must have time to think and to look and to consider. And the modern process—that of looking quickly at the whole field and then diving down to a particular—was reversed by Darwin. Out of long long consideration of the parts he emerged with a sense of the whole. Where we wished for a month at a collecting station and took two days, Darwin stayed three months. Of course he could see and tabulate. It was the pace that made the difference. And in the writing of Darwin, as in his thinking, there is the slow heave of a sailing ship, and the patience of waiting for a tide. The results are bound up with the pace.
Tidepooling can be a very addictive activity. You walk along looking for movement, patterns, or colors, or you gently turn over rocks to see what hides beneath (always replacing the rocks so that the animals get their homes back). Spotting an anemone waving its tentacles, you lean in closer and discover an entire world in miniature: a living diorama hollowed out of rock and filled with a few cups of seawater. A patch of seaweed is host to a tiny nudibranch grazing on its favorite food. A flicking movement turns out to be a crab sorting through pebbles. A small jet of water from under a rock ledge might be the octopus Sue glimpsed for a millisecond before it slipped away. There were plants that looked like animals or rocks and animals that looked like plants or rocks. Everywhere we went, there were things we did not recognize and could not categorize even at a basic level. This constant exposure to the unknown—combined with a relative lack of schedule and obligation for each day—was somewhat intoxicating and one of the greatest pleasures of our trip.

Below is a sampling of what we saw. Some images are identified, some are tentatively identified, others are perhaps misidentified (or labeled with outdated names), and still others are included because they are intriguing or fun. Most of the photos were taken with the camera held just above the water's surface.


NUDIBRANCHS
Mexican dancer nudibranch (Elysia diomedea), Sue's favorite nudibranch, with its fringes and bright blue horns. 2" long. Isla Coyote, Bahia Concepcion. 

Ink-stain nudibranch (Polycera alabe) gazing out over its underwater domain. About ⅔" long. Roca Solitaria off Bahia Agua Verde.

Aeolid nudibranch species. About 1" long. Isla Danzante.

Unknown nudibranch. About ⅔" long. Roca Solitaria off Bahia Agua Verde.



SEA STARS

Bradley's sea star (Mithrodia bradleyi). Honeymoon Cove, Isla Danzante.

Common sun star (Heliaster kubiniji). Bahia San Pedro (Sonora). Often seen just at the tide line, washed by waves.

Yellow-spotted star (Pharia pyramidata). Playa Coyote, Bahia Concepcion. We saw many of these while snorkeling but they were rarely close to the surface.

Sea star. Isla Coyote, Bahia Concepcion.


WORMS

Common fireworm (Eurythoe complanata), a stinging worm. 2" long. Bahia San Marte. John Steinbeck and Ed Ricketts collected hundreds of these during their 1940 expedition to the Gulf of California (Sea of Cortez).

Spiral-gilled tube worm (Spirobranchus giganteus). Each set of spirals was about half an inch across. Roca Solitaria off Bahia Agua Verde.

Featherduster worm (Sabellid sp.). The fan closes up quickly when the worm senses danger, such as the shadow of Sue's camera, and then it reopens gradually after about 30 seconds. Bahia San Marte.

Flatworm species. About 1" long. Roca Solitaria off Bahia Agua Verde.



SEA ANEMONES

Anemone (Bunodosoma sp.?) with sea urchins. Bahia San Pedro (Sonora).

Warty anemone species (Bunodosoma sp.)? What a color! Roca Solitaria off Bahia Agua Verde.

Warty anemone (Bunodosoma sp.). Bahia San Pedro (Sonora).

Warty anemone (Bunodosoma sp.). Bahia San Pedro (Sonora).

Anemone (Bunodosoma sp.?). Isla Danzante.

Mat anemone (Palythoa ignota)? A colonial species. Caleta San Juanico, Gulf Coast of BCS.

Warty anemone (Bunodosoma sp.). Bahia San Pedro (Sonora).

Anemone? Bahia San Pedro (Sonora).


CRABS

Lumpy-claw crab (Eriphia squamosa), an aptly named critter. Bahia San Marte.

Unknown small crab from Bahia San Marte. Sue calls it the "domino" crab.


Unidentified crab. Its shell is camouflaged with green, red, yellow, and white splotches. Can you tell where the crabs shell stops and the rock begins?


Curtis found this small crab on our anchor chain as we were leaving Bahia Concepcion (BCS) to cross back to Sonora. In the photo below, you can see she is carrying eggs! We put her back in the water before crossing.





SEA URCHINS

Black sea urchin (Stomopneustes variolaris)? Roca Solitaria off Bahia Agua Verde.


SEAWEED

Colorful seaweed? Sue found it difficult at times to distinguish between animals and plants. Roca Solitaria, off
Bahía Agua Verde.


SNAILS

Unknown snails with wonderful geometrically marked shells. Isla Danzante.



CORALS

Coral at Caleta San Juanico, Gulf Coast. We saw more colorful corals in deeper water but could not get photos.

Coral? Bahia San Pedro (Sonora).


HYDROIDS (maybe)

Maybe a stinging hydroid, although there are other similar-looking organisms. Roca Solitaria, off Bahía Agua Verde.


Hydroid? Roca Solitaria, off Bahía Agua Verde.


MISCELLANEOUS, not in perfect focus

Tiger snake eel (Myrichthys maculosus): a lucky daytime find! Its head was in a crevice so it didn't notice Sue's kayak
drifting overhead. Bahia Concepcion, near Playa Coyote.

Venus's girdle (Cestum veneris), a type of comb jelly. At least 12" long. Sue saw this creature swimming next to her kayak in Honeymoon Cove, Isla Danzante.

Cortez barrel shrimp (Gnathophyllum panamense). About 1" long. Bahia San Marte.

Sue's motley assortment of invertebrate and intertidal fauna field guides:

  • Sea of Cortez Marine Invertebrates, Alex Kerstitch & Hans Bertsch
  • Marine Animals of Baja California: A Guide to the Common Fishes and Invertebrates, Daniel W. Gotshall
  • Tidepool Animals from the Gulf of California, Wesley M. Farmer
  • The Edge of the Sea of Cortez: Tidewalkers' Guide to the Upper Gulf of California, Betty Hupp & Marilyn Malone
  • Common Seaweeds of the Gulf of California [bilingual], Mark D. Readdie, Marla Ranelletti, Richard M. McCourt