The diverse underwater life of Monastery Beach

Mike Guardino’s truck slips into the gravel pull-off, and we start assembling the SCUBA rigs. From years of local experience, the CHS science teacher knows better than anybody the great significance that the aquatic fauna of Monterey Bay area holds.

Boy with seastarMore specifically, Monastery Beach itself is a great treasure, with its kelp forests surrounding a vast sand bank, which leads out to the steep, rocky Monterey Canyon. On this day of rough tides, Guardino and I get in the water on Monastery’s north side to view the nature it has to offer.

The most conspicuous lifeform on any dive at Monastery is the majestic giant kelp (Macrocystis pyrifera). While not a true plant (kelp is a form of brown algae), giant kelp is the closest thing underwater resembling plant life, other than eelgrass (Zostera marina), a flowering plant that inhabits the beach’s rocky shallows.

Monastery is home to a great number of invertebrates, including a dozen species of sea stars. The bat star (Asterina miniata) is most common, but the gooey leather star (Dermasterias imbricata), spiny giant star (Pisaster giganteus) and ochre star (Pisaster ochraceous), commonly found in tide pools, are among the most regularly encountered invertebrates.

If lucky, one can come across the many-armed sunflower star (Pycnopodia helianthoides), the world’s largest and most voracious sea star species.

Other invertebrates found at Monastery from the echinoderm phylum are the crack-dwelling purple sea urchin (Strongylocentrotus purpuratus), sand dollar (Dendraster excentricus), warty sea cucumber (Parastichopus parvimensis) and several species of brittle star (class Ophiuroidea).

Brown jellyfish (Chrysaora melanaster), purple jellyfish (Pelagia noctiluca) and comb jellies (Beroe sp.) gracefully float around the water column. Many crab species can be seen hanging from the kelp, such as the giant sheep crab (Loxorhynchus grandis).

Clinging to the rocks are colorful feather duster worms (Eudistylia polymorpha), which instantly hide their flashy plumes when they feel a disturbance in the water, along with red abalones (Haliotis rufescens), large gumboot chitons (Cryptochiton stelleri) and ubiquitous giant green anemones (Anthopleura xanthogrammica).

Some of the more colorful invertebrates are our local sea slugs, or nudibranchs: The Monterey dorid (Doris montereyensis) is a bright lemon yellow; the opalescent nudibranch (Hermissenda crassicornis) is translucent blue with bushy orange branches; the clown nudibranch (Triopha catalinae) is white with orange spots; and the sea hare (Aplysia californica), one of the world’s largest species, is dark purple and releases a cloud of ink if disturbed.

There is also a great diversity of vertebrates. A dozen species of rockfish (Sebastes sp.) either hide in the rocks or swim in great schools in the kelp, as commonly seen with the blue rockfish (S. mystinus).

Also abundant are the speckled kelp greenling (Hexagrammos decagrammus) and the painted greenling (Oxylebius pictus), the latter a master at camouflaging with the rocky bottom.

Massive lingcod (Ophiodon elongatus) lethargically move along the rocky bottom, and monkeyface eels (Cebidichthys violaceus) are common in crevices.

Numerous species of flatfish inhabit the sandy bottoms adjacent to the kelp forest, notably the pacific sanddab (Citharichthys sordidus), along with big skates (Raja binoculata), bat rays (Myliobatis californica) and pacific electric rays (Torpedo californica).

One can also see air-breathers underwater: Harbor seals (Phoca vitulina) will often swim alongside divers and tug at their fins, while birds such as Elegant terns (Thalasseus elegans) and pelagic cormorants (Phalacrocorax pelagicus) can often be seen diving underwater.

Home to a rich variety of wildlife in kelp forests legendary for their biodiversity and historical context, our local dive spots should never be overlooked. While the frigid temperatures may be a deterrent to some, they certainly don’t stop the many species of vertebrates and invertebrates from proliferating or the enclave of local divers from calling these reefs their underwater home.

-Ari Freedman