Author Dianne Hales

Marine science

The Sexiest Tenants of the Tide Pool

Jul 24, 2026 | , , , , , , , ,

They are the rock stars of marine invertebrates.  Fabulous and flamboyant, they live fast, reproduce furiously and die young.   But they are also evolutionary marvels:  chemical wizards, crafty thieves, sly poisoners—and the sexiest of intertidal residents.

Beachcombers call them sea slugs. Marine biologists categorize them as nudibranchs (rhymes with swanks and translates as “naked gills”), relatives of snails that shed their shells early in life. While many aquatic creatures rely on camouflage, nudibranchs flaunt eye-popping colors—regal purple, hot pink, electric blue, neon yellow—and exuberant patterns.

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Summer School for Seabirds

Jul 10, 2026 | , , , , , , , , , ,

There’s a baby boom on the northern California coast.  

Cliffs and offshore rocks that seemed almost lifeless through winter are teeming with seabird families. Through my binoculars, I watch tiny Western Gulls wobbling on spindly pink legs, secretive Pigeon Guillemots ferrying fish into invisible nests, and Common Murres preparing their youngsters for one of the most astonishing leaps in the bird world.

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A Nest to Call Home

May 29, 2026 | , , , , , , ,

The mission: Construct a home for soon-to-be-born offspring.

The rules: Use only scavenged materials.  Carry them to the site in your mouth. Employ nothing but your appendages as tools.  Ensure shelter from wind, water, and roving bandits.

The seabirds in love introduced in a previous post set to work. As monitors for the Seabird Protection Network on the Northern California coast, we watch and wonder: Where can these parents-to-be, who spend much of the year over open water, find safe haven on our rugged shore?

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A Seal Mom’s Lullaby

May 1, 2026 | , , , , , , ,

Their sleek, torpedo-shaped bodies dive deep and glide gracefully through the sea. On land they “galumph,” rolling back on their hind flippers then belly-flopping forward. Although harbor seals  and other pinnipeds (fin-footed animals, including sea lions and walruses) may seem more at home in water, their distant ancestors once walked the earth.

Like us, harbor seals are warm-blooded, air-breathing mammals with hearts and lungs. The first time I observed a breeding colony, I realized that I have something else in common with females of the species:  We are Moms, fiercely devoted to and protective of our children.

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Bringing an  Endangered Sea Snail Back from the Brink

Mar 20, 2026 | , , , , , , ,

On a sunny January afternoon in Bodega Bay, some 70 miles north of San Francisco,  the White Abalone Culture Lab is humming with activity.

It’s spawning day. Alyssa Frederick, the lab’s program director, invites me into an industrial room full of troughs and tubs of bubbling seawater. The abalone program is tucked away in the UC Davis Bodega Marine Laboratory, a research facility devoted to studying ocean and coastal health. The goal is to bring the endangered sea snails, known for their iridescent shells and delicate meat, back from the brink.

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What’s A Sand Dollar Worth?

Mar 6, 2026 | , , , , , , , ,

On a blustery March morning, I crouch at the Pacific’s edge to inspect a delicate white disc tossed onto the beach by the surging tide. Suddenly a passer-by shouts:

“They call them ‘dollars,’ but they aren’t worth anything!”

The naturalist in me bristles. I want to run after the stranger and make him look—really look—at the remarkable creature in my hand. Even in death, the intricate skeleton of a Pacific sand dollar (Dendraster excentricus) retains its elegance and beauty.

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Star Power

Feb 20, 2026 | , , , , , , , ,

In the galaxy of shimmering sea stars, none shone brighter than the spectacular sunflower star. Bigger, bolder and hungrier than any of its kin, Pycnopodia helianthoides could unfurl as many as two dozen arms, rocket across the ocean floor and devour a purple sea urchin in moments. As an apex predator—dubbed the “Death Star” by awed divers—it feared none and was feared by all.

Then, almost overnight, it vanished.

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The Amazing Journey of Modern Whales

Feb 6, 2026 | , , , , , , , , ,

“Do you think whales ever walked the earth?”I thought the captain of a whale watch boat in Monterey Bay was asking a trick question.  But it’s no riddle—it’s a scientifically documented, evolutionary fact.

The largest creatures on the planet, whales are classified, along with dolphins and porpoises, as cetaceans, from an ancient Greek word for sea monster.  However, they descended from rather humble four-legged mammals that hunted and fished along the riverbanks of what is now Pakistan and India.

In one of evolution’s most dramatic U-turns, these land dwellers returned to the ocean from which their ancestors had emerged. In a geological blink—roughly 10 million years—they reshaped their bodies for an aquatic life. Fur thinned. Limbs flattened. Tails strengthened.  Nostrils began their slow migration to the top of the head. Hooves gave way to flukes

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Snow in the Sea

Jan 9, 2026 | , , , , , , , ,

It’s snow time in  the Northern Hemisphere, the season of winter wonderlands and skiers’ delight. But most landlubbers don’t realize—as I didn’t until recently—that it’s always snowing in the sea.

This underwater snowfall, known as marine snow, drifts through every ocean on the planet. The term was coined in the early 1950s by Japanese researchers who described “snowflakes” swirling in waters stirred by their submersible. Invisible from shore and rarely noticed even by sailors, the silent drizzle helps keep the oceans productive and the planet healthy.

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