Sunflower stars and the hunger of recovery
May 22, 2026
The water off English Bay carries a different weight now than it did ten years ago. Below the surface, where kelp forests once swayed above a seafloor patrolled by the largest sea stars in the world, something fundamental shifted and is only now beginning to shift back. The rocky bottom here tells a story of absence and slow return.The sunflower star (Pycnopodia helianthoides) was the apex predator of these subtidal zones until 2013. Picture an animal the size of a manhole cover, twenty-four arms radiating from a central disc, moving across the rocks with surprising speed on thousands of tube feet. These stars could hunt down sea urchins, abalone, and other mollusks with relentless efficiency. A single sunflower star might consume a dozen sea urchins in a day, keeping their populations in check and preserving the kelp forests that depend on that balance. Then sea star wasting disease swept through the Pacific coast. The sunflower stars began dissolving, their tissue breaking down until nothing remained but empty shells scattered on the sand.The absence created a cascade. Without sunflower stars hunting them, purple sea urchin populations exploded. The urchins grazed kelp forests down to bare rock, creating what marine biologists call urchin barrens. Species like the northern abalone (Haliotis kamtschatkana), already struggling from overharvest, lost critical habitat as the kelp disappeared. The abalone, large marine snails that graze algae from rock surfaces, need the complex three-dimensional structure that healthy kelp forests provide. They shelter in crevices during the day and emerge at night to feed on drift algae that settles from the canopy above. Without kelp, the seafloor became a simplified landscape of rock and urchin spines.Now, nearly a decade later, individual sunflower stars are returning to these waters. They appear first as juveniles, small and cautious, but carrying the same predatory potential that once shaped this ecosystem. Each returning star represents a test of whether the marine environment can support their recovery. The survivors seem to carry some resistance to the wasting disease, though scientists are still learning what makes some populations more resilient than others. Where sunflower stars reestablish, urchin populations begin to decline. Kelp begins to recruit in patches. The seafloor starts to rebuild its complexity, one predator-prey interaction at a time. The process moves slowly, measured in years rather than seasons, as each returning star must find enough food to grow and eventually reproduce.Somewhere below the surface of English Bay, a sunflower star the size of a dinner plate moves through the underwater landscape. Its tube feet test the texture of each rock, chemical sensors detecting the scent trails of potential prey. The water above reflects the late spring light, filtering down to illuminate this careful work of reconstruction. The star's presence changes everything around it, not through force, but through the simple fact of being where it belongs, hunting where it evolved to hunt, maintaining balances that took millennia to establish and only a few years to lose.
Barn swallows and the insects of late spring
May 21, 2026
The air above Stanley Park carries a different weight this morning. Barn swallows (Hirundo rustica) slice through it in sharp turns, their wings catching light as they bank and dive. Each pass through the warming air brings insects into their mouths. The swallows have been back for weeks now, but their hunting has changed. Where they once flew leisurely loops to rebuild strength after migration, they now fly with purpose.These threatened birds time their breeding to match the emergence of flying insects from Vancouver's wetlands and forests. Midges rise from the surface of Beaver Lake in soft clouds, their brief adult lives measured in hours. Crane flies unfold from the damp soil beneath the cedars. Small moths flutter up from the understory as the day warms. The swallows read this emergence like a calendar. Their mud nests, tucked under the eaves of park buildings, now hold eggs or newly hatched young that demand constant feeding.A barn swallow catches insects at the rate of one every few seconds during peak hunting. The parent birds alternate trips, one staying with the nest while the other works the air above the lake and meadows. They target different insects at different times of day. Morning brings the emergence of aquatic midges, their synchronized hatching triggered by water temperature and light. Afternoon thermals lift beetles and flying ants from the forest floor. Evening calls up the caddisflies and small moths. Each insect species follows its own rhythm, but together they create the abundance that barn swallow reproduction requires. The timing must align. Too early, and there are not enough insects to feed growing nestlings. Too late, and the young will not be strong enough for the long flight south.The swallows' flight patterns trace these invisible insect highways in the air. They work the edges where forest meets open water, where warm air rises from sun-heated surfaces, where insects concentrate. Watch one bird for a minute and you begin to see the aerial landscape it reads. A sudden climb means insects caught in an updraft. A series of tight turns marks a swarm too dense to pass through. The bird's tail spreads and closes like a rudder, adjusting its path through air thick with prey. Each successful hunt means another few grams of protein delivered to the nest, another day closer to fledging young that will join the hunt themselves. The morning air holds both the insects and their hunters, each following patterns older than the city that now surrounds this green space.
Ochre stars and the rocky shore's balance
May 20, 2026
The tide has pulled back from the rocky shores of English Bay, leaving behind a mosaic of pools that catch the late spring light. Water drips steadily from barnacle-crusted ledges. In these temporary windows between sea and sky, ochre sea stars (Pisaster ochraceus) move with patient precision across the exposed stone.These five-armed hunters are deceptively slow. An ochre star travels perhaps six inches in an hour, but this deliberate pace masks a predatory efficiency that shapes everything around it. The star's tube feet, hundreds of them arranged along each arm's underside, grip and release in coordinated waves. When it encounters a California mussel (Mytilus californianus), the real work begins. The star wraps its arms around the mussel's shell and begins to pull. Not with sudden force, but with steady, inexorable pressure. The mussel's adductor muscles, designed to clamp the shell shut against crashing waves, cannot sustain this prolonged contest. Eventually, the shell opens just a crack. The star pushes its stomach out through its mouth and into that narrow gap, digesting the mussel from the inside.This hunting strategy maintains the rocky shore's intricate balance. Without ochre stars, mussels would carpet every available surface. Their dense beds would crowd out the barnacles, anemones, chitons, and snails that depend on open rock for attachment. The star's selective pressure keeps mussel populations in check, creating the patchwork of species that defines these intertidal communities. Each cleared space becomes an opportunity for something else to settle and grow. The star is what ecologists call a keystone species. Remove it, and the entire structure of the tide pool ecosystem shifts toward mussel dominance.But ochre stars face their own pressures. Sea star wasting syndrome has devastated populations along the Pacific coast, and these animals are now listed as threatened. The stars that remain carry the ecosystem's complexity on their slow-moving arms. In late spring, as water temperatures rise and prey becomes more active, the surviving stars intensify their foraging. They follow chemical trails through the water, homing in on the scent of mussels and other prey. Their timing aligns with the season's abundance. Mussels are filtering more plankton from the warming water, growing fat and reproductive. The stars, in turn, build the energy reserves they need for their own spawning in early summer. Watch the water in these pools as it settles between waves. Somewhere below the surface, patient hunters are maintaining a balance that has persisted here for thousands of years.
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