Guardians of the Sea: Marine Birds on the Frontlines of a Changing Ocean

From the fog-laden cliffs of Newfoundland’s Cape St. Mary’s to the puffin-packed rock stacks of Elliston, Canada’s marine birds paint a living tapestry of life at sea on the East Coast.

Atlantic puffins, northern gannets, and black guillemots are some of the charismatic seabirds that define these coasts, their colonies alive with squawks, flapping wings, and the constant bustle of survival. These birds offer a glimpse into the incredible diversity of marine birds worldwide, whose lives are shaped by the rhythms of the ocean. Yet beneath this vibrant spectacle lies a warning: the seas are changing, and the survival of these birds hangs in the balance. From Newfoundland to the far reaches of the world’s oceans, marine birds are navigating the same shifting seas, facing the same pressures from climate, scarce prey, and human activity.

Marine birds are masters of precision. Puffins juggle dozens of tiny fish like capelin in their beaks, ferrying them back to hungry chicks. Northern gannets dive from dizzying heights, slicing into the water to chase schools of herring and mackerel. Black guillemots hunt the nearshore labyrinth of kelp, snatching fish, shrimp, and sea worms with lightning reflexes. For all of them, timing is everything: the right food at the right moment is the difference between thriving and failing. But the balance is fracturing. Rising ocean temperatures are shifting prey farther, deeper, and sometimes out of reach entirely.

Small forage fish like capelin and sand lance, once abundant each spring and summer, are arriving too early, too late, or not at all. Puffins time their breeding so chicks hatch when food is plentiful, but when capelin scatter, parents must fly farther, work harder, and often return with smaller, less nutritious meals. The consequences are stark: fewer chicks survive, fledglings are lighter, and fewer adults return to breed.

Northern gannets face a similar fight. Their success depends on predictable schools of herring and mackerel. Shifts in currents and water temperatures push prey into unfamiliar depths or distant waters. Gannets can dive deep, but every extra trip drains energy they need to feed their chicks.

Black guillemots, tied to their rocky nearshore homes, feel these shifts acutely. Declines in sea worms and small crustaceans ripple through the food web, reducing the fish and invertebrates that sustain them. With fewer options nearby, raising young becomes an uphill battle.

Life in Large Colonies: A Strength Under Threat

Marine birds nest in huge colonies for good reason. Thousands of gannets on cliffs, puffins in burrows, and guillemots on narrow ledges gain protection from predators, share information about food, and coordinate breeding.

At Cape St. Mary’s Ecological Reserve, 30,000 northern gannets gather each summer in a tumult of wings and calls. In Elliston, the puffin colony draws visitors and photographers, a living symbol of biodiversity. These colonies are more than scenic, they’re barometers of ocean health.

But when prey is scarce, dense colonies can become a disadvantage. Competition at feeding grounds rises, energy demands increase, and chicks are less likely to survive, affecting entire colonies.

Overfishing Adds Pressure

The challenges don’t stop with climate. Decades of commercial fishing have thinned stocks of the very fish these birds depend on. Harvesting capelin, herring, and other forage fish competes directly with wildlife. Scarce prey forces birds already stressed by warming seas to travel farther, risking their own health to feed the next generation.

The ripple effects of overfishing are profound. Entire food webs wobble under the pressure. Some birds find fewer energy-rich fish; others face shortages of both fish and invertebrates. Combined with warming seas, depleted stocks make raising chicks, and maintaining healthy populations, even more difficult.

What We Can Do: Choices That Matter

Though they may seem like distant symbols of the wild, our daily choices can have a lasting impact on the world these birds call home.

Choosing sustainable seafood. Look for labels like Ocean Wise, a Canadian program highlighting ocean-friendly options. Supporting responsible fisheries protects the food marine birds rely on.

Reducing food waste. Greenhouse gas emissions drive climate change, and much of it comes from the food we throw away. Planning meals, storing food properly, and composting scraps all contribute to a healthier planet and more resilient oceans.

Getting involved in citizen science and stewardship. Organizations like Birds Canada and Nature Canada track colonies, stranded wildlife, and ocean health with public help. Every observation, every hour volunteered, fuels research and strengthens conservation.

Supporting science-based fisheries management. Advocate, vote, and engage in policies that protect key forage species and prioritize ecosystem health. Careful planning and sustainable catch limits help ensure fish populations remain strong for wildlife and for coastal communities alike.

Canada’s marine birds are more than symbols of wild coasts; they are sentinels of a changing ocean. From puffins juggling capelin in their beaks to gannets plunging in perfect arcs, these birds reveal the rhythms of a living sea. By making thoughtful choices in seafood, energy use, and conservation, we can ensure the wings, calls, and bustling colonies of these remarkable birds continue to thrive, here, and around the world, for generations to come.