Spotting whales and dolphins was easier than usual this year. Orcas (killer whales) spent much of the summer in Active Pass and along local shores, delighting ferry travelers and boaters.

Humpbacks were regularly observed in B.C. waters, Pacific white-sided dolphins cruised through Howe Sound, and gray whales thrilled Vancouverites and tourists, from Granville Island to Kits Beach.

Marine mammals are doing better than a few decades ago, when hunting, aquarium capture and ocean pollutants had brought many to the brink of extinction.

We also know much more about them.

Only in the 1970s did biologist Michael Biggs discover that there are completely separate orca populations, with different morphology, diet, and sounds.

Near the Fraser estuary, we have resident and transient orcas.

The southern residents, grouped in J, K and L pods, feed on chinook, other salmon, and squid; they are most commonly seen here between June and October.

They travel in large family groups, led by a matriarch, and stay together their whole lives.

These orcas are on the endangered species list.

Transient orca pods normally consist of the matriarch, the eldest male offspring and, at most, one or two other offspring.

They move fast and erratically along the coast, chasing down their prey of harbour seals, seal lions, and other marine mammals.

Their numbers may have increased in recent years, as more are being seen.

The False Creek gray whale made international news, yet these gentle giants are regular visitors to the mouth of the Fraser River and Boundary Bay on spring migration.

They churn up amphipod crustaceans by rolling on the mud bottom of the bay, sifting the tiny creatures through great baleen plates in their mouths.

A few spend each summer feeding in Boundary Bay and are visible from Crescent Beach in 性视界传媒.

They are part of a slowly increasing population of 鈥渟easonally resident鈥� gray whales, maternally guided from Baja California to their feeding grounds and showing site fidelity in subsequent years.

The rest of the eastern Pacific population, about 26,000 animals, travels up the coast from Baja to spend the summer off Alaska; they leave northern waters in mid-October and arrive back in Mexico in December.

This tremendous migration, over 8,000 km one way, is one of the longest of all the mammals, challenged only by the humpback whale, a species which is also slowly returning to the Georgia Strait.

Like the gray whale, humpbacks were hunted out and took decades to return.

The northern Pacific population, fewer than 1,400 in 1966, is now about 20,000.

This success in restoring whales to the Strait is heart warming and shows what can be done with good legislation.

To ensure whales and dolphins survive into the future, sustained effort is needed to maintain food sources, eliminate pollution, and prevent boat-mammal collisions.

For more information and to report observations, visit the Orca Sightings Network website at www.orcanetwork.org

Anne Murray is the author of two nature books: A Nature Guide to Boundary Bay and Tracing Our Past - A Heritage Guide to Boundary Bay, available at bookstores. Visit  www.natureguidesbc.com