After a thrilling week of marine mammal displays in the Vancouver area, scientists and researchers say they're excited about the possibility that something is finally going right in the ocean.

Metro Vancouverites were delighted earlier this week when a grey whale made a tour of downtown from False Creek. The excitement only grew when a pod of more than 150 Pacific white-sided dolphins frolicked off Horseshoe Bay on Thursday.

Andy Miller, staff scientist with the Wilderness Committee of Western Canada, told CTV News that he's as pleased as everyone else about seeing such an abundant number of sea mammals so close to the city.

"The whales and dolphins are a sign of what could be just normal, everyday life in Vancouver, if we keep on this trend of taking better care of the oceans, taking better care of the fisheries, and thinking about the stuff we put down the drain," Miller said.

Grey whales were once bordering on extinction in the Eastern Pacific, but have made an amazing recovery in the last century.

"Their population has doubled over the past 20 years, up to 20,000 animals now," Miller said.

Pacific white-sided dolphins were also severely threatened by gillnet and drift net fisheries until the early 1990s, when those industries started to decline.

A convergence of positive factors has brought the animals back from the brink.

The fact that this is an El Nino year has helped -- warmer waters are beckoning both the invertebrates and small fish sought by the grey whales and dolphins.

Other factors leading to the recent sightings, Miller says, are government efforts to place restrictions on chemical dumping in local waters.

Mill and mine closures along Howe Sound have also helped herring and other small sea creatures to return in record numbers, bringing the larger mammals along with them.

"All levels of government have put a ton of money into cleaning up a bunch of toxic waste sites. There's still a lot to clean up but we're certainly going down the right path," Miller said.

Still, he's hesitant to say that B.C.'s ocean life is in the clear.

"I still think we need to be vigilant. TransAlta wants to put a pipeline with tar-sands oil through the Lower Mainland. All this controversy about oil and gas exploration, and drilling -- this maybe is an opportunity to have a collective discussion as a society of whether we want whales and dolphins or whether we want oil and pipelines."

Miller's other wish is for the B.C. government to follow the lead of Pacific coastal states like Alaska and California, which have banned fishing for herring.

He believes that could go a long way towards seeing even more spectacular displays of nature in our local waters.