A recent scientific expedition in Howe Sound held a surprise for researchers.
Last month, Vancouver Aquarium fish research scientist Jeff Marliave was a guest aboard the WE Ricker as Fisheries and Oceans Canada officials conducted mid-water trawling in Howe Sound. The scientists were gathering information on the different species hauled aboard.
“This is the first time the deep trawl has ever been done [in Howe Sound],” Marliave said.
What scientists found was unexpected. The nets caught adult herring, a species previously thought to migrate out of the sound once individuals reached the adult stage.
“The mythology is that they all move out to the open ocean,” Marliave said. “And maybe there was a while where they were from places where the government biologists were looking, but they never looked here.”
The boat's net yielded older herring opposite Bowen Island and a high density of two-year-old herring in the surface waters near Squamish. That could explain the white-sided dolphins' concentration in the region in the past couple of years, Marliave speculated. Krill was also found in abundance, which is ocean creatures' fundamental food source, he noted.
The recent explosion of life in Howe Sound seems to be centred around Squamish, Marliave said. He likens the herrings' return to the area to that which occurred in the maritime provinces in the mid-1990s.
“Things are right and they bounced back,” Marliave said. “There probably have been some herring [in the sound] all along.”
Marliave questioned whether the increased numbers can be partly attributed to shifting weather. In the past two years, the coast was hit with two La Niñas — an ocean-atmosphere phenomenon in which the Pacific Ocean's sea surface temperature is lower than average.
“I think we have had a climate regime shift, because it is just such a change,” Marliave said.
Further research on krill could provide answers, Marliave said. However, recent government cutbacks have taken much scientific work off the menu.
“Nobody is looking at that,” he said. “It is not cheap.”
Marliave is a part of the Howe Sound Research Program, an initiative funded by concerned citizens who want to see the natural history of the area documented. Exploration of the “living laboratory” has led to research breakthroughs and new discovers of marine life. For information on the program visit the aquarium's website at www.vanaqua.org.