Graphic Monday: Boreal caribou declining in B.C., humpback whales experience resurgence
The past few decades have been good to British Columbia’s humpback and sperm whales. But the province’s boreal caribou and a tiny, vital smelt species are not doing so well.
The data, released in February 2013 on the province’s Data BC website, ranks vertebrates by their conservation status. Species are assessed on three major factors, according to Eric Lofroth, manager of the B.C. Conservation Data Centre: their population numbers, threats to the organism, and trends in the organism’s population and habitat.
But declining population numbers don’t necessarily mean an animal’s protected: A high-risk ranking might place an animal on the lists of species that require special consideration – meaning flagging them for further investigation, but wouldn’t confer “endangered” status.
“Those are policy decisions that are up to other folks,” said Lofroth. Species are added to provincial endangered and threatened species lists by provincial regulation. Being on this list increases penalties for violations of the B.C. Wildlife Act.
Some of the species thriving the most are new to B.C.; other native species are slowly failing.
Here are some highlights from the data.
This small bird’s status has gone from almost “critically imperiled” to “secure.” But the gray flycatcher is a recent immigrant to B.C., said Lofroth. “It expanded its range over Washington and Oregon during the 70s and 80s and moved into BC since probably the mid-80s,” he said.
This pretty hummingbird is another relatively recent immigrant to the province. “I can remember a time in the early 1980s where Anna’s hummingbirds were very uncommon in Victoria,” said Lofroth. They were originally found in the northwestern United States. Humans may have directly helped the hummingbird move in. “They were probably only to make it here over the winter because of hummingbird feeders. They’re very abundant in Victoria now, probably the most abundant hummingbird.” Lofroth said their range now extends as far north as the Queen Charlotte Islands, though he said that there are no studies on whether climate change helped this bird extend its range.
The whaling era hit humpbacks hard, according to John Ford, head of the Cetacean Research Program for the federal Department of Fisheries and Oceans. They were slow and lived close to shore, so they were easy for whalers to catch. One estimate showed that there were only about 1500 humpbacks in the entire North Pacific in the 1960s, Ford said.
Now, there are an estimated 20,000 humpbacks in the North Pacific, with about 2,500 of those in B.C. waters every year, he said. Although estimates are imprecise, this might be close to their historical numbers. “They’ve been increasing at perhaps 4 or 5 per cent for many years. And they’re now recolonizing many areas of the BC coast where they’ve been absent since early days.”
The reason for the resurgence? No more hunting. Whaling stations were shut down in 1967, said Ford, although Japanese and Soviet whaling continued until about 1975.
Although they still face some threats, such as being tangled in fishing gear and occasional ship strikes, the humpback’s varied diet and flexibility in habitat has helped it recolonize B.C. waters.
Similarly, the sperm whale is also much less threatened after the whaling industry was shut down in the 1960s.
“Generally they’re thought not to be in any particular trouble; there’s no particular threats or risks that they face, their numbers are probably secure,” said Ford. But he’s not sure, since sperm whales are very difficult to count. “We don’t know whether numbers increasing or stable or what.”
The problem is that the whales live in very deep water – along the continental shelf and beyond. And more than that, sperm whales often spend an hour at a time under water, which means that a passing ship might not even know they’re there.
Researchers have set up stations to record the distinctive underwater clicking of sperm whales, but are still having trouble coming up with precise numbers of the whales in B.C. waters. Still, they regularly hear clicking, so they know whales are out there.
These forest-dwelling caribou are normally found in the northeast corner of the province, but their numbers are dwindling. They are currently listed as a threatened species under the Species at Risk Act.
And they’re not just in trouble in B.C. Over the last 20 years, caribou populations have decreased more than 30 per cent across Canada, according to Environment Canada. They’re threatened by everything from habitat loss, predation and climate change to parasites, disease and noisy humans.
In October 2012, the federal government released a nationwide boreal caribou recovery strategy in response to the declining population. The plan is to mitigate habitat loss, protect critical habitat, and to make sure that caribou populations are stable and self-sustaining.
In B.C., there were approximately 1300 boreal caribou in 2011, according to the B.C. Ministry of Environment. The provincial caribou protection plan includes strategies to protect habitat from industrial activities, reduce predators and restore some previous caribou habitats.
These small smelts are also known as “candlefish”, according to Jake Schweigert, Head of Conservation Biology for the federal Department of Fisheries and Oceans. “Apparently if you dry them out, you can light them on fire because they’re got such a high oil content,” he said.
The oil made them a part of the early trade with First Nations, he said. But now their population is dwindling – they’re at perhaps only 10-20 per cent of their historical numbers, according to research currently being done at UBC, he said.
And no one knows why. “One might suspect that it’s somehow linked to global warming, but trying to figure out what the factors are behind the decline is pretty difficult,” he said.
It’s possible that changes to B.C. rivers are partly to blame, since the fish swim upriver to spawn. But population declines are also being seen in remote rivers that haven’t seen any development. Shrimp fishing may also be an issue. Eulachon and shrimp tend to cohabit, said Schweigert, and this means that the fish are scooped up by shrimp trawlers.
Fisheries and Oceans have enacted some measures to protect the fish, such as restricting First Nations fisheries and putting up some enclosures around the mouths of rivers to protect spawning. But it’s too soon to tell if these measures have been effective, he said.
The small fish has a big impact: Eulachon are an important source of food for many organisms along the B.C. coast. “Pretty much everything,” eats them, said Schweigert, including seals, sea lions, sturgeon, halibut and flounder. “If they continue to decline or were to disappear entirely, there would be a marked impact on some of the fish predators and some of the marine animals that feed on them.”