Pacific electric ray.

COLUMN: Shocking migratory changes bring electric rays to Canada’s Pacific

Trawl fishery records show 88 of these rays in B.C. waters since 1996.

By David Suzuki

Gary Krause was mystified by an unusual fish he caught in his trawl net off B.C.’s Pacific north coast in October. It was a Pacific electric ray, named for a pair of organs behind its head that can knock a human adult down with a powerful shock.

Trawl fishery records show 88 of these rays in B.C. waters since 1996.

Fishers like Krause, who worked an astounding 4,000 days at sea over the past 35 years, are often the first to observe the beginnings of fundamental ecosystem shifts. In 2008, he also identified the first ever brown booby, a tropical seabird, in Canada’s Pacific waters.

Why are creatures like electric rays, which prefer warmer southern California or Baja waters, turning up with greater frequency further north?

Unlike land temperatures, which constantly fluctuate, ocean temperatures are usually stable, with virtually no daily changes, little seasonal differentiation and only minor shifts over decades. Most marine animals prefer a narrow temperature range and move only in response to changes.

Short-term oceanographic events, such as El Niño and the Pacific “blob” – an enormous area of unusually warm water in the North Pacific –demonstrate that while oceans may be relatively stable, they aren’t immune to temperature shifts.

These phenomena explain the appearance of unexpected species off B.C.’s coast over the past winter, including a Guadalupe fur seal, green sea turtle and Risso’s dolphins.

Higher water temperatures are also changing the relative concentrations of microscopic, occasionally toxic algae.

While these marine oddities don’t necessarily indicate a full-scale ecosystem shift, they may be signs of what to expect as the planet warms.

Shorter-term phenomena correspond with longer-term oceanographic changes around the world. These changes promise to fundamentally alter the cast of characters in marine ecosystems before we’ve had the opportunity to adequately study them.

Climate change is pushing more species of fish closer – and faster – to the cooler North and South poles than similar climate-provoked wildlife movements on land. Fish are moving an average of 277 kilometres every decade and phytoplankton are speeding along at 470 kilometres. Land-based wildlife are inching along at an average of six kilometers a decade.

These shifts are bringing together species that have never had contact before, introducing new predators that could result in regional extinctions. In addition to moving, phytoplankton, which produce half the world’s oxygen and support most ocean life, have been declining dramatically over the past century, an average of one per cent a year.

Sea levels are also rising quickly because of climate change.

Over the past two decades, global levels have risen more than twice as fast as in the 20th century.

As water warms up, it expands. Thermal expansion in warmer ocean waters has been the greatest contributor to global sea level rise over the past century – although rapid melting of glaciers, polar ice caps, and Antarctic and Greenland ice sheets is also a factor.

Higher ocean temperatures also stress coral reefs, which then release algae, causing the corals to bleach and often die.

Australia’s Great Barrier Reef just experienced its worst bleaching ever, with the Great Barrier Reef Marine Park Authority reporting that half the coral in the northern parts of the reef were dead, according to a Guardian article.

Along with environmental impacts, warming oceans will create economic insecurities for industries such as fisheries. One study predicted a nearly 50 per cent decline in B.C. First Nations’ catches for culturally and commercially important fish by 2050.

We can help marine life by reducing greenhouse gas emissions to keep global average temperature increases below the 1.5 C goal set out in the December Paris Agreement.

Well-monitored fisheries, like those in British Columbia, will become essential data-collection points for understanding shifting marine environments.

Although it’s difficult to reverse temperature and other oceanographic changes that climate change has already set in motion, we may be able to lessen the impact through habitat protection, strong fisheries management and robust scientific monitoring.

The Pacific electric ray is just one of many marine canaries warning us of changing ecosystems. We’d be wise to listen to these signals.

•••

David Suzuki is with the David Suzuki Foundation.

 

 

 

 

 

 

 

 

 

Just Posted

Whisky society commits to charity donation in wake of whisky raids

Refund of Victoria Whiskey Festival tickets won’t impact charity beneficiaries

Victoria housing provider launches crisis prevention program to combat homelessness

Pacifica Housing aims to address challenges before tenants risk evictions

Victoria wins crucial WHL contest over Giants in Langley

Royals take over second in B.C. Division ahead of Vancouver

Cordova Bay group against plaza redevelopment

Cordova Bay shopping centre has three, four-storey buildings

Man hospitalized after early morning Sooke Road crash

Police say injuries are non life-threatening

WATCH: Giant waves smash Ucluelet’s Amphitrite Point

Folks made their way to Ucluelet’s Amphitrite Point Lighthouse on Thursday, Jan.… Continue reading

Wind warning back in effect around Vancouver Island

80 km/h winds expected Saturday, Jan. 20, on east coast of Island, 100 km/h on west coast

VIDEO: Thousands join women’s march events across B.C.

Today marks one year since the first Women’s March on Washington

UPDATE: BC Transit’s handyDart service strike delayed

LRB application by contractor means new strike notice must be issued by union

Two Canadians, two Americans abducted in Nigeria are freed

Kidnapping for ransom is common in Nigeria, especially on the Kaduna to Abuja highway

Are you ready for some wrestling? WWE’s ‘Raw’ marks 25 years

WWE flagship show is set to mark its 25th anniversary on Monday

B.C. woman who forged husband’s will gets house arrest

Princeton Judge says Odelle Simmons did not benefit from her crime

Women’s movement has come a long way since march on Washington: Activists

Vancouver one of several cities hosting event on anniversary of historic Women’s March on Washington

Liberals’ 2-year infrastructure plan set to take 5: documents

Government says 793 projects totalling $1.8 billion in federal funds have been granted extensions

Most Read