Creating a window on 'oceans in motion'

Scientists and resource managers could soon have a highly detailed picture of marine conditions and the migrations of fish and ocean animals throughout the world, according to international experts convening a landmark conference in Canada June 27-30.

Academics, scientists and technical experts at the meeting aim to throw open a large, vivid new global window on marine life by expanding worldwide the work of two pioneering North America-based programs that follow the movements of important species using electronic tags.

Convening at Dalhousie University, Halifax, the experts will announce a global collaboration, the Ocean Tracking Network, whose goal is to tag a vast range of ocean animals large and small with low-cost devices that vary in size from an almond to a AA battery and to follow them via an extensive international array of acoustic receivers on the sea floor.

Tags harmlessly collect and report information as an animal travels along, and can record water temperatures, salinity and even light conditions encountered at various depths and locations. Depending on the variety of tag used, the data is revealed when an animal is recaptured, surfaces (sending the archived data to a satellite) or passes one of many acoustic receivers arrayed on the ocean floor along the coastal shelf, akin to the process of scanning UPC codes at a store check-out.

“Every fish, every pelagic animal is a submarine and we have much to learn by electronically harvesting information about their movements,” says Prof. Ron O'Dor, who leads the Dalhousie-based Ocean Tracking Network, the meeting host. “Today we know less about our marine life – how these animals live, where they go – than we know about the back side of the moon.

“Revolutionary new technologies open the path not just to smarter fisheries management, to better sea life conservation measures, and to the potential of abundant and sustainable stocks of commercial fish, they will also provide scientists with a massive increase in observations of rapidly shifting marine conditions in this era of climate change,” says Dr. O'Dor.

The conference marks the first meeting of all stakeholders in the global enterprise – including scientists who tag animals, scientists and government officials who will collect, interpret and use the data, and technology experts who have made it possible to follow the migration of these animals, often in near real-time.

The meeting will help determine priority species for tracking – from salmon to whales and from polar bears to penguins – and priority areas for ocean floor acoustic monitoring arrays.

“These are key questions: which species do we want to track and exactly where do we wire up the world to create an effective global system of watching the oceans in motion,” says Dr. O'Dor.

Continental shelves average about 80 km (50 mi) wide, and the edge of the shelf occurs at an average depth of about 200 m (660 ft), where it falls steeply into the deep sea. Salmon and many other marine animals travel extensively along shelves.

A pilot array has been successfully demonstrated by the British Columbia-based Project POST (Pacific Ocean Shelf Tracking), part of the international Census of Marine Life. The current array stretches more than 1,750 km, from Oregon through British Columbia to north of the Alaskan panhandle.

POST has revealed the Pacific migration routes of young wild salmon from US and Canadian rivers. Knowing their usual travels along marine highways has far-reaching implications for authorities that need to determine when fisheries should be open or closed to conserve endangered stocks. Other scientists from around the world attending the conference have placed related technology on a variety of other fish species, including sturgeon, halibut, sharks and tunas.

Among other benefits, the array technology will provide insights into how animal behaviours change should ocean waters continue to warm. POST leader David Welch will be joined at the Dalhousie conference by Census of Marine Life colleagues from California-based Project TOPP (Tagging of Pacific Pelagics), who have forged the process of tracking large open ocean animals with tags that report in via satellite whenever they surface.

TOPP has to date tracked thousands of individual Pacific Ocean animals spanning 21 top predator species, including whales, tuna, elephant seals, seabirds, sea turtles and sharks.

“Tiny microprocessors and sophisticated remote sensing systems now make it possible for scientists to explore the vast reaches of the open ocean from the perspective of the marine animals, whose extraordinary travels make them highly effective 'oceanographers',” says the project's Principal Investigator, Prof. Barbara Block of Stanford University.

“TOPP is excited to be part of this new Ocean Tracking Network and the promise it holds of enlarging the number and variety of species under surveillance throughout a new, integrated global network.”

Changing the way the world sees the oceans

Dr. O'Dor says the Ocean Tracking Network has agreed with local authorities to install an initial new array in Prince William Sound to track salmon sharks in the northern Gulf of Alaska region.

And he says partners to track marine animals and the state of ocean conditions have been identified on all continents.

The OTN plans a highly interconnected network that spans 14 ocean regions: The Arctic and Southern Oceans, the Indian Ocean (East, West), the Atlantic (NE, NW, SE, SW), the Mediterranean, and the Pacific (NE, NW, SE, SW and Mid-ocean).

The group says funding sought from Canada of roughly US$32 million to supply the Canadian array technology would potentially leverage total spending by all partners estimated at US $150 million in such areas as ship time, tagging, data harvesting and interpretation.

“Contrary to 19th-century views that the oceans were essentially infinite, the 20th century showed us that human activities can transform ocean ecosystems on a global scale and the 21st century, so far, leaves little doubt that problems will compound as climate change occurs,” says Dr. O'Dor, who is also Senior Scientist for the Census of Marine Life.

“We hope that together we can lay the foundation for better management of living resources in the sea,” says Dr. Block. “Technology is enabling scientists to collect information that is vital for future marine management.”