40 years ago Alaska pioneered the use of sonar to track salmon runs
January 16, 2012
The goal of making Alaskans more aware of one of Alaska’s most important fish counting tools has been accomplished with the launch of new web based project that lets visitors see three types of sonar in action.
The site explains that traditional tools such as weirs and counting towers can be used to count salmon in clear, narrow streams, but not in wide, turbid rivers.
“To gauge salmon runs we can’t see, we have taken a lesson from one of Mother Nature’s fish finding experts. In glacial silt laden bays and rivers, beluga whales find salmon by emitting high pitched calls and listening for returning echoes. Similarly, we have adopted sonar as a tool to detect salmon not by sight, but by sound,” it explains.
Sometimes conditions are so harsh, the equipment can’t operate properly, such as at the Pilot Station site on the Yukon River.
“It is a mile wide and you almost have to imagine sand dunes changing in a wind storm on the bottom,” said Debby Burwen, a research biologist with Fish and Game’s sport fish division in Anchorage who helped spearhead the project. “But that is where they need to count the salmon because they are trying to ensure that enough fish escape to Canada. In order to do that, they have to know how many fish are coming into the river.”
Burwen said people also don’t realize that managers never depend solely on sonar information, especially on the more complicated rivers, like the Yukon and the Kenai.
“But the public doesn’t know that. So when we do have a problem, say on the Yukon, they look askance at all sonar,” she said. “They think that once again the sonar is broken, and Fish and Game doesn’t know what it is doing.”
“We write these wonderful reports and we communicate with other scientists, but if your user groups don’t know what you’re doing, what good is it.”
The sonar web site project provides virtual tours of all 13 rivers, as well as radio programs and downloadable brochures. www.alaskafisheriessonar.org
Friday the 13th
This column went to press on Friday the 13th – A life of danger and uncertainty has seafarers observing a strict set of rules that are steeped in myth and superstition.
Many sea going beliefs are based on the Bible. For example, Friday is the worst day to set out to sea because most sources credit that to the belief that Christ was crucified on a Friday. Similarly, Sunday is the best day to begin a voyage, because Christ’s resurrection on that day is seen as a good omen. Thus the old adage, ‘Sunday sail, never fail.’
A traditional view for centuries was that women had no place at sea. They weren’t strong enough and men would be distracted from their duties, angering the seas and dooming a ship. Lore has it, however, that a naked woman would calm the seas. That’s why many vessels have a bare breasted figurehead of a woman on the bow.
Some others: For hundreds of years bananas have been regarded as bad luck – reasons stem from causing ships to disappear to spider bites. Pouring wine on the deck will bring good luck on a long voyage as a libation to the gods. Dolphins swimming with a ship are a good omen, while sharks following is a sign of inevitable death.
Black cats are considered lucky – not so flowers, which could be used for a funeral wreath. It’s unlucky to kill an albatross or a gull at sea, as they host the souls of dead sailors. And whistling on the bridge will whistle up a storm. Cutting your hair or nails at sea is a no no, and don’t ever step onto a boat with your left foot, or stir a pot or coil a line counter clockwise.
Marine myth has it that sailors pierced their ears to improve their eyesight. A gold earring was both a charm against drowning and the price paid to Davy Jones to enter the next world if a sailor died at sea.
This year the US became the first country to put catch limits on every species it manages. That includes all fish and shellfish caught in waters from three to 200 miles from shore. For Alaska, that means 80% of the total annual catch.
The outlook this year for both supply and markets is good. Market expert Ken Tally summed it up as ‘supplies of major species are expected to increase worldwide, with prices to stabilize with the strong demand.’
Pollock – the world’s largest food fishery – is holding steady for the biggest producers: Alaska and Russia. For cod, the groundfish bellwether global fisheries are picking up in the Atlantic, and the Barents and Baltic Seas. In Alaska, Pacific cod supplies this year are expected to increase 4.2 percent.
Total groundfish catches in the Gulf of Alaska are pegged at 3% higher to about a half billion tons. That includes a nice 15% increase for black cod (sablefish).
Here is something you don’t often hear: for fisheries in the Bering Sea and Aleutian Islands region, scientists said groundfish stocks could sustain a catch of 2.5 million tons – or roughly 5.5 billion pounds in 2012. But years ago overseers on the North Pacific Fishery Management Council – with full support of the industry - imposed a 2 million ton cap on total allowable groundfish catches in the BS/AI as a conservation measure.
This year marks the 21st year for this weekly column that focuses on Alaska’s seafood industry. It began in 1991 in the Anchorage Daily News, and now appears in over 20 newspapers and web sites. A daily spin off – Fish Radio – airs weekdays on 30 radio stations in Alaska. My goal is to make all people aware of the economic, social and cultural importance of Alaska’s fishing industry to our state, the nation and the world.