By Robert J. Galbraith for the Toronto Star 10/08/10
Two-hundred kilometres east of Quebec City, along the North Shore of the St Lawrence River, lies some of the most magnificent scenery to be found in North America. This region is rugged, raw and picturesque, and attracts close to a million tourists yearly. But it is not only humans that are attracted to this natural wonder. More than 13 species of marine mammals can be found here. Among these are ten species of whales, including the snow-white beluga and the largest animal ever to exist on earth; the blue whale.
The presence of such a high concentration of whale prey is due to a unique convergence of oceanographic conditions referred to as upwelling and tidal mixing. The waters of the Saguenay River, the St Lawrence River and the deep Laurentian Trench (which funnels cold, saline ocean water westward) meet at the mouth of the Saguenay Fjord where they are violently forced upwards (upwelling) by the abrupt end of the trench.
These colliding bodies of water bring nutrient-rich waters from the deep abyss up to the surface, where they trigger an explosion of life forms that are the base of the food chain, turning the St. Lawrence Estuary into a constantly churning, whale food factory.
However, between 2000 and 2005, whale researchers became concerned when they noticed a large drop in the number of fin and minke whales in the park. They didn’t know the reason behind it, or the future effect on the whales and the multi-million-dollar whale watching industry, but they knew they had to investigate.
In 2008, Parks Canada researchers and their main collaborators (the Department of Fisheries and Oceans, the Group for Research and Education on Marine Mammals (GREMM) and a number of universities) decided to undertake a long term study to address the mystery of what influences prey numbers, their distribution, abundance and variability, while focusing primarily on the two main prey types; including capelin and sand lance (small sardine-sized fish), and krill, a shrimp-like component of zooplankton. By putting all this information together, they hope they will be able take steps to ensure that vital habitats used by the prey and predators are protected.
“That’s why the whales are here in the first place, because of the availability of the prey,” explained Nadia Menard, an ecosystem scientist with Parks Canada and the head of the study, based in Tadoussac.
“This is the second year of what we hope will be a long term study, to see how the situation with prey availability and the marine mammals that feed on it will evolve, focusing on their feeding habitat. We want to know the options available as food. It will also help us to better understand the underlying reasons for the high biodiversity in the park.”
What the scientists came to realize is that they didn’t understand the basic, underlying ecological processes controlling the whales’ prey. As well, they didn’t have a means or program in place to monitor the prey.
“We don’t know the basic question of how many whales come into an area in a given year. Or how is capelin being produced and where? How does it even get here? We don’t know if this prey comes from Saguenay, the Gulf or upstream in the St. Lawrence,” Menard confessed. “It’s all part of the big puzzle for which we have a few pieces, but until we put it all together, through this research, we really can’t see the image, or general view of how this ecosystem works.”
The prey not only influences the numbers of whales utilizing an area, but they are the keystone prey species that feed the entire biodiversity of the Marine Park and St Lawrence estuary in general. If the prey species drop in numbers, so do the whale numbers. “It is the abundance and concentration of prey that dictates how many predators will be found in an area,” described the researcher. “But this basic ecological info was not available and we know there are many factors involved. We want to try to document these ups and downs. We needed to get a better grasp of what to expect, or what was going on, as we know there’s good years and bad years as environmental conditions are not a constant.”
All the whale species that use the estuary are migratory, except for the beluga, which lives in the area year round.
After leaving the estuary on migration around October -November, many of the whales, it is thought, don’t eat for as much as six months while they seek warmer waters in the Caribbean and other warm water regions of the Atlantic where they calf and mate. (Most whales don’t like ice as it affects their ability to capture food and they could become trapped beneath it and drown. It is also too cold to give birth to calves).
The southern breeding waters may be warm and clear, but they are also void of prey, so the whales have to fatten up in the St Lawrence so they can build up the needed blubber resources to fuel them through this lean period, till they return the following spring to the estuary. This is why the Marine Park is so vital. It’s all about eating as much as possible as fast as possible while the table is laid.
There’s a continual feeding frenzy going on offshore of Tadoussac, Les Bergeronnes and Les Escoumins, the heart of the whale feeding grounds. It is a feasting ‘ground zero,’ where creatures from the smallest krill, up to the 200-ton blue whale, fatten up. But there are at least two distinct feeding areas.
One of these is just off Tadoussac at the mouth of the Saguenay, where minke and beluga whales chase fish through the boiling, churning, white-capped waters. It is raw nature at its best. This is where ripping currents caused by the merging bodies of water are boosted by the incoming and outgoing tides and wind.
This washing machine effect helps the whales trap the fish. It is specialized hunting which only a few species like the beluga and minke can utilize, because of the force of the currents.
A handful of kilometres downstream from the washing machine, where the water settles more peacefully, you can find grey seals, harbour seals, harbour porpoise, finback, minke and humpback whales and a host pelagic birds, all feeding on the fish and krill drawn to the slow churning waters near the shoreline where the prey concentrates. This area could be considered the whale watching Mecca of North America, for anyone interested in whales, nature and sea life.
The Marine Park and surrounding area is known worldwide as one of the best whale watching destinations on the planet and a 2008 study showed that over to 500,000 tourists brought in between $80 million and $100 million in economic spin-offs for this North Shore, Manicouagan region.
There have been at least 13 species of marine mammals seen in the Park, including seals and dolphins. Some of these include the more locally common, minke, finback, humpbacks and beluga, but even blue whales and more rarely, sperm whales are occasionally seen.
Menard explained that the belugas can eat up to 50 different species of prey. “But capelin and sand lance (two species of small, silvery fish) seem to be their favourites. We would like to protect the breeding and rearing habitat of the capelin, but we first must know where they came from and factors that influence their abundance.” Special emphasis will be put on small fish like capelin because there is very little known about them, though it is at the top of the menu for a large number of species. “We hope to understand the predator’s options for food. Right now there is a herring spawn happening for example.”
The researcher used the example of the sea urchin fishery to describe her point of why we need to understand the interconnected web of the ecosystem, to ensure sustainable use.
“The sea urchin fishery in this area is relatively new, beginning in the 1990’s, and at its beginning there were very few rules governing the harvest. They were fished 12 months a year with no limit. Sustainable fisheries are a big issue worldwide, so the Department of Fisheries and Oceans, in collaboration with Parks Canada and local fishermen, led a study to find out just how much we can take (of urchins). From the study, it was concluded that they can only take so much fishing pressure or else we risk a collapse of the species. So fisheries managers restricted the harvest to one month a year in a defined area and only 5 boats are allowed to partake.”
Fishermen trap the sea urchins and remove their egg sacks, which are a very expensive delicacy in many parts of the world, especially in Japan.
“There is a small capelin industry based in Les Escoumins (about 25 kilometres north east of Tadoussac), so “We need to know how much we can fish for it before it starts to affect the marine mammals and even the bird life,” explained Menard. “We need to protect the spawning grounds for these small fish that many of the whales utilize. If we over-fish it, it will have a direct, negative affect on the marine mammals and also the pelagic birds,” described Menard. “We know a lot about major commercially fished species such as cod or snow crab, but not for non-commercial or less targeted species such as sand lance or capelin.”
Some whale species found in the Park are listed as endangered or threatened, so the best way to take steps to protect an animal is to know everything possible there is to know about it, including its food needs.
To understand the complex relationships and document the prey, Menard and her colleagues visit different sites aboard a Parks Canada boat, using hydro-acoustic sonar devices for locating the prey concentrations, coupled with routine oceanographic and biological sampling methods, such as using fine-meshed plankton nets for collecting prey.
A sampling grid records biological and physical parameters in the Marine Park as well as surrounding waters for comparison. An observer on board is dedicated to survey wildlife species (marine mammals and birds). All data is geo-referenced for GIS, (geographic information systems that combine the merging of cartography, statistical analysis, and database technology.) to allow mapping of physical (depth, salinity, temperature) and biological (pelagic fish and zooplankton biomass estimates, numbers of whales, seals or seabirds observed at the surface) factors.
The study will give a clearer understanding of what’s going on beneath the surface of the Marine Park and influence decision-making based on science for Parks Canada and its partners such as the Department of Fisheries and Oceans. “There’s a lot of co-operation between the different groups doing research, on the basic biological mechanisms that are operating in the system,” described Menard.
The study is primary to ensure that the whales have the best survival conditions. It will allow the researchers to develop a monitoring program based on ecosystem components (biodiversity and processes) and link much of the present and past research, which has focused on physical oceanography or on top-level predators (whales, seals and seabirds).
Regionally, it will provide information to influence fisheries managers to the importance of preserving prey species and for municipal planning to protect spawning areas from coastal development.
Menard says that there was a rebound in whale numbers in 2006, compared with the observed lows between 2000-2005, and that the numbers have been fairly consistent since then. But this only makes researchers like Menard thirst even more, to find the reasons behind these fluctuations, to understand them. This is the fuel that drives the researchers on, as they try to unlock the secrets of the whales of the St. Lawrence Estuary.
The Saguenay-St. Lawrence Marine Park and its surrounding waters, are a very special place for those that visit, and if you open your eyes and mind, it has a way of putting you in your place on a worldly perspective. It is also the best holistic medicine for the soul that one can find, and, as you stand on the shoreline or on the deck of a whale watch boat viewing these amazing cetaceans, be ready for a life-changing, spritual experience.
We owe it to the creatures that inhabit this natural, watery treasure, and to those yet unborn generations of humans, to do our best to preserve this special place in perpetuity to the best of our abilities, not for domination or plunder, but so we can hold our heads high and boast to the world that we are a progressive, civilized nation where we protect and preserve all forms of life, including our marine heritage.
“The origins of life clearly originated from the oceans,” explained Menard, “and although we’re obviously terrestrial animals, we still have that fascination for where all life initially originated. The whales here are like the ambassadors to our past and future with the sea. ”
Sidebar—Even at night the gorging doesn’t cease, and visitors to the area who camp along the waterfront will be entertained by the loud spouting of minke and finback whales that slide by like ships in the night, just a few metres offshore from your tent. You go to sleep serenaded and soothed by the resonance of their spouting that echoes through the water to the shoreline granite, where your tent stands and into your ear drums. You are awakened in the morning by the swoosh of more spouting – a whale alarm clock!
Pierre Beland, a beluga expert and research scientist with the St Lawrence National Institute of Eco Toxicology, explained that, “plankton migrates and moves closer to the surface of the water at night, as compared to during the day, (when they are found deeper). Here the depth plunges to over 1000ft, just metres offshore. Small fish feeding on the plankton move closer to the shoreline to take advantage of the concentrating. Then whales like the minke, move closer to shore to trap and eat the small fish against the rock structures that line the shore. But it’s the plankton that drives the whole thing,” unveiled the 63-year-old researcher. “This is an evolutionary strategy, a never ending battle between predator and prey.”
RJG – August, 2010.