Some of Banff’s endangered snails may be in hot water – again.
There are predictions that one of the thermal springs which is home to the Banff Springs snail is going to completely dry up this spring, posing an imminent threat to the future of this tiny, exclusive population.
One of the biggest problems is there is no finalized emergency response plan and no facility in which to put the fragile snails in the event Kidney Spring indeed stops flowing.
Parks Canada has decided against intervening and rescuing the snails if the hot spring runs dry as expected in the coming months – which would be only the second time on record.
“We’re going to let nature take its course,” said Bill Hunt, Banff National Park’s resource conservation manager.
“We’ve made up our minds we won’t do anything if the spring dries, because there’s no effective way to store them.”
Parks has not, however, made a decision on whether the snails would be re-established should water flow predictions come true and the snails disappear.
“We would have to evaluate whether we want to reintroduce them again into Kidney spring,” said Hunt.
“One argument is that that’s inappropriate if we think that the water source is unreliable, but on the other hand, any time you can have your eggs in more than one basket, it helps ensure the persistence of the species.”
The lemon-seed sized snails on Sulphur Mountain, known as Physella johnsoni, are found nowhere else in the world and survive now only in seven hot springs.
The latest survey put the total numbers in all seven springs at about 19,700. Almost 10,000 of those snails were found within the Upper Middle Springs.
At the last count conducted at Kidney Spring on Feb. 18, there were just 543 individuals, down from 1,925 just four weeks earlier.
The population in the Kidney Spring was reintroduced in November 2003 and has thrived since then. The year before was the only other known time that spring ran empty.
Snail expert Dwayne Lepitzki said the biggest threat to the survival and persistence of this endangered species is the stoppage of the springs. Based on previous patterns in the Sulphur Mountain thermal springs, the Kidney Spring may completely run dry in the coming months.
He said the decision on whether or not to salvage this population of snails is not an easy one, saying there is presently no emergency aquarium facility in which to hold them.
“It’s an awful lot easier to move 50 snails from one spring than it is to save 50 caribou or 50 grizzly bears, but these are the types of difficult decisions to be made,” said Lepitzki.
“The big difference here is that they are found nowhere else in the world but here, and you have one jurisdiction in charge of the survival of the species.”
What used to be a rare occurrence of springs drying up along the Sulphur Mountain thrust fault is becoming more and more commonplace.
While there are many theories, scientists believe recent flow anomalies in the springs are ultimately caused by climate change.
The Upper Hot Springs have run dry 12 times in the last 15 years, typically in late winter and early spring. The popular tourist attraction is supplemented with tap water when this happens.
The only other documented times the Upper Hot Springs experienced low flows or completely stopped flowing were in 1970 and 1923.
The general pattern is the highest elevation springs will dry first. Kidney Spring, which sit second highest on the mountain, only ever ran dry in 2002, but came to within a trickle last spring.
Lepitzki said the water levels were extremely low last spring, down to as little as 5.5 litres per minute, and subsequently, the population dropped to just 37 individuals last July.
That’s just a little trickle. There was not much water. To give you an idea, it can fill a four litre milk jug in less than a minute,” he said.
“Luckily, the water came back and the snail population survived, although it dropped down to the lowest we’ve seen ever since we re-established the population in 2003.”
A research and recovery program on the unique Banff snail, its habitat and threats has been ongoing since the fall of 1995.
Both Parks Canada and Lepitzki said a five-year captive breeding program has proven snails can be raised in aquarium tanks, but there are limits and concerns.
The program was put in place to have extra snails on hand for re-establishment purposes, as well as to look at reproductive issues such as how many eggs snails lay and how quickly they hatch.
Lepitzki said the breeding program revealed snails could survive in aquarium tanks containing thermal water, but they couldn’t maintain genetic stocks.
Snails were also raised in heated tap water inside an aquarium, but, he said, the chemistry of municipal water changed the physiology of the snail shells and their behaviour.
He said some of the individuals raised in tap water were transported in a little mesh bag and transferred back into the tank containing hot springs water.
“They laid eggs and those eggs hatched, so we know it’s possible as an emergency basis to maintain the snails in tap water for short periods of time,” he said.
“But by removing them from their natural habitat, you’re changing them, just like when you move any animal from the wild into a pen or a tank. It’s feasible, but what are the biological consequences?”
Mike McIvor, president of the Bow Valley Naturalists, said he believes Parks should save some of the snails in the event the Kidney Spring stop running.
“It would seem the short-term sensible thing to do is to maintain a certain number of individuals off-site as a precautionary act so that if it does dry up and then flow is restored, then these animals could be returned to where they came from,” he said.
“If you’re really concerned about a handful of populations of an endangered species, presumably the foremost concern is to be as cautious and precautious as possible,” he added.
“I would think the recovery plan should include some consideration of options – since they know this has happened before – to be considered when that happens.”
Hunt said Parks Canada carefully considered whether to let nature take its course or to try to rescue the snails if the springs run dry.
But, he said, there could be lessons learned from not intervening.
“We could learn whether these snails have evolved to have a mechanism to cope with that change of water flow,” said Hunt.
Professor Masaki Hayashi, Canada Research Chair in Physical Hydrology in the Department of Geoscience at the University of Calgary, said predictions might turn out to be true.
He said the flow rate measured at the Kidney spring in mid February was very low (24 L/min), which is the second lowest for February since monitoring began in 2003.
Hayashi said the hot water is “pushed up” from the deep rock formation through a fault zone, where the rock is intensely fractured. This requires pressure.
“Pressure goes up in early summer, presumably due to the recharge of groundwater by snowmelt water, and gradually goes down over fall and winter,” he said.
“When pressure builds up sufficiently high in summer, it can maintain the flow until the following summer. However, in years following relatively small amount of groundwater recharge, pressure may not be high enough to sustain the flow over winter,” he added.
“This seems to be what is happening at Kidney spring this year. We are not entirely sure about where and how groundwater is recharged. That is the topic requiring further research.”
