It’s the very definition of big fish in a small pond — in this case, a whole lot of supersized goldfish in a Toronto-area stormwater pond.

Last summer, biologists were surprised (and more than a little concerned) to discover some 20,000 goldfish in a pond the size of a couple of basketball courts. Likely flushed down the toilet, the tiny pets were obviously thriving. Not only are they breeding, but some have become massive three-pound versions of the ubiquitous fish in a bowl.

Given that stormwater ponds are incredibly dirty and polluted, ecologists are the University of Toronto and Fisheries and Oceans Canada are concerned that the extra-large, extra-tolerant fish may become “superinvaders” that will outcompete native species as they invariably spread and make their way into the Great Lakes ecosystem.

The story, reported in Scientific American, noted that Asian carp are already present in the Great Lakes, but that these urban pond fish could wreak even more havoc as they have adapted to a low-oxygen, warm-water environment.

Future management comes down to prevention. Fish owners need to know how important it is to return unwanted pets to the store or give them to a friend instead of dumping them. And land developers and engineers may need to design stormwater ponds, perhaps building barriers between ponds and adjacent waterways or stocking them with goldfish predators such as native largemouth bass.

Outfoxed

“Animal rescuers forced to think outside the fox,” said the punny headline in the Montreal Gazette in late March. The wily fox made headlines throughout March as it eluded members of Sauvetage Animal Rescue intent on removing it from the Old Port of Montreal.

Would-be rescuers, who tried everything from traps to nets to chasing, were concerned that the fox, which had been sheltering beneath the King Edward Pier, might end up in the water once the ice melted. If it couldn’t get back up onto the pier, they believed it risked being swept away by the current.

Eventually, the Quebec wildlife department (the Ministère des Forêts, de la Faune et des Parcs ) stepped in, telling the group to cease and desist. “Foxes are independent and autonomous,” said ministry biologist Jean Sébastien Messier. “The animal is not in danger. It has all the means at its disposal to move, whether by walking or swimming.” 

There have been no fox updates since March 23, so it would seem the fox has, indeed, outsmarted both man and ice.

Less room for mushroom

From the polar bear’s plight to never-before-seen levels of wildfire, the rapid loss of ice in the Canadian High Arctic and bad news are a well-known combination. The latest in the list of potential casualties is fungal biodiversity, according to findings published in the journal Sustainability. As glaciers melt and retreat, researchers on the Walker Glacier on the far northern coast of Ellesmere Island found that the fungi on the glaciers are losing their habitat. Fungi play crucial roles in the nutrient cycle of High Arctic ecosystems as decomposers, however little is known about the fungi living in these regions. 

The Walker Glacier has retreated more than 80 meters in the last 70 years, and the rate of retreat is accelerating sharply. We now lose 3.3 metres per year. The scientists involved with the study found multiple new strains of fungi that are unique, ice-dependent and unable to survive in the areas surrounding the glaciers called glacial forelands. Their adaptation to extreme temperatures, bright light exposure and winter deep freezes means they are likely to have many unusual biochemical properties that may be useful in industrial production, pharmaceuticals and other sectors. 

“A loss of such fungi before they are even discovered would be a great loss to society,” says lead author of the study Masaharu Tsuji of Asahikawa College, Japan.

Planting a seed