ecology

Asian grass carp pose ecological threat to Great Lakes: U of T scientist part of Canadian-American research team

ullahnor — Fri, 27 Jan 2017 20:10:56 +0000

Asian grass carp pose ecological threat to Great Lakes: U of T scientist part of Canadian-American research team

ullahnor Fri, 01/27/2017 - 15:10

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U of T biologist Nick Mandrak says that while not all invasive species have a high ecological impact, grass carp are voracious eaters, capable of consuming 40 per cent of their body weight per day (photo by Ken Jones)

Don Campbell

Author legacy

Don Campbell

Topic

Breaking Research

fisheries

Great Lakes

Carp

U of T Scarborough

ecology

Asian grass carp pose a significant ecological threat to the Great Lakes and that threat could be extreme over the next 50 years.

This is the major finding of a large binational risk assessment authored by a team of American and Canadian researchers, including Nick Mandrak, associate professor of biological sciences at U of T Scarborough.

“We don’t want grass carp in the Great Lakes, and we need to act now in order to eradicate the population in the Sandusky River,” says Mandrak, referring to the grass carp population already spawning in the Sandusky River in Ohio, which is connected to Lake Erie.

The peer-reviewed study, led by Fisheries and Oceans Canada and coordinated by the Great Lakes Fishery Commission, has researchers from Fisheries and Oceans Canada, U of T, the U.S. Geological Survey and the U.S. Fish and Wildlife Service.

Mandrak himself has conducted risk assessments on silver and big head carp in the past and also authored the first Canadian risk assessment of Asian carp in 2004 when he worked at Fisheries and Oceans Canada.

He says while not all invasive species have a high ecological impact, grass carp are different. For one, they’re voracious eaters, capable of consuming 40 per cent of their body weight per day. As a result, they can grow quite large, up to 30 cm long in their first year of life, meaning they have no natural predators in the Great Lakes. They also produce a lot of eggs, which means even in the short period of time when they can be eaten by larger fish, there are often too many to make a dent in their numbers.

And if you think a cold Canadian climate will deter them, think again. Mandrak has done field research on grass carp living in Siberian lakes covered by more than a metre of ice.

A joint American and Canadian report co-authored by U of T Scarborough Associate Professor Nick Mandrak finds that grass carp pose a significant threat to the Great Lakes. (Photo courtesy of the Asian Carp Regional Coordinating Committee)

Grass carp were first introduced to North America from Asia as bio-control agents in the 1960s. They were brought in specifically to control aquatic vegetation like weeds growing in aquaculture ponds mostly used by the channel catfish industry.

“Unfortunately, they escaped from those controlled environments into the wild either by floods or through being released on purpose,” says Mandrak.

Since then, they’ve migrated up the Mississippi River into the Great Lakes region where they are reproducing in the Sandusky River. Grass carp have already been found in Lakes Michigan, Erie and Ontario.

The concern is that since fish don’t obey borders, there’s nothing preventing them from entering Canadian waters. Once there, Mandrak says grass carps could severely decimate wetlands, which are important spawning habitats for native fish.

“We need to be concerned because we share the Great Lakes, and the economic impacts would be significant especially when you look at commercial fishing and tourism,” he says.

Mandrak points to one aquatic system in South Africa where 13 of the 14 aquatic species of vegetation were destroyed within two years of grass carp being introduced.

He adds we’re at the point early in the invasion curve where grass carp populations can be eradicated if rapid response is taken. If not, we could end up with scenarios from the past like sea lampreys and zebra mussels, two species that upended the ecology of the Great Lakes.

“This study organizes a lot of the information we know about grass carp and the risk they pose to the Great Lakes,” Mandrak says. “Now we need to figure out what next steps can be taken to manage the problem.”

U of T researchers discover new creatures great and small

ullahnor — Mon, 23 Jan 2017 16:48:24 +0000

U of T researchers discover new creatures great and small

ullahnor Mon, 01/23/2017 - 11:48

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The lobster-like marine predator was one of six new species discovered (illustration by Lars Field)

Christine Elias

Author legacy

Christine Elias

Topic

Breaking Research

Species

Evolutionary Biology

Faculty of Arts & Science

ecology

Fossil

Dinosaur

Subheadline

6 new species discovered in past five years

From a deep-sea creature that predates dinosaurs by 250 million years to a chameleon-like lizard in the Dominican Republic, meet six new species – some living and some extinct – that have been discovered by scientists at U of T's Faculty of Arts & Science over the last five years.

The “Wendy” dino – named for legendary Canadian fossil hunter and discoverer Wendy Sloboda – has been called “one of the most striking horned dinosaurs ever found.”

An early member of the Triceratops family, the elaborate horns and head ornamentation of Wendiceratops pinhornensis set it apart from its relatives.

The dino, found in southern Alberta in 2010, lived 79 million years ago, making it one of the oldest named members of the horned dinosaur family.

The research on Wendiceratops was completed by David Evans, an associate professor in U of T’s department of ecology and evolutionary biology and a curator of vertebrate paleontology at the Royal Ontario Museum, and Michael Ryan of the Cleveland Museum of Natural History.

It has greatly increased the understanding of the evolution of horned dinosaurs.

This chameleon-like lizard – a Greater Antillean anole named Anolis landestoyi for Miguel Landestoy, the naturalist who first spotted and photographed it – is one of the first new anole species found in the Dominican Republic in decades.

The new species was described by Luke Mahler, an assistant professor of ecology and evolutionary biology, as helping to piece together a long-standing puzzle of similar looking species that exist on different Caribbean islands.

“As soon as I saw the pictures, I thought, 'I need to buy a plane ticket,'” says Mahler, who was the lead author of the published article on the discovery.

U of T researchers find plants evolving to adapt to urbanization-driven environmental conditions

ullahnor — Fri, 06 Jan 2017 14:32:20 +0000

U of T researchers find plants evolving to adapt to urbanization-driven environmental conditions

ullahnor Fri, 01/06/2017 - 09:32

Cutline

Frost-covered clover (photo by Marc Johnson)

Blake Eligh

Author legacy

Blake Eligh

Topic

A tiny plant is providing big clues about how urbanization is driving the evolution of living organisms.

New research from U of T reveals the first evidence that the common white clover changes genetically to adapt to urban environments.

The study by U of T Mississauga researchers Ken Thompson and Marc Johnson also reveals surprising new information about the effect that city temperatures may play in the process. Marie Renaudin of AgroSup Dijon is a co-author on the paper, which appears in the journal Proceedings of the Royal Society B.

“Humans build cities and live in them, but many other organisms live in our cities too,” says Thompson, who conducted the research while working on a master’s degree in ecology and evolutionary biology at U of T. “We wanted to see whether natural populations are adapting to urbanization. We also wanted to understand the ecological features of cities that might be driving such adaptations.”

The researchers studied white clover, which is commonly found in both urban and rural environments. Established traits of the plant include cyanogenesis, a poisonous chemical defence system that protects clover from herbivores.

When crushed, chemicals in the leaves combine to create hydrogen cyanide, which deters slugs and other creatures from eating the plant. But the chemical protection comes at a cost – if the clover freezes, those same compounds harm the plant. As a result, clover has evolved to be less likely to display cyanogenic traits in cold climates and more likely to display cyanogenic traits in warm climates.

“We saw this as the ideal model system to test if organisms adapt to cities,” says Johnson, an associate professor of biology at U of T Mississauga. “We know clover adapts to temperature variation at continental scales, and we know there are similar temperature changes across cities like Toronto, New York, Montreal and Boston.”

The research team sampled thousands of plants from clover populations along 50-kilometre paths between the urban core of Toronto and rural areas outside the city, looking for evidence of evolutionary changes in cyanogenic traits.

Air temperatures in cities are often a few degrees higher than surrounding rural areas due to a sparse tree canopy and acres of asphalt and concrete that absorb and reflect the sun’s heat. Because of this “urban heat island effect,” the researchers expected to find evidence of cyanogenic traits in urban clover.

“We expected the urban plants to have more cyanide in the city because warmer temperatures would result in less freezing,” says Thompson, who is now working on his PhD at the University of British Columbia. “But we found the exact opposite – populations are evolving decreased levels of cyanide toward the urban centre.”

The same pattern was repeated in clover samples from Boston and New York City.

“Data tells us that the air temperature is warmer in the city centre,” Thompson says. “We needed temperature data from the plant’s perspective.”

The team monitored ground-level temperature sensors over the winter. The sensors revealed a surprise – despite warmer urban air temperatures during the day, it is much colder at ground level in the city centre at night than it is in the country. They called it the “urban cold island effect.”

By analyzing satellite images, the researchers concluded that snow cover played a crucial part in the process.

“Snow is a great insulator of the ground so plants buried under snow are much warmer than plants that are not,” Thompson says. “Rural populations are more insulated by snow, but we found a decrease in snow cover in urban populations, leaving plants exposed to cold temperatures. This appears to cause natural selection for plants that lack cyanogenic traits in cities.”

The sole outlier in the study was Montreal, which experiences more urban snow cover than the other cities in the study.

“We’re learning that organisms are rapidly adapting to the unique environmental conditions associated with urbanization,” Thompson says. “We know a lot about the climates of cities, but this research shows that cities are having surprising effects on living organisms. We need more data on how evolution is happening to understand the effect of urbanization on living organisms.”

U of T evolutionary biologist Stephen Wright takes Steacie Prize

geoff.vendeville — Thu, 15 Dec 2016 16:50:38 +0000

U of T evolutionary biologist Stephen Wright takes Steacie Prize

geoff.vendeville Thu, 12/15/2016 - 11:50

Cutline

Stephen Wright, a professor and Canada Research Chair in Population Genomics, was awarded the prestigious Steacie Prize (photo courtesy of the Natural Science and Engineering Research Council of Canada)

Peter Boisseau

Author legacy

Peter Boisseau

Topic

Faculty of Arts & Science

Subheadline

“The genome itself is not this blueprint – it’s a society of genes where there is all this evolutionary activity going on in its own right”

Evolutionary biologist and world-renowned plant genomicist Stephen Wright of the ��Ƶ has capped a remarkable year by winning the prestigious Steacie Prize.

The prize is awarded annually to a scientist or engineer 40 years of age or younger for notable contributions to research in Canada.

“It’s certainly a big honour for our group,” says Wright, a professor and Canada Research Chair in Population Genomics with U of T’s department of ecology & evolutionary biology.

“It’s an especially exciting thing for our department since this is the second year in a row that we have received this,” adds Wright, noting that his colleague Aneil Agrawal, a distinguished professor of evolutionary genetics, was the 2015 Steacie Prize winner. “It’s also a great coup for our field.”

Wright says the back-to-back awards speak to the growing stature of evolutionary biology and genomics in the sciences.

Just as he was finishing his undergraduate degree, the first plant genome was being mapped out. Since then, the study of evolutionary plant genomics has skyrocketed with a rapidly growing number of species now catalogued in huge data sets.

“I sort of grew up as the field was growing up,” Wright says.

“Our ability to address these questions is still exploding.”

Wright has already established himself as one of the world’s most influential scientists in this emerging field of plant population and evolutionary genomics.

Earlier this year, he won a Natural Science and Engineering Research Council of Canada (NSERC) E.W.R. Steacie Memorial Fellowship. It is helping to fund his lab’s new research on herbicide-resistant “super weeds,” a growing threat to global food security and the livelihood of millions of farmers.

Koffler Scientific Reserve

sgupta — Thu, 07 Jan 2016 20:47:15 +0000

Koffler Scientific Reserve sgupta Thu, 01/07/2016 - 15:47

URL

https://ksr.utoronto.ca/

Global Change Science, Centre for

sgupta — Thu, 07 Jan 2016 20:47:13 +0000

Global Change Science, Centre for sgupta Thu, 01/07/2016 - 15:47

URL

https://cgcs.physics.utoronto.ca

ecology

Asian grass carp pose ecological threat to Great Lakes: U of T scientist part of Canadian-American research team

U of T researchers discover new creatures great and small

Read more about the anole

Read more about the lobster-like marine predator

U of T researchers find plants evolving to adapt to urbanization-driven environmental conditions

U of T evolutionary biologist Stephen Wright takes Steacie Prize

Read more about the fellowship

Koffler Scientific Reserve

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Global Change Science, Centre for

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