Nova Scotia gold mine issues
invasive & vulnerable species
Chinese mystery snails
wide-spread issue for the province.
We are continuing this research
in 2019. If you are interested in potential applications of our
research, joining our research group or would like to contribute to our
data analyses, please
email Dr. Linda
Nova Scotia lakes and rivers have
been impacted by introduced and invasive aquatic species.
To date, most focus on freshwater non-native species have been on sport
fish species. In particular, chain pickerel and
smallmouth bass are of high interest. Both species were first illegally
introduced to Nova Scotia lakes
around the 1940's and have now spread
throughout the province. Chain pickerel has been associated with
declines in amphibians and native fish species. We are also
interested in Chinese mystery snails, an aquarium & food
native to east Asia, which may be spreading through the Shubenacadie
system and the rest of Nova Scotia.
We are collaborating
of Fisheries & Oceans, Nova
Scotia Fisheries &
Breton University, Eastern
Charlotte Waterways, New
Brunswick Museum, and other groups & colleagues to
identify the impacts
and presence of invasive species. The DEEHR team is
out several investigations looking at chain pickerel, smallmouth bass,
Chinese mystery snails and other species,
including those projects:
- Assessing impact of chain pickerel on freshwater food
also include known Species At Risk (SAR) in Nova Scotia and New
- How mercury contaminants biomagnify in food webs with
chain pickerel and smallmouth bass.
- Ecology and presence of Chinese mystery snails in
lakes across the Halifax Regional Muncipality.
- Culturing and maintaining wild-collected Chinese
mystery snails in the laboratory.
Chain pickerel (Esox
is a widely introduced fish species in Nova Scotia lakes. It is an
aggressive ambush predator which will consume a wide variety of food
ranging from dragonfly larvae to fish to frogs. Small mammals, birds
and turtles have even been found in chain pickerel stomachs!
Chain pickerel is associated with significant declines in
fish and amphibian populations and will impact native sport fisheries.
Our work looks how chain pickerel may be affecting contaminant transfer
and vulnerable species in many lakes across Nova Scotia and New
Brunswick. Currently, we analyzing data for numerous lakes from Sydney
in Cape Breton to Yarmouth in southern Nova Scotia. In addition, we are
studying the impacts of chain pickerel on Species-at-risk organisms
lampmussel in Cape Breton lakes and small-bodied
rainbow smelt in Lake Utopia.
Chinese mystery snails, Cipangopaludina
chinesis (synonyms: Bellamya
chinensis, Paludina chinensis),
are more recently discovered in Nova Scotia, and are thought to be
probable aquarium species released inappropriately into lakes. Those
snails have been reported
widely across the USA
but are not as well studied in Canada. This snail species
orginates from the far east of Asia & Russia regions. Chinese
mystery snails are a very hardy species which can tolerate a wide range
of temperatures in freshwater ecosystems. Those snails have a
"trapdoor" (operculum) covering their shell opening providing
significant protection. Chinese mystery snails have gills for
underwater respiration and can survive extended periods in air. In
addition, those snails are live-bearing (does not lay eggs), with
female snails having the capacity to contain over 100 fertilized
embryos for eventual development and release as juvenile snails. We are
investigating the presence, abundance and impacts of Chinese mystery
snails across the province. We are also investigating reports
Chinese mystery snails in freshwater ecosystems across Canada.
There is concern that the Chinese mystery snails may be
distrupting native mussel and snail populations, impacting fish feeding
patterns and even shifting nutrient cycling in lakes which could
encourage algal blooms.
bass are widespread across Nova Scotia and were introduced around the
same time as Chain pickerel. Those are native to other parts
Canada, but not in Nova Scotia. Smallmouth bass are visual predators
and prefer warmer clearwater lakes, and can significantly reduce frog,
turtle and nearshore fish populations in lakes. Impacts are
widespread and impact the entire food web. In lakes with both
chain pickerel and smallmouth bass, biodiversity and native species
both can be greatly reduced. We are studying the impacts of
non-native fish species across Nova Scotia to better understand
trophodynamics and contaminant transfer.
- Alien species in Nova Scotia. NS Government public
communication document. Link.
- NS Fisheries & Aquaculture AIS page with
links to fishing regulations and tips for preventing spread. Link.
- NS Lake bythometry maps & water chemistry
"Impact of introduced chain pickerel (Esox niger) on lake
communities in Nova Scotia, Canada" SC Mitchell, JE LeBlanc &
Heggelin. 2010. PDF
"Geographic distribution of smallmouth bass, Micropterus dolomieu,
Nova Scotia: history of early introductions and factors affecting
current range." JE LeBlanc. 2010. DFO Can. Sci. Advis. Sec. Res. Doc.
2010/028. PDF document.
"Occurrence of the Chinese mystery snail, Cipangopaludina chinesis
(Gray, 1834) (Mollusca: Viviparidae) in the Saint John River system,
New Brunswick with review of status in Atlantic Canada. DF
McAlpine et al. 2016. BioInvasions Records 5(3):149-154. PDF Document.
- Sarah Kingsbury's Chinese mystery snail MSc research website. Link.
- USGS Map of Chinese mystery snails across the USA. Link.
- Summary of the Yellow lampmussel (Lampsilis cariosa)
status. DFO Species at Risk. PDF Document.
- COSEWIC 2013 Status Appraisal Summary on the Yellow
cariosa in Canada. PDF Document.
2008 Assessment and Update Status Report on the Rainbow smelt (Osmerus
mordax) - Lake Utopia large-bodied and small-bodied populations in