UPEI researchers confirm status of rare species in P.E.I. freshwater rivers
CHARLOTTETOWN –
New joint research between UPEI and Nature P.E.I. has determined the status of four aquatic species in P.E.I.’s freshwater rivers.
In a March 30 release, UPEI said the research team used environmental DNA, traces of genetic material shed by species into the environment, to determine the presence or absence of three rare species of mussel and one group of host fish, river herring.
Researchers were able to find small traces of the pearlshell and alewife floater mussels in Island rivers, while the brook floater mussel was not detected.
The university said freshwater mussels on P.E.I. often go overlooked and can be threatened by declines in juvenile host species, such as Atlantic salmon, or by declining water quality, particularly where there are high sediment loads.
Runs of river herring—another poorly known species on P.E.I. also known as gaspereau or blueback herring— were also detected in half of the surveyed rivers.
PhD candidate Kyle Knysh directed the study at UPEI in the Michael van den Heuvel lab.
“The study has drawn our attention to the plight of the rarer freshwater mussels on P.E.I. with just over a handful of populations still known to exist in Island watersheds, however, there is good news,” said Knysh. “The eDNA technique allowed us to discover an additional population of eastern pearlshell mussel in the Bear River and a second known population of the alewife floater.”
Gracee Gallant, an undergraduate student who worked on the mussel part of the project, said her observations show that the eastern pearlshell is generally only present in watersheds with Atlantic salmon populations.
“The eastern pearlshell may be exclusively dependent on the salmon as a host during the early part of its life cycle,” said Gallant. “Atlantic salmon are now only present in a fraction of their former range on P.E.I., so we can observe how one threatened species can affect the existence of another.”