Oxygen, high temperatures linked to P.E.I. fish kill

RIVERTON, P.E.I. — A neighborhood watershed group and provincial employees have been in elements of the Morell River on Aug. 15 cleansing up after a fish kill found Friday, Aug. 12.

Rosie MacFarlane, a freshwater fish biologist with the Division of Surroundings, stated a highways crew found the useless fish whereas eradicating a beaver dam on the Jessie Maybelle Highway close to Lorne Valley.

“We really feel that oxygen is unquestionably an element on this fish kill as a result of the readings we bought right here on Friday have been very, very low,” she stated when SaltWire Community met up along with her on the sting of the stream Aug. 15. “That’s the very first thing we have a look at in a fish kill is the temperature and oxygen. In different circumstances, these have all the time been good, however right here, straight away, that despatched out a little bit of an alarm that it was not a contented place.”

Her workforce collected round 100 fish on Friday, and efforts Monday morning picked up one other 120 in a brief part between Jessie Maybelle Highway and the Heatherdale Highway.

Most have been brook trout, however a information launch despatched Aug. 13 stated there have been additionally red-bellied dace, sticklebacks and a mummichog.

“It actually exhibits that we have now some rivers which can be value caring for.” — Matt Sheidow, wildlife technician

It’s vital to gather as lots of the useless fish as doable, stated MacFarlane.

“Now we have to grasp the scope of the kill,” she stated.

Summer time employees from the Morell River Administration Co-operative have been on the job, accumulating useless fish out of the river and taking them again to their base of operations to be recognized, measured and added to the physique rely. Finally, the fish will likely be disposed of by incineration.

The high-temperature, low oxygen situations have been significantly exhausting on massive, mature fish such because the brook trout that are plentiful within the river system due to stream enhancement teams just like the Morell River Administration Co-operative.

Many trout have been over 18 inches lengthy and able to reproduce within the fall, stated Matt Sheidow, wildlife technician with the province.

“It actually exhibits that we have now some rivers which can be value caring for,” he stated.

Uncommon situations

MacFarlane works carefully with watershed teams on P.E.I. and is conversant in the Morell River system and the work that has gone into making it fascinating for brook trout.

She stated in an strange 12 months, temperatures within the flat part of the East Department attain the very higher restrict of what brook trout can face up to, however there has by no means been any mortality due to the excessive temperatures earlier than.

“This 12 months, we had an prolonged warmth wave which was a little bit uncommon and we additionally had an obstruction right here at this culvert,” she stated referring to the beaver dam within the stream crossing on the Jessie Maybelle Highway.

“It raised the water degree up right here by a few foot and a half, so it could have exacerbated the temperature concern in addition to the photosynthesis and so forth from the crops that might be related up right here. Then at evening, you’d have decomposition and oxygen ranges would lower.”

All of it added as much as a bigger than regular quantity of poor-quality water dammed up above the street, which was then washed downstream by the heavy rain the earlier week.

“It might have been OK, as much as that time,” she stated.

She stated that in sizzling climate, the trout will hunt down a cool or shady part of the river; she’s even seen a number of nosed right into a spring to benefit from the chilly, oxygenated water.

So, one other issue within the kill might have been the nice and cozy water flooding downstream and depriving the fish of their cool hiding spots, she stated.

The fish kill and the situations resulting in it have been unrelated to the work the group is conducting on Mooney’s Pond. MacFarlane stated the 2 spots are in utterly totally different sections of the river system.

Subsequent steps

Samples of fish and water have been despatched away to Surroundings Canada labs, and one other set of samples went to the Canadian Wildlife Well being Co-operative situated on the Atlantic Veterinary School in Charlottetown.

MacFarlane additionally took temperature and oxygen readings all through the river on the weekend and can accomplish that once more within the week. She and Sheidow put in a number of oxygen loggers within the stream, which can gather dissolved oxygen readings at common intervals over the following few days.

The East Department of the Morell River is closed to angling for the rest of the season. Indicators will likely be posted quickly to advise fishers.

Alison Jenkins is a well being reporter with the SaltWire Community in Prince Edward Island. She could be reached by e-mail at [email protected] and adopted on Twitter @ReporterAlison.