invertebrates

Rearing Pond Salvage Saves Crayfish, Lamprey and Coho

Hoy/Scott Watershed Society conducted our annual rearing pond salvage on May 29.

Coho smolts were released on May 18. The floor boards were removed. The water drained from the pond leaves lots of discoveries for invertebrates and crustaceans like crayfish, stoneflies and lamprey. We found crayfish, coho fry and smolts and caddis fly. All were released into the stream.

Thanks to our volunteers who helped out.

After the salvage, the City of Coquitlam arranges for the pond mud and sediment to be removed via McCrae's Environmental Services (a vacuum truck), and then the pond will be pressure washed and floorboards returned. The creek water will then be reintroduced to make way for the transfer of Coho fry from the hatchery.

This year our back pond area will also be cleaned.

A final look in the rearing pond before dark.

Rearing Pond Invertebrate Salvage

Mucky business, but good fun making discoveries!

Hoy/Scott Watershed Society conducted the annual rearing pond salvage on May 31.

Coho smolts were released on May 14. The water drained from the pond leaves lots of discoveries for invertebrates and crustaceans like crayfish, stoneflies and lamprey for discovery. We found crayfish, juvenile lamprey, coho fry, and caddis fly. All were released into the stream.

Thanks to our volunteers who helped out. Interesting was the shared relevant knowledge and experiences related to the activity expressed by participants!

Floorboards over the pond were first removed. After the salvage, the City of Coquitlam arranges for the pond mud and sediment to be removed via McCrae's Environmental Services (a vacuum truck), and then the pond will be pressure washed by the Society, floorboards returned, and then the creek water is reintroduced.

A very large crayfish! It was returned to Hoy Creek.

Later this month, the rearing pond will then be ready for the next coho brood to be transferred from the hatchery to live there until May 2024.

Aquatic Invertebrate Survey Conducted at Hoy Creek

Invertebrate sampling

On Saturday, September 23, approximately 8 volunteers from of Hoy-Scott Watershed Society took part in an invertebrate survey, of which details were provided to the Pacific Streamkeepers Federation 'Streamkeepers Database.' Numerous curious members of the public, who happened to be walking by the area also participated. 

To start, two 30x30 cm samples were taken from Hoy Creek immediately upstream of the Hoy Creek hatchery using a D frame net designed for invertebrate surveys.

Water containing the invertebrates from the creek (the samples) was divided into several wash basin sized samples. Kids and adults then patiently inspected each sample, capturing all the aquatic invertebrates using a spoon or pipette, placing them into an ice cube square according to the type of invertebrate.

Nearly 400 invertebrates from the two 30x30 cm samples were counted and sorted into 12 different groups (taxa).  That works out to a density of over 2000 aquatic invertebrates per square metre of creek bed!

Aquatic-Invertebrate.jpg

The observations were then used to conduct basic water quality and diversity assessments of the creek using several different indices (e.g. Pollution Tolerant Index, EPT Index, Predominant Taxon Ratio).

Our sample achieved a 'good' rating (the highest rating) across all four indices.

The most abundant aquatic invertebrates in the samples were caddisflies. Their cases (houses they build themselves and attach to rocks) could be seen all over the rocks where the samples were taken.

There were also mayflies, scuds, aquatic works, leeches, water mites and stoneflies captured.

The prize catch of the day were two giant stoneflies, which measured nearly 5 cm in length.

A great find! Two large stoneflies. 

A great find! Two large stoneflies. 

Data was uploaded to the Pacific Streamkeepers Federation website and is available HERE.