Zebra mussels, a prohibited aquatic invasive species, have been found in a variety of moss/algal ball products for aquariums or water gardens sold in western Canada, including in Saskatchewan.
Invasive zebra mussels found in aquarium item sold at pet stores, ODFW says - KTVZ
Category: Local - Page 13 - The Dakotan
B.C. Conservation seizes thousand of moss balls due to hidden invasive species
Wabamun Watershed Management Council
Habitats of Freshwater Algae - ScienceDirect
Precautions urged after zebra mussels found in ornamental plant
Invasive zebra mussels found hiding in aquarium plants for sale at pet stores - Natural Resources
CryptoLlama #957 - Llama Adventure Club
Information on the disposal of moss balls
Utah DWR warns of invasive zebra mussels found in aquarium moss balls
Check your aquariums! Zebra mussels have been found in aquarium
Invasive Zebra Mussels Found in Moss Balls
CryptoLlama #953 - Llama Adventure Club