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Freshwater pests
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Do you know your hornwort from your lagarosiphon?
As well as managing pest plants and animals across our region, ORC’s Biosecurity team work to prevent freshwater pests from entering and spreading throughout our waterways.
One of the ways the team do this is through an educational programme called Check, Clean, Dry.
Freshwater pests
Didymo
Didymo is a thick pinkish-brown layer that covers rocks and plants in freshwater, often forming flowing 'rat tails' with white-cream ends that look like soggy toilet paper, and feels like wet cotton wool | Unwanted organism
Egeria
Egeria is a fast-growing freshwater weed that forms dense underwater meadows, blocks waterways, and harms aquatic life | Exclusion
Freshwater gold clam
Freshwater gold clam is a tiny invasive clam that clogs waterways, threatens native species, and spreads via boats | Unwanted organism
Hornwort
Hornwort is an invasive underwater weed that forms thick mats, and blocks waterways. New plants grow from broken stem fragments spread by boats, trailers, and gear | Exclusion
Lagarosiphon
Lagarosiphon is a fast growing, invasive aquatic weed that forms dense mats that choke waterways and harm ecosystems | Site-led
Lake snow
Lake snow is a sticky buildup of algae that forms floating clumps in lakes. These clumps can clog filters and pumps in water supplies, stick to fishing lines, boats, equipment, and wetsuits, and cause dirty “pea-soup” water conditions | Organism of interest
Toxic algae
Toxic algae in rivers form brown or black mats, while in lakes they make the water look murky or like "pea soup" with green scums on the surface. Both are harmful to humans and animals | Monitored
Check, Clean, Dry
CHECK your gear and remove pests. CLEAN your gear thoroughly. DRY it for 48 hours before moving to another waterway!
Report Pollution
Call the Pollution Hotline 0800 800 033 or fill in the form on this page
Marine pests
Marine pests are sneaking into Otago’s waters, posing a serious threat to our native species, marine industries, and treasured coastlines. Let’s work together to keep Otago’s waters safe and pest-free!
