On Friday 11 August, the Mountains to Sea Wellington Team headed to Tunnel Gully in Upper Hutt for a Health and Safety Field Practical for Fresh Water with our new team! For this training, Liz and Kara were joined by some of the fresh faces who have come on board in the past two months, including Maddy, Alice, Abbey, Sheryl, Steve, Rachel, and Kedron.
Freshwater Manager Liz Gibson led the day's training, giving us an overview of health and safety considerations along with smart tips for managing community and school groups activities in an outdoor setting. Identifying site hazards and safe access points to the stream was a key activity, which also gave us a chance to look at a few different stretches of the beautiful Collins Stream, plus a bonus encounter with a very hungry kererū!
After gathering on a lovely stream-side bank, Alice showed us how to set a gee minnow trap, which catches small fish like inanga and bullies, so we can gauge the biodiversity levels in the stream.
Then we practiced some of the freshwater monitoring that we do as part of our educational programmes. Alice and Steve collected macro-invertebrates via the stone method, where a stone is picked up and any critters on it are gently brushed into the observation tray. Because the water was raised and fast flowing due to rain overnight, the stone method didn't prove successful, however the kick method brought the party! Sheryl, Abbey, and Rachel tried giving the stream a wee and gentle kick and used a net to catch some of the critters that were dislodged in the process.
After collecting critters (aka macro invertebrates) from the stream, we identified them to see what types were thriving in this area. We used the SHMAK - Stream Health Monitoring and Assessment Kit -which includes a cool Freshwater Invertebrate Identification Guide. Each bug's photo and description comes with a "tolerance score" which indicates how sensitive each critter is to pollutants and stressors in the stream. Species with green numbers are more sensitive, and only likely to survive if the stream is clean. We found some 10's in Collins Stream! The star of the day was the Stonefly Nymph / Stenoperla, pictured below - a 10 for sure!
Abbey then set up the Water Clarity Tube, which might be the coolest tool in the SHMAK test! This test uses a giant clear tube and a set of magnets. Working in two's, each person looks through the tube and identifies how far they can move the magnet along the length of the tube before it disappears from sight. This test gauges how much sediment is in the stream, and you can see it in action here.
Finally, Liz showed us Wilderlab's eDNA kit, which can identify tiny traces of genetic material that is left behind as living things pass through the water or soil. Rachel and Alice worked as a team to demonstrate the collection of a water sample for eDNA. To take the sample, Alice filled the 50ml syringe and passed it to Rachel who pushed the collected water through a filter. They repeated this 20 times!! Rachel's hands got tired, but Steve stayed on for moral support!
The snow-capped mountains proved to be a fabulous office for the day. Hats off to you Collins Stream, and thanks for having us! Great to see that you are holding some robust biodiversity and hosting lots of our most sensitive critters.