Otago Regional Council (ORC) ran three separate water-based programmes over summer, covering water quality monitoring across lakes and rivers, freshwater pest education and engagement and a boatie watercraft safety campaign around coastal and Central Otago.

The separate summer programmes all registered positive levels of public engagement and understanding around the educational aspects of water health, personal boat safety and aquatic pest controls, ORC reported this week.

ORC water quality scientist Helen Trotter said the summer recreational water quality monitoring programme, which ran from December to March, incorporated weekly testing.

This was carried out at more than 30 river, lake and coastal sites across Otago to assess potential health risks from bacteria and toxic algae in waterways.

“Water quality was generally suitable for swimming across Otago during summer- even if the weather was less than ideal at times,” Helen said.

 In total the programme collected and analysed more than 450 water samples from over 30 sites.

Helen said high bacteria counts at levels unsuitable for swimming were detected at 10 sites during the summer, representing about three percent of all samples collected.

“For most sites this meant a single occurrence which was typically associated with rainfall in the surrounding catchment, immediately prior to the sampling,” she said.

Helen said while no blooms were observed at the monitored river swim sites, toxic algae was confirmed at several other rivers sites across the region and listed on the ORC toxic algae notifications webpage.

“In several cases, toxic algae observations were initially reported by members of the community which is a good sign people are engaging with the resources available on LAWA, via the ORC website.”

“We encourage people to take an active interest in how to keep themselves, their pets and others in their communities safe,” she said.

During the off-season LAWA will display the long-term grade for monitored swim sites which indicates the generally suitability of a site for swimming and other water-contact recreation.

Water quality and conditions can change quickly at any time of the year. For advice on whether it’s recommended to swim, go to the swim smart checklist here.

During the summer two Central Otago-based ORC ambassadors surveyed 320 recreational water users, from a total 830 interactions with members of the public.

ORC environmental Implementation manager Libby Caldwell said while there had been some “solid” areas of awareness around the Check, Clean, Dry (CCD) campaign, to keep watercraft free of pests, there remained room for improvement – between those who were ‘aware’ (238 people, or 74 percent) of CCD and those ‘unaware’ (82 people, or 26 percent).

While 35.3 percent of respondents used dishwashing liquid or hot water—both proven methods for removing pests—24.4 percent did not clean their watercraft at all or did so insufficiently, and 27.8 percent relied only on a water rinse.

For drying, the majority (67.5 percent) correctly allowed their equipment to dry for more than 24 hours, while 32.5 percent dried it for less than the recommended time in total.

Two-hundred and 72 respondents (85.3 percent) were able to list at least one freshwater pest.

The most common freshwater pest named was Didymo, listed by 95.6 percent of the 272 respondents, followed by Lagarosiphon, at 47.4 percent.

Libby said while it was encouraging people were well aware of Didymo and Lagarosiphon, they needed to recognise other pests not yet in the region such as the Gold Clam or Hornwort to help check their spread.

“Thorough washing of watercraft and trailers and then drying for more than 24 hours is the best combatant,” she said.

PHOTO: Wānaka App