A summary of the issues regarding the most recent bloom….

Another Shuswap algae bloom
A Shuswap Passion column for the Shuswap Market News
By Jim Cooperman
May 21, 2010

It is orange, smelly and a major concern for all of us who care for our lakes. Once again the Shuswap is experiencing a massive algae bloom that began on May 11th at the mouth of the Shuswap River in Mara Lake and as of May 13th had made it to Sicamous. With no answers yet on the 2008 bloom, the government experts are continuing to scratch their heads as to why these blooms are occurring.

There are basically three types of lakes; oligotrophic with clear water, mesotrophic with clear to opaque water and eutrophic with cloudy water. Shuswap Lake is mostly oligotrophic, except for Salmon Arm Bay that is mesotrophic and now leaning towards eutrophic. However the trends are showing changes in many areas of lake, including Mara Lake, with increasing concentrations of phosphorus and nitrogen, the two key nutrients for the growth of algae.

Monitoring efforts have been underway in the Salmon River for a number of years and the results as presented by the Fraser Basin Council show a steady decline in water quality due to an increase in nutrient concentrations. Over this same time period, there has been an increase in livestock numbers with new larger dairy operations moving into the valley. Although the Ministry of Environment has undertaken new ‘nutrient loading’ studies since the 2008 bloom, it still hesitant to suggest any specific causes for that bloom.

A fact sheet has been released by the ministry on the Mara Lake bloom that explains the bloom is made up of Ochromonas, a golden-brown Chrysophyate algae that was the same kind observed in the 2008 bloom. Although it is not toxic, no one would want to drink the acrid foul smelly water near the bloom. In 2008, the ministry reported that this kind of algae requires cold water to bloom and now the fact sheet blames the onset of warmer surface temperatures as one of the causes. And with climate change, the fact sheet predicts that more blooms are likely.

According to the fact sheet, blooms like this usually dissipate after ‘a week or so’ and yet the fact sheet also claims that the bloom will ‘probably’ make its way into Shuswap Lake. Are these blooms a sign of water quality deterioration? ‘Not necessarily,’ according to ministry fact sheet, as there are many complex factors that result in blooms like this besides excess nutrients, including the status of predators, the presence of certain bacteria and calm water.

While lakeside residents would likely all agree that because of the bad smell the lake is deteriorating, the ministry looks at the advantages to the fisheries of these blooms which produce more food for fish. However, that is not to say the ministry is not concerned as they are planning more studies into the possible sources of the nutrients needed for algae growth.

Meanwhile, local residents coordinated by the Shuswap Water Action Team (SWAT) are into their second year of volunteering their labour, boats, and fuel, to help the local Ministry of Environment staff conduct lake water studies using Secchi disks to gauge the clarity of the water throughout the lake. This year they plan to undertake an additional study to determine how much algae will grow on disks suspended below the surface in about twelve sites. Locals have often stated their concerns that buoys, docks and boats get coated with algae whereas years ago this was not a problem. SWAT is providing some funding to help with the algae tests which were not in the Ministry of Environment’s budget.

The Shuswap Lake Integrated Planning Process developed a strategic plan that includes a detailed monitoring program that would have the capability of determining the sources of these blooms. However, the plan, which also includes many other much needed projects, is stalled due to lack of funding.

The situation in the Shuswap stands in stark contrast to the history of looking after Okanagan Lake, where concerns about water quality led to the creation of the Okanagan Basin Water Board over 40 years ago. A 1974 summary report described phosphorus as the major nutrient responsible for ‘undesirable algae blooms’ and recommended an action plan that including improvements to waste water management as well as the ‘complete removal of all direct polluting discharges to stream waters.’ Hopefully this second bloom will help convince our political leaders to show leadership and undertake the kind of collaborative efforts that helped Okanagan Lake recover years ago.

SEE WATER ISSUES for more details…