On a recent trip to Florida, I had the pleasure of a kayak nature tour through Estero Bay near Fort Myers. The guides were very knowledgeable and gave us a wealth of information about the many wading birds, including rare Reddish Egrets and Roseate Spoonbills and other aquatic life including the endangered manatees. It was wonderful to be able to experience these elements of the natural world in such close proximity to a developed urban centre.
Roseate Spoonbill in Estero Bay, photo courtesy of Manatee Guides
However the next day after a hike through the Ding Darling Nature preserve we went to cool off in a swim at a beach on Sanibel Island and were a little dismayed to see a few dead fish on the shore. Later, watching the local news we heard there was a red tide bloom close by that had left hundreds of dead fish on Bonita Beach. I started to think about the similarities between red tide and blue-green algae in terms of their negative effects on aquatic eco-systems. Although both red tide (Karenia brevis) and blue-green algae (Cyanobacteria) are naturally occurring(historical records describe occurrences from several hundred years ago) there is no question that the frequency and size of these blooms are increasing.
Here is a time line of the occurrence of red tide along the southwest coast of Florida dating back to the 16th century. 1998 was the first year of an unbroken run of annual red tide episodes and 2005 saw a red tide bloom that lasted most of a year and resulted in a dead zone near Sarasota, the size of Rhode Island.
It’s fascinating( in a perverse way) that the timing of the increased frequency of red tides off the southwest coast of Florida is so similar to the increase in size and frequency of blue- green algae blooms in Lake Winnipeg , where they first came to public attention in the late 1990’s. Both are fueled by an excess of nutrients, phosphorus and nitrogen, that is being flushed into our waters from human waste, animal waste, fertilizers and natural run- off. The amount getting into the waters is increasing due to the frequency of flood events, increased drainage throughout our landscapes, and general increased human development. The similarities between red tides and blue-green algae blooms are obvious in terms of their negative effects including threats to aquatic life, loss of income for communities reliant on fishing and tourism and decreased property values on shorelines and water quality decline.
My recent experience in Florida combined with news of terrible blue-green algae blooms throughout many American States this year and finally the deteriorating state of Lake Winnipeg, make me think that these water quality problems are becoming overwhelmingly rampant. We must take action immediately to stop the flow of phosphorus and nitrogen into our waterways. We know how to do it, now we just have to commit resources and energy to get going on it.
H2O: Ideas & Action for Canada's Water 