Algal summer on the way in the USA

14 July 2013

North Carolina’s Jordan Lake is the subject of some algal-related controversy as blue-green algal blooms threaten the beneficial uses of this rather attractive waterbody.  There seem to be all sorts of end of pipe solutions being sought, rather than dealing with the problem at source (the “living with eutrophication” scenario that I have discussed on previous occasions).  Amongst these have been the use of aerators which, reportedly, have not achieved anything at all:

Much has been made of installing numerous aerators in the lake itself as a means of controlling algal blooms and restoring the lake’s water quality. This has been based on the experience of Greenfield Lake in Wilmington, in which aerators were installed in 2005. The aerators have in fact increased dissolved oxygen levels in lake areas near the aerators. However, they have done nothing to reduce nutrient concentrations within the lake, and the number of algal blooms in Greenfield Lake has actually increased since the installation.

Artificial aeration or circulation using “new” technology will not lead to meeting the water quality criterion in Jordan Lake; this conclusion is based on the results of many studies involving in-lake aeration or circulation technology. Despite recent statements coming from NC DENR, the Jordan Rules are based on a plan that will meet the water quality standard, which is required for approval of the cleanup plan by NC DENR and the U.S. EPA.

Technology has a role to play in lake restoration; however, such technologies are best used to control and reduce nitrogen and phosphorus inputs on land before they reach the water. Once in the water, nutrients become extremely expensive to remove and disrupt the lake’s fish and wildlife communities.

Preventing pollution from getting into a lake is way better than trying to fix a polluted lake!  Unfortunately Jordan Lake is one of many, many cases where the need to deal with pollution is being wilfully avoided!

Jordan Lake is a major drinking water supply for the Research Triangle area and a heavily used recreational area. Over the years, inputs of nitrogen and phosphorus have led to large algal blooms that impair this waterway, causing the U.S. EPA to require North Carolina to devise a plan (called a TMDL – total maximum daily load) to reduce nutrient inputs. Over several years, a variety of stakeholders worked out a plan involving compromise that was signed by Gov. Bev Perdue.

However, the General Assembly is now considering delaying pollutant controls for three years and suggests that using as-yet unidentified technology within the lake proper can clean it up. The best and cheapest way to improve water quality is to keep the nutrients from entering the lake in the first place.

Stupid is as stupid does!

Oneida Lake (New York) has had some beaches closed due to algal blooms.   Also in NY, blue-green algae have been found in several lakes but declared to not be of the toxic variety.  The manatee deaths reported previously for the Indian River Lagoon (Fla) have been linked to three types of algal toxin.  Delaware lakes are reportedly in excellent condition right now!

The Dorothy State’s South Park Lake is under an algal warning, while in New Hampshire a dog has reportedly become ill after coming into contact with water from Effingham Lake.  Those taking part in ‘drag boat races’ (I kid you not) at Dexter Lake in Oregon have also been warned about algal problems.

In the UK, Peterborough’s popular Ferry Meadows lake is currently covered by a blanket of algae (the report does not say which type – a major failing of most similar press reports – but from the pictures it looks like it could be the harmless Cladophora “blanket weed”).   The need for the public to be alert to the presence of algae has been announced in Scotland’s Tayside.

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In Canada, an algal bloom has been reported for the Athabasca River – causing an oily sheen on the water extending for kilometers and similar problems are restricting the enjoyment of Pelican Lake (Manitoba).

Note To Droplets Readers:  The CyanoAlert and related articles carried by Droplets will terminate at the end of July due to funding constraints. Apologies to all our regular readers but this is beyond our control.

 

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