The development of a 2,2′-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) radical cation decolourisation assay for evaluating total antioxidant status in an alga used to monitor environmental impacts in urban aquatic habitats

A simple and reproducible algal tissue extraction protocol and a total antioxidant, radical cation decolourisation spectroscopic assay has been developed. This was applied to ascertain the potential for using algae and their stress responses as biological and biochemical indicators of environmental impacts in urban ponds. Total antioxidant and soluble protein profiles were constructed for the green alga Cladophora glomerata, which was seasonally sampled, from three sustainable urban drainage systems (SUDS) ponds located in an industrial and residential development created on a former Greenfield area in Fife, Scotland. Algal antioxidant profiles were impacted by a combination of lifecycle and pond structural parameters, including: seasonal sampling time, pond site and pond structure (e.g. inlet, outlet). The assay, as applied to algae as primary producer–indicator organisms is recommended for use in aquatic environmental monitoring programmes, which have a requirement to maintain the health status of disturbed aquatic urban ecosystems.