Case Studies: Ecotoxicology and Great Crested Newts

A research project into the potential harmful effects of run-off from a sustainable urban drainage system on population of Great Crested Newts at Worcestershire Acute Hospital’s NHS Trust.

Summary of Data

The information on ecotoxicology and amphibians within the UK is sparse.

There are no standard toxicology tests for any of the native amphibians, including Great Crested Newts (Triturus cristatus) within the UK.

In addition very little ecotoxicological work has been conducted on the Great Crested Newt or the native Smooth Newt (Triturus vulgaris) and Palmate Newt (Triturus helvaticus): probably less than 1% of all World-wide amphibian research. Most work has been carried out on the African Clawed Toad (Xenopus laevis). The second most researched species appears to be the European Common Frog (Rana temporaria).

There is therefore no scientific standard available to provide an early warning in the event of substances toxic to amphibians entering the Sustainable Urban Drainage System (SUD system).

The majority of tests which have been carried out under laboratory conditions and not in the field. Ecotoxicological research in the field is problematic because of the variable possible interactions with other substances and the effects of external influences such as temperature, dilution by rainwater and the like.

A summary of scientific research relevant to this study and an account of potentially harmful substances and their known toxic affect is listed in the conclusion.

Substances which may pose a potential toxic hazard to Great Crested Newts which could enter the system are: hydro-carbons, salt, organic sediment, lead, pesticides, herbicides and nitrates.

Summary of Recommendations

• Use of potentially harmful chemicals should be restricted. This may for example involve not using salt to clear ice from car-parks and access roads, not using pesticides and restricting the use of herbicides on the hospital grounds.
• Oil interceptors will be located in storm drains within car-parks to remove oil and other residues before they enter the balancing pools.
• Aquatic plants should be encouraged to grow in the balancing pools to act as a natural filter, restricting the movement of chemicals which could pose a toxic threat.
• A procedure for the regular visual inspection of the water quality from the car park, the balancing pools and oil interceptors should be initiated.
• The oil interceptors and balancing pools will be included in the hospital planned preventative work schedules.
• A spillage procedure will be executed to remove pollutants from the water discharge system before it enters the off-site water course.
• Periodic chemical analysis will take place at the balancing pools to monitor variance in water quality against an agreed datum. Variance of chemical constituents by a consequential amount will initiate remedial action to return water quality to datum levels.