Impact Type: Deposition of pollutant
Key Concerns:
The natterjack toad is at the edge northern of its geographic range in the UK. This range has declined sharply over the course of the 20th century. Most of the decline has occurred on lowland heathland sites (Beebee 1977). Tests under laboratory and field conditions have shown that decreasing pH has serious effects on natterjack breeding success (Beebee et al. 1990). When the pH drops below 5, the growth rates of larvae are heavily retarded, even when excess food is available. Natterjacks are an r-selected species which relies on rapid larval growth for reproductive success, therefore even small reductions in pH can have major impacts on natterjack populations (Beebee et al. 1990).
Additional Comments:
Amphibian growth and development is also effected by temperature. The effect of acidification will potentially be greater in the north due to the lower ETS.
| Critical Load/ Level |
|---|
|
No estimate available |