The great crested newt is a european protected species with particular relevence to the UK (kent in particular) with regard to planning issues. The decline is due to a number of factors, including a large-scale loss of breeding ponds. Intensification of agriculture has resulted in many farm ponds becoming redundant, leading to neglect, and a decline in the suitability of the surrounding habitat. Many new ponds that would otherwise be suitable for this species are stocked with fish, which predate on both eggs and larvae. Ponds that survive in agricultural land often become polluted with pesticides and fertilisers. (Source: arkive.org)