Nutrient cycling has an essential role in terms of alleviating excessive nutrient loading and sustaining the productivity
rates of marine species. The economic valuation of this service is rather difficult due to the high degrees of uncertainty
about anthropogenic effects. Costanza et al. (1997) employed a replacement cost method and estimated the value of
marine nutrient cycling in the £0.10 - £0.29 per m3 range, which corresponds to a total replacement cost between £800
billion and £2320 billion derived from the UK waters. However, this value estimate should be used with caution.