Phosphorus in lakes - Eutrophication indicators in lakes

Indicator Fact Sheet (Deprecated)

Prod-ID: IND-14-en

Also known as: WEU 003

expired

Note: new version is available!

Nutrients in transitional, coastal and marine waters

Topics: Marine , Water ,

This content has been archived on 03 Mar 2015, reason: Other (New version data-and-maps/indicators/nutrients-in-transitional-coastal-and-3/assessment was published)

Assessment made on 01 May 2004

Generic metadata

Classification

Topics:

Marine , Water

DPSIR: State

Identification

Indicator codes

WEU 003

Contents

Policy issue: Is the condition regarding eutrophication of Europe's lakes improving?

Figures

Change in average summer or annual concentration of phosphorus (µg P/l). Based on all lakes with data for all four periods, 386 in total

Key assessment

During the past few decades there has been a gradual reduction in phosphorus concentrations in many European lakes. Discharges of urban wastewater have been a major source of pollution by phosphorus, but as purification has improved and many outlets have been diverted away from lakes, this source of pollution is gradually becoming less important. Agricultural sources, both from animal manure and from diffuse pollution by erosion and leaching are similarly important and need attention to obtain good water quality in the lakes. The improvements have generally been relatively slow despite the pollution abatement measures taken. This is at least partly because of the slow recovery due to internal loading and because the ecosystems can be resistant to improvement and thereby maintain a bad steady state. Particularly in shallow lakes, such problems may call for restoration measures.