HELCOM Guidelines for the annual and periodical compilation and reporting of waterborne pollution inputs to the Baltic Sea (PLC-Water)

Abstract

Since the establishment of the Convention for the Protection of the Marine Environment of the Baltic Sea Area (Helsinki Convention) in 1974, the Commission for the Protection of the Marine Environment of the Baltic Sea Area (Helsinki Commission or HELCOM for short) has been working to reduce the inputs of nutrients to the sea. Through coordinated monitoring, HELCOM has, since the mid-1980s been compiling information about the magnitude and sources of nutrient inputs into the Baltic Sea. By regularly compiling and reporting data on pollution inputs, HELCOM is able to follow the progress towards reaching politically agreed nutrient reduction input goals. In 2007, the HELCOM Baltic Sea Action Plan (BSAP) was adopted by the Baltic Sea coastal countries and the European Union (HELCOM 2007). The BSAP has the overall objective of reaching good environmental status in the Baltic Sea, by addressing eutrophication, hazardous substances, biodiversity, and maritime activities. The BSAP was updated in 2021 (HELCOM Baltic Sea Action Plan – 2021 update). The new BSAP identifies a complex of measures which are to be implemented by Contracting Parties to the Helsinki Convention by 2030 and aims to achieve good environmental status of the Baltic Sea by the end of this period. The BSAP establishes maximum allowable inputs (MAI) of nutrients as key environmental targets to achieve good status in terms of eutrophication derived through modelled calculations by the Baltic Nest Institute (BNI) in Sweden. The Action Plan also adopts nutrient input ceilings (NIC) for all Baltic Sea countries and other contributors to the total input of nutrients as a prerequisite for achieving MAI. Since MAI and NIC are based on the best available scientific information and are subject to review when new scientific knowledge is available, the 2021 BSAP calls for targeted regional studies to improve the quality of the assessment data particularly on natural background losses, atmospheric deposition, retention, transboundary loads and other aspects. The BSAP also requests all Contracting Parties to implement all nutrient input reduction measures necessary to achieve the NICs by 2027 at the latest. In the 2021 Baltic Sea Action Plan the HELCOM Contracting Parties agreed on the continuous follow-up of the implementation of maximum allowable inputs and nutrient input ceilings which assumes annual assessment of MAI and assessment of progress towards NICs every two years. This follow-up requires that Contracting Parties timely provide sufficient and consistent data on nutrient loads to the Baltic Sea. It requires maintaining and enhancing monitoring programmes and networks striving for harmonized methods to estimate nutrient inputs. Since large amount of nutrients are transported to the Baltic Sea through national borders, strengthening cooperation with river basin management authorities, including non-HELCOM countries, is the way to improve knowledge on transboundary inputs and develop adequate measures for their minimization. Finally, the 2021 BSAP calls HELCOM countries to submit an account listing, as detailed as possible, the planned and implemented measures in different sectors and catchments alongside an estimation of their effectiveness to HELCOM by 2023 in order to demonstrate whether National Net Nutrient Input Ceilings can be achieved with these measures. This information is to be a part of PLC work on assessment of the effectiveness of measures to reduce input of nutrients. The present document contains a revised and updated version of the guidelines that was prepared as part of the project Eighth Baltic Sea Pollution Load Compilation (PLC-8). It provides the Contracting Parties of the Helsinki Commission a guidance in their national monitoring programmes and reporting of pollution inputs in order to compile harmonized data and produce reliable region-wide PLC assessments. The Guidelines concern monitoring of either airborne or waterborne input of contaminants, since the assessment products are intended to demonstrate a holistic approach, including assessment of total inputs as well as identification of major pathways and sources of pollutants. The updated Guidelines also include procedures for the reporting of data for HELCOM pollution load compilation (PLC) and releasing of PLC products based on reported data. The Guidelines are aligned with EU quality assurance standards and OSPAR methodologies.