TMAP Monitoring Handbook

1 Introduction

Nutrient concentrations can be used to assess the trophic status of coastal and marine waters and to determine the cause of eutrophication problems.

The monitoring is carried out in accordance with the OSPAR Eutrophication Strategy (2003) taking into account the specific conditions of the Wadden Sea area (van Beusekom et al., 2001 & 2005).

The Wadden Sea is effected by nutrient inputs from rivers (mainly from Rhine/IJssel, Ems, Weser and Elbe), atmosphere (N compounds) and North Sea waters (due to the residual long-shore current). Together with organic compounds, which are retained in the Wadden Sea it may result in accelerated eutrophication.

2 Objectives

Trilateral policy and management aims “to achieve, as far as possible, a natural and sustainable ecosystem in which natural processes proceed in an undisturbed way” (Guiding Principle).

With respect to the “Quality of Water and Sediment” the following Target applies to nutrients (Wadden Sea Plan):

• A Wadden Sea which can be regarded as an eutrophication non-problem area.

The monitoring of nutrients in water is carried out to assess the effects of changes in the input of nutrients on

• chemical processes,
• natural processes (primary production, food chain fluxes, production, decomposition),
• selected key species (effects on the abundance and physiological functioning of species),
• selected communities (as indicators of changes in the environmental conditions).

Furthermore, the monitoring of nutrients should document the efficiency of policy targets on the reduction of nutrient inputs.

3 Monitoring requirements

Wadden Sea Plan (WSP)

WSP

Targets on “Water and Sediment”

• Background concentrations of natural micropollutants.
• Concentration of man-made substance as resulting from zero-discharges.
• A Wadden Sea ecosystem which can be regarded as eutrophication non-problem area.
• Improvement of habitat quality for conservation of species.

EC Habitats Directive (HD)

HD

None

Water framework directive (WFD)

WFD

Article 8 chapter 1.ii:
Monitoring of surface waters: the ecological and chemical status and ecological potential
Annex V: 1.2.3 (transitional waters), 1.2.4 (coastal waters), 1.2.5 (heavily modified or artificial water bodies): physico-chemical elements – general conditions: Nutrient concentrations remain within the range normally associated with such undisturbed conditions.

Oslo Paris convention (OSPAR)

OSPAR

OSPAR Eutrophication Strategy: In accordance with the general objective, OSPAR’s objective with regard to eutrophication is to combat eutrophication in the OSPAR maritime area, in order to achieve and maintain a healthy marine environment where eutrophication does not occur.

Common Procedure for the Identification of the Eutrophication Status of the OSPAR Maritime Area (Ref. No. 2005-3). Assessment Parameter Category I: Degree of nutrient enrichment: Nutrient concentrations (area specific): elevated level(s) of winter DIN and/or DIP.

EcoQO Issue 9.1: Eutrophication status of the North Sea. EcoQO 9.1.1 Winter nutrient concentrations: Winter concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) should remain below a justified salinity-related and/or area-specific % deviation from background not exceeding 50%.

Other EC Directives 

UWWT, Nitrates Directive, IPCC

• Urban Waste Water Treatment Directive (UWWT Directive) (91/271/EEC)
• Nitrates Directive (91/676/EEC)
• IPCC Directive (96/61/EC)
• Various directives with regard to ambient air quality and emissions to air

4 Definitions

OSPAR categories of maritime waters

Problem areas with regard to eutrophication are defined as “those areas for which there is evidence of an undesirable disturbance to the marine ecosystem due to anthropogenic enrichment by nutrients”. This means that these areas show an increased degree of nutrient enrichment accompanied by direct and/or indirect or other possible eutrophication effects.

Potential problem areas with regard to eutrophication are defined as “those areas for which there are reasonable grounds for concern that the anthropogenic contribution of nutrients may be causing or may lead in time to an undesirable disturbance to the marine ecosystem due to elevated levels, trends and/or fluxes in such nutrients”. This means that these areas show an increased degree of nutrient enrichment, but that data are not sufficient, or not fit for the purpose, for assessing direct, indirect or other possible eutrophication effects.

Non-problem areas with regard to eutrophication are defined as “those areas for which there are no grounds for concern that anthropogenic enrichment by nutrients has disturbed or may in the future disturb the marine ecosystem.”

5 TMAP Monitoring Strategy

The TMAP approach has been based on the OSPAR strategy which is currently tuned with the WFD (EMMA activities, GIC Guidance on eutrophication). The Wadden Sea is still regarded as “eutrophication problem area” under OSPAR. It is likely that the “good ecological status” under the WFD will not be reached until 2015 because of high nutrient inputs.

Information basis for trilateral assessment are national monitoring programs which have been established under OSPAR and the WFD. These can be regarded as sufficient to assess the eutrophication status and the Target implementation (see Tab. 5.1).

A conceptual model has been developed that links riverine input and organic matter input with the nutrient cycles in the Wadden Sea. On that basis, autumn values of N remineralization products (NH4 + NO2) as a Wadden Sea specific indicator of the eutrophication status of the Wadden Sea (Beusekom et al., 2001, 2005).

(Table 5.1) Parameters with monitoring locations and frequencies and the relation to the other monitoring requirements.

Remarks:

*Number of stations per region depends on number of WFD water body typed to be covered. Regions: NL, Nds/HH, S-H, DK

5.1 Parameters

Monitoring shall consider the following nutrient species

• dissolved inorganic NO3-N, NO2-N, NH4-N and ortho-PO4
• total nitrogen and phosphorus

The following supporting parameters should also be measured (not mandatory)

• dissolved silicate (voluntarily: particulate silicate)
• organic carbon (POC, DOC, TOC) and co-variables (oxygen, pH, suspended matter, turbidity, temperature, salinity)

5.2 Monitoring locations

For each of the four region (The Netherlands, Niedersachsen/Hamburg, Schleswig-Holstein, Denmark), at least one sampling location per WFD water body type should be established as appropriate. The existing time series should be continued.

With regard to nutrient monitoring, it can be distinguished between 8 areas in the Wadden Sea mainly based on the different hydrological regimes. The main criteria were the degree of influence of rivers and the exchange with the adjacent North Sea (residence time of freshwater or seawater in a tidal basin and the flushing time) (see also De Jong et al., 1999).

For the selection of monitoring stations, areas with different levels of remineralization should be selected. Furthermore, also the occurrence of nutrient limitation in summer in some areas of the Wadden Sea have to be taken into account. These 8 areas are either more or less influenced by rivers or are dominated by North Sea water (numbering according to figure 1).

Influenced by rivers:

• Ho Bugt (Varde Å) (12)
• Weser-Elbe region (5, 6, 7, 8)
• Ems-Dollart estuary (3)
• Western Dutch Wadden Sea: influence of the river Rhine, higher flushing time than in the Eastern Dutch Wadden Sea (1)

North Sea dominated type:

• Sylt-Rømø basin and Fanø (10, 11)
• North Frisian Wadden Sea: occurrence of nutrient limitation in summer (9)
• East Frisian Wadden Sea: high remineralization (4)
• Eastern Dutch Wadden Sea: high remineralization (2)

Depending on the monitoring purpose and on the parameter, monitoring should be executed either in all areas or in selected areas (to be selected on national level).

6 Methods

The OSPAR „JAMP eutrophication monitoring guidelines: Nutrients” are also valid within the TMAP. For co-variables, standard methods should be followed for the determination of oxygen, pH, suspended matter, turbidity, temperature, salinity (see respective JAMP guidelines).

Sample treatment

a. Storage
Nutrient determinations should be carried out as soon as possible after sampling. Ammonia should be analyzed immediately after sampling, the others within a few hours after sampling with samples protected from light and stored in a refrigerator between sampling and analysis.
If immediate analysis is not possible samples must be preserved. At present, deep freezing and the addition of mercury chloride followed by a refrigeration and protection from light are the main recommended methods. However, because no preservation method can be generally recommended, each laboratory must validate ist storage method.

b. Filtration
Sea water contains microorganisms and other suspended matter of different composition. In some cases, these particles bias the measurement of the determinant in the soluble phase. The suspended matter can be removed either by filtration or centrifugation. Unnecessary manipulation of the sample should be avoided, but in particle-rich waters (e.g. coastal waters, during plankton blooms), filtration or centrifugation may become necessary. It is important that the procedure used for filtration/centrifugation has been validated.
For removing algae from the water sample, a GF/C filter is adequate. For work in open oceans with low concentrations of suspended matter, GF/F filters are considered suitable for suspended matter separation from open sea water. Filtration in closed systems with a neutral gas is recommended. Centrifugation is especially advisable for samples destined for ammonia determination (Extract from: ICES Techniques in Marine Environmental Sciences No. 35).

Analytical procedures

a. Nutrients
The determination of nutrients is based on standard colorimetric methods (Grasshoff et al., 1983; Kirkwood, 1996).

b. Organic carbon
Standard methods should be followed for the determination of dissolved, particulate and total organic carbon (see respective JAMP guidelines).

c. Co-variables
Standard methods should be followed for the determination of oxygen, pH, suspended matter, turbidity, temperature, salinity (see respective JAMP guidelines).

7 Parameter

8 Frequency and time

The sampling frequency should be selected according to the specific monitoring objective. The sampling should be carried out 1 - 2 hours after high tide.

• Calculation of inputs: daily, weekly or bi-weekly sampling during the whole year at stations in input areas (e.g. estuaries).
• Winter concentrations: monthly or weekly sampling during winter (Nov./Dec. - Feb.) at selected stations or transects on a salinity gradient.
• Nutrients cycles: monthly sampling during the whole year (in selected tidal basis) or higher frequency, at least the same as for the biological samples (see plankton).

For details see [Table 5.1].

9 Assessment

OSPAR has developed a set of common assessment parameters and their corresponding area-specific assessment levels. In the WFD, a CIS guidance document has been prepared, which focused particularly on harmonization of assessment methods and criteria across European water policy (CIS, 2005).

Nutrient inputs (riverine and atmospheric), concentrations and N/P ratio are assessed a Causative Factors (Category I: Degree of nutrient enrichment).

Area specific assessment criteria for nutrient concentrations have been developed in the Wadden Sea countries and will also be applied for the TMAP.

[Remark: Values still preliminary, to be included later]

Table 9.1 Assessment of riverine inputs and nutrient concentrations in the Wadden Sea.

Wadden Sea specific eutrophication criteria have been developed and applied in the QSR 2004 (Beusekom et al. 2001, 2005). N remineralisation products (NH4, NO2) indicate enhanced organic matter turnover caused by riverine inputs and can be applied as a measure of the eutrophication status (Tab. 3) and to classify the Wadden Sea into Non-Problem, Potential Problem and Problem areas.

Table 9.2: Classification of the Wadden Sea into Non-Problem, Potential Problem and Problem areas based on autumn concentrations of NH4 + NO2 (µM) as proposed by van Beusekom et al. (2001; 2005). The division into subregions is based on the availability of seasonal data. The present autumn values refer to values during the period 1997 – 2002. Non-problem conditions were based on background values for the western Dutch Wadden Sea. Values for the other areas are proportionally assigned on the basis present day values (1997 - 2002). Values for the Sylt Rømø Bight are based on the measured data and not calculated as in the table presented by van Beusekom et al. (2001). All threshold values were formally derived and an uncertainty range of ± 1µM should be added.

Fig. 9.1 Monitoring stations for nutrients in water

10 Reporting

Data should be reported annually to the national TMAP data unit (according to the national regulations) to be available for trilateral assessments (see TMAP Data Handling Manual).

11 Quality assurance

Appropriate monitoring protocols should be developed on national level. Intercalibration exercises should be carried out nationally and in the framework of the TMAP.

Quality assurance information together with detection limits and levels of accuracy should be reported

[to be included: reference to existing QA procedures and SOP]

12 Monitoring authorities

Denmark

Danmarks Miljøundersøgelser (DMU, NERI)

Miljøministeriet, Miljøcenter Ribe

Germany

ARGE Elbe, Hamburg

ARGE Weser

Bundesamt für Seeschifffahrt und Hydrographie, Hamburg (BSH)

Landesamt für Landwirtschaft, Umwelt und ländliche Räume (LLUR)

Landesbetrieb für Küstenschutz, Nationalpark und Meeresschutz (LKN)

Nationalparkverwaltung Niedersächsisches Wattenmeer (NLPV)

Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz (NLWKN)

Behörde für Stadtentwicklung und Umwelt, Hamburg (BSU)

Netherlands

Rijkswaterstaat Waterdienst, Lelystad

13 Literature

Beusekom, J.E.E. van, H. Fock, F. de Jong, S. Diehl-Christiansen & B. Christiansen, 2001: Wadden Sea Specific Eutrophication Criteria. Wadden Sea Ecosystem No. 14. Common Wadden Sea Secretariat, Wilhelmshaven, Germany.

Beusekom, J.E.E. van, P. Bot, J. Göbel, M. Hanslik, H.-J- Lenhart, J. Pätsch, L. Pepezak, T. Petenati & K. Reise, 2005: Eutrophication. In: K. Essink, C. Dettmann, H. Farke, K. Laursen, G. Lüerßen, H. Marencic & W. Wiersinga (Eds.). Quality Status Report 2004. Wadden Sea Ecosystem No. 19. Common Wadden Sea Secretariat. Wilhelmshaven, Germany.

CIS, 2005: Towards a guidance document on eutrophication assessment in the context of European water policy. November 2005.

Grashoff, K., M. Ehrhardt & K. Kremling, 1983: Methods of Seawater Analysis, Verlag Chemie, Second Edition.

Kirkwood, D. ,1996: Nutrients: Practical notes on their determination in sea water. ICES Techniques in Marine Environmental Sciences (TIMES), No. 17.

OSPAR, 1997d: JAMP Eutrophication Monitoring Guidelines: Nutrients, 4 pp.

OSPAR, 2003: 2003 Strategies of the OSPAR Commission for the Protection of the Marine Environment of the North-East Atlantic. Reference number: 2003-21.

OSPAR, 2005: Synergies in Assessment and Monitoring between OSPAR and the European Union Analysis of synergies in assessment and monitoring of hazardous substances, eutrophication, radioactive substances and offshore industry in the North-East Atlantic. Volume 1. Ref-No. 2005/230

OSPAR, 2007: EcoQO Handbook - Handbook for the application of Ecological Quality Objectives in the North Sea. First Edition 2007. Ref.-No. 2007/307