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ANNEXU.K.QUALITY OF SHELLFISH WATERS

a

However, pending the adoption of a Directive on the protection of consumers of shellfish products, it is essential that this value be observed in waters in which live shellfish directly edible by man.

Abbreviations:
G

=

guide

I

=

mandatory

ParameterGIReference methods of analysisMinimum sampling and measuring frequency
1.

pH

pH unit

7 — 9

Electrometry

Measured in situ at the time of sampling

Quarterly
2.Temperature oCA discharge affecting shellfish waters must not cause the temperature of the waters to exceed by more than 2 oC the temperature of waters not so affected

Thermometry

Measured in situ at the time of sampling

Quarterly
3.Coloration (after filtration) mg Pt/l [X1A discharge affecting shellfish waters must not cause the colour of the waters after filtration to deviate by more than 100 mg Pt/l from the colour of waters not so affected]

Filter through a 0·45 µm membrane

Photometric method, using the platinum/cobalt scale

Quarterly
4.Suspended solids mg/lA discharge affecting shellfish waters must not cause the suspended solid content of the waters to exceed by more than 30 % the content of waters not so affected
  • Filtration through a 0·45 µm membrane, drying at 105 oC and weighing

  • Centrifuging (for at least five minutes, with mean acceleration 2 800 to 3 200 g), drying at 105 oC and weighing

Quarterly
5.Salinity ‰12 to 38 ‰
  • ≤ 40 ‰

  • Discharge affecting shellfish waters must not cause their salinity to exceed by more than 10 % the salinity of waters not so affected

ConductimetryMonthly
6.

Dissolved oxygen

Saturation %

≥ 80 %
  • ≥ 70 % (average value)

  • Should an individual measurement indicate a value lower than 70 %, measurements shall be repeated

  • An individual measurement may not indicate a value of less than 60 % unless there are no harmful consequences for the development of shellfish colonies

  • Winkler's method

  • Electrochemical method

Monthly, with a minimum of one sample representative of low oxygen conditions on the day of sampling. However, where major daily variations are suspected, a minimum of two samples in one day shall be taken
7.Petroleum hydrocarbons

Hydrocarbons must not be present in the shellfish water in such quantities as to:

  • produce a visible film on the surface of the water and/or a deposit on the shellfish,

  • have harmful effects on the shellfish

Visual examinationQuarterly
8.Organohalogenated substancesThe concentration of each substance in shellfish flesh must be so limited that it contributes, in accordance with Article 1, to the high quality of shellfish productsThe concentration of each substance in the shellfish water or in shellfish flesh must not reach or exceed a level which has harmful effects on the shellfish and larvaeGas chromatograpny after extraction with suitable solvents and purificationHalf-yearly
9.

Metals

SilverAg
ArsenicAs
CadmiumCd
ChromiumCr
CopperCu
MercuryHg
NickelNi
LeadPb
ZincZn

mg/l

The concentration of each substance in shellfish flesh must be so limited that it contributes in accordance with Article 1, to the high quality of shellfish products

The concentration of each substance in the shellfish water or in the shellfish flesh must not exceed a level which gives rise to harmful effects on the shellfish and their larvae

The synergic effects of these metals must be taken into consideration

Spectrometry of atomic absorption preceded, where appropriate, by concentration and/or extractionHalf-yearly
10.

Faecal

coliforms/100 ml

≤ 300 in the shellfish flesh and intervalvular liquidaMethod of dilution with fermentation in liquid substrates in at least three tubes in three dilutions. Subculturing of the positive tubes on a confirmation medium. Count according to MPN (most probable number). Incubation temperature 44 oC ± 0·5 oCQuarterly
11.Substances affecting the taste of the shellfishConcentration lower than that liable to impair the taste of the shellfishExamination of the shellfish by tasting where the presence of one of these substances is presumed
12.

Saxitoxin

(produced by dinoflagellates)