Zinc bromide

Toxicity to other aquatic organisms

Administrative data

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable study which meets basic scientific principles

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Inhibition of carbon fixation as a function of zinc uptake in natural phytoplankton assemblages.

Author:

Davies AG & Sleep JA

Year:

1979

Bibliographic source:

J. mar. biol. Ass. U.K. 59: 937-949

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Photosynthetic inhibition (C fixation) test on phytoplancton communities in the field, designed for dose-response

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Zinc

EC Number:

231-175-3

EC Name:

Zinc

Cas Number:

7440-66-6

IUPAC Name:

zinc

Details on test material:

No information on salt used

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

The tests with zinc (plus 65Zn as a radioactive tracer) were carried out in natural sea water from Plymouth . The zinc background concentration in seawater was 0.4, 0.8 and 7.6 µg l-1 in the three samples

Test organisms

Test organisms (species):

other: multispecies test

Details on test organisms:

A series of three samples of varying biological composition were taken (100% diatoms - predominant species Rhizosolenia alata; 60% dinoflagellates/40% diatoms – predominant species Scrippsiella aff. trochoidea and R. stolterfothii; and 60% diatoms/40% dinoflagellates – predominant species as previous sample)

Study design

Test type:

static

Water media type:

saltwater

Limit test:

no

Test conditions

Test temperature:

14°C

Salinity:

35 ppt

Nominal and measured concentrations:

Nominal Zinc concentrations: 6 concentrations tested, 3 replicates / treatment

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

18 h

Dose descriptor:

NOEC

Effect conc.:

>= 7 - <= 13 µg/L

Nominal / measured:

estimated

Conc. based on:

dissolved

Basis for effect:

other: C fixation rate

Remarks on result:

other: estimated from graph

Effect concentrations 2

Duration:

18 h

Dose descriptor:

LOEC

Effect conc.:

>= 10 - <= 15 µg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Basis for effect:

other: C fixation rate

Details on results:

The lowest concentrations of zinc which caused detectable inhibition of carbon fixation ( i.e. rates lower than 90% of the mean control values) were reported as being in the range of 10 to 15 µg l-1. From the dose-response curves presented in the paper, estimated EC10 levels were in the range of 7 to 13 µg l-1.
Test details: only fixation rates lower than 90% of the mean control value can be ascribed to zinc inhibition
Dose-response: yes
Control data: graphed

Reported statistics and error estimates:

no statistics reported

Any other information on results incl. tables

no remark

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Relevant field study useful to check the protection level provided by the HC5 following from statistical extrapolation of single species tests data.

Executive summary:

Davies and Sleep (1979) studied the effect of zinc on carbon fixation rates of natural phytoplankton communities present in the English channel. A series of three samples of varying biological composition were taken in July 1978, at approximately weekly intervals, at the same location. The tests with zinc (plus⁶⁵Zn as a radioactive tracer) were carried out in natural sea water. The zinc background concentration in seawater was 0.4, 0.8 and 7.6 µg l^-1in the three samples. The lowest concentrations of zinc which caused detectable inhibition of carbon fixation ( i.e. rates lower than 90% of the mean control values) were reported as being in the range of 10 to 15 µg l^-1. From the dose-response curves presented in the paper, estimated EC10 levels were in the range of 7 to 13 µg l^-1.