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Ecotoxicological information

Sediment toxicity

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Administrative data

Endpoint:
sediment toxicity: long-term
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well performed study. Effect concentrations based on measured pore water sulfide concentrations. Concentrations were relatively constant during the 49-day exposure.

Data source

Reference
Reference Type:
publication
Title:
Sublethal effects of hydrogen sulfide in sediments on the urchin Lytechinus pictus.
Author:
Thompson B, Bay S, Greenstein D, Laughlin J
Year:
1991
Bibliographic source:
Marine Environmental Research 31: 309-321.

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
A sodium sulfide solution was pumped to the sub-sediment reservoir (0.5 mL/min, reservoir solutions replenished every 2-3 days), where it diffused up through the sediment layer. Clean aerated seawater flowed above the sediment layer (flow-through system).
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Na2S.9H2O
- No further details provided

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples were taken from each aquarium at the beginning and end of the 49-d exposure period.
A syringe fitted with a 5-µm filter was inserted 1 cm into the sediment and 5 mL of pore water was withdrawn in each of the three replicate samples. It was assumed that the water was an integrated sample of pore water from about the top 2 cm of the sediment.

Test substrate

Vehicle:
no
Details on sediment and application:
see test conditions and description of mehod

Test organisms

Test organisms (species):
other: Lytechinus pictus (sea urchin)
Details on test organisms:
TEST ORGANISM
- Common name: sea urchin
- Source: collected by otter trawl in northern Santa Monica Bay, California, USA
- Age of animals at beginning of exposure: test diameter = 14-23 mm (adult)
- Feeding during test: no data

ACCLIMATION
- Acclimation period: 30 d
- Acclimation conditions (same as test or not): yes
- Type and amount of food: no data
- Feeding frequency: no data

Study design

Study type:
laboratory study
Test type:
flow-through
Water media type:
saltwater
Type of sediment:
natural sediment
Limit test:
no
Exposure duration
Duration:
49 d
Exposure phase:
total exposure duration
Post exposure observation period:
none

Test conditions

Hardness:
no data
Test temperature:
15°C
pH:
8.03
Dissolved oxygen:
5.1 mg/L (overlaying water)
Salinity:
34 g/L
Ammonia:
0.37 mg/L
Nominal and measured concentrations:
Measured total sulfides in sediment pore water at the start of testing: 0.1-19.2-52.4-88.1 mg S2-/L
Measured total sulfides in sediment pore water at the end of testing: 0.5-16.6-46.2-83.7 mg S2-/L
Mean H2S (calculated): 0.034-1.1-3.1-5.7 mg H2S/L
Details on test conditions:
TEST SYSTEM
- Test container (material, size): aquaria of 7-mm clear plexiglass (24x15.5 cm)
- Sediment volume: 4 cm thick
- Aeration: only the clean seawater flowing above the sediment layer was aerated
- A sodium sulfide solution was pumped to the sub-sediment reservoir of each aquarium, where it diffused up through the sediment layer. Clean seawater flowed (18 mL/min) above the sediment layer.
- Systems were allowed to equilibrate for at least 60 days

EXPOSURE REGIME
- No. of organisms per container (treatment): 15
- No. of replicates per treatment group: 3
- No. of replicates per control: 3
- Feeding regime: no data
- Type and preparation of food: no data
- Amount of food: no data

RENEWAL OF OVERLYING WATER
- Details on volume additions: 0.5 mL/min (sulfide solution), i.e., renewal every 2-3 days
- Flow-rate: 18 mL/min (overlying water)

OVERLYING WATER CHARACTERISTCS
- Type of water: seawater
- For seawater characterization see above

SOURCE OF NATURAL SEDIMENT
- Location and description of sampling site: Newport Bay
- Contamination history of site: clean, natural sediment was used

CHARACTERIZATION OF (ARTIFICIAL; delete if not applicable) SEDIMENT
- Particle size distribution
- % sand: 96.5%
- % silt: 2%
- % clay: 1.5%
- Further constituents
- Total organic carbon: 0.11%

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): survival, growth (test diameter and wet weight), and male and female gonad production (wet weight)

Results and discussion

Effect concentrationsopen allclose all
Duration:
49 d
Dose descriptor:
NOEC
Effect conc.:
1.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
mortality
Duration:
49 d
Dose descriptor:
LOEC
Effect conc.:
3.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
mortality
Duration:
49 d
Dose descriptor:
NOEC
Effect conc.:
3.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: growth (test diameter)
Duration:
49 d
Dose descriptor:
LOEC
Effect conc.:
5.7 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: growth (test diameter)
Duration:
49 d
Dose descriptor:
NOEC
Effect conc.:
< 1.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: growth (wet weight)
Duration:
49 d
Dose descriptor:
LOEC
Effect conc.:
1.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: growth (wet weight)
Duration:
49 d
Dose descriptor:
NOEC
Effect conc.:
3.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: female gonad production (wet weight)
Duration:
49 d
Dose descriptor:
LOEC
Effect conc.:
5.7 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: female gonad production (wet weight)
Duration:
49 d
Dose descriptor:
NOEC
Effect conc.:
< 1.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: male gonad production (wet weight)
Duration:
49 d
Dose descriptor:
LOEC
Effect conc.:
1.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: H2S
Basis for effect:
other: male gonad production (wet weight)
Reported statistics and error estimates:
Significant effects were identified using nested ANOVAs tested pairwise against the controls.

Applicant's summary and conclusion

Conclusions:
In this test, the sea urchin Lytechinus pictus was exposed to H2S for 49 days by pumping sodium sulfide solutions through the sediment in a flow-through system. The most critical (not-unbound) NOEC was observed for survival and was 1.1 mg H2S/L.