Huntington Research Centre Report

SUMMARY

Test Substance : Bore- Plate
Test Species : Brown shrimp (Crangon crangon)
Test Type : Acute toxicity. 96 h LC 50
Test Conditions : Semi-static test conditions according to guidelines issued by the Ministry of Agriculture, Fisheries and Food, Burnham-on-Crouch, U. K.

Results

Test substance : Bore- Plate

96h LC50                95% confidence limits (mg/l) 
   (mg/l) 
> 10000                                  -

There were no significant mortalities or other adverse reactions to exposure in 40 shrimp exposed to a test concentration of 10000 mg/l for a period of 96 hours.

INTRODUCTION

This report contains a description of the methods used and the results obtained during a study to investigate the acute toxicity of Bore-Plate to brown shrimp (Crangon crangon).

The study was commissioned by Drill Aid Ltd. and undertaken between 13 - 17 November 1989.

Dates of Protocol Approval

Study Director : 3 November 1989.

HRC Ltd. Management : 3 November 1989

Sponsor : 9 November 1989.

MATERIALS AND METHODS

Test Substance

Identification : Bore- Plate

Description : Black powder.

Purity : 100%.

Date of receipt : 8 November 1989.

Expiry : After December 1990.

Storage : In original container at room temperature.

Method of preparation : Direct dispersion in water.

Test Species

Name : Brown shrimp (Crangon crangon).

Source : P. Garnett, King's Lynn, Norfolk.

Acclimatisation : Dates: 3-13 November 1989. (Stock received: 3 November 1989).

Temperature: 14 ± 1C.

Dissolved oxygen : >= 8.l mgO2/l.

Mortalities : 2.8%.

Mean length : 4.3 cm (SD = 0.5).

Mean weight : 1.61g (SD = 0.48).

Test Water

Synthetic sea water (Synthetica(R) ) at 32% S and aerated for at least 12 hours prior to use.

Exposure Conditions

Test vessels : Glass aquaria holding 40 1 of test media.

Experimental design : 1 test concentration in duplicate, plus 1 control; 40 animals per test concentration.

Method of initiation: Shrimp were placed in prepared test media.

Loading: 0.81 g bodyweight/litre

Photoperiod: 16 h light : 8 h dark

Temperature: 14 ± 1C

Aeration: Via two propeller stirrers

Test concentrations: 10000 mg/l in duplicate

Medium renewal: Daily

Duration of exposure: 96 hours

Criteria of death: Absence of (i) respiratory movement and (ii) response to physical stimulation

Records

All raw data and other documents generated at HRC during the course of this study, together with a copy of this final report, have been lodged in the HRC Archives, Huntingdon, England.

RESULTS

There were no significant mortalities or other adverse reactions to exposure in 40 shrimp exposed to a test concentration of 10000 mg/l for a period of 96 hours.

Time (h)                    LC50 (mg/l)          95% confidence limits (mg/l)
   3                                >10000*                                 -
   6                                >10000                                   -
   24                              >10000                                   -
   48                              >10000                                   -
   72                              >10000                                   -
   96                              >10000                                   -

 
   Concentration (mg/l)           LT50 (h)        95% confidence limits (h)
            10000*                          >96                             -

* 10000 mg/l was the highest concentration employed in this test. It was considered unnecessary and unrealistic to test at concentrations in excess of 10000 mg/l. Good suspension of the test substance throughout the water column was achieved with the aid of the propeller stirrers fitted to each exposure vessel

 

Share on