53b 



OYSTERS 



WATER 



CONDITIONING 

 4-6weeks ot 20°C 



SPAWNING 



Temp, roised to 25°- 30°C. 

 for 2-3 hours, sperm added 



INNOCULATION 



20-30 thousond zygotes, 

 1/2 hours older lcss,odded 

 to each culture 



CARRY - ALONG 

 CONTROLS 



Three 4-liter sea water I 



I 



L 



samples from loborotory 



COLLECTION 



4-liter somple 

 by seoplone 



TRANSPORT 



Al I somples to loborotory 

 within 3hours of collection 



BIOASSAY 



LABORATORY CONTROLS 



Equol to 10% of 

 number of field samples 







INCUBATION OF 

 3 REPLICATE 

 ONE-LITER CULTURES 

 for eoch field 6 control somple 

 -ot 20°C for 48 hours 



,._. j: 



TERMINAL SWL 

 AND SALINITY ANALYSES - 



250 ml. 



J 



ALIQUOT SAMPLE 

 Contoifiing 100-200 larvae 



CHLOROPHYLL 

 ANALYSIS 



50 ml. 



INITIAL S V7L 

 AND SALIfilTY ANALYSES 



250 ml. 



RESPONSE measure: ILNTS 

 Percent obnc, liicl lorvoe 



Flo'/j diagram of the f i eld-saraple oyster-larva response study, 



