Appendix C: Specimen Collection Methods and Data Recording 



For some species, such as rock oysters, it is preferable to remove the top shell while the 

 oyster is attached to the rock and carefully collect the soft parts using pre-cleaned scalpels. 



1.7.6 Bivalve Samples for Analysis and the Gonadal Index Sample 



In addition at each station, at least 10 bivalve specimens should be collected for the gonadal 

 index sample. Oyster will be shucked and mussels shells will be split open prior to storing in 

 preservative. The procedures for preparing each type of bivalve are described below. 



1.7.6.1 Mussel Sample 



To split the shells, the tip of an oyster or clam knife should be carefully inserted between 

 the shells immediately posterior to the joint where the byssus emerges, and rotated to pry the shells 

 apart. A 90-degree rotation of the knife blade should cause the blade to be wedged firmly in place, 

 such that a scalpel blade can easily be inserted to sever the posterior adductor muscle. This 

 procedure should allow the shells to open with little or no additional force. If the mussel is small, 

 rotation of the knife blade could tear the adductor muscle and no further severance would be 

 required. 



Place the drained soft parts of 100 individuals in a mortar, add a known quantity of sodium 

 sulfate and macerate the tissues with pre-cleaned stainless steel knife and a pestle. This constitutes 

 the desiccated sample for chlorinated pesticide analysis. It should then be stored in a pre-cleaned 

 container for shipment. 



Place the additional sample of 10 mussels from each station or each split in a 0.5 1 wide- 

 mouth plastic jar prefilled with Dietrich's fixative. 



Seal the jar securely, label it, and store at ambient temperature. 



Mark the "Bivalve -Gonadal Index" box under "Samples Collected" on the Bivalve 

 Observations Log. 



Check jars periodically for excess CO2 buildup caused by acid degeneration of the shells. 

 Jars may require opening and reseating to relieve pressure. 



1.7.6.2 Oyster Sample 



To remove the oyster tissue, the oyster should be pressed with a flattened hand on a firm, 

 flat surface. 



In the case of rock oysters, the top shell should be knocked off the fixed bottom shell be 

 carefully topping a pre-cleaned pointed object (e. g., diving knife) placed at the hinge. 



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