Fall Entrainment Sampling Reduction 



Early in 1978 an evaluation of the entrainment ichthyoplankton 

 program recommended a reduction in the fall (October through December) 

 sampling effort from 18 samples per week to 6 (3 day and 3 night samples, 

 one day per week) . The basis for the reduction was that the samples 

 collected in October through December contain low numbers of fish eggs 

 and larvae and did not provide much quantitative information on dominant 

 entrained ichthyoplankton taxa. A two-thirds reduction in the number of 

 samples collected in these fall months was demonstrated not to affect 

 our ability to meet the objectives of the entrainment studies. The fall 

 reduction was implemented in 1981 after receiving Nuclear Regulatory 

 Commission (NRC) approval. 



Flow Meter Chang e 



A change in the entrainment sampling flow meter system was made in 

 February 1980. The change involved replacement of the NAI-Electronic 

 Readout Box (ERB) system with an array of four General Oceanics (GO) 

 model #2030 flow meters. The bases for discontinuing use of the ERB 

 were high design and fabrication costs, poor maintenance record, and 

 inability to account for vertical and horizontal differences in flow. 

 The advantages of the GO array were its low cost and maintenance 

 requirements, ability to account for vertical and horizontal flow differ- 

 ences, and linear response over a range of velocities. The GO meters 

 were identical to those used in the offshore plankton program and could 

 be calibrated regularly by NUSCo personnel. 



The validity of using four GO flowmeters versus the ERB was assessed 

 indirectly since concurrent sampling data with both flow meter systems 



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