systems, with their greater wave action and generally stronger currents, have 

 a much better potential for self cleaning than the low-energy systems. Other 

 types of habitats, such as critical habitats of endangered species, and re- 

 gionally important commercial habitats, such as commercially worked oyster 

 reefs, should also be given high priority on any habitat sampling priority 

 list. 



Table 3. General Habitat Priority Sampling Scheme 



1. Marshes a) high productivity 



b) nursery ground 



c) low energy system 



2. Mangrove swamps a) high productivity 



b) nursery ground 



c) low energy system 



3. Mud flats a) high productivity 



b) low energy system 



4. Sandy beaches a) delicate ecological balance 



b) high energy system 



5. Rocky shores a) delicate ecological balance 



b) high energy system 



Replicate Sampling 



As a general rule, it is better to get statistically valid results from 

 a small prudently selected number of sampling stations than to cover the en- 

 tire spill area out obtain results that are not statistically valid. It is 

 obvious that to obtain data that can be treated statistically, replicate 

 samples must be collected at each analytical sampling station. It is im- 

 possible, however, to accurately determine the number of samples per sta- 

 tion required to obtain data within certain error limits unless knowledge of 

 the population mean and variance is available. Fortunately, the mean and 

 variance measurements of a collection of samples can be used to estimate the 

 population mean and variance. The estimated values of these parameters 

 can then be used to predict the number of samples required to stay within 

 the desired error limits. 



Two-stage sampling procedures in which the mean and variance of the 

 first-stage samples are used to determine the number of replications required 

 for a certain degree of precision in the second sampling stage are often used 

 in biological investigations (Cox 1952). Similarly, the mean and variance of 

 analytical samples taken in Phase I of this documentation procedure should 



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