K-38 
Summary (cont.) 
• For each iteration of the bootstrap simulation, the assessment data are 
compared to the reference data to estimate proportion of sites with scores 
below the threshold 
• This is done for each of one or more habitats wilhin a segment (i e . some 
segments have sites in more than one habitat) 
• See next slides for the two examples 
£ 
§ 
Cr 
1 > 
/ 
/ 
/ 
IBI scores 
2.0 
2 . 7 - 
5 % 
3 3 
9 
* 
♦ a* • 
* Habitat A 
• Habitat B 
»• -t. 
. * « 
appendix k 
2006 303(d) Assessment Methods for Chesapeake Bay Benthos 
