Figure A.2 Density-dependent flux of NH 4 (black triangles and dotted line) and NO 3 (gray circles 
and solid line) associated with Neotrypaea californiensis (a) and Upogebia pugettensis (b). 
Positive values = efflux from sediments, negative values = uptake by sediments. Dashed and 
dotted curves represent best-fit regression models for flux =y(shrimp burrow density). Solid 
black line represents 0 nitrogen flux. 
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