Appendix G. Average 15N signatures of macrofauna exposed to 15N-labeled Spartina detritus in tidal flat vs. Hybrid sediments for (A) 17-d exposure, surface; (B) 17-d exposure, litter bags; (C) 74-d exposure, surface; (D) 74-d exposure, litter bags. Paired t tests were carried out using species as replicates to evaluate difference between surface and subsurface signatures. All were nonsignificant: (A) P = 0.361, (B) P = 0.434, (C) P = 0.211, (D) P = 0.588.