Table 2. Trophic enrichment factors (mean ± standard deviation) of δ¹⁵N and δ¹³C from three diet sources used in the diet mixing analyses.

Source	TEF for δ15N	TEF for δ13C
Filamentous algae	2.15±0.62	0.26±0.33
Periphyton	2.36±0.38	0.34±0.23
Fucus vesiculosus	2.05±0.45	−0.4±0.29
McCutchan et al. [35]	2.3±0.28	0.4±0.17
Aita et al. [36]	3.5±0.2	0.9±0.39
Syväranta et al. [37]	3.0±0.5	0.5±0.2

These factors were calculated using the equations suggested for invertebrate consumers in Caut et al. [34]. Average from colony sites and standard deviation are shown. Also shown are trophic enrichment factors from three previous studies which were also used to compare model results. In these cases, the same enrichment factors were used for the three source species.