TABLE 5.

Pairwise Spearman correlations (ρ) of δ ¹⁵N of phytobenthos (PB) and particulate organic matter (POM) with macroinvertebrate specimens of different feeding types.

Food source	Feeding type	Site	ρ	p	N	Significance	Food source	Feeding type	Site	ρ	p	N	Significance
POM	Active filter feeder	BY22	−0.393	0.396	7		PB	Active filter feeder	BY22	0.000	1.000	7
		RBA3	−0.224	0.537	10				SB21	0.612	0.066	10
		RB21	0.648	0.049	10	*			RB22	0.624	0.060	10
		SB21	0.806	0.008	10	**			RBA3	0.685	0.035	10	*
		RB22	0.818	0.007	10	**			RB21	0.758	0.016	10	*
	Passive filter feeder	SB21	0.600	0.097	9			Passive filter feeder	SB21	0.367	0.336	9
	Grazer	RBA3	−0.224	0.537	10			Grazer	SB21	0.100	0.810	9
		SB21	0.150	0.708	9				BY22	0.257	0.658	6
		BY22	0.371	0.497	6				RBA3	0.648	0.049	10	*
	Shredder	BY22	−0.721	0.024	10	*		Shredder	BY22	0.127	0.733	10
		RBA3	−0.055	0.892	10				RB22	0.406	0.247	10
		RB21	0.661	0.044	10	*			RBA3	0.697	0.031	10	*
		RB22	0.818	0.007	10	**			SB21	0.830	0.006	10	**
		SB21	0.891	0.001	10	***			RB21	0.891	0.001	10	***
	Predator	RBA3	0.429	0.299	8			Predator	RBA3	0.000	1.000	8
		RB21	0.833	0.015	8				RB21	0.571	0.151	8
		SB21	0.929	0.007	7	**			SB21	0.857	0.024	7	*

Note: Correlations are based on mean enrichment levels across all sampling reaches and grouped by distance downstream of the isotope inlet. Significant results are indicated in bold; significance levels are indicated as *(p < .05), **(p < .01) and ***(p < .001).