Fig 1.
Hyporheic macroinvertebrate sampling sites on six streams in (A-F) the UK and (G-L) France.
River Ashop (A) coarse-grained and (B) fine-grained sites; Black Brook (C) coarse and (D) fine sites; River Lathkill (E) coarse and (F) fine sites; Ain River (G) coarse and (H) fine sites; Albarine River (I) coarse and (J) fine sites; Bienne River (K) coarse and (L) fine sites.
Table 1.
Characteristics of the UK (Ashop, Black Brook, Lathkill) and French (Ain, Albarine, Bienne) study streams, including hyporheic water quality and surface substrate characteristics at coarse-grained (C) and fine-grained (F) sites.
Fig 2.
Equipment and mode of operation for two hyporheic macroinvertebrate pump-sampling techniques.
(A) The Bou-Rouch pump (not to scale); (B) the vacuum pump (not to scale); (C) priming the Bou-Rouch sampling apparatus with filtered stream water in the Albarine River; and (D) vacuum-pump sample collection in the Albarine.
Fig 3.
Rank frequency distribution (%) of macroinvertebrate taxa collected using Bou-Rouch (A) and vacuum-pump (B) hyporheic sampling techniques in the River Ashop, UK.
A, adult; L, larvae; P, pupae.
Fig 4.
Rank frequency distribution (%) of macroinvertebrate taxa collected using Bou-Rouch (A) and vacuum-pump (B) hyporheic sampling techniques in the Black Brook, UK.
A, adult; L, larvae; P, pupae.
Fig 5.
Rank frequency distribution (%) of macroinvertebrate taxa collected using Bou-Rouch (A) and vacuum-pump (B) hyporheic sampling techniques in the River Lathkill, UK.
A, adult; L, larvae; P, pupae.
Fig 6.
Rank frequency distribution (%) of macroinvertebrate taxa collected using Bou-Rouch (A) and vacuum-pump (B) hyporheic sampling techniques in the Ain River, France.
A, adult; L, larvae; P, pupae.
Fig 7.
Rank frequency distribution (%) of macroinvertebrate taxa collected using Bou-Rouch (A) and vacuum-pump (B) hyporheic sampling techniques in the Albarine River, France.
A, adult; L, larvae; P, pupae.
Fig 8.
Rank frequency distribution (%) of macroinvertebrate taxa collected using Bou-Rouch (A) and vacuum-pump (B) hyporheic sampling techniques in the Bienne River, France.
A, adult; L, larvae; P, pupae.
Fig 9.
Hyporheic macroinvertebrate assemblage metrics estimated by Bou-Rouch and vacuum-pump sampling techniques.
Mean ± 1 SE per 6-L sample: abundance in (A) UK and (B) French streams/sites; taxa richness in (C) UK and (D) French streams/sites. C, coarse-grained sites; F, fine-grained sites.
Fig 10.
Rarefaction curves of taxa richness, for samples collected using two hyporheic macroinvertebrate pump-sampling techniques, Bou-Rouch (BR, blue) and vacuum-pump (VP, red) sampling.
Sample-based incidence curves for: (A) the Ashop; (B) Black Brook; (C) the Lathkill; (D) the Ain; (E) the Albarine; (F) the Bienne; and sample-based incidence curves rescaled to the number of incidences, for: (G) the Ashop; (H) Black Brook; (I) the Lathkill; (J) the Ain; (K) the Albarine; (L) the Bienne. To allow rescaling to produce smooth curves, the expected number of incidences in t samples was calculated as (t / total number of samples)*total number of incidences. Solid lines indicate the estimated number of taxa; shaded areas indicate upper and lower 95% CIs.
Table 2.
Non-parametric estimators of macroinvertebrate taxa richness in hyporheic samples collected from three streams in the UK and France using Bou-Rouch and vacuum-pump sampling techniques.
Fig 11.
Non-metric multidimensional scaling ordination of macroinvertebrate assemblage composition characterized by two hyporheic pump-sampling techniques in three streams in: (A) the UK; (B) France.
The two techniques are Bou-Rouch (BR) and vacuum-pump (VP) sampling. Albarine and Bienne samples are separated into coarse-grained (C) and fine-grained (F) sites due to differences in assemblage composition. Lines link individual samples to the stream/site-technique group centroid. N = 8 for Ain, Black Brook and Ashop BR; n = 7 for Lathkill BR; n = 6 for Lathkill VP; and n = 5 for Ashop VP stream-technique groups (other samples contained no macroinvertebrates); n = 4 for Albarine and Bienne site-technique groups. The high NMDS1 score of a Lathkill VP sample (indicated by a thick border) was reduced from 3.1 to aid presentation.
Table 3.
Recommendations for use of Bou-Rouch or vacuum-pump sampling techniques in different types of hyporheic macroinvertebrate community surveys.