Fig 1.
Bathymetric map of the Paleovalleys Shelf, Espírito Santo State, Brazil built with survey data from [12, 34, 35] and depicting sampling sites in incised valleys-IVs (triangles) and rhodolith beds-RB (circles).
Upper left insert shows the main sedimentary facies [data from 30, 31] and Marine Protected Areas. Middle left insert shows the location of the study region (black rectangle) within Eastern Brazil. Lower right insert shows the mooring site within the incised valley (IV1). Mooring within the rhodolith bed was placed in site RB1.
Table 1.
Sampling sites and data collection (ADP: Acoustic Doppler Current Profiler, CTD: Conductivity, Temperature and Depth profiler, BRUV: Baited Remote Underwater Video).
Fig 2.
Incised valley viewed from the channel toward the wall (A, site IV1) and rhodolith bed (B, site RB1).
Fig 3.
Temperature-Salinity diagram with moorings’ and casts’ data from the incised valley—IV and rhodolith bed—RB.
Dashed lines represent the density contours.
Fig 4.
Diel and spatial variation of Photosynthetically Active Radiation—PAR (A), Chlorophyll (B) and Oxygen concentration—O2 (C), and spatial contrasts of pH (D), Turbidity expressed in Formazine Turbidity Units (E) and Coloured Dissolved Organic Matter—CDOM (F) in the incised valley—IV (blue) and rhodolith bed—RB (orange). The boxplot displays the median (central line), lower (Q1) and upper (Q3) quartiles within the box. Outliers are represented by isolated dots.
Table 2.
Pigments’ concentrations (mg/m3), microbial diversity and abundance (cel/L) in the incised valley (IV) and rhodolith bed (RB).
Fig 5.
Current speed and direction near the bottom in: A) the incised valley-IV and B) the adjacent rhodolith bed-RB (sites IV1 and RB1). Current roses show current speed frequencies and directions in the ebb and flood tides; red lines represent the resultant vector. Left and right vertical axes represent horizontal speed and tidal amplitude (black and blue lines), respectively. Horizontal axes represent local time.
Fig 6.
Abundance-based rarefaction (solid line) and extrapolation curves (dotted lines) for reef fishes derived from BRUV sampling in the incised valley-IV (blue) and in the rhodolith bed-RB (orange).
Black curve represents a pooled estimate.
Fig 7.
Reef fish community structure.
A and B: Relative abundance and biomass of each reef fish trophic guild at the incised valley (IV) and rhodolith bed (RB). Error bars represent Standard Errors (SE); vertical axes with values increasing in opposite direction. Legends: HERB—Herbivores; MCAR—Macro carnivores; MINV—Mobile invertivores; OMNI—Omnivores; PLAN—Planktivores; SINV—Sessile invertivores. C: Principal Coordinate Analysis (PCO) with reef fish biomass data (expressed in kg). Sampling strata are color-coded in order to expose benthic habitats contrasts. Only species with the greatest contribution to the ordination are shown (1—Chaetodon striatus, 2—Chromis encrysura, 3—Prognathodes brasiliensis, 4—Chaetodon sedentarius, 5—Mycteroperca acutirostris, 6—Stegastes pictus, 7—Acanthurus chirurgus, 8—Chromis flavicauda, 9—Bodianus pulchellus, 10—Acanthurus coeruleus, 11—Sparisoma axillare, 12—Cephalopholis fulva, 13—Halichoeres dimidiatus, 14—Paranthias furcifer, 15—Pomacanthus arcuatus, 16—Sphoeroides spengleri, 17—Seriola dumerili, 18—Malacanthus plumieri, 19—Ptereleotris randalli, 20—Pagrus pagrus, 21—Calamus sp.).
Fig 8.
Representative species of the benthic and reef fish assemblages associated with the incised valley.
Codes: 1—Antipathus sp., 2—Cirripathes sp., 3—Stichopathes sp.1, 4—Stichopathes sp. 2, 5—Stylopathes sp., 6—Tanacetipathes sp. 1, 7—Tanacetipathes sp. 2, 8—Muricea sp.1, 9—Muricea sp. 2, 10—Swifitia sp., 11—Crinoids, 12 –Encrusting sponges, 13—Crustose Coralline Algae (CCA), 14—Stegastes pictus, 15—Chaetodon sedentarius, 16—Holacanthus tricolor, 17—Bodianus pulchellus, 18—Cephalopholis fulva, 19—Chromis enchrysura, 20—Chaetodon striatus.
Fig 9.
Benthic cover at the rhodolith bed (left) and incised valley (right), with a detailed account of sessile macroinvertebrates. Error bars represent Standard Errors (SE).