Ecosystem function: Trait diversity, bioturbation, and bio-irrigation potentials of macrobenthic invertebrate communities in the Red Sea

The ecosystem functions of macrobenthic invertebrates were studied in the Red Sea. In total, 193 taxa were recorded. The functional traits of biomass (B) and density (D), such as infauna with internal irrigation (B - 53.4 %), blind-ended burrows, no burrow systems (D - 44.5 %), surface filter (B - 41.5 %), and surface deposit feeders (D - 50.8 %) were dominant attributes with significant regional and depth differences. However, irrigation depth 0 to 2 – 5 cm (B - 50 %, D - 45 %); movements through the sediment matrix mobility pattern (B - 68.3 %, D - 47.2 %), and reworking superficial modifiers (B - 54.2 %, D - 45.2 %) also significantly dominated. The functional individuals, biomass, richness, density, and diversity were 11 ± 1 (Mean ± SE) species m⁻², 1.25 ± 0.26 g m⁻², 1.70 ± 0.13 Fd’, 361 ± 57 ind. m⁻², and 2.76 ± 0.11FH' (log²). These indices decreased with increased depth and were higher in the north compared to the central region. The composition of bioturbation potential community index (BPc) and bio-irrigation potential community index (IPc) values was significantly (P < 0.05) higher in the north (29.46 ± 5.48, and 42.12 ± 10.33) and shallower (55.32 ± 12.79, and 83.76 ± 26.93) depth zones. The taxa Aglaophamus dibranchis, holothuria, sand dollar, and Glycinde sp.1 were responsible for higher BPc, and the taxa sand dollar, Spionidae indet. Notomastus latericeus , Glycinde sp.1, and Prionospio spp. contributed higher to IPc. The environmental variables MGS, silt/clay, depth, latitude (region), As, and Fe influenced functional density ( P = 0.191 ) and biomass ( P = 0.182 ), and MGS, depth, latitude, As, Mn, and Pb also influenced bioturbation ( P = 0.224 ) and bio-irrigation ( P = 0.218 ) of the macrobenthic community. Generally, the functional attributes influence deep-sea nutrient cycling by enhancing benthic and pelagic coupling processes on the Red Sea coast, particularly in relation to coastal developmental activities.