Potential impact of mangrove clearance on biomass and biomass size spectra of nematode along the Sudanese Red Sea coast

•The potential effect of mangrove clearance on the distribution of nematode biomass and biomass size spectra was investigated.•Sediment composition was altered as a result of mangrove clearing.•Clear differences in individual biomass, total biomass, and community composition were observed between sites.•Nematode biomass size spectra shifted towards smaller size classes in cleared site.•The graphical representation of nematode assemblage is promising tool for detecting the impact of clearance on mangrove.

The potential effect of mangrove clearance on nematode assemblage biomass, biomass size spectra (NBSS) and abundance/biomass curves (ABC) was investigated in three sites representing a varying degree of mangrove clearance as well as in three stations established at each sites representing high-, mid- and low-water levels. Results revealed significant differences in sediment and nematode characteristics between the three sites. Although both the cleared and the intact mangrove had comparable biomass values, clear differences in biomass size spectra and abundance biomass curves were observed. The results suggested that the variation in the silt fraction and the food quality positively affected the total biomass. Mangrove clearance has caused a shift from a unimodal to a bimodal biomass size spectrum at all water levels, owing to an increase in smaller-bodied opportunistic non-selective deposit feeding nematodes. The ABC further confirmed the effect of clearance by classifying the cleared mangrove as moderately to grossly disturbed.