Can benthic foraminifera serve as proxies for changes in benthic macrofaunal community structure? Implications for the definition of reference conditions

Abstract

Benthic macrofauna is one of the most widely used biological groups to assess the ecological status of marine systems. Lately, attention has been paid to similar use of benthic foraminifera. In this study, distribution patterns of benthic foraminiferal and macrofaunal species were investigated simultaneously in 11 fjords in southeastern Norway in order to assess correlations and responses to environmental conditions. Selected fjords allowed to investigate contrasted environmental conditions from low total organic carbon (TOC) content (sediment TOC < 2.7%) in normoxia (bottom-water [O] > 2 mL O.L) up to high TOC content (> 3.4%) in severe hypoxia (< 0.5 mL O.L). Environmental parameters comprised bottom-water dissolved oxygen, grain size, total organic carbon, total nitrogen (TN), pigments and depth below threshold (DBT). Foraminiferal and macrofaunal community data were significantly correlated (Procrustes analysis m = 0.66, p = 0.001). Hence, benthic foraminiferal distribution patterns mirror those of benthic macrofauna. However, as opposed to the foraminifera, macrofauna was not recorded at the most oxygen-depleted stations and, hence, was more sensitive to severe oxygen depletion. With regard to assigning species to ecological groups for ecological quality status assessment, the results suggest that species, e.g. Spiroplectammina biformis (foraminifera), Scalibregma inflatum (macrofauna), may exhibit different ecological requirements depending on their habitat. Considering the observed congruent patterns of benthic foraminifera and macrofauna, palaeo-communities of benthic foraminifera could be used as indicators of reference conditions for benthic macrofaunal community structure. This would however need further developments of algorithms to perform such a translation.

Indicative value of benthic foraminifera for biomonitoring: Assignment to ecological groups of sensitivity to total organic carbon of species from European intertidal areas and transitional waters

“…In the Pertuis Charentais, a significant positive correlation between Foram-AMBI and AMBI values (based on macrofauna) confirmed previous correlations found between foraminiferal and macrofaunal communities and indices (Alve et al, 2019;Bouchet et al, 2018b). However, only a 50% agreement in terms of EcoQS between Foram-AMBI and AMBI was reported.…”

Benthic foraminifera to assess ecological quality statuses: The case of salmon fish farming

“…Both are benthic and sedentary organisms, their distribution patterns depending directly on the environmental conditions. Furthermore, foraminiferal and macrofaunal community compositions in SE Norwegian fjords were significantly correlated suggesting that benthic foraminiferal distribution patterns mirror those of benthic macrofauna (Bouchet et al, 2018b). Intercalibration of benthic foraminiferal and macrofaunal biotic indices further confirm the complementarity of these two groups (Alve et al, 2019).…”

“…Specifically, fish farms induce clear shifts in the community structure of benthic foraminifera (Pochon et al, 2015), promote tolerant species (Angel et al, 2000) and lead to moderate to poor EcoQs (Bouchet et al, 2018a). In Norwegian fjords, benthic foraminiferal communities significantly correlate with benthic macrofauna communities, indicating that foraminifera can also be considered as good indicators of environmental conditions (Bouchet et al, 2018b). Foraminiferal indices based either on diversity (Alve et al, 2009;Bouchet et al, 2013 and on the sensitivity of species to organic pollution (Alve et al, 2016;Barras et al, 2014;Dimiza et al, 2016;Jorissen et al, 2018), have been designed and successfully applied to assess EcoQs of benthic habitats (Alve et al, 2019;Bouchet et al, 2018aDamak et al, 2020;Dijkstra et al, 2017;Dolven et al, 2013;El Kateb et al, 2020;Francescangeli et al, 2016;Melis et al, 2016).…”

Opportunities and challenges in incorporating benthic foraminifera in marine and coastal environmental biomonitoring of soft sediments: from science to regulation and practice

“…Many studies have demonstrated the potential of foraminifera to reflect environmental changes of coastal and open marine systems on soft sediments (e.g., Alve, 1995;Burone et al, 2006;Mojtahid et al, 2006;Frontalini et al, 2009;Frontalini & Coccioni, 2011;Martins et al, 2013Martins et al, , 2016Martins et al, , 2019Bergamin et al, 2019). In Norwegian fjords, it has been shown that benthic foraminiferal communities significantly correlate with benthic macrofaunal communities, confirming that foraminifera can be as good sentinels of environmental conditions as macrofaunal (Bouchet et al, 2018a). Furthermore, foraminiferal indices based on diversity (Alve et al, 2009; and on the sensitivity of species to organic pollution (Barras et al, 2014;Dimiza et al, 2016;Alve et al, 2016; have been designed, and successfully applied to assess ecological quality statuses Dolven et al, 2013;Barras et al, 2014;Francescangeli et al, 2016;Dijkstra et al, 2017;Bouchet et al, 2018b;Jesus et al, 2018;Alve et al, 2019;Melis et al, 2019).…”