Cold-Water Coral Mound Archive Provides Unique Insights Into Intermediate Water Mass Dynamics in the Alboran Sea During the Last Deglaciation

Abstract

The Alboran Sea is widely recognized to host numerous cold-water coral ecosystems, including the East Melilla Coral Province. Yet, their development through time and response to climatic variability has still to be fully understood. Based on a combined investigation of benthic foraminiferal assemblages, foraminiferal stable isotope compositions, grain size analysis, sediment geochemistry, and macrofaunal quantification, this study identifies key events and processes having governed coldwater coral development at the East Melilla Coral Province between Greenland Stadial 2.1 and the Early Holocene. The transition from Greenland Stadial 2.1 to Greenland

Monsoonal forcing of cold-water coral growth off southeastern Brazil during the past 160 kyr

“…As fresh-water admixture to the SMW and SACW may have increased water column stratification and hence the density contrast to the AAIW, the concentration of sediment and food particles at the nepheloid layer may also have been more pronounced. The link between monsoonal activity and CWC growth proposed here is in line with studies from the western Mediterranean Sea (Fentimen et al, 2020), the Gulf of Cádiz (Wienberg et al, 2010), and the tropical eastern Atlantic off Angola (Hanz et al, 2019), which all inferred that terrestrial input via dust or fluvial runoff can ultimately fuel CWC colonies. Notably, HSs occurred during phases of intermediate and low sea level, which facilitated the bypass of sediment across the shelf and thus allowed for an efficient supply of terrestrial organic matter to Bowie Mound (Fig.…”

“…Aside from processes directly affecting the watermass properties bathing CWCs, several studies also point to the importance of sea surface productivity in providing food to the deep ocean (Davies et al, 2009;Soetaert et al, 2016). However, despite the proximity of CWC mounds situated on the continental slope to adjacent continents, the role of terrestrial nutrient and POC input is still a matter of debate (Wienberg et al, 2010;Hanz et al, 2019;Fentimen et al, 2020).…”

“…The presence of CWC-bearing mounds off Brazil was first reported by and Sumida et al (2004) along the continental slope at intermediate water depths, between 500 and 1000 m, bathed by Antarctic Intermediate Water (AAIW). At Bowie Mound, the dominat-ing species is S. variabilis, which is adapted to colder (as low as 3-4 • C; Fallon et al, 2014;Flögel et al, 2014;Gammon et al, 2018) and less aragonite-saturated waters than L. pertusa (Thresher et al, 2011;Flögel et al, 2014;Bostock et al, 2015;Gammon et al, 2018).…”

Benthic foraminiferal faunas associated with cold‐water coral environments in the North Atlantic realm

“…Benthic foraminiferal assemblages have hence been widely used to reconstruct past environmental conditions (Gooday, 1993;Jorissen et al, 2007 and references therein). Previous studies suggest that benthic foraminiferal assemblages are a useful and promising tool to identify the environmental conditions governing present and past CWC reef and mound development (Fentimen et al, 2018;2020a;Fink et al, 2012;Margreth et al, 2009Margreth et al, , 2011Rüggeberg et al, 2007;Schönfeld et al, 2011;Stalder et al, 2014Stalder et al, , 2015Stalder et al, , 2018. However, no integration of these results in one comparative study has yet been done.…”

“…activity at an extremely high temporal resolution (Fentimen et al, 2020a;Fink et al, 2012;Hebbeln et al, 2016;López Correa et al, 2012;Stalder et al, 2014). Thus, rather than providing a continuous sedimentary record but at a low temporal resolution, CWC mounds yield a highly detailed view of restricted time windows.…”