Using cold-w ater coral m ini-m ounds as analogue fo r giant m ound
grow th: assessment o f environm ental drivers and anthropogenic
impact
C o lla rtT im 1, Kerry Howeii2, Heather Stewart3, Jean-François Bou rille t4, Estefanía Llave5, D om inique
Blamart6 and David Van Rooij1
1 Renard Centre o f Marine Geology (RCMG), Ghent University, Belgium
Tim.Collart@ UGent.be
2 Marine Institute, Plymouth University, UK
3 British Geological Survey (BGS), UK
4 Institute Français de Recherche pour l’E xploitation de la Mer (IFREMER), France
5 Institute o f Geology & Mineral Exploration (IGME), Spain
6 Laboratoire des Sciences du C lim at et de L’Environnem ent (LSCE), Gif-sur-Yvette, France
C old-water corals (CWC) are found along the whole north-eastern A tla n tic Margin fro m Norway to
the G ulf o f Cadiz. In the Porcupine Seabight, these coral reefs (m ainly Lophelia pertusa and
M adrepora oculata) accum ulate into large m ounds o f up to 250m high (e.g. Challenger Mound),
which have been well studied over the past tw o decades (Roberts et al., 2006). The detailed
m echanism o f the start-up phase o f such large CWC m ounds is however not yet fu lly understood.
Therefore, it is essential to study analogues o f these stages th a t are not well recorded in larger
mounds. The FWO MINIMOUND project (2013-2016) aims to investigate the initia tio n , grow th and
demise o f ‘sm all’ CWC m ounds and to determ ine the role o f clim atic and hydrocarbon-seepage
related processes as well as anthropogenic impact. This h igh-resolution m u ltid iscip lin a ry study w ill
focus on three ‘ m in im o u n d ’ provinces along the Biscay continental m argin: (1) the Explorer and
Dangeard Canyons on the Celtic Margin (Stewart et al., 2013), (2) the Guilvinec Canyon on the
Arm orican Margin (De Mol e t al., 2011) and (3) the Upper Ferroi Canyon on the Cantabrian Margin.
These m inim ounds are fossil (9.7ka BP) and occur at relative shallow depth on the interface between
the Eastern North A tla n tic Central Water (ENACW) and the M editerranean O utflow Water (MOW).
C ontrastingly, m ost present-day living CWC reef habitats dwell in the deeper MOW depth range,
relying on the density and dynamics o f th is w ater mass fo r th e ir food supply.
The objectives o f the project are th re efold : (1) the establishm ent o f a ch ro no stratig ra ph ic
fram e w o rk and the reconstruction o f palaeoceanographic changes over the last 15.000 years in
order to determ ine the im pact o f glacial to interglacial clim ate change on the ENACW-MOW interface
and the CWC habitats (Frank e t al., 2011); (2) the m inim ound province at the Upper Ferroi Canyon
shows a close association w ith hydrocarbon-seepage (pockm arks) which allows to assess the role o f
hydrocarbon related processes in CWC mound fo rm a tio n ; (3) the potential im pact o f anthropogenic
fisheries activities w ill be investigated.
These objectives w ill be tackled th ro u g h a coupled geophysical, sedim entological and integrative
approach, including the palaeoceanographic and biogeochem ical study o f USBL guided cores in
cooperation w ith the BGS (UK), LSCE (Gif-sur-Yvette, France), IFREMER (France), IGME (Spain) and IEO
(Spain). Two sam pling cam paigns w ith the R/V Belgica w ill be undertaken. In addition to core
collection, drop fram e images w ill be acquired to allow habitat m apping and predictive m odeling o f
the CWC habitats in cooperation w ith the Marine Institute o f Plymouth U niversity (UK).
References
De Mol L., D. Van Rooij, H. Pirlet, J. Greinert, N. Frank, F. Quemmerais, J.-P. Henriet. 2011. Coldw ater coral habitats in the Penmarc'h and Guilvinec Canyons (Bay o f Biscay): Deep-water versus
shallow -water settings. Marine Geology 282(1 -2):40-52.
Frank N., A. Freiwald, M. Lopez Correa, C. W ienberg, M. Eisele, D. Hebbeln, D. Van Rooij, J.-P.
Henriet, C. Colin, T. van Weering, H. de Haas, P. Buhl-Mortensen, J.M. Roberts, C. De Mol, E.
D ouville, D. Blamart, C. Hatte. 2011. Northeastern A tla n tic cold-w ater coral reefs and climate.
Geology 39 (8):743-746.
Roberts J.M., A.J. Wheeler, A. Freiwald. 2006. Reefs o f the deep: the biology and geology o f coldw ater coral ecosystems. Science 31 2(5773):543-547.
Stewart H.A., J.S. Davies, J. Guinan, K.L. Howell. 201 3. The Dangeard and Explorer canyons, South
Western Approaches UK: Geology, sedim entology and newly discovered cold-w ater coral m in i­
mounds. Deep Sea Research Part II: Topical Studies in O ceanography (0).
-
27
-