Distributional patterns of deep-sea coral assemblages in three submarine canyons off Newfoundland, Canada

Abstract

Deep-sea corals are fragile and long-lived species that provide important habitat for a variety of taxa. The rarity of in situ observations in deep waters off Newfoundland, Canada, motivated the first extensive deep-sea research cruise to that region in 2007. We conducted 7 dives in 3 canyons (Haddock Channel, Halibut Channel, and Desbarres Canyon) with ROPOS (Remotely Operated Platform for Ocean Science). Over 160 000 coral colonies were enumerated and, of the 28 species found, Acanella arbuscula, Pennatula spp., and Flabellum spp. were most frequently observed. The largest coral observed was Keratoisis grayi at over 2 m in height. Corals spanned the entire depth range sampled (351 to 2245 m) and inhabited all bottom types surveyed, but boulder and cobble habitats were most species-rich. Assemblages differed significantly with depth class and bottom type. The unique assemblage at outcrops was strongly driven by the presence of Desmophyllum dianthus. Keratoisis grayi, D. dianthus, and Anthomastus spp. were largely absent in mud-sand habitats. Sea pen meadows covered large tracts of muddy seafloor spanning >1 km. Acanella arbuscula and Flabellum spp. characterised large coral fields with abundant corals but relatively low species richness. These results highlight not only the importance of hard structure in determining patterns of coral distributions, abundances, and assemblages, but also the need to focus conservation efforts on a variety of habitats to ensure protection for the full suite of deep-sea coral species.

First record ofProtoptilum carpenteri(Cnidaria: Octocorallia: Pennatulacea) in the Mediterranean Sea

“…The depth of the first finding, 412-451 m, is in agreement with the lower limit of distribution of the species reported in the literature for the Atlantic Ocean (Baker et al 2012). By contrast, the depth of the second finding, about 242 m, lowers the minimum bathymetrical limit known for this species.…”

“…Protoptilum carpenteri shows a North Atlantic distribution and it is considered a deep-sea species (Kükenthal 1915 (Jungersen 1904); from the North Atlantic to the Azores, between depths of 650 and 4270 m (Grasshoff 1981); from Baffin Bay to Newfoundland (Canada), between depths of about 600 and 1000 m (Gilkinson & Edinger 2009); in Newfoundland, off the Grand Banks, between about 400 and 2300 m in depth (Baker et al 2012). Therefore, this species can live in a wide bathymetric range, since it is certainly present between depths of 400 and 4270 m in the Atlantic Ocean.…”

Cold-Water Coral Habitats in Submarine Canyons of the Bay of Biscay

“…Some seapen species can retract completely within the sediment, as has been observed for Protoptilum carpenteri (Packer et al, 2007;Baker et al, 2012) and K. stelliferum, Pennatula phosphorea, and Virgularia mirabilis (De Clippele et al, 2015). This may suggest that some seapen species are resilient to trawling compared to other corals.…”

Diversity, distribution and spatial structure of the cold-water coral fauna of the Azores (NE Atlantic)

“…Moreover, our analysis did not account for bottom type, which means that there may be also a confounding effect of this variable, known to greatly influence coral distribution (e.g. Baker et al, 2012), on the perceived vertical gradient of the coral fauna.…”

“…Widely distributed throughout the world's oceans, they can be found on continental shelves and margins, edges and slopes of oceanic islands, seamounts, canyons and ridges (e.g. Cairns, 2007;Wareham and Edinger, 2007;Molodtsova et al, 2008;Mortensen et al, 2008;Reveillaud et al, 2008;Baker et al, 2012), especially in areas of high currents and/or enhanced suspended or re-suspended organic matter (Davies et al, 2009;Guinan et al, 2009).…”