Estimation of in situ distribution of carbonate produced from cold-water octocorals on a Japanese seamount in the NW Pacific

Abstract

The importance of the deep, cold-water hexacorals as cold-water bioherms and their contribution to marine carbonate production has been demonstrated elsewhere. However, no research has been carried out to examine the contribution of carbonate production by deep, coldwater octocorals (CWOC), even though this group comprises a major component of cold-water coral fauna in the NW Pacific. To assess the contribution of CWOC carbonate production on the Shiribeshi Seamount (43°34-36' N, 139°31-35' E), Sea of Japan, remotely operated vehicle (ROV) dive video archives and deposited specimens of Primnoa pacifica (Octocorallia, Primnoidae) were analysed. To estimate the carbonate weight per colony, the diameter of cross-sections of branches or stems and the carbonate weight per volume of specimens were measured. Colony volumes were then calculated from the video footage. The amount of carbonate standing stock (CSS) was calculated at each dive line by analysing the distribution of CWOC and specimen data. The average (± SD) weight percentage of sclerites per colony of P. pacifica was 37.93 ± 7.45%, with the range 25.47 to 49.19%. It was estimated that the total amount of CSS of coral would be over 0.65 t at all dive lines (22 753 m 2 ) at the seamount. Maximum CSS was 70.64 g m -2 and maximum carbonate production was up to 3.61 ± 0.06 g m -2 yr -1. In comparison with the other CSS in non-tropical areas, our results show that CWOC may potentially contribute to carbonate production in cold-water environments.KEY WORDS: Carbonate production · Sea of Japan · Deep-water gorgonian corals · Non-tropical · Deep sea · Deep-sea coral Resale or republication not permitted without written consent of the publisher

Characteristics of the Mesophotic Megabenthic Assemblages of the Vercelli Seamount (North Tyrrhenian Sea)

“…However the distribution of suspension feeders seems to be mainly related to the current regime. Hydrodynamism in fact may affect sedimentation rates, larval settlement and, together with localized vertical nutrient fluxes and material retention, the productivity of the area [6] , [9] – [12] .…”

Temperate carbonate cycling and water mass properties from intertidal to bathyal depths (Azores)

“…Indeed, long-lived taxa, like deep-sea oysters (Wisshak et al, 2009c), hydrocorals (Wisshak et al, 2009a), scleractinians (e.g. Adkins et al, 2004) and isidid octocorals (Matsumoto, 2009), may be important (accretionary) carbonate producers on decadal to centennial timescales.…”

“…The carbonate system was computed from the measured temperatures, salinities, phosphates, TA and DIC concentrations using the CO2SYS program (Lewis and Wallace, 1998) with the dissociation constants for carbonic acid of Mehrbach et al (1973) after the refit of Dickson and Millero (1987). Reported pH-values were given in the total hydrogen scale.…”

A revision of the genus Calcigorgia (Cnidaria, Octocorallia, Acanthogorgiidae) with the description of three new species

“…japonica and C. spiculifera in the North East Pacific coast are found in quite shallow waters, such as scuba depth below 50 m, but never found at that depth range in the North West Pacific. These depth differences are commonly observed in other octocoral species such as Primnoa pacifica (Cairns, 2011;Matsumoto, 2005Matsumoto, , 2010 between the North West Pacific and the North East Pacific. The distribution of the genus is now extended to the south at the latitude 33°23'30"N with C. gracilis sp.…”