Carbon Sequestration Within Silica Bodies Extracted from Kelp Cultured in the East China Sea

Abstract

To re-evaluate ecological effects of kelp culture in marginal seas, the silica body content in kelp cultured in the East China Sea and the carbon content in the silica body extracted from kelp were measured. The silica body content in kelp cultured in the sea ranged from 0.20 to 0.60 % and the carbon content in the silica body extracted from kelp was 0.27 ± 0.06 %. The carbon sequestration rate in silica bodies extracted from kelp cultured in the East China Sea was 2.47 ± 0.40 t.a−1 from 2000 to 2011. In the East China Sea, the production of the silica body of kelp in the kelp culture zone was 6.56 ± 1.06 g.m−2.a−1. The carbon sequestration rate in the silica body of cultured kelp in the East China Sea was 0.02 ± 0.00 g.m−2.a−1, which accounted for 1.43 % of CO2 flux from air to sea. The carbon fixed in the silica body extracted from kelp might be one part of the missing carbon sink. Considering carbon content in silica bodies extracted from kelp cultured in the East China Sea, carbon sequestration of kelp culture in the marginal sea should be re-evaluated and some missing carbon sinks caused by anthropogenic factors might be reduced.