Sulfide oxidation in deep Baltic Sea sediments upon oxygenation and colonization by macrofauna

• Published in: Marine biology Vol. 166; no. 11; pp. 1 - 12
• Main Authors: Bonaglia, Stefano, Marzocchi, Ugo, Ekeroth, Nils, Brüchert, Volker, Blomqvist, Sven, Hall, Per O. J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2019; Springer; Springer Nature B.V
• Subjects: amphipod; Amphipoda; Anoxia; Anoxic sediments; Aquatic crustaceans; Benthos; Biomedical and Life Sciences; Bioturbation; Bottom water; Burrowing organisms; Closed ecological systems; Colonization; Communities; Ecology; Ekologi; Epifauna; Freshwater & Marine Ecology; Functional groups; genus marenzelleria; Hydrogen sulfide; Hydrogen sulphide; hypoxia; Incubation period; Life Sciences; Macrofauna; Manganese; Marine & Freshwater Biology; Marine & Freshwater Sciences; Marine biology; Marine crustaceans; Meiobenthos; Meiofauna; Mesocosms; Microbial activity; Microbiology; Microorganisms; monoporeia-affinis; Nitrogen compounds; nutrient fluxes; Oceanography; Organic chemistry; organic-matter mineralization; Original Paper; Oxidation; Oxidation-reduction reaction; Oxygen; Oxygenation; Polychaeta; polychaetes marenzelleria spp; Pore water; reduction; Sediment; Sediments; Sediments (Geology); sulfate; Sulphides; tolerance; Zoobenthos; Zoology; Sweden; Baltic Sea
• ISSN: 0025-3162; 1432-1793; 1432-1793
• DOI: 10.1007/s00227-019-3597-y

Coastal and shelf sediments affected by transient or long-term bottom water anoxia and sulfidic conditions undergo drastic changes in macrofauna communities and abundances. This study investigates how early colonization by two macrofaunal functional traits (epifauna vs. infauna) affects oxygen, sulfide, and pH dynamics in anoxic sediment upon recent bottom water oxygenation. Large mesocosms (area 900 cm
2
) with 150-m-deep Baltic Sea soft sediments were exposed to three treatments: (1) no animals; (2) addition of 170 polychaetes (
Marenzelleria arctia
); (3) addition of 181 amphipods (
Monoporeia affinis
). Porewater chemistry was investigated repeatedly by microsensor profiling over a period of 65 days. Colonization by macrofauna did not significantly deepen penetration of oxygen compared to the animal-free sediment. Bioturbation by
M. affinis
increased the volume of the oxidized, sulfide-free sediment by 66% compared to the animal-free control already after 13 days of incubation. By the end of the experiment
M. affinis
and
M. arctia
increased the oxidized sediment volume by 87 and 35%, respectively. Higher efficiency of epifaunal amphipods in removing hydrogen sulfide than deep-burrowing polychaetes is likely due to more substantial re-oxidation of manganese and/or nitrogen compounds associated with amphipod mixing activity. Our results thus indicate that early colonization of different functional groups might have important implications for the later colonization by benthic macrofauna, meiofauna and microbial communities that benefit from oxidized and sulfide-free sediments.