Estimating the effect of burrowing shrimp on deep-sea sediment community oxygen consumption

Abstract

Sediment community oxygen consumption (SCOC) is a proxy for organic matter processing and thus provides a useful proxy of benthic ecosystem function. Oxygen uptake in deep-sea sediments is mainly driven by bacteria, and the direct contribution of benthic macro- and mega-infauna respiration is thought to be relatively modest. However, the main contribution of infaunal organisms to benthic respiration, particularly large burrowing organisms, is likely to be indirect and mainly driven by processes such as feeding and bioturbation that stimulate bacterial metabolism and promote the chemical oxidation of reduced solutes. Here, we estimate the direct and indirect contributions of burrowing shrimp (Eucalastacus cf. torbeni) to sediment community oxygen consumption based on incubations of sediment cores from 490 m depth on the continental slope of New Zealand. Results indicate that the presence of one shrimp in the sediment is responsible for an oxygen uptake rate of about 40 µmol d−1, only 1% of which is estimated to be due to shrimp respiration. We estimate that the presence of ten burrowing shrimp m−2 of seabed would lead to an oxygen uptake comparable to current estimates of macro-infaunal community respiration on Chatham Rise based on allometric equations, and would increase total sediment community oxygen uptake by 14% compared to sediment without shrimp. Our findings suggest that oxygen consumption mediated by burrowing shrimp may be substantial in continental slope ecosystems.

Integral functions of marine vertebrates in the ocean carbon cycle and climate change mitigation

“…For example, the disruption of Atlantic cod populations in most North Atlantic fisheries led to increased abundance of northern shrimp (Pandalus borealis), which forage in sediments between 100 and 500 m depth. 102 In sediment communities, increased abundance of bioturbators (organisms that physically disturb sediment, e.g., by burrowing or digging) can result in enhanced oxygen provision, 103 used as a proxy for organic matter processing (i.e., OC). However, the impact of sediment disturbance by shrimp on C longevity at these depths is unknown.…”