Implications for the mesopelagic microbial gardening hypothesis as determined by experimental fragmentation of Antarctic krill faecal pellets ...

• Main Authors: Cavan, Emma, Kawaguchi, So, Boyd, Philip
• Format: Dataset
• Language: English
• Published: Dryad 2020
• Subjects: Antarc*; Antarctic; Antarctic Krill
• Online Access: https://dx.doi.org/10.5061/dryad.r7sqv9s9x; https://datadryad.org/stash/dataset/doi:10.5061/dryad.r7sqv9s9x

1. Detritivores need to upgrade their food to increase its nutritional value. One method is to fragment detritus promoting the colonisation­ of nutrient-rich microbes, which consumers then ingest along with the detritus; so-called microbial gardening. Observations and numerical models of the detritus-dominated ocean mesopelagic zone have suggested microbial gardening by zooplankton is a fundamental process in the ocean carbon cycle leading to increased respiration of carbon-rich detritus. However, no experimental evidence exists to demonstrate that microbial respiration rates are higher on recently fragmented sinking detrital particles. 2. Using aquaria-reared Antarctic krill faecal pellets we showed fragmentation increased microbial particulate organic carbon (POC) turnover by 1.8x, but only on brown faecal pellets, formed from the consumption of other pellets. Microbial POC turnover on un-and fragmented green faecal pellets, formed from consuming fresh phytoplankton, was equal. Thus, POC content, ... : Data on oxygen uptake by microbes on fragmented and unfragmented feacal pellets in a laboratory experiment (O2_FP.csv), the size of the faecal pellets (csv files BL1...GS4.csv) and the particulate organic carbon content of the faecal pellets (POC_FP.csv). R code to analyse the data and make the figures from the publication will be available at www.github.com/e-cavan. ...