Working Group: Towards a better understanding of fish contribution to carbon flux

Working group towards a better understanding of fish contribution to carbon flux - PI: Grace Saba (Rutgers University)

Objective: We will begin to tackle the issue of the carbon flux contribution from upper trophic levels. This contribution is completely ignored in present-day carbon budgets and is likely significant due to high abundances of fish in certain regions (i.e., coastal zones, mesopelagic) and previous documentation of high fish contribution to total carbon flux. Products of the working group meeting will include: 1) a review paper on fish carbon flux with a concluding section on research priorities identified during the meeting; and 2) a science plan for submission of collaborative proposals to funding agencies to expand our knowledge of fish contribution to carbon flux, ranging from single-species laboratory experiments to incorporating fish carbon estimates into regional and global biogeochemical models.


  1. Synthesize the existing research on fish carbon flux
  2. Recognize challenges in measuring fish carbon flux and discuss approaches to resolve them
  3. Develop research priorities to fill in the large gaps in understanding fish carbon flux
  4. Identify opportunities to obtain resources needed to move this research forward

View the workshop summary or download PDF

Publications and Products

Saba, G.K., Burd, A.B., Dunne, J.P., Hernández‐León, S., Martin, A.H., Rose, K.A., Salisbury, J., Steinberg, D.K., Trueman, C.N., Wilson, R.W. and Wilson, S.E. (2021), Toward a better understanding of fish‐based contribution to ocean carbon flux. Limnol Oceanogr.

Fishes Contribute Roughly 1.65 Billion Tons of Carbon in Feces and Other Matter Annually

Press release by Rutgers: Scientists have little understanding of the role fishes play in the global carbon cycle linked to climate change, but a Rutgers-led study found that carbon in feces, respiration and other excretions from fishes – roughly 1.65 billion tons annually – make up about 16 percent of the total carbon that sinks […]

Fish C Workshop_Group photo

OCB workshop report: Towards a better understanding of fish contribution to carbon flux

This workshop, held March 4-5, 2019 at Rutgers University, was attended by 14 researchers from 11 different institutions. The workshop focused on synthesizing the existing research on fish carbon flux, discussing challenges in measuring fish carbon flux, and determining approaches for estimating fish contribution to carbon flux on variable scales. Presentations and discussions were specifically targeted toward best approaches for determining: fish biomass on regional and global scales, relative amounts of carbon forms produced from fish (i.e., release of sinking fecal pellets, excretion of particulate inorganic carbon and dissolved organic carbon, respiration of carbon dioxide), and carbon flux estimates from fish biomass (i.e., bioenergetics, size-based allometric relationships, stable isotopes). Planned products resulting from this workshop and ongoing working group efforts include two peer-reviewed manuscripts focused on the synthesis of fish carbon flux research and a quantitative analysis of fish carbon flux. Learn more about the working group and view presentations from this workshop on the project’s web page. A full workshop report will be available in the next few months. Learn more on the workshop webpage.


March 4-5, 2019: First Working Group Meeting (New Jersey, USA)

February 11, 2019: Fourth Working Group web conference

January  15, 2019: Third Working Group web conference

September 26, 2018: Second Working Group teleconference

June 15, 2018: First Working Group teleconference

Grace Saba (Lead) - Rutgers University

Nicola Beaumont - Plymouth Marine Laboratory

Adrian Burd - University of Georgia

Peter Davison - Farallon Institute

John Dunne - NOAA GFDL

Santiago Hernández-León - Institute of Oceanography and Global Change

Angela Martin - University of Agder

Kenneth Rose - UMCES

Joe Salisbury - University of New Hampshire

Deborah Steinberg - VIMS

Clive Trueman - National Oceanography Centre Southampton

Rod Wilson - University of Exeter

Stephanie Wilson - Bangor University

Relevant Publications

Working group proposal (PDF)

Burd, A.B., A. Buchan, M. Church, M. Landry, A. McDonnell, U. Passow, D. Steinberg, H. Benway. Towards a transformative understanding of the biology of the ocean’s biological pump: Priorities for future research. Report of the NSF Biology of the Biological Pump Workshop, February 19–20, 2016 (Hyatt Place New Orleans, New Orleans, LA), 67 pp., DOI:10.1575/1912/8263.

Honjo, S., T.I. Eglinton, C.D. Taylor, K.M. Ulmer, S.M. Sievert, A. Bracher, C.R. German, V. Edgcomb, R. Francois, M.D. Iglesias-Rodriguez, B. van Mooy, and D.J. Repeta. 2014. Understanding the role of the biological pump in the global carbon cycle: An imperative for ocean science. Oceanography 27(3):10–16,

Saba, G.K. & Steinberg, D.K. Abundance, Composition, and Sinking Rates of Fish Fecal Pellets in the Santa Barbara Channel. Sci. Rep. 2,716; DOI:10.1038/srep00716 (2012).

Siegel DA, Buesseler KO, Behrenfeld MJ, Benitez-Nelson CR, Boss E, Brzezinski MA, Burd A, Carlson CA, D’Asaro EA, Doney SC, Perry MJ, Stanley RHR and Steinberg DK (2016) Prediction of the Export and Fate of Global Ocean Net Primary Production: The EXPORTS Science Plan. Front. Mar. Sci. 3:22. doi: 10.3389/fmars.2016.00022

Steinberg, DK and MR Landry (2017) Zooplankton and the Ocean Carbon Cycle. Annu. Rev. Mar. Sci. 2017. 9:413–44 DOI:10.1146/annurev-marine-010814-015924

Turner, JT (2014) Zooplankton fecal pellets, marine snow, phytodetritus and the ocean’s biological pump. Progress in Oceanography 130 (2015) 205–248 DOI: