DOI: 10.5061/dryad.n2z34tn49
title: Seafloor primary production in a changing Arctic Ocean

description: Phytoplankton and sea ice algae are traditionally considered to be the
 main primary producers in the Arctic Ocean. In this Perspective, we
 explore the importance of benthic primary producers (BPPs) encompassing
 microalgae, macroalgae, and seagrasses, which represent a poorly
 quantified source of Arctic marine primary production. Despite scarce
 observations, models predict that BPPs are widespread, colonising ⁓3
 million km2 of the extensive Arctic coastal and shelf seas. Using a
 synthesis of published data and a novel model we estimate that BPPs
 currently contribute ⁓77 Tg C yr-1 of primary production to the Arctic,
 equivalent to ~20-35% of annual phytoplankton production. Macroalgae
 contribute ⁓43 Tg C yr-1, seagrasses contribute ⁓23 Tg C yr-1, and
 microalgae-dominated shelf habitats contribute ⁓11-16 Tg C yr-1. Since
 2003, the Arctic seafloor area exposed to sunlight has increased by ~47000
 km2 yr-1, expanding the realm of BPPs in a warming Arctic. Increased
 macrophyte abundance and productivity are expected along Arctic coastlines
 with continued ocean warming and sea ice loss. However, microalgal benthic
 primary production has increased in only a few shelf regions despite
 substantial sea ice loss over the past 20 years, as higher solar
 irradiance in the ice-free ocean is counterbalanced by reduced water
 transparency. This suggests the complex impacts of climate change on
 Arctic light availability and marine primary production. Despite
 significant knowledge gaps on Arctic BPPs, their widespread presence and
 obvious contribution to coastal and shelf ecosystem production call for
 further investigation and for their inclusion in Arctic ecosystem models
 and carbon budgets.
description: # Seafloor primary production in a changing Arctic Ocean 
 [https://doi.org/10.5061/dryad.n2z34tn49](https://doi.org/10.5061/dryad.n2z34tn49) The dataset contains the following files: * **Figure 2A_Pan Arctic microalgal BPP.dat**: An ASCII file containing four columns showing 'Year' in columns 1 and 3, and pan-Arctic microalgal benthic primary production (in teragrams of carbon per year; Tg C yr-1) in columns 2 and 4 for Gattuso et al. (for years 1998-2018) and Singh et al. (for years 2003-2020) datasets. - **Figure 2B_Seabed area exposed to PAR.dat**: An ASCII file containing two columns: Year (column 1) and Seabed area exposed to photosynthetic active radiation (PAR) (column 2) in square kilometers.  * **Figure 3A_BenthicPAR.dat**: An ASCII file containing Latitude (column 1; 60.0-89.8 degrees), and Longitude (row 1; -180 to 179.8 degrees), and corresponding daily integrated photosynthetic active radiation (PAR, in moles of PAR per square meter per day, mol PAR m-2 d-1) reaching the seafloor, estimated using the Singh et al. model.  - **Figure 3B_MicroalgalBPP.dat**: An ASCII file containing Latitude (column 1; 60.0-89.8 degrees), and Longitude (row 1; -180 to 179.8 degrees), and corresponding daily microalgal benthic primary production (BPP, in millimoles of oxygen per square meter per day, mmol O2 m-2 d-1), which was computed from daily seabed PAR using the functional relationship presented in Fig. S2.  * **Figure 3C_trend_KdPAR.dat**: An ASCII file containing Latitude (column 1; 60.0-89.8 degrees), and Longitude (row 1; -180 to 179.8 degrees), and the trend in attenuation coefficient of photosynthetic active radiation (KdPAR) for the month of August (2003-2020). Analysis based on Singh et al. benthic photosynthetic active radiation (PAR) data. - **Figure 3D_trend_BPP.dat**: An ASCII file containing Latitude (column 1; 60.0-89.8 degrees), and Longitude (row 1; -180 to 179.8 degrees), and the trend in daily benthic primary production (BPP, in millimoles of oxygen per square meter per day, mmol O2 m-2 d-1) for the month of August (2003-2020). Analysis based on Singh et al. benthic photosynthetic active radiation (PAR) data. * **Figure 5_panArctic primary production.dat**: An ASCII file containing two columns with annual estimates of Arctic marine photosynthetic net primary production by known sources, in teragrams of carbon per year (Tg C yr-1). - **Figure S1 and Figure S2.dat**: An ASCII file containing 7 columns of data summarizing the aquatic eddy covariance datasets that were used to derive the relationship between daily seabed photosynthetic active radiation (PAR, in moles of PAR per square meter per day, mol PAR m-2 d-1) and daily microalgal benthic primary production (in millimoles of oxygen per square meter per day, mmol O2 m-2 d-1).