A global dataset of seaweed net primary productivity

Abstract

Net primary productivity (NPP) plays a pivotal role in the global carbon balance but estimating the NPP of underwater habitats remains a challenging task. Seaweeds (marine macroalgae) form the largest and most productive underwater vegetated habitat on Earth. Yet, little is known about the distribution of their NPP at large spatial scales, despite more than 70 years of local-scale studies being scattered throughout the literature. We present a global dataset containing NPP records for 246 seaweed taxa at 429 individual sites distributed on all continents from the intertidal to 55 m depth. All records are standardized to annual aerial carbon production (g C m−2 yr−1) and are accompanied by detailed taxonomic and methodological information. The dataset presented here provides a basis for local, regional and global comparative studies of the NPP of underwater vegetation and is pivotal for achieving a better understanding of the role seaweeds play in the global coastal carbon cycle.

Global seaweed productivity

“…The global maps presented here were mostly informed by measurements based on biomass accumulation, as that is the most common methodology used to measure NPP [83% of records; see the Supplementary Materials and ( 23 )]. SD around models averaging individual predictions based on photorespirometry or biomass accumulation measurements was largest in areas with high predicted NPP (e.g., Humboldt upwelling), as well as coastlines where little or no NPP measurements were available (e.g., Arctic, Amazon basin, Bay of Bengal, and South China Sea) (fig.…”

“…The dataset, the references included in it, and a full description its characteristics and the methods used to compile it can be found in ( 23 , 50 ). Briefly, we first conducted a formal search of the literature in the Scopus database using the search terms “primary AND product* OR growth or npp and (seaweed OR alga* OR kelp OR rocky AND reef OR turf OR temperate AND reef OR coral OR polar OR Arctic),” which yielded 470 entries (September 2020).…”

“…When multiple and distinct species, spatial locations, depths, or methods were examined separately within a site or study, these were entered as separate case studies (separate rows). A wide range of metadata was also recorded for each study and can be found in ( 23 ). Briefly, this included information on the vegetation type, taxa examined, whether the study measured the NPP of single or multiple species, whether NPP required aggregation (e.g., for species in the same sampled depth and area, such as canopy and understory seaweeds), latitude and longitude, depth range, duration of the study, sampling frequency, and method used to obtain the data and method used to calculate NPP.…”

“…Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. The data and code stored can be found in the Figshare nonprofit repository (doi: 10.6084/m9.figshare.16681816 ) ( 50 ), and the descriptor of the dataset used can be found in Scientific Data ( https://doi.org/10.1038/s41597-022-01554-5 ) ( 23 ).…”

“…Compiled NPP measurements cover more than 400 unique sampling sites distributed across all ocean realms (fig. S1), spanning seaweed habitats from pole to pole and from the high-tide mark to depths of >50 m. Our dataset ( 23 ) quantifies net carbon production on a yearly per-area basis (i.e., gC m −2 year −1 ) and contains information on more than 240 species or taxonomic entities, encompassing all major seaweed clades and functional forms. We use this dataset to model and map area-based seaweed NPP, yielding the first predictions of the geographical distribution of NPP for any vegetated habitat in the coastal ocean.…”