A Global Dataset on Nutrient Removal Capacity by Marine Macroalgae

Why seaweed farms matter for our seas

All over the world, coastal waters are getting overloaded with nutrients like nitrogen and phosphorus from farms, cities, and industry. This nutrient overload, known as eutrophication, fuels massive algal blooms, dead zones, and the loss of marine life. At the same time, there is growing interest in seaweed farming as a climate‑friendly industry. This study brings those two stories together by asking a simple question with big implications: how well can different kinds of seaweeds act as natural water filters for our coasts?

Turning a scattered literature into one clear picture

Until now, evidence about seaweeds cleaning up coastal nutrients was scattered across hundreds of separate studies, each using different species, locations, and experimental setups. The authors systematically searched global research databases in multiple languages and screened 3,662 studies published between 1995 and 2024. After applying strict criteria—such as requiring clear species names, precise locations, and measurable nutrient removal—they distilled this down to 149 solid studies. From these, they extracted 2,011 individual records that capture how much nitrogen and phosphorus various seaweeds can remove under particular environmental conditions.

What the global seaweed cleanup looks like

The resulting open dataset spans 113 species of marine macroalgae—red, green, and brown seaweeds—from 234 sampling sites in 23 countries on six continents. Most records come from East Asia, especially China, which is a global hotspot of seaweed aquaculture and coastal nutrient problems. The dataset tracks when and where each study took place, what species were tested, and which forms of nitrogen and phosphorus they removed. It also includes details like water temperature, salinity, pH, light, and how dense and heavy the seaweed was. Together, these details allow researchers and planners to see how nutrient removal varies among species, regions, and farming conditions.

How the team checked and organized the data

To make this resource reliable, the authors invested heavily in data quality checks. Each data point was read out of the original papers—often from tables and graphs—and entered using a standard template, then independently verified by a second person. Scientific names were cross‑checked against an international taxonomic database so that all species are labeled consistently. Geographic coordinates were checked on digital maps and corrected if they fell on land instead of sea. Suspect extreme values were identified using statistical methods and then traced back to the source papers; true extremes were kept but clearly flagged, so future users can decide how to treat them. Wherever possible, missing environmental data such as temperature or light period were filled in using local records or reasonable defaults, while missing nutrient measurements were left blank instead of guessed.

From raw measurements to usable indicators

Beyond compiling numbers, the authors translated them into common indicators that can be compared across studies. For each record, they provide nutrient removal rate (how fast seaweed pulls nutrients out of the water relative to its weight and time), removal efficiency (the percentage of nutrients taken out of a given water volume), and total removal amount (how much nitrogen or phosphorus ends up stored in the seaweed’s tissues). They explain how these measures were calculated and caution that some—especially efficiency—cannot be fairly compared if experiments lasted for very different lengths of time. Instead, they recommend that users focus on removal rate when comparing species or designing farms, because it already accounts for both time and biomass.

How this helps clean and restore coastal waters

The authors do not claim that seaweeds alone can fix coastal pollution, but their dataset provides the strongest evidence yet for where and how seaweed farming can be part of the solution. By bringing together global measurements in a single, open resource, the study allows governments, industry, and conservation groups to pick seaweed species and farming conditions that best match local waters and cleanup goals. It also highlights important gaps, such as the relative lack of data from tropical and polar regions. For a lay reader, the bottom line is that seaweeds are more than salad and industry—they are living tools that, when carefully chosen and cultivated, can help turn nutrient‑choked coasts back toward clearer, healthier seas.

Citation: Xie, P., Feng, W., He, J. et al. A Global Dataset on Nutrient Removal Capacity by Marine Macroalgae. Sci Data 13, 477 (2026). https://doi.org/10.1038/s41597-026-06874-4

Keywords: seaweed, eutrophication, marine aquaculture, nutrient pollution, coastal restoration