We searched the published literature for data on the density-dependence of seaweed growth under different nutrient levels. The search was based on the Web of Science®, accessed in May 2019, using a combination of keywords including "seaweed & remediation", "seaweed & bioremediation", "seaweed & nitrogen removal" and "seaweed & phosphorous removal". These searches yielded a total of 164 papers reporting growth rates and biomass density for seaweed. We retrieved the growth rates, biomass density, concentration of the dominant forms of inorganic nutrients - ammonia, nitrate and phosphate - and incident irradiance, and recorded the taxa (chlorophyta, phaeophyta or rhodophyta). This generated a raw dataset containing a total of 1729 experimental assessments. For all the assessments, we further converted all growth rates to units of % day-1 and biomass density (i.e. the seaweed biomass per unit habitat volume) to g FW L-1.