Quantification of Effectiveness of Nutrient Bioextraction by Seaweed
Approximately $1M total, maximum $300K per award 3‐5 fixed amount grants
The purpose of this announcement is to (1) solicit proposals focused on the development of enabling solutions capable of quantifying fate and transport of biologically relevant nitrogen species with high‐spatial and high‐temporal resolution in the context of seaweed farms in the marine environment, and (2) provide a timetable for the submission of Full Applications.
Nitrogen migration from anthropogenic sources, such as agricultural runoff or wastewater discharge, is responsible for eutrophication of marine systems causing anoxia, ecological disruption and reduction in productivity of natural systems and fisheries. Eutrophication can result in widespread “dead zones” and contribute to proliferation of toxic microalgae and/or cyanobacteria, as recently seen on Florida’s Gulf Coast. One potential solution is the large‐scale cultivation of nitrogen‐fixing seaweeds in these eutrophic marine systems. Seaweeds are non‐vascular macroalgae plants capable of rapid growth via carbon fixation and effective uptake of nitrogen, predominately in the form of nitrate. When deployed in eutrophic marine systems, cultivation of seaweeds on a large scale may provide local, and possibly regional, mitigation of excess nutrient concentration via bioextraction. ARPA‐E’s MARINER program targets the development and deployment of new technologies for the economically viable production of seaweeds on a scale sufficient for bioenergy production. The effectiveness of deploying seaweed farms for nutrient concentration extraction will be significantly influenced by local and regional geographic conditions. It is therefore important to identify the geographies along US coastlines that are the most suitable candidates for testing and deploying this eutrophication mitigation strategy.
In addition to the revenue from the harvested seaweed, seaweed farms deployed in eutrophic marine areas could generate additional benefits – and potentially revenue – for the ecosystem services they provide. In order to appropriately value the nutrient mitigation services provided by seaweed cultivation, appropriate methodologies are needed for accurate, low‐cost nitrogen monitoring within the context of seaweed farming systems to quantify the amount of nitrogen present and assimilated by seaweed cultivation. ARPA‐E seeks solutions that will add value to the MARINER program and provide technology‐to‐market (T2M) opportunities for large scale seaweed cultivation.
A proposal can cover one, two, or all three technical areas of interest outlined below.
1. Identification of geographies where seaweed farms could have a proximal positive impact on nitrogen removal, including empirical assessment of nitrogen loading on a temporal basis. Specifically, ARPA‐E envisions that seaweed farms should have a “local” effect to remove nitrogen and improve water quality for enhancement of ecosystem productivity. With that goal in mind, geographic areas of high nitrogen inundation need to be assessed for seaweed farm production. Target geographic areas will require temporal nitrogen assessment to quantify and compare the seasonality of nitrogen influx with the biological growing season of seaweeds.
2. Concepts for real‐time assessment and validation of nitrogen flux and uptake within and around macroalgae farms. Specifically, new solutions are required for accurately monitoring the transport and fate of nitrogen in and around individual seaweed farms with appropriate spatial and temporal resolution. Current monitoring techniques mostly rely on laborious manual sampling and analysis resulting in low‐to‐moderate spatial and temporal resolution. Such data is a challenge to interpret and less likely to influence management decisions. ARPA‐E is therefore interested in the development of solutions that integrate spatially distributed analytical monitoring with computational modeling of nitrogen transport through and uptake by seaweed farms.
3. Validated methods for rapid and reliable determination of the nitrogen tissue content of seaweed. When seaweed is harvested, the amount of nitrogen contained in its tissue is the minimal amount of nitrogen removed from the local environment. In order to attribute a proper value for this removal service, accurate and reliable measurements of the nitrogen content are crititical. The desired quantification methods need to be able to take into account and appropriately standardize the timing and conditions of harvest, the storage conditions until analysis, and any required sample preparation procedures for the species of seaweed under consideration.