SeaweedPaddock: Initial Modeling and Design for a Sargassum Ranch

Sherman, Martin T.; Blaylock, Reginald B.; Capron, Mark E.; Stewart, Jim R.; DiMarco, Steven F.; Thyng, Kristen M.; Hetland, Robert D.; Mh, Kim; Sullivan, Corey; Moscicki, Zach; Tsukrov, Igor; Swift, Michael; Chambers, Michael D.; James, Scott C.; Brooks, Maureen T.; Herzen, Brian Von; Jones, Anthony T.; Piper, Don

doi:10.1109/oceans.2018.8604848

Cited by 5 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To address these issues, several offshore macroalgae aquaculture facilities have been designed and evaluated (e.g. the SeaweedPaddock by Sherman et al (2019), the offshore ring by Buck and Buchholz (2004), or the depth-cycling strategy by Navarrete et al (2021) in which macroalgae are physically towed into the deep nutrientrich water at night). Moreover, the Advanced Research Projects Agency-Energy (ARPA-E) of the U.S. Department of Energy has committed more than 60 million dollars on the Macroalgae Research Inspiring Novel Energy Resources (MARINER) program to develop the technologies for macroalgal biomass production, including integrated ocean cultivation and harvesting systems (APAR-e, 2021).…”

Section: Introductionmentioning

confidence: 99%

Carbon Dioxide Removal via Macroalgae Open-ocean Mariculture and Sinking: An Earth System Modeling Study

Keller

Oschlies

2022

Preprint

View full text Add to dashboard Cite

Abstract. In this study we investigate open-ocean macroalgae mariculture and sinking (MOS) as ocean-based carbon dioxide removal (CDR) method. Embedding a macroalgae model into an Earth system model, we simulate macroalgae mariculture in the open-ocean surface layer followed by fast sinking of the carbon-rich macroalgal biomass to the deep seafloor (depth > 3,000 m). We also test the combination of MOS with artificial upwelling (AU), which fertilizes the macroalgae by pumping nutrient-rich deeper water to the surface. The simulations are done under RCP4.5 a moderate emission pathway. When deployed globally between years 2020 and 2100, the simulated CDR potential of MOS is 270 PgC, which is further boosted by AU to 447 PgC. More than half of MOS-sequestered carbon retains in the ocean after cessation at year 2100 until year 3000. The major side effect of MOS on pelagic ecosystems is the reduction of phytoplankton net primary production (PNPP) due to the nutrient competition and canopy shading by macroalgae. MOS shrinks the mid layer oxygen minimum zones (OMZs) by reducing the organic matter export to, and remineralization in, subsurface and intermediate waters, while it creates new OMZs on the seafloor by oxygen consumption from remineralization of sunken biomass. MOS also impacts the global carbon cycle, reduces the atmospheric and terrestrial carbon reservoir when enhancing the ocean carbon reservoir. MOS also enriches the dissolved inorganic carbon in the deep ocean. Effects are mostly reversible after cessation of MOS, though recovery is not complete by year 3000. In a sensitivity experiment without remineralization of sunk MOS biomass, the entire MOS-captured carbon is permanently stored in the ocean, but the lack of remineralized nutrients causes a long-term nutrient decline in the surface layers and thus reduces PNPP. Our results suggest that MOS has a considerable potential as an ocean-based CDR method. However, MOS has inherent side effects on marine ecosystems and biogeochemistry, which will require a careful evaluation beyond this first idealized modeling study.

show abstract

Section: Introductionmentioning

confidence: 99%

Carbon Dioxide Removal via Macroalgae Open-ocean Mariculture and Sinking: An Earth System Modeling Study

Keller

Oschlies

2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Therefore, it not only avoids "permanently" occupying coastal space but also saves high anchoring cost to reduce losses of farm structures and macroalgae as a result of high current and wave forces during storms. The only free-floating macroalgae-harvesting applications known to the authors are those taking place with Sargassum rafts in the northern Caribbean Basin and the Atlantic Ocean [2].…”

Section: Introductionmentioning

confidence: 99%

Simulating the Trajectory and Biomass Growth of Free-Floating Macroalgal Cultivation Platforms along the U.S. West Coast

Whiting

Wang

Yang

et al. 2020

JMSE

View full text Add to dashboard Cite

Trajectory tracking and macroalgal growth models were coupled to support a novel macroalgae-harvesting concept known as the Nautical Off-shore Macroalgal Autonomous Device (NOMAD). The NOMAD consists of 5 km long carbon-fiber longlines that are seeded and free float southward along the U.S. West Coast for approximately 3 months before harvesting off the California coast, taking advantage of favorable environmental conditions. The trajectory and macroalgal growth models were applied to answer planning questions pertinent to the techno-economic analysis such as identifying the preferred release location, approximate pathway, timing until harvest, and estimated growth. Trajectories were determined with the General NOAA Operational Modeling Environment (GNOME) model, using 11 years of current and wind data, determining probabilities by running nearly 40,000 Monte Carlo simulations varying the start time and location. An accompanying macroalgal growth model was used to estimate the growth of macroalgae based on the trajectory tracks and environmental forcing products, including light, temperature and nutrients. Model results show that NOMAD lines transit south in the months of April to September due to seasonal currents, taking approximately 3 months to reach Southern California. During transit, NOMAD lines are dispersed but typically avoid beaching or passing through marine sanctuaries. NOMAD lines can yield up to 30 kg wet weight per meter of cultivation line.

show abstract

“…1 Terrestrial material scale and costs (including moisture content and heating values) are from references in SMS#4, 22, 23[55,57,58,[76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93]. Macroalgae scale and cost are interpolated from MARINER projected technologies and systems in SMS#6[94][95][96][97]. The techno-economic analyses were funded by the U.S. DOE's ARPA-E MARINER Program[40] 2.…”

mentioning

confidence: 99%

Restoring pre-industrial CO2 levels while achieving Sustainable Development Goals

Capron¹,

Stewart²,

N’Yeurt³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Unless humanity achieves United Nations Sustainable Development Goals (SDGs) by 2030 and restores the relatively stable climate of pre-industrial CO 2 levels (as early as 2140), species extinctions, starvation, drought/floods, and violence will exacerbate mass migrations. This paper presents conceptual designs and techno-economic analyses to calculate sustainable limits for growing high-protein seafood and macroalgae-for-biofuel. We review the availability of wet solid waste and outline the mass balance of carbon and plant nutrients passing through a hydrothermal liquefaction process. The paper reviews the availability of dry solid waste and dry biomass for bioenergy with CO 2 capture and storage (BECCS) while generating Allam Cycle electricity. Sufficient wet-waste biomass supports quickly building hydrothermal liquefaction facilities. Macroalgae-for-biofuel technology can be developed and straightforwardly implemented on SDG-achieving high protein seafood infrastructure. The analyses indicate a potential for (1) 0.5 billion tonnes/yr of seafood; (2) 20 million barrels/day of biofuel from solid waste; (3) more biocrude oil from macroalgae than current fossil oil; and (4) sequestration of 28 to 38 billion tonnes/yr of bio-CO 2 . Carbon dioxide removal (CDR) costs are between 25-33% of those for BECCS with pre-2019 technology or the projected cost of air-capture CDR.

show abstract

SeaweedPaddock: Initial Modeling and Design for a Sargassum Ranch

Cited by 5 publications

References 9 publications

Carbon Dioxide Removal via Macroalgae Open-ocean Mariculture and Sinking: An Earth System Modeling Study

Carbon Dioxide Removal via Macroalgae Open-ocean Mariculture and Sinking: An Earth System Modeling Study

Simulating the Trajectory and Biomass Growth of Free-Floating Macroalgal Cultivation Platforms along the U.S. West Coast

Restoring pre-industrial CO2 levels while achieving Sustainable Development Goals

Contact Info

Product

Resources

About