Seaweed industry, including farming and sustainable wild harvesting, can offer nature-based solutions for climate and environmental change, thus minimizing threats to biodiversity and human welfare and therefore contributing to the United Nation Sustainable Development Goals. Seaweed farming is a multibillion-dollar industry and the fastest-growing aquaculture sector worldwide with high potential for scalability. However, little is known about the consequences, either positive or negative, of seaweed farming and wild harvesting in the surrounding natural ecosystems, and there is a complete lack of mechanistic understanding on the potential impacts of prospective large-scale seaweed farming. This session aims to bring together the current state-of-the-art research on environmental consequences of seaweed farming and harvesting, as well as discuss possible future trajectories of large-scale seaweed farming. This session welcomes research studies, industry and social initiatives, and policy strategies, from across the globe aiming at the assessment, management, and implementation of seaweed farming and harvesting from artisanal to industrial scales. Particularly, we welcome works on: 1) carbon capture by seaweed farms and overall contribution to carbon cycling including natural export pathways, induced sinking and its impacts 2) seaweed ocean acidification amelioration potential; 3) production of high-value molecules for industry replacing carbon intensive commodities and potential contribution to circular economy, global food security and livelihoods; 4) regenerative ocean farming, including seaweed and its effect in water quality through nutrient remediation and control of harmful algal blooms; 5) biodiversity enhancement by seaweed farms and effects in coastal areas; 6) observations or modeling studies that focus on seaweed cultivation as an ecological restoration tool for environmental and climate change impacts; 7) studies of Life Cycle Assessments to account for total GHG emissions in the seaweed industry and methodologies to verify carbon credits. ;

Lead Organizer: Glaucia Fragoso, NTNU (glaucia.m.fragoso@ntnu.no)

Co-organizers:

Ana Borrero, Seaweed Solutions (borrero@seaweedsolutions.com)

Aurora Ricart, Bigelow Laboratory for Ocean Sciences (aricart@bigelow.org)

Presentations

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06:30 PM

Biofouling in seaweed farming: The challenges and solutions (4860)

Primary Presenter: Sofie Spatharis, University of Glasgow (sofie.spatharis@glasgow.ac.uk)

Seaweed farming offers a zero-input production system with multiple benefits including CO₂ absorption, biodiversity enhancement, healthy food production and sustainable coastal communities. Despite the rapid expansion of seaweed farming, a major factor limiting the productivity of seaweed aquaculture in the mesotrophic waters of the North Atlantic, is the proliferation of biofouling organisms on the seaweed blades. This unwanted growth results in increased processing costs, decreased product value and risks for public health. Target biofouling species include invertebrates and algae, which settle from the plankton as larvae or spores respectively. Despite the obvious challenges, solutions are possible by carefully planning the harvesting time, location/depth and species of the farmed seaweed. In this study, data were collected during a full production cycle from a Scottish seaweed farm.  Epibionts (including meroplanktonic zooplankton and epiphytic algae) were monitored from their early life stages by combining microscopy (zooplankton, phytoplankton and epibionts from the blades) and molecular approaches (environmental DNA metabarcoding and epibionts barcoding). Succession patterns of epibionts were observed during the studied period and lags were identified as well as variation in the intensity of biofouling by depth. This information can be paramount for predicting, preventing, and mitigating biofouling in seaweed aquaculture to safeguard the economic viability of the industry.

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06:30 PM

Technological tools for cost-effective monitoring of kelp farms. (5032)

Primary Presenter: Glaucia Fragoso, NTNU (glaucia.m.fragoso@ntnu.no)

Cultivated seaweed is the fastest-growing aquaculture sector worldwide and a multibillion-dollar industry. Monitoring environmental conditions (e.g. temperature, salinity, nutrients and irradiance) and biofouling organisms in a seaweed farm is important for making decisions related to growth optimisation. Deployment of underwater robots for line inspection, in combination with “deep-learning” approaches, have the power to provide a fast and reliable estimation of seaweed biomass. Here, we show state-of-the-art, yet cost-effective, and scalable technologies aimed at optimising monitoring in a Norwegian kelp farm. Robotic monitoring of kelp farms, including biomass growth, was assessed using a mini, cost-effective, remotely operated vehicle (ROV). For a fast and reliable estimation of kelp biomass, a robust set of images to build a data-centric machine learning platform was collected, where we developed computer vision applications supported by AI algorithms. Preliminary results from the MoniTARE project showed that there is a strong correlation (R²=0.85) between the ground-truth biomass (manually collected) and the biomass inferred through 2D computer vision techniques from recorded images. We also propose low-cost technological ideas for frequent monitoring of larval concentrations of bryozoans in the water column to assist in early fouling detection. Automation of kelp farm monitoring has the potential to revolutionize the industry by offering scalability of production and improved yield predictions.

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