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A 20-year retrospective review of global aquaculture

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The sustainability of aquaculture has been debated intensely since 2000, when a review on the net contribution of aquaculture to world fish supplies was published in Nature. This paper reviews the developments in global aquaculture from 1997 to 2017, incorporating all industry sub-sectors and highlighting the integration of aquaculture in the global food system. Inland aquaculture—especially in Asia—has contributed the most to global production volumes and food security. Major gains have also occurred in aquaculture feed efficiency and fish nutrition, lowering the fish-in–fish-out ratio for all fed species, although the dependence on marine ingredients persists and reliance on terrestrial ingredients has increased. The culture of both molluscs and seaweed is increasingly recognized for its ecosystem services; however, the quantification, valuation, and market development of these services remain rare. The potential for molluscs and seaweed to support global nutritional security is underexploited. Management of pathogens, parasites, and pests remains a sustainability challenge industry-wide, and the effects of climate change on aquaculture remain uncertain and difficult to validate. Pressure on the aquaculture industry to embrace comprehensive sustainability measures during this 20-year period have improved the governance, technology, siting, and management in many cases.

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Nature
Authors
Rosamond L. Naylor

Blue Foods: Seafood's role in a more sustainable and equitable food system

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Food sourced from the ocean, rivers and lakes—blue foods—hold enormous potential for transforming the global food system. Thousands of species of fish, shellfish and algae can play an essential role in achieving food security, tackling malnutrition and providing millions of livelihoods. Yet this diverse group is often overlooked in major policy discussions, especially when compared to food sourced from land. To close this gap, an interdisciplinary team known as the Blue Food Assessment(link is external) (BFA) is working to incorporate blue foods into global policy dialogues, starting with the UN Food Systems Summit(link is external) this September, and affect positive change across communities, companies and countries.

Launched in 2020, the BFA is a joint initiative of Stanford's Center for Ocean Solutions and Center on Food Security and the Environment, the Stockholm Resilience Center at Stockholm University(link is external) and EAT(link is external). The team will provide the most systematic assessment to date of how the extraordinary diversity of blue foods can offer vital nutritional benefits, vary in their environmental impact, and spur economies at local to global scales. By bringing new scientific insights to light and summarizing opportunities and challenges for policymakers, the BFA team aims to position blue foods as a critical tool in the shift toward more sustainable, healthy and equitable food systems.

In a recent Q&A, BFA co-chairs Rosamond Naylor and Beatrice Crona(link is external) shared their hopes for the BFA and discussed how the ocean provides life and livelihoods—this year’s World Oceans Day(link is external) theme—for many coastal communities, especially those that produce or consume blue foods. 

Read the Q&A here.

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Mapping Crop Types in Southeast India with Smartphone Crowdsourcing and Deep Learning

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High resolution satellite imagery and modern machine learning methods hold the potential to fill existing data gaps in where crops are grown around the world at a sub-field level. However, high resolution crop type maps have remained challenging to create in developing regions due to a lack of ground truth labels for model development. In this work, we explore the use of crowdsourced data, Sentinel-2 and DigitalGlobe imagery, and convolutional neural networks (CNNs) for crop type mapping in India. Plantix, a free app that uses image recognition to help farmers diagnose crop diseases, logged 9 million geolocated photos from 2017–2019 in India, 2 million of which are in the states of Andhra Pradesh and Telangana in India. Crop type labels based on farmer-submitted images were added by domain experts and deep CNNs. The resulting dataset of crop type at coordinates is high in volume, but also high in noise due to location inaccuracies, submissions from out-of-field, and labeling errors. We employed a number of steps to clean the dataset, which included training a CNN on very high resolution DigitalGlobe imagery to filter for points that are within a crop field. With this cleaned dataset, we extracted Sentinel time series at each point and trained another CNN to predict the crop type at each pixel. When evaluated on the highest quality subset of crowdsourced data, the CNN distinguishes rice, cotton, and “other” crops with 74% accuracy in a 3-way classification and outperforms a random forest trained on harmonic regression features. Furthermore, model performance remains stable when low quality points are introduced into the training set. Our results illustrate the potential of non-traditional, high-volume/high-noise datasets for crop type mapping, some improvements that neural networks can achieve over random forests, and the robustness of such methods against moderate levels of training set noise. Lastly, we caution that obstacles like the lack of good Sentinel-2 cloud mask, imperfect mobile device location accuracy, and preservation of privacy while improving data access will need to be addressed before crowdsourcing can widely and reliably be used to map crops in smallholder systems.

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Remote Sensing
Authors
David Lobell
Sherrie Wang
Stefania Di Tommaso

Finding Food Security Underwater

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Laura Anderson
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The ocean could produce up to 75 percent more seafood than it does today and drive sustainable economic growth, holding a key role in solving global hunger. Center on Ocean Solutions Co-Director Jim Leape joined Stanford Earth Professor Roz Naylor for a conversation about food security, the current COVID-19 pandemic and how global food policies can better integrate “blue foods” from marine and freshwater systems. 

"COVID-19 is disrupting processed and widely traded seafood products, such as salmon, shrimp and tuna," states Naylor. "However, locally produced and consumed food systems are actually faring much better. This is especially true for some small-scale fisheries, where local fishing groups have taken the initiative to sell seafood locally and new markets are emerging during the COVID-19 period. Production and consumption have become more tightly connected as a result."

Both Leape and Naylor are part of the global Blue Food Assessment, the first comprehensive review of aquatic foods and their roles in the global food system. Naylor will discuss the assessment with collaborators during the Virtual Ocean Dialogues on June 3rd. 

The pair also highlighted promising innovations for sustainable future food systems. "Illegal fishing defeats efforts to manage the resource sustainability and cheats the fishers who are playing by the rules," Leape explains. "And we can end it. Emerging technologies are bringing much greater transparency into the fishing industry."

"If we want healthy oceans in the future, we have to be thinking about a wide range of innovations, and the institutions, financial incentives, and public trust needed to turn these innovations into real market solutions," says Naylor. 

 

Read the full Stanford ReportQ&A >

Explore the new Blue Food Assessment website >

Learn more about our work curbing illegal fishing >

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On the role of anthropogenic climate change in the emerging food crisis in southern Africa in the 2019–2020 growing season

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Researchers including David Lobell analyze how human-caused climate change has impacted a water deficit in Southern Africa and might contribute to a rising food security crisis in the region.

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Global Change Biology
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David Lobell

Innovation Needed to Meet Global Food Security Challenges

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Join us for a talk with agricultural and development economist Christopher B. Barrett, this quarter’s visiting scholar with the Center on Food Security and the Environment. Barrett is the Stephen B. and Janice G. Ashley Professor of Applied Economics and Management and an International Professor of Agriculture with Cornell’s Dyson School of Applied Economics and Management.

Professor Barrett will discuss food systems advances over the past 50 years that have promoted unprecedented reduction globally in poverty and hunger, averted considerable deforestation, and broadly improved lives, livelihoods and environments in much of the world. He’ll share perspectives on the reasons why, despite those advances, those systems increasingly fail large communities in environmental, health, and increasingly in economic terms and appear ill-suited to cope with inevitable further changes in climate, incomes, and population over the coming 50 years. Barrett will explore the new generation of innovations underway that must overcome a host of scientific and socioeconomic obstacles.
 
Also a Professor of Economics in the Department of Economics, Barrett is co-editor in chief of the journal Food Policy, is a faculty fellow with David R. Atkinson Center for a Sustainable Future and serves as the director of the Stimulating Agriculture and Rural Transformation (StART) Initiative housed at the Cornell International Institute for Food, Agriculture and Development.
 

Lectures
Global Food Security Symposium Series
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