Revolutionizing Marine Conservation with Photogrammetry & Ensuring Access for All
Large-area imagery, also known as ‘Structure from Motion of Photogrammetry’, is a technology that allows anyone to create detailed 3D models of the environment. Scientists and conservation practitioners are increasingly using large-area imagery to study coral reefs.
These models can be used to monitor change over time, assess the efficacy of coral restoration efforts, and communicate the importance of conserving these vital ecosystems. While this technology offers a variety of benefits, concerted training and capacity building efforts are still needed to make this technology broadly accessible.
The Nature Tech Collective was joined by member Dr. Orion McCarthy, Science Lead at Seatrees and Project Manager at the Scripps Institution of Oceanography, to learn more about the potential and real-world applications of photogrammetry for marine conservation.
Why is it so important to visualise our underwater environment?
Climate change, overfishing, pollution, and coastal development are threatening coral reefs around the world. Coral reefs and other marine ecosystems are changing faster than ever before, but this change can be difficult to detect with the naked eye, even by seasoned researchers.
Large-area imagery allows us to peel back the ocean so that anyone, even people who aren’t SCUBA certified, can virtually dive and travel through time. This can make the drivers of ecosystem degradation much clearer to researchers and communicate conservation needs to policy makers and the general public.
How is photogrammetry used to study coral reefs?
Large-area imagery, enabled through modern photogrammetry, can provide a detailed digital twin of the environment, giving researchers the power to study change over time in ways that were not possible before.
For coral reefs, researchers can now track the fate of individual coral colonies, assess the overall health of the reef, and understand the impacts of disturbances such as storms or bleaching events.
What steps are involved in generating the 3D imagery of coral reefs?
Typically, these 3D models are produced from underwater photos collected by divers that swim in a grid pattern over the reef - these images may also be collected by drones or autonomous underwater vehicles.
These images are then processed using specialized software, such as Agisoft Metashape, to create 3D point clouds, digital elevation models, and 2D ortho projections (photo mosaics).
These data products enable researchers to measure habitat complexity, coral growth rates, and create detailed habitat maps. Additionally, the use of large-area imagery is not limited to coral reefs: it has been applied in a variety of terrestrial and marine settings, making it a versatile tool for studying environmental change more broadly.
While large-area imagery can reconstruct static components of the environment (e.g., corals, rocks) with high accuracy, it is not able to reconstruct flora and fauna that move (e.g., fish, kelp).
Why is 3D large-area imaging a game changer for marine conservation conservation?
One of the primary advantages of large-area imagery is its ability to create a reusable, high-resolution dataset of virtual ecosystems. This capability allows for multiple research questions to be addressed using the same data, minimizing the need for costly and time-consuming field work, especially helpful in remote locations.
For instance, researchers at the Scripps Institution of Oceanography used this technology to annotate and track hundreds of coral colonies in remote locations such as Palmyra Atoll in the Pacific Ocean.
Here are some examples of their photogrammetry reconstruction work in action:
Without modern photogrammetry technology, this is a feat that would be logistically challenging and expensive to achieve using traditional field methods.
Photogrammetry also supports the monitoring of large areas, and can be scaled to cover entire hectares of coral reefs: large-area imagery can also be used to monitor the success of restoration efforts, providing visual and quantitative data on coral growth and recovery.
A collaborative project in Bali, Indonesia (led by Ocean Gardener and supported by Seatrees and Scripps) is using low-cost GoPro cameras to capture images of coral nurseries established on biodegradable materials, demonstrating that high-quality restoration can be conducted and monitored even with basic equipment.
What are the challenges associated with using photogrammetry for large-area imaging in conservation?
Despite its potential to advance coral reef conservation and restoration efforts, uptake of large-area imagery has been hindered in the conservation community and in the Global South. Many organizations, especially in the Global South, struggle to adopt this technology due to financial constraints and lack of technical expertise.
A study led by McCarthy, which involved a literature review of large-area imagery applications and a survey of coral reef scientists and conservation practitioners, aimed to identify and address barriers that prevent users from accessing this technology.
Survey participants repeatedly cited barriers such as the cost of equipment, the need for specialized training, and limited staff capacity to process and store large amounts of data. While there is a growing interest in using large-area imagery, its uptake has been uneven, with a significant gap between the research being conducted and the needs of conservation practitioners.
Looking forward: How can we make large-area imagery and other forms of nature tech more accessible?
Several steps need to be taken to make large-area imagery more accessible. These include developing standardized and accessible imaging methods and standard operating procedures (SOPs), creating user-friendly and free software tools, and conducting applied conservation research that meets the needs of practitioners.
Imaging Guides & Training Programs
Initiatives such as the development of comprehensive imaging guides and the advent of software like TagLab, which uses machine learning to assist with data processing, are significant steps forward. Additionally, training programs, workshops, and capacity-building activities are crucial for helping organizations, especially those with limited resources, to adopt and effectively use this technology.
Partnerships that focus on sharing resources, equipment, and expertise can also help to level the playing field, enabling more organizations to benefit from large-area imagery.
The importance of building capacity for conservation at the local level
Beyond large-area imagery, other forms of nature tech require significant training and expertise to operationalize, including eDNA, bioacoustics, and machine learning. Nature tech has immense potential to scale up conservation science, but we don’t want innovation to come at the expense of equity. It is simply not acceptable to outsource all nature tech data collection and analysis.
Building local science capacity is a major part of conservation – it increases local ownership and leads to more durable outcomes. Our pursuit of higher resolution, more comprehensive datasets is not worth it if we undermine the ability of local scientists to monitor changes in their own backyard. Nature tech can and should be broadly used. Training and capacity building efforts can help us get there, and need to be embedded into the business plans of all nature tech organizations: these efforts are foundational to the mission of nature tech organizations.
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Large-area imagery represents a significant advancement in the field of coral reef science and conservation with applications in other ecosystems: It provides a powerful tool for documenting and understanding changes in these vital ecosystems, supporting both research and practical conservation efforts. As this technology continues to evolve and becomes more integrated into conservation practices, it promises to enhance our ability to monitor, understand, and ultimately protect these critical marine habitats.
However, to fully realize the potential of this technology, it is essential to address the barriers to its adoption, particularly for organizations in the Global South, which are on the frontlines of nature loss but face more resource limitations.
By developing accessible methods and tools, providing training and capacity building, and fostering partnerships, the conservation community can ensure that large-area imagery becomes a widely used and effective tool for protecting and restoring coral reefs.
The future of coral reef conservation may well depend on making technologies like large-area imagery not just advanced, but also accessible and equitable for everyone who relies on them.