The scope of coral degradation is vast. Corals cover more than 284,300km² [1] of the ocean floor and, consequently, it is difficult to deliver probiotics on a large scale even with the aid of our mechanism. To bring our probiotics into the realm of reality for coral conservation, we have designed pieces of hardware to maximize the benefits of our probiotic biofilm that are not disruptive to the coral holobiont or damaging to the environment. Additionally, we also developed these mechanisms into services to increase the ease of access and use for different audiences.

To tackle the scalability issues of probiotics, we designed a comprehensive delivery system that can reduce the cost and time of probiotic delivery, which we call Deliveray. To do this, we chose to utilize a spray mechanism that can allow probiotics to be delivered using an autonomous underwater vehicle (AUV). We took inspiration from the company EvoLogics.

With coral being dispersed over large areas underwater, the difficulty of individual delivery to these corals is high. To address this, we created a pneumatic spray mechanism to disperse atomized droplets of bacterial solution, including our engineered bacteria and probiotics. Doing so creates a wide range for the dispersion of our bacteria while ensuring high velocities so that they can be directed efficiently toward coral.

A highly concentrated mixture of the two bacterial species is held inside the body of the UAV. Together, these two solutions will be combined in a pneumatic spray system consisting of reservoirs of the two liquids that feed into a nozzle and spray droplets through pressurization by compressed nitrogen. Pneumatic sprays allow the liquid to be formed into droplets that can be easily absorbed by the coral. The pneumatic sprays are most beneficial as not only are they lightweight, but they are also pressured by pressurized air, eliminating the need for electricity, which would cause hazards in the ocean. The pressurized air also serves as a water prevention mechanism, preventing water from entering the device, which would potentially break the spray.

With their ability to operate independently and navigate the intricate underwater terrain, we not only utilize human-controlled but also autonomous water vehicles, opening new horizons in coral conservation efforts. We utilized these capabilities to allow for the large-scale implementation of our mechanism. We attached the spray mechanism to a UAV, making it possible to use probiotics over a larger area with reduced time and labor demands.

At the heart of this UAV's design lies its biomimetic propulsion system, inspired by the motion of manta rays. Its flexible wing-like structures, composed of lightweight yet durable materials, can reduce the impact on coral ecosystems. The UAV's propulsion mechanism harnesses the power of oscillating, undulating wing motions, with high-efficiency motors and actuators steering these motions.

This design helps address the disruptions to coral ecosystems traditionally caused by human activity. Sound pollution from traditional AUVs can impact coral biological processes and cause stress to the coral [2]. This design not only propels the AUV more quietly, it also does so more efficiently [3]. The decrease in AUV operation volume can minimize human disturbance, while the higher energy efficiency of this AUV design can allow for reduced energy consumption and the AUV being able to cover greater distances.

The UAV's navigation system combines various sensors and technologies for precise underwater maneuvering. An Inertial Measurement Unit (IMU), comprising accelerometers, gyroscopes, and magnetometers, provides crucial data on acceleration, orientation, and heading. Depth sensing, facilitated by a pressure sensor (barometer), ensures accurate depth calculations. A GPS receiver, when near the surface, offers global positioning data for surface operations and initial positioning before submerging. Meanwhile, sonar systems, including forward-looking and sidescan sonars, deliver real-time images of underwater terrain, aiding in obstacle avoidance and precise coral distance determination. In summary, this UAV represents a paradigm shift in coral conservation, a fusion of innovative technology and ecological sensitivity. With its biomimetic design, probiotic delivery precision, AI-powered coral recognition, and robust navigation, it promises to be an invaluable ally in the ongoing battle to protect and preserve the world's fragile coral ecosystems.

The UAV's effectiveness is further elevated by an advanced coral identification AI system. Equipped with high-resolution cameras and sensors, the UAV captures intricate underwater imagery. An AI-based machine learning algorithm, trained on a diverse dataset of coral reef images, scrutinizes these images in real-time to identify and map coral reefs with unparalleled accuracy, facilitating targeted spraying of our solution.

All these components, from the biomimetic propulsion system to the coral identification AI, harmoniously coalesce within a sturdy and waterproof housing. This seamless integration ensures the UAV's endurance and reliability in the challenging underwater environment. Moreover, robust communication systems enable remote monitoring and control during critical missions.

The concept of autonomy in our planned UAV is undeniably appealing, signifying the ability for independent operation. However, it's crucial to acknowledge that while autonomy brings undeniable advantages, it may not always ensure the utmost accuracy and effectiveness.

In response to this recognition, we have formulated a strategy to embark on a preliminary testing phase that incorporates human intervention. This phase aims to assess the efficiency of our spray, UAV, and navigation systems. By employing human labor in this testing endeavor, we intend to evaluate the delivery mechanism's efficacy, and we have established a specific target to measure success: the percentage reduction, denoting the proportion of coral reefs preserved per unit area (m2).

The human testing period will be rigorously conducted until we achieve a substantial percentage reduction of at least 80%. This benchmark underscores our commitment to ensuring the highest level of effectiveness and precision before advancing to the autonomous phase and introducing our solution to the market. By setting this ambitious goal, we prioritize the preservation of coral reefs and enhance the credibility and reliability of our delivery system, assuring our customers that it has been rigorously tested and proven to deliver exceptional results.

We first started with a sketch of our design, mapping out the possible components that we would need to show in a graph (Fig 5).

Then, we broke each component down and created a 3D model of each model. Each component is then combined to form our final prototype (Figures 6, 7, 8).

[1] Ocean-climate.org WHAT IS A CORAL REEF? (n.d.). https://ocean-climate.org/wp-content/uploads/2017/03/coral-reefs_07-12.pdf
[2] Ferrier‐Pagès, C., Leal, M. C., Calado, R., Schmid, D. W., Bertucci, F., Lecchini, D., & Allemand, D. (2021). Noise pollution on coral reefs? — A yet underestimated threat to coral reef communities. Marine Pollution Bulletin, 165, 112129–112129. https://doi.org/10.1016/j.marpolbul.2021.112129
[3] BOSS Project | EvoLogics. (2013). EvoLogics GmbH. https://evologics.de/projects/boss