Unmanned Underwater Vehicles (UUVs) have been used heavily by marine industries for a number of years, with ongoing improvements to capability and affordability.
Unmanned Underwater Vehicles (UUVs) have been used heavily by marine industries for a number of years, with ongoing improvements to capability and affordability. UUVs can be used for geophysical mapping, inspection of structures or pipelines, surveillance and emergency response. UUVs can be divided into two broad categories: Autonomous Underwater Vehicles (AUVs) or Remotely Operated Vehicles (ROVs). AUVs are self-contained devices carrying their own propulsion systems and onboard data capture and storage systems, that often follow pre-programmed survey protocols. ROVs are tethered, meaning that they are physically connected to another vessel, and usually transmit data and power through the tether. This limits the range and manoeuvrability of these devices but means that they can be piloted manually.
There has been a recent surge in the use of Unmanned Aerial Vehicles (UAVs) or ‘drones’ as an alternatives to traditional survey methods. Drone provide additional options for collecting data, and can be autonomous (like AUVs), with pre-programmed flight paths that they follow for a survey or they can be piloted manually (similar to ROVs).
AUVs are self-propelled robots that are not connected (or ‘tethered’) to a mother vessel, and do not require direct human control during data collection. This gives them greater mobility, range, and/or speed. They can be used in remote and hostile environments hitherto inaccessible to vessels, such as under ice in polar regions or deep water hydrothermal vents (Graham et al., 2013).
Thanks to advancing technology, AUV usage is pushing boundaries, and has expanded from military and security purposes to emergency response and entertainment. Commercially, AUVs are used by Oil & Gas (O&G) companies to map the seafloor prior to installation and construction of rigs, platforms, or pipelines (Shukla and Karki, 2016). Within the research field, AUVs are used also for seafloor mapping or oceanographic measurement. For example, AUVs are used for studies of chemosynthetic communities in hydrothermal ecosystems, where emitted fluids can be over 400 °C (German et al., 2008; Nakamura et al., 2013), or abyssal zone imaging of sea floor biodiversity (Nakazawa, Ushio & Kondoh, 2011). Their usage in research projects is reflected by an ever-increasing diversity of peer-reviewed publications, which has flourished over the last ten years (Wynn et al., 2014).
AUVs are now also being used for Passive Acoustic Monitoring (PAM) of marine mammals and mitigation during offshore industrial activities. Baumgartner et al., 2013 used two underwater electric gliders to detect the calls of fin (Balaenoptera physalus), humpback (Megaptera novaeangliae), sei (Balaenoptera borealis), and North Atlantic right whales (Eubalaena glacialis) in the Gulf of Maine. To assess accuracy of detection from gliders using PAM, a visual ground-truthing aerial survey was conducted. From the 10 instances when whales were detected visually, nine were also detected acoustically, proving their efficacy.
ROVs are used commonly within offshore industries. The ROV operator is typically located on-board a vessel, platform or on land whilst navigating the ROV to perform repair work, infrastructure inspection or ecological survey. ROVs have also been used in military operations for mine hunting and port security. ROVs can maintain neutral buoyancy whilst attached to a tether from a ship.
OSC owns and operates ROVs, and regularly analyses pre-collected ROV data collected from industrial ROVs presenting the work in peer-reviewed papers. For example, in 2018, OSC Scientists at OSC identified a diverse range of reef-dependent and transient pelagic species on a platform in the North Sea, with clear depth zonation and evidence of reproduction, suggesting the high ecological value of the platform . In 2019, scientists at OSC also published the first account of fish and invertebrates colonising a newly-installed platform
UAVs can be effective conservation tools by providing valuable data that can be used to create legislative frameworks (Bevan et al., 2018; Gomes et al., 2018). They has been utilised in a number of different ways; counting datasets with crocodiles; discovering nest sites of Cape vultures and establishing migration routes of great whales. There has been recent diversification in drone use. For example, the amusingly-named SnotBot drone, created as a custom-built partnership between Ocean Alliance and Olin College of Engineering, has been used to collect samples of whale mucous in a petri dish. This ‘snot’ contains DNA, mucous, parasites and many more substances that can be used to establish a number of parameters regarding individual identity, population dynamics, and even the whale’s health.
Over the last ten years, there has been increasing development in the use of UAVs in industry and research. UAVs offer lower human risk ; however, currently, a certified pilot and an inspection engineer is required to conduct commercial aerial drone surveys which can be costly (Sudevan et al., 2018; Saadawi, 2019), and since a drone halted operations over Heathrow airport in January 2018, a permit in the UK is now required to fly drones over public space.