Sixty-six years ago, George Orwell portrayed in his novel 1984 a fictional entity called ‘Big Brother’ who is claimed to rule a totalitarian state, creating a society that is under total surveillance by the authorities. Citizens are constantly reminded of this by the slogan ‘Big Brother is watching you’, which is omnipresent on screens. In modern human society, Big Brother has come to signify the abuse of civil rights, specifically in terms of mass surveillance. As bad as it may seem for human populations, however, mass surveillance is arguably the most important and the most potent tool at the disposal of ecologists and conservationists to protect animal populations and their habitats in increasingly human-dominated landscapes and seascapes.
In early 2014, the Bimini Biological Field Station (BBFS) established its equivalent of ‘Big Brother’: an extensive acoustic underwater listening array placed strategically in Bimini’s diverse marine habitats to monitor by means of telemetry the movements of sharks and rays. Each animal is fitted with a 10-year transmitter that broadcasts its acoustic signal every 90 seconds or so. If it is within range of a receiver (about 500 metres away), its identity and the date and time are recorded. The data build up – from minute to hour to day, month and year – across different tidal phases, seasons, etc. For the next three years I will use this data to identify what drives the movements, habitat preferences, spatial hotspots and mechanisms of habitat partitioning for Bimini’s local sharks and rays.
Only a few months ago I arrived at the BBFS as a Principal Investigator to lead this project and have recently summarised the data from the past 18 months. Some 48 sharks and rays from seven species were detected by Bimini’s ‘Big Brother’ over this period. Interestingly, my first exploratory analysis has revealed that some species visit diverse habitats throughout Bimini (for example, an adult lemon shark was detected on 34 receivers), whereas others are more restricted in their movements (a southern stingray was picked up on only seven receivers). It also appears that some habitats off south-western Bimini function as important corridors or highways for shark movement, as between 20 and more than 30 individuals were detected in them. In addition, I was excited when I received information that our sharks were ‘making moves’ outside the array of receivers. Two male nurse sharks were detected in Andros and Grand Bahama, and lemon sharks were found to be migrating between Jupiter (Florida), Bimini and Florida Keys.
Surveillance arrays like the one deployed at Bimini provide valuable information about the behaviour of sharks and rays and their use of habitat and space on a small geographical scale. This information is crucial for the effective conservation of local habitats, but we also need to know about shark and ray movements on a much larger scale – around countries or even continents – if we are to protect populations and conserve them for generations to come. Hence, small receiver arrays are gradually becoming larger and connected to other receiver arrays, creating networks on a large geographical scale. So is mass surveillance all that bad? I guess it’s a matter of perspective.