Dear Friends and Colleagues, as you may know, Sharks, as apex predators, are vital to maintaining healthy marine ecosystems, and at the same time, their populations are plummeting due to human actions. It is estimated for example that the population of pelagic oceanic white tip sharks is reducing by 17% per year [1] and I've heard (can't find a reference) that populations in the eastern indian/western pacific are at 1% of normal levels. Such reductions in populations create "trophic cascades" that produce wide-ranging changes in populations of different species all the way down the food chain [2]. And the marine ecosystem is a key source of human nutrition; it comprises between 13% and 17% of global human protein intake [3]. As you may also know, there is currently a shark attack crisis in New South Wales [4]. While most people in the region oppose killing sharks in response to the crisis, existing solutions, netting and culling reduce those same threatened populations of sharks upon which the sustainability of marine food supply d ecosystems depend [5], and are arguably ineffective [6]. Apparently the most successful approach at avoiding attacks is the use of human spotters, as used in Cape Town, where people in tall towers scan the sea close to shore [6]. But please watch this Youtube video <https://www.youtube.com/watch?v=q2U3gjwJfS4> [7] from Pismo Beach, California. The shark is spotted at about 1:20 into the video. This drone, a phantom 3, is sending live video back to the operators, who are using remote control. What we can see from this video is that the point of view of drones is far superior to that of spotters. My first thought is that autonomous drones could provide a cheap and scalable solution to patrolling beaches to prevent shark attacks. I expect that processors like the Pi 2 have easily enough processing power to both plan and execute search patterns along beaches, and perform the image recognition necessary to reliably detect potentially dangerous sharks. A drone might also be able autonomously to visit surfers and swimmers near to the shark and warn them, either by some signal such as flashing red LEDs or an audible message (language issues notwithstanding). The drone would have to be able to identify swimmers and surfers in the water (not easy; sharks confuse seals and surfers all the time), but computing an optimal route to visit suspected swimmers should be relatively easy :-). I imagine that sooner or later it will be possible to construct cheap rugged solar powered docking/charging shelters that drones could depart from and return to, to charge and shelter from the elements after patrols. Satellite communications could provide status reports for maintenance. My second thought is that as a community, we probably have all the necessary expertise to construct a working prototype that at least demonstrates feasibility. Such a prototype would have to be able to fly above the ocean along a beach under its own control for a useful period of time, at least 15 minutes, and demonstrate that it can identify a shark in the water (we could use a rubber shark <https://www.youtube.com/watch?v=9dghbyBaQyI> for testing ;-) ). Our community includes people doing image recognition with the Pi, radio control experts, users of 3D printers, and some exceptional programmers. If a small, strong group could be formed with the relevant expertise we may be able to develop a prototype in a short enough time frame to be relevant. Of course, availability of time is a big issue. I couldn't contribute more than a few hours a week. But nothing ventured, nothing gained. So I'm writing this message to the Squeak and Pharo communities, and bcc'ing a few friends I know that have relevant expertise to ask for two things; first, for good information on scoping out the project, possible technologies, power budgets, costs, what is available off-the-shelf (both in hardware and known algorithms) and what we would need to construct ourselves, and second, for volunteers. Who among us are really excited by this project, have relevant expertise and are motivated to make a contribution? [1] www.sharkadvocates.org/cites_4sharks_owt_fact_sheet.pdf [2] http://www.globalshark.ca/pressmaterial/cascading/fig1_web.pdf [3] http://www.who.int/nutrition/topics/3_foodconsumption/en/index5.html [4] http://www.bbc.com/news/world-australia-34398516 [5] http://www.theguardian.com/environment/2015/sep/29/shark-hit-australian-comm... [6] http://www.nonswsharkcull.net/latestnews/tag/shark_spotting/ [7] https://www.youtube.com/watch?v=q2U3gjwJfS4 crazier ideas: Infra red cameras are becoming cheap and easily available. Species like Great White and Bull Shark have elevated metabolisms, effectively they are warm blooded, so these two facts may allow spotting at night. Sharks are extremely sensitive to electrical fields; maybe some kind of transmitter could be fitted to a drone, e.g. via a wire suspended in the water, that could generate a field that could direct the shark away from swimmers _,,,^..^,,,_ best, Eliot