Removal of introduced rats from islands is a proven and powerful conservation tool that can help restore ecosystem functioning and/or processes. Haida Gwaii, British Columbia, Canada, is an isolated marine archipelago with distinct flora and fauna that have evolved during 14,000 years of isolation from the mainland. Approximately 1.5 million seabirds from 13 species nest on the islands of Haida Gwaii, including 50% of the global ancient murrelet population, a federally designated species at risk in Canada. Within Gwaii Haanas National Park Reserve and Haida Heritage Site (located at the southern end of Haida Gwaii) there are 9 designated Important Bird Areas (IBAs), established primarily to denote important seabird nesting sites. However, unintentional historical introductions of rats to islands within IBAs and throughout Haida Gwaii have led to the demise of several seabird nesting colonies. In September 2013, Parks Canada Agency, in partnership with Coastal Conservation and Island Conservation, implemented Canada’s first aerial broadcast eradication of black rats from two islands within the Ramsay Island and Northern Juan Perez Sound Islands IBA, where seabird colonies and ecosystem processes have been negatively impacted by this species. The eradication of black rats from Murchison and Faraday Islands posed several challenges including ensuring adequate bait density to maximize the probability of eradication success while minimizing risks to native species. Our planning efforts focused on addressing bait competition by non-target species, the consequence of bait interception by the forest canopy, minimizing bait entering the marine environment, mitigating potential negative impacts to non-target species, and determining the ideal timing for the eradication operation. We present here a summary of these challenges and the measures that were implemented to address them.

Distributed mobile robotics (DMR) involves teams of networked robots navigating in a physical space to achieve tasks in a coordinated fashion. A major challenge in DMR is to program the ensemble of robots with formal guarantees and high assurance of correct operation. To this end, we introduce Drona, a framework for building reliable DMR applications. This paper makes three central contributions: (1) We present a novel and provably correct decentralized asynchronous motion planner that can perform on-the-fly collision-free planning for dynamically generated tasks. Moreover, the motion planner is the first to take into account the fact that distributed robots may have clocks that are only synchronized up to a tolerance, i.e., they are almost synchronous; (2) We formalize the DMR system as a mixed-synchronous system, and present a sound abstraction-based verification approach for DMR systems, and (3) Drona provides a state-machine based language for safe event-driven programming of a DMR system and the code generated by the compiler can be executed on platforms such as the robot operating system (ROS). To demonstrate the efficacy of Drona, we build and verify a priority mail delivery system. Using our abstraction-based verification approach we were able to find, within a few minutes, bugs which could not be found by performing random simulation for several hours. Our verified decentralized motion-planner scales efficiently for large number of robots (upto 128 robots) and workspace sizes (upto a 256×256 grid).

The oxidative transformation product of a common tire preservative, identified as N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6-PPDQ), has recently been found to contribute to "urban runoff mortality syndrome" in Coho salmon at nanogram per liter levels. Given the number of fish-bearing streams with multiple stormwater inputs, large-scale campaigns to identify 6-PPDQ sources and evaluate mitigation strategies will require sensitive, high-throughput analytical methods. We report the development and optimization of a direct sampling tandem mass spectrometry method for semiquantitative 6-PPDQ determinations using a thin polydimethylsiloxane membrane immersion probe. The method requires no sample cleanup steps or chromatographic separations, even in complex, heterogeneous samples. Quantitation is achieved by the method of standard additions, with a detection limit of 8 ng/L and a duty cycle of 15 min/sample. High-throughput screening provides semiquantitative concentrations with similar sensitivity and a full analytical duty cycle of 2.5 min/sample. Preliminary data and performance metrics are reported for 6-PPDQ present in representative environmental and stormwater samples. The method is readily adapted for real-time process monitoring, demonstrated by following the dissolution of 6-PPDQ from tire fragments and subsequent removal in response to added sorbents.