April and May have been busy months and we've been working on a range of interesting projects.
Animal welfare is an important consideration in control operations to insure humane treatment of the animals, and audits are often used as a means to determine the level of undesirable outcomes (e.g., shot outside target zone, wounding without killing). Darryl has been working with Jordan Hampton (Ecotone Wildlife Veterinary Services, Australia) and Dave Forsyth (NSW Department of Primary Industries, Australia) to develop suggested guidelines on sample size requirements for such audits to ensure that statistically robust results are obtained. They are currently working on a paper detailing these guidelines.
Irrigation schemes often take water from rivers and other natural water courses, meaning that fish can be at risk of getting caught in such schemes. Clearly this is undesirable from the perspectives of all involved, so a range of mitigation methods are used to reduce the risk of fish entering the system. One method is the use of permeable rock bunds that allow the diverted water to enter the irrigation scheme, but are a deterrent to some fish as salmonids are believed to avoid the structure due to the size of the cavities within the bund. We have been assisting the Central South Island Fish and Game Council (New Zealand) to analyse the data from trials they conducted to assess the effectiveness of such a structure, using releases of hatchery-raised juvenile salmon at key points within a diversion scheme. The results are still confidential at this point, but a key consideration of our analysis was accounting for the very low recapture rate of released salmon.
In May, Darryl traveled to Woods Hole, Massachusetts (USA) to conduct an introductory occupancy modelling workshop. Woods Hole is home to a number of different institutions that are involved in marine research, and is the site of the oldest aquarium in the USA. Participants were mainly from NOAA and the University of Massachusetts - Amherst, and as always, they were working on a diverse range of species, although it was probably the most whale biologists Darryl has ever had in a single course! He has lost track of how many times he has given a form of this course since 2006 (closer to 70 than 60), but it was Darryl's first trip to Cape Cod. Check out our courses page for the location of other upcoming courses.
Contact us if you have any questions about these, or other, projects.