911勛圖

Congratulations to Britny Martlin on the successful defence of her PhD thesis, ���Bodies, water and sonar: Searching for submerged decedents using recreational fish finders���.

Britny���s work aimed to determine if the public can assist with the detection of submerged decedents in shallow outdoor waterbodies using recreational fish finders.

Abstract

When a decedent is submerged, there is no guarantee they will be found and recovered. Modern recreational fish finders are an untapped resource for underwater detection, are already widely operated by the public, technologically advanced sensors which incorporate high frequency Sidescan sonar and accurate GPS plotting capabilities. This thesis aimed to determine if the public can assist with the detection of submerged decedents in shallow outdoor waterbodies using recreational fish finders.

Outdoor water-related fatalities in B.C. between 2010 and 2021 were retrospectively analyzed to determine current recovery success and displacement patterns of submerged decedents. Results demonstrated that, overall, 16% of decedents submerged in B.C.���s outdoor waterbodies are not recovered, with 26% of decedents unrecovered from the coastal ocean alone. Further, there is a short period of opportunity (<24 hours) for recovery in the coastal ocean.

Validation of recreational fish finder technology was completed through the detection of human proxies and human volunteers submerged at shallow depths (<7.5 m) in 1) two indoor freshwater environments, and 2) two outdoor environments (a freshwater lake and a nearshore coastal location). Results demonstrated that recreational fish finders with high frequency (800 kHz) Sidescan sonar can detect human bodies submerged in fresh and saltwater environments, both within the water column and on the bottom.

The ability of the boating public to accurately detect a single human proxy submerged in a shallow (~8 m) nearshore coastal location using recreational fish finders with minimal training was then assessed. The proxy was successfully detected by volunteers with an accuracy of 5-10 m when using high frequency (800 kHz) Sidescan sonar.

The results from this thesis have positively demonstrated that the public can indeed utilize modern recreational fish finders to accurately detect submerged decedents in shallow waters. There is now clear and legitimate potential to engage the boating public as ���eyes on the water��� to help locate a greater number of submerged decedents. Isolated communities may also benefit from community-based engagement utilizing this currently existing and ubiquitous technology.

Congratulations again Britny, on this well-deserved achievement!