Photogrammetry provides accurate lobster buoy count
Tenants Harbor, Maine
July/August 2009
The Client:Maine Department of Marine Resources
The Project: To help MeDMR scientists determine how trap numbers affect the lobster population, the agency contracted Kappa Mapping to inventory the number of buoys marking lobster traps in Tenants Harbor. Nearly 3 million traps bring in 78 million pounds of lobster annually, adding $228 million to Maine’s economy and making the industry’s sustainability a hot topic.
Our Work: Aside from the traditional and unreliable method of hand-counting from a boat, how do you count thousands of buoys in a constantly moving ocean? Our solution? We used conventional photogrammetry to acquire overlapping aerial photos of the harbor under calm, glare-free conditions. By matching buoys in adjacent photos and using navigation-grade GPS photo positions to georeference the imagery, and then leveling the stereomodels, we could confidently identify the buoys and accurately count 10,000 in a 3.5 square nm area.
Future Benefits: Successful use of this technique will enable scientists to...
- Suggest buoy reduction percentages, potentially ensuring the industry’s sustainability while improving efficiencies and boosting catch.
- Assess large whale risk and shipping channel conflict assessments.
