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Liese Siemann, Ph.D.
Senior Research Biologist
Interests & Expertise
  • Bycatch reduction  

  • Ecological modelling

  • Optical survey methods and algorithm development

  • Protected species issues

  • Animal welfare issues

Ph.D., Biological Oceanography
Massachusetts Institute of Technology/Woods Hole Oceanographic Institution
B.A. Biology
Cornell University


Improving automated detection of scallops and flounder in optical surveys with stereo detection methods

The Atlantic sea scallop (Placopecten magellanicus) is the focus of one of the most valuable fisheries on the east coast of the United States. This survey will lead to improved precision in scallop biomass estimates by increasing the effective coverage of industry and federal optical surveys through increased annotation rates and precision of object detection. It will also improve annotation rates for key bycatch species, specifically flounder species. We plan to develop detectors to (1) improve detection of scallops and differentiate between live, dead, and swimming scallops and (2) detect flounder in optical survey images using the stereo image pairs taken during Habitat Mapping Camera system (HabCam) surveys.

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Liese started working at Coonamessett Farm Foundation in September 2014. Previously, she worked for seven years at the Marine Biological Laboratory studying animal camouflage using novel image analysis and statistical methods and raising multiple species of cuttlefish and octopus. She also spent five years as the administrator of the Woods Hole Science and Technology Education Partnership. Liese received a BA in Biology from Cornell University and a PhD in Biological Oceanography from the Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program. Her dissertation focused on modelling the molecular population genetics of long-finned pilot whales. She has taught college courses on marine resource management and cetacean biology. At CFF, Liese’s research focuses on using innovative methods to design bycatch reduction technologies, model animal-fishing gear interactions, and assess marine animal populations.

Development and testing of an inexpensive GPS radio buoy system for early notification of whale entanglements
Funded by: Marine Mammal Commission and CFF

Liese leads CFF's team to develop and test an inexpensive, GPS radio buoy system that provides early notification of marine mammal entanglements in the vertical buoy lines of commercial fishing gear. By providing a readily available, rapid notification system to identify entanglement events, the technology has the potential to response times of rescue crews and thus improve the  frequency and outcomes of disentanglement efforts. Additional uses for this technology are currently being explored.

Quantifying the Selectivity Characteristics of an Extended Link Apron using a Dredge Cover Net
Funding provided by NOAA/NMFS Atlantic Sea Scallop Set-Aside Grant Program

The traditional apron configuration for a scallop dredge consists of 4-inch rings connected by two links side-by-side. Since 2016, CFF has been developing and field-testing a dredge apron with extended links in both the horizontal and vertical direction (two-way apron) and in only the vertical direction. While the two-way apron is effective in reducing the relative catch of small scallops and flatfish, the catch of larger scallops is also impacted but to a lesser degree. Because maintenance of target catch is of primary concern for any gear modification, CFF researchers hypothesized that an apron using extended links only in the vertical direction could achieve the same conservation objectives while still maintaining catch of larger scallops. Preliminary testing of the vertical extended link apron indicates this hypothesis is valid, however, a more comprehensive understanding of the non-target species efficiency of the one-way extended link apron is needed for an accurate assessment of this modification’s impact on flatfish bycatch and mortality in the scallop fishery. The current project evaluates this by using a dredge cover net. Results from the project are providing greater insight about the impacts of implementing the one-way extended link apron.