PelagiCam: a novel underwater imaging system with computer vision for semi-automated monitoring of mobile marine fauna at offshore structures

  • Emma V. Sheehan
  • Danielle Bridger
  • Sarah J. Nancollas
  • Simon J. Pittman


Engineered structures in the open ocean are becoming more frequent with the expansion of the marine renewable energy industry and offshore marine aquaculture. Floating engineered structures function as artificial patch reefs providing novel and relatively stable habitat structure not otherwise available in the pelagic water column. The enhanced physical structure can increase local biodiversity and benefit fisheries yet can also facilitate the spread of invasive species. Clear evidence of any ecological consequences will inform the design and placement of structures to either minimise negative impacts or enhance ecosystem restoration. The development of rapid, cost-effective and reliable remote underwater monitoring methods is crucial to supporting evidence-based decision-making by planning authorities and developers when assessing environmental risks and benefits of offshore structures. A novel, un-baited midwater video system, PelagiCam, with motion-detection software (MotionMeerkat) for semi-automated monitoring of mobile marine fauna, was developed and tested on the UK’s largest offshore rope-cultured mussel farm in Lyme Bay, southwest England. PelagiCam recorded Atlantic horse mackerel (Trachurus trachurus), garfish (Belone belone) and two species of jellyfish (Chrysaora hysoscella and Rhizostoma pulmo) in open water close to the floating farm structure. The software successfully distinguished video frames where fishes were present versus absent. The PelagiCam system provides a cost-effective remote monitoring tool to streamline biological data acquisition in impact assessments of offshore floating structures. With the rise of sophisticated artificial intelligence for object recognition, the integration of computer vision techniques should receive more attention in marine ecology and has great potential to revolutionise marine biological monitoring.


Monitoring aquaculture motion detection video analysis pelagic mussel farm ecosystem function 



We would like to thank our engineering technician, Julian Seipp, at University of Plymouth for help in the construction of the PelagiCam units. We are grateful for technical support from Dr Luke Holmes, Richard Ticehurst, Dr Martin Canty and Lyme Bay fishermen Robert King and Kieran Perree for field assistance and funding and logistical support from Offshore Shellfish Ltd.


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Authors and Affiliations

  1. 1.School of Biological and Marine SciencesUniversity of PlymouthPlymouthUK
  2. 2.Department of Animal ScienceUniversity of CaliforniaDavisUSA

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