New Technologies for Environmental Impact Assessments in the Deep Sea

Identifying new technologies for the acquisition of baseline data in the deep sea in a minimally intrusive way

Water samples collected concurrently with image data for ground truthing

The Issue: Environmental Impact Assessments (EIAs) depend on our ability to determine whether variability in biological community compositions, organism abundances, distributions, sizes and reproductive status are within naturally-occurring levels or have occurred as the result of anthropogenic disturbances. For disturbances that are likely to cause local extinctions, such as some deep-sea mining scenarios, larval supply and their ability to recruit to and survive in the altered habitat will govern the recovery potential at any given site. The acquisition of such baseline data should ideally be done in a minimally intrusive fashion so as not to impact the environment as a result of such baseline surveys – as such, the identification and dissemination of new technologies for investigating the deep sea is critical. Furthermore, protocols for surveys, subsequent analysis and data sharing should be standardized to enable comparisons of datasets obtained at different sites, at different times and by different people.

The working group: This DOSI working group consisting of 40 members, aims to identify and disseminate technologies that would enable the above goals to be met.

Current Activities:

  • Standardisation: work continues of the development of an ISO standard for Marine environment impact assessment (MEIA) – performance specifications for in situ image-based surveys in deep seafloor environments.
  • New technologies:
    • Work continues on the development of software to bridge the gap between high quality video data collected in situ and currently available cloud-based image annotation tools, and on easily implementable protocols for meta-barcoding analyses of deep sea meiofauna. See Past Activities below for related fieldwork.
    • Work is ongoing to develop tools for the quantification of microplastics in sediments (see Publications below in Past Activities)
  • A sub-group of DOSI members, led by Dr Amy Baco from Florida State University, are working on: “A community consensus on designating Vulnerable Marine Ecosystems (VMEs) from imagery”. Under UNGA resolution 61/105, management of fisheries in areas beyond national jurisdiction requires identification of vulnerable marine ecosystems (VMEs). Criteria to designate a VME include uniqueness, functional significance, fragility, structural complexity, and certain life history traits. Currently the only quantitative way to assess VME locations is to use fisheries trawl bycatch data. Besides potentially destroying the VME in gathering these data and method caveats, the threshold for designating a VME from trawls varies among FAO regions. Imagery data from scientific surveys is a less destructive approach, however there currently is not a framework for designating VMEs from images. Thus, the goal of this project is to bring together a large international team to establish first pass consensus guidelines across regions for designating VMEs from images.

Past Activities (in reverse chronological order):


  • 11 March-22 April 2021, Environmental Impact Assessment cruise to Clarion-Clipperton Zone for Deep Green/The Metals Company to do world’s first EIA of midwater. Several new technologies developed through the work of DOSI’s Technology Working Group were employed. Lindsay took part remotely due to Covid19.
  • 12-25 December 2020 cruise on R/V Kaimei to test the following equipment:
    •   – RamaCam – A combined holographic camera and Raman spectrometer for measuring particle morphologies and constituents with a view to detecting, characterizing and quantifying suspended microplastic particles in the deep ocean’s midwaters.
    •   – a 3D shadowgraph camera system to produce image-based machine learning training sets of deep ocean plankton
  • 22-28 February 2020 cruise on the R/V Yokosuka (cruise YK20-E02) was carried out to further develop a science payload for submersible platforms of opportunity, incorporating an 8K video camera, two HD cameras, two NTSC cameras, a line laser, three pairs of LED stick lights, CTDs, altimeter, and compass. On board testing, further development and optimization of a video annotation system incorporating Aphia IDs for taxonomy was also done during this cruise.
  • May/June 2017: New technologies for surveying vent plumes and larval distributions around areas targeted for Deep Sea mining were tested during an expedition to the Okinawa Trough, Japan. A holographic camera capable of capturing nine holograms per second was deployed in combination with a re-engineered digital Continuous Plankton Recorder, in order to capture the fine-scale distributions of larvae around vents to help in efforts to model larval dispersal between sites and assess connectivity. These technologies were deployed on a towed camera array with an Autonomous Visual Plankton Recorder (VPR) and a prototype 4K VPR imaging the same water parcel.
  • Boreal summer 2016: An intercalibration experiment comparing the datasets collected with an Autonomous Visual Plankton Recorder (VPR), an Underwater Video Profiler (UVP) and a GoPro in a pressure housing with controlled lighting was carried out during the Hidden Ocean cruise to the Arctic Ocean


July 2021: The following were published as international standards by ISO committee (TC8/SC13), through a working group DL was a member of, and are expected to be used for environmental impact assessments for seabed mining.

ISO 23731: Long-term in-situ imaged-based surveys in deep-sea environments

This is a standard for procedures and settings for long-term in-situ camera observations with subsea instruments. This standard is applicable to both submersible probes and seabed-mounted instruments, and can also be applied to video observation methods using the platform like Japan’s domestically produced “Edokko Mark 1″* series. By standardizing the observation method, we were able to facilitate comparative studies with observation results from different locations. Available here.

ISO23732: General protocol for observation of meiofaunal community

This is a standard for efficient procedures to determine the abundance, morphology and community composition of small benthic organisms living in marine sediments. In conventional survey methods, individuals are sorted by hand while being observed under a microscope. This standard establishes a rapid and efficient survey procedure by combining sample preparation with FlowCam (particle image analyzer) and metagenomics. Available here.

  • A chapter on new techniques for standardization of Environmental Impact Assessments was published:
    • Furushima, Y., Yamakita, T., Miwa, T., Lindsay, D., Fukushima, T., Shirayama, Y. (2019) New Techniques for Standardization of Environmental Impact Assessment. in Environmental Issues of Deep-Sea Mining (ed. Sharma R), pages 275-313. ISBN: 978-3-030-12695-7, DOI:10.1007/978-3-030-12696-4_11
  • A review on estimating particle fluxes using optical instruments was also published. Such instruments and methodology are valuable tools for Environmental Impact Assessments (EIAs) in the deep sea, particularly with respect to sediment discharge in the midwater during mining operations:
    • Giering, S.L.C., Cavan, E.L., Basedow, S.L., Briggs, N., Burd, A.B., Darroch, L., Guidi, L., Irisson, J-O., Iversen, M.H., Kiko, R., Lindsay, D.J., Marcolin, C.R., McDonnell, A.MP., Möller, K.O., Passow, U., Trull, T. and Waite A.M. (2020) Sinking organic particles in the ocean – flux estimates from in situ optical devices. Frontiers in Marine Science 6: 834. doi: 10.3389/fmars.2019.00834
  • High-resolution holographic imaging has been combined with the chemical information available from Raman spectroscopy to create a sensing method that could one day be used to detect, identify and measure the distribution of particles found in the ocean in situ without any sample preparation or manipulation. The demonstrated approach, published in the journal Applied Optics, paves the way for long term, global scale analysis of marine particulates and microplastics using large networks of observation platforms, such as floats or gliders. The technique would also be invaluable for carrying out Environmental Impact Assessments (EIAs) in the deep sea, particularly with respect to sediment discharge in the midwater during mining operations:
    • Takahashi, T., Liu, Z., Thevar, T., Burns, N., Mahajan, S., Lindsay. D., Watson, J. and Thornton, B. (2020) Identification of microplastics in a large volume by integrated holography and Raman spectroscopy. Applied Optics 59(17): 5073-5078. doi: 10.1364/AO.393643
    • Read at here
  • Work has also been ongoing on developing tools for the quantification of microplastics in sediments.
    • Nakajima, R., Tsuchiya, M., Lindsay, D.J., Kitahashi, T., Fujikura, K., Fukushima, T. (2019) A new small device made of glass for separating microplastics from marine and freshwater sediments. PeerJ 10/2019; 7(19):e7915, DOI:10.7717/peerj.7915
    • Nakajima, R., Lindsay, D.J., Tsuchiya, M., Matsui, R., Kitahashi, T., Fujikura, K., Fukushima, T. (2019) A small, stainless-steel sieve optimized for laboratory beaker-based extraction of microplastics from environmental samples. MethodsX 07/2019; 6, DOI:10.1016/j.mex.2019.07.012
  • Publications on the dissemination of technologies for EIAs in the deep sea:
    • Lindsay DJ, Hidaka M, Watanabe HK, Yahagi T, Grossmann MM, Mori M, Yamamoto H. Baseline data on planktonic communities inside and outside submarine calderas: survey methods and preliminary results. 2019 KIOST International Symposium on Hydrothermal Ecosystem and Indian Ocean. Busan, Korea, 4 November 2019.
    • Lindsay DJ. State of the art in marine monitoring technologies: high-performance imaging surveys. France-Japan Workshop on Subsea Observatory in the South Pacific and its surrounding ocean: scientific frontiers and technical challenges, Noumea, New Caledonia, 19 September 2019. (Oral)


  • 7 July 2021, Japan-India Workshop including discussions on technology sharing for plastic pollution surveys from coast to deep ocean.
  • 3 March, 7 April, 14 May, 3 June, 9 July, Plankton image sorting online workshops
  • 17 February 2021, France-Japan workshop on Deep Sea Observatory for South Pacific to scope applicable technologies.
  • 22-24 February 2021, Saudi Arabia-Japan workshop including discussions on technology sharing for deep ocean surveys of the already warm Red Sea as a proxy for a warming global ocean.
  • 2nd EcoDeep Workshop, March 2017, Tokyo, Japan.
  • Identifying technologies needed for Midwater Exploration and surveys, including vent plume work, were discussed during a workshop at the Ocean Sciences meeting in Hawaii.
  • Technologies for imaged-based, environmentally friendly surveys were discussed during the Marine Imaging Workshop in Kiel, Germany in February 2017.
  • A first workshop aiming to identify and review current and emerging technologies relating to underwater image acquisition, real-time and post-cruise image annotation, data sharing and archiving was convened in November 2015 in JAMSTEC and was funded by JAMSTEC, the Schmidt Ocean Institute and the Australian Embassy in Tokyo. See DOSI New Technologies WG Marine Imaging Workshop Report – December 2015 for further detail.
  • Outcomes of the DOSI workshop were presented at the Marine Video Workshop, March 2016, Rhode Island, USA.