Technology

Stereo-Video

A while back Dr Caine Delacy used stereo-video to determine fish density, biomass, diversity and community structure along 1 500 km of the Western Australian coastline. The EAMT team will introduce this technology to the East African coastline, as we sample the coral reef ecosystem from Mozambique to Kenya.

Assessments of reef fish communities have historically been assessed mostly through fishing surveys, which cannot be used in sensitive areas, such as marine protected areas, or through the use of underwater visual census using SCUBA. However, visual census is hampered by the high errors associated with diver subjectivity and between-diver variability. Using this technique, the accuracy and precision of data collection rely entirely on the skill of the individual observer in identifying species, counting individuals and estimating the lengths of fish and the boundaries of the survey area. The use of stereo-video surveys to monitor reef fish communities can vastly reduce the errors that plague more traditional survey techniques.

 

Stereo-video benefits

 

Firstly, when using cameras in stereo, individual fish length can be measured to within 95% accuracy. Secondly, complementary to obtaining the length measurement, the position of the individual fish relative to the centre of the cameras is obtained, thus the boundaries of the agreed survey area can be adhered to (and any individuals outside this boundary do not impact on the data). Thirdly, the problem of species misidentification (particularly prevalent in novice observers) is eliminated, as the video footage is stored and can be analysed in the laboratory, where reference materials can be consulted.

 

Why?

 

Biological assessments aimed at detecting temporal change require baseline data on abundance, diversity and fish size structure, against which more recent data can be compared, to show trends. However, to date there has been no collection of baseline data spanning the length of the east African coral reef ecosystem, using a standardised methodology.In fact, data sets spanning such large expanses of reef ecosystem are rare in marine science and conservation.

 

· The data collected during the EAMT will thus be an invaluable resource, representing the first such baseline, using a standardized technology and sampling design throughout, against which future data can be compared.

 

· These data will allow us to comprehensively assess the status of the coral reef fish resources along Africa’s east coast, as well as the human impacts thereon.

 

· The resultant database will also provide a means to assess the performances and design of marine protected areas in the region, will be available for biogeographic studies, and will provide local and national governments with a tool for conservation planning at local and national scales.

 

· Data regarding the health of the fishes and the corals can also help us to understand the influence of climate change in this region

SeaGIS is the creator and developer of the software used  in the stereo-video technology and we are also using SeaGIS hardware

Bahari Explorer

Bahari Exploreris a low cost, open-source underwater robot capable of serious scientific research. We aim to disrupt the barrier for ocean adventurers and researchers to conduct and access critical scientific data on our marine environment

 

The Goal:

 

We believe that the hardcore scientific research can be enabled through low-cost ROV technology. This technology can and should be more easily accessible to ocean adventurers and researchers and will result in bridging the academic/real-world gap. We aim to remove this barrier with the Bahari Explorer.

 

 

Join the community and develop this with us:Bahari Explorer on GitHub

 

 

5 Year Vision

 

To develop the Bahari Explorer into a generation of multiple ROV’s working as a community, remotely gathering key scientific data, yet still affordable to users and explorers on the ground, where this technology is most needed.

  • Ability to house probes to recordenvironmental data (such as temperature, depth, conductivity etc) in amodular format
  • The ROV must be wireless, therebybeing remotely operated without a tether to the surface vessel, yet stillable to transfer video-imagery to surface
  • The ability for multiple ROVs towork in conjunction, as a network
  • The network of ROVs must have thecapabilities for 3D mapping, filming, recording ecological data
  • This can be a platform/model thatcan be scaled up to different scientific applications, as the scientificcommunity requires
  • The unit/technology must remainaffordable, cost-effective and easily developed, using accessiblematerials

Background:

 

Taking the open sourced OpenROV concept into a tool to scientifically explore our marine environment. The Bahari Explorer will take a number of steps forward in realising this concept by adapting the ROV for stereo-imagery (scientific methodology used by divers to access reef and reef fish community data). The ROV will require modifications with respect to power generation, motherboard operation and hydrodynamic design to achieve this task. The 1st generation Bahari Explorer will consist of a single unit able to access stereo-imagery data at depths beyond the safe diver operation limits. The Bahari Explorer will enable new scientific data to be collected in a low-cost contextualized manner, the ramifications of which are limitless!