Pobie Bank Reef Still Imagery Analysis 0923S

Project Aims

JNCC wishes to commission a contract to undertake the analysis of seabed still imagery collected on the 0923S survey from a drop-frame camera. Seabed imagery will be analysed using the image annotation software BIIGLE. During 0923S imagery data was collected for both MPA monitoring, and ground truthing purposes.

The total number of sampled drop camera monitoring stations was 97 and the total number of images after filtering to ensure 40 good quality images per station is 3,880. Analysis of 10 groundtruthing stations with 383 images is to be included as a costed extra only, however the total cost including costed extras must not exceed the stated value of the contract.

More detailed metadata will be provided including information from logs and the survey report. Representative images from each station from the 0923S survey are shown in Annex C, and the successful contractor will be provided with access to the 2023 BIIGLE project, the annotated 2023 PBR video imagery and the 2020 PBR seabed imagery to aid with identification.

• Project Background

JNCC and Marine Directorate (MD) conducted a survey aboard MRV Scotia (0923S) in 2023 to gather evidence to monitor Pobie Bank Reef SAC (PBR) (Figure 1) and inform assessment of the extent and condition of the designated features of the site. This is the second monitoring survey in a repeat timeseries at PBR, three years after the first survey in 2020, and aims to generate comparable results to make long-term conclusions about the condition of the site.

PBR is located in the North Sea approximately 20 km east of the Shetland Islands. The site has an area of 966 km2 and a depth ranging of 70 m to 100 m. The designated features of PBR are listed in Table 1. More information on PBR can be found in the JNCC SIC https://jncc.gov.uk/our-work/pobie-bank-reef-mpa/.

The 0923S survey departed from Aberdeen on the 23rd July 2023 and returned to Aberdeen on the 4th August 2023. This survey forms the Time 1 (T1) repeat survey in the PBR timeseries, following on from T0 in 2020. The monitoring aims and objectives relating to seabed imagery are:

• Collect evidence to inform Type 1 (sentinel) monitoring of the physical and biological structure and function relating to Annex 1 Reef at Pobie Bank Reef SAC
• Collect evidence to inform the physical extent and distribution of the Annex 1 Reef within Pobie Bank Reef SAC
• Collect evidence to inform the physical extent and distribution of the Annex 1 Reef outside the proposed fisheries management measures in Pobie Bank Reef SAC

Imagery was collected with a drop-frame camera (DC) system, towed by the vessel at a target speed of 0.5 knots and a target altitude of 1 m.

The following instruments were mounted on the drop-frame camera

• Kongsberg OE 14-408 digital stills camera (10 MP) mounted in a planar (downwards facing) orientation
• High definition SubC 1 Alpha video camera in a planar orientation
• Four-point (green) laser-scaling with the bottom two set to 67 mm spacing
• Additionally: four SEALED lamps, Valeport CTD, Ultra-short Baseline (USBL) acoustic positioning beacon

During 0923S, 107 camera sampling stations were visited (Figure 1), including the monitoring and groundtruthing stations. In total, 3,880 still images (40 per station) from the 97 monitoring stations will be analysed. Analysis of the 10 groundtruthing stations is included as a costed extra only (see section 4.4).

All imagery will be made available for analysis via a BIIGLE project. Access to the imagery via the BIIGLE can be provided on request to aid in the tendering process (see contacts for technical information on page 1) and more detailed metadata will be provided to the successful contractor following contract award.

Figure 1: Locations of camera stations sampled at Pobie Bank Reef SAC during 0923S

The following will be supplied to the successful contractor

• Access to 2023 BIIGLE project with all stills and label trees.
• 2020 and 2023 PBR cruise reports (available online)
• MEDIN-compliant analysis proforma and still image EQA comparison spreadsheet
• Access to the 2020 PBR annotation catalogue and label tree in BIIGLE (for use as a reference collection)
• Access to the 2023 PBR video analysis folder in BIIGLE
• Project Objectives

JNCC wishes to commission a contract to undertake the analysis of seabed still imagery from the 0923S survey as set out in the sections below. The successful contractor will:

• Undertake the analysis as set out below and adhering to the NMBAQC Epibiota interpretation guidelines (Turner et al, 2016).
• Use BIIGLE to annotate still images as described below. Alternative image annotation software may be used subject to agreement with the project officer.
• Ensure that still image reference collections used in analysis outputs are identical to those used in the naming of the original media to enable future reconciliation between data and media. If identical naming is not possible, a suitable alternative should be sought with JNCC.
• Produce a final analysis report including, at a minimum, sections detailing the methodology, results , and details of all QA work undertaken with any remedial action deemed necessary. The report should be no longer than 15,000 words including all tables and appendices and be provided electronically via email as a Microsoft Word document and PDF.
• Provide substrate and taxonomic image reference collections for each substrate type and taxon identified from imagery.
• (Costed extra) Undertake the analysis as set out for the monitoring stations for an additional 383 still images from the 10 groundtruthing stations.
• (Costed extra) Create a subset of 100 still images annotated in a way suitable to act as training data for artificial intelligence model training as described below

Some information, where specified, may be recorded directly into the proformas provided. The majority will be recorded first into BIIGLE and then used to populate the proforma. No analysis additional to what is described in this document is required. Any deviation from this methodology should be approved in writing by the project officer.

4.1 Stills Processing

Stills should be analysed in BIIGLE using the label trees shown in Table 2. Annotations should be added to stills as either tier 1 or tier 2 labels depending on the label tree used. Optionally tier 1 labels may be added directly into the proforma instead of being applied to still images, where this is done it must be consistent (i.e. there should not be a mixture of BIIGLE annotations and proforma entries for JNCC image quality). More details on the still annotation types and how they should be applied are provided in Appendix A.

Substrate Tier 1

Stills will be analysed to extract the following information

• Each still will be assigned an Image quality using labels from two label trees. If a still image is given a score of zero (NMBAQC equivalent), no further analysis should be carried out for that image and the contractor should alert JNCC to replace the image with one of suitable quality:
• JNCC image quality, a summary of these labels is shown in Table 3.
• NMBAQC image quality, a summary of these scores is shown in Table 4 and described in more detail in section 3.1 of Turner et al (2016).
• Annotate each still using the Biota label tree. This tree is pre-populated with a list of taxa identified in 2020 and new species should be added. For each still image, taxa should be identified and quantified using the standardised approach detailed in Appendix B. Where a previously unidentified taxon is observed, the following approaches should be used:
• Solitary and/or erect epifaunal species present (to the lowest taxonomic level for which identification can be guaranteed) using counts (achieved by using the point annotation tool within BIIGLE).
• Colonial and/or encrusting epifaunal species present as far as possible (to the lowest taxonomic level for which identification can be guaranteed) using percentage cover (achieved by using the polygon, magic wand, magic SAM or brush tools within BIIGLE).
• Special cases, such as where a taxon is present in high densities (i.e. Ophiothrix fragilis, Caryophyllia smithii, faunal turf), may be recorded directly into the tier 1 spreadsheet as an estimate of count, or estimate of percentage cover to the nearest 0.5%. These cases are identified in Appendix B.
• Use laser points label tree to annotate lasers and calculate image area in BIIGLE. Analysts are not to use the automated laser detection tool in BIIGLE.
• Identify evidence of anthropogenic impacts on the seabed:
• Use the litter label tree to record the presence of litter using the categories listed in Annex 5.1 of the Joint Research Centres Guidance on Monitoring of Marine Litter in European Seas .
• Use the Anthropogenic label tree to annotate trawl marks or anthropogenic impacts other than litter. This will not be a complete label tree and new labels may need to be added to the label tree.
• Use the substrate label tree to record the substrate types present to the nearest 0.5 percent directly to the proforma
• 10 x 10 superimposed grids should be used to aid estimates of percentage cover
• Any comments from the analyst which are considered of importance can be recorded in the spreadsheet

A reference collection of representative images must be provided for each Biota label and Substrate identified.

Table 3. JNCC image quality categories

• Imagery quality level • Description
• Fauna • Most fauna can be identified (e.g. including smaller taxa such as brittlestars etc.)
• Conspicuous fauna • Large and conspicuous fauna can be identified (e.g. sponges, soft corals etc.)
• Substrate • The substrate type can be identified, but the fauna cannot (e.g. the water column is obscured / the camera is too high off the seabed)
• Zero • No visibility of the seabed, substrate cannot be reliably identified.

Table 4. Summary of N