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Metadata: 2021 Scallop Underwater TV Survey in the North Sea
Abstract:
King scallop (Pecten maximus) underwater TV (UWTV) survey carried out in the North Sea by RV Cefas Endeavour in 2021. A drop frame mounted camera was used to record high definition (HD) video and numerous still photo images of the seabed for 20 minute tows. Observations of scallops were recorded by trained staff. These data are used to estimate biomass in areas that are not fished by the fishing fleet, but support populations of scallops and which may contribute to recruitment in dredged areas. This complements data collected as part of the wider scallop stock assessment in the region. Each sampling station has associated positional and ancillary data (e.g. salinity and temperature).
Data holder:
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
| Other details | ||
| Internal code | Internally assigned metadata identifier | 10628 |
| Title | The title is used to provide a brief and precise description of the dataset such as 'Date', 'Originating organisation/programme', 'Location' and 'Type of survey'. All acronyms and abbreviations should be reproduced in full. | 2021 Scallop Underwater TV Survey in the North Sea |
| File Identifier | The File Identifier is a code, preferably a GUID, that is globally unique and remains with the same metadata record even if the record is edited or transferred between portals or tools. | CEFASbee5b8b1-dc62-431d-9581-82fb26a91418 |
| Resource Identifier | This is the code assigned by the data owner. | CEFAS21481 |
| Resource type | The resource type will likely be a dataset but could also be a series (collection of datasets with a common specification) or a service. | dataset |
| Start date | This describes the date the resource starts. This may only be the year if month and day are not known | 2021-05-14 |
| End date | This describes the date the resource ends. This may only be the year if month and day are not known | 2021-05-21 |
| Frequency of updates | This describes the frequency with which the resource is modified or updated i.e. a monitoring programme that samples once per year has a frequency that is described as 'annually'. | notPlanned |
| Abstract | The abstract provides a clear and brief statement of the content of the resource. | King scallop (Pecten maximus) underwater TV (UWTV) survey carried out in the North Sea by RV Cefas Endeavour in 2021. A drop frame mounted camera was used to record high definition (HD) video and numerous still photo images of the seabed for 20 minute tows. Observations of scallops were recorded by trained staff. These data are used to estimate biomass in areas that are not fished by the fishing fleet, but support populations of scallops and which may contribute to recruitment in dredged areas. This complements data collected as part of the wider scallop stock assessment in the region. Each sampling station has associated positional and ancillary data (e.g. salinity and temperature). |
| Lineage | Lineage includes the background information, history of the sources of data, data quality statements and methods. | The survey deployed the STR SEASPYDER, which is an acquisition system that allows uninterrupted recording of high definition (1920x1080 resolution at 25 frames per second) video footage along with high definition (18 megapixel) photography and interfacing telemetry data of depth, heading and altitude from the seabed. The stills camera is fitted with 18-megapixel digital single-lens reflex (SLR) camera that offers total control for all photographic parameters (focus, shutter speed and aperture) synchronised with a STR subsea strobe that provide the correct illumination to obtain the stills. The drop frame has attached six LED underwater lamps and two dot and two-line lasers used as size reference. Additionally, the drop frame has mounted a data logger that records temperature, pressure, and salinity. The data logger is plugged to a fluorometer and an optical dissolved oxygen sensor. Real-time data are transferred through a fibre optic cable mounted in a winch in the port side of the research vessel (RV) directly to the surface unit for visualisation in the ships main laboratory. This includes high definition (HD) video, photos, telemetry (depth, heading and altitude) and imaging sonar. The surface unit also has a software, used as interface for the control of a whole system, for adding an overlay to the footage. This overlay shows the ID for each station, transect and the telemetry data for their posterior analysis and visualization. Beds where scallop fishing takes place had already been defined for scallop dredge surveys. For underwater television (UWTV), survey area boundaries were defined as likely scallop ground (from habitat modelling), as well as areas considered by industry to contain scallop populations but cannot be fished due to unsuitable ground type, conservation management, or gear conflict issues. Once the un-dredged zones had been determined, random positions were selected. A random stratified sampling design was used. As it is not clear if scallop density is randomly distributed across the whole bed, it was considered important to ensure broad spatial coverage of the sampling design. Therefore, within each bed, blocks were used to represent the different strata. Broad spatial coverage is provided by ensuring that most blocks are sampled. Within each block, one valid cell was selected at random, the midpoint of which is a potential sampling position. The drop frame was towed at 0.4 knots, with a track duration of 20 minutes resulting in a distance covered of just under 250 m. An altimeter on the drop frame enabled it to be maintained at a relatively consistent depth of 0.5 m above the seabed. Field of view was determined by the view within the drop frame (~1.35 m), and determination of scale was facilitated by point lasers fitted to the camera mounts to mark a consistent distance on the seabed. The angle of the cameras to seabed was approximately 53°. Video images were viewed live on board the RV and all observed scallops counted. Digital stills were manually taken when scallops or indications of scallops were observed to provide more detailed images for subsequent count confirmation. Video footage was reviewed later by trained staff for additional verification and following a standard procedure. Median counts per transect were standardised to area. |
| Related keywords | ||
| Keyword | General subject area(s) associated with the resource, uses multiple controlled vocabularies | Biota abundance, biomass and diversity |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Underwater Photography | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Fauna abundance per unit area of the bed | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Shellfish abundance and biomass in water bodies | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Seabed photography | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Species distribution | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Benthic boundary | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | Marine Environmental Data and Information Network | |
| General subject area(s) associated with the resource, uses multiple controlled vocabularies | data.gov.uk | |
| Geographical coverage | ||
| North | The northern-most limit of the data resource in decimal degrees | 54.75 |
| East | The eastern-most limit of the data resource in decimal degrees | 3 |
| South | The southern-most limit of the data resource in decimal degrees | 53.25 |
| West | The western-most limit of the data resource in decimal degrees | -0.5 |
| Responsible organisations | ||
| Role | The point of contact is person or organisation with responsibility for the creation and maintenance of the metadata for the resource. | pointOfContact |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| data.manager@cefas.co.uk | ||
| Role | The originator is the person or organisation who created, collected or produced the resource. | originator |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| data.manager@cefas.co.uk | ||
| Role | The custodian is the person or organisation that accepts responsibility for the resource and ensures appropriate care and maintenance. If a dataset has been lodged with a Data Archive Centre for maintenance then this organisation is be entered here. | custodian |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| data.manager@cefas.co.uk | ||
| Role | The distributor is the person or organisation that distributes the resource. | distributor |
| Organisation name | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| Delivery point | Cefas Lowestoft Laboratory, Pakefield Road | |
| Postal code | NR33 0HT | |
| City | Lowestoft | |
| Administrative area | Suffolk | |
| Country | UK | |
| data.manager@cefas.co.uk | ||
| Role | The owner is the person or organisation that owns the resource. | owner |
| Organisation name | Department for Environment, Food and Rural Affairs (DEFRA) | |
| defra.helpline@defra.gov.uk | ||
| Resource locators | ||
| Locator URL | Web address (URL) that links to the resource | https://data.cefas.co.uk/view/21481 |
| Locator name | Name of the web resource | Cefas Data Portal |
| Dataset constraints | ||
| 20.1 Limitations on Public Access - Access constraints | This states `otherRestrictions` from ISO vocabulary RestrictionCode and is an INSPIRE/GEMINI requirement. | otherRestrictions |
| 20.2 Limitations on Public Access - Other constraints | noLimitations | |
| 21.1 Conditions for Access and Use - Use constraints | This states `otherRestrictions` from ISO vocabulary RestrictionCode and is an INSPIRE/GEMINI requirement. | otherRestrictions |
| 21.2 Conditions for Access and Use - Other constraints | https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ | |
| Version info | ||
| Date of publication | The publication date of the resource or if previously unpublished the date that the resource was made publicly available via the MEDIN network. | 2022-06-08 |
| Date of last revision | The most recent date that the resource was revised. | 2023-08-22 |
| Date of creation | The date that the resource was created. | 2022-05-30 |
| Harvest date | The date which this record has been (re)harvested from the provider. | 2026-04-19 |
| Metadata date | The date when the content of this metadata record was last updated. | 2023-08-22 |
| Metadata standard name | The name of the metadata standard used to create this metadata | MEDIN |
| Metadata standard version | The version of the MEDIN Discovery Metadata Standard used to create the metadata record | 3.1.1 |