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Metadata: CCTV development on Western Irish Sea nephrops vessels 2009/10 - Fisheries Science Partnership
Abstract:
To develop a cost effective method in monitoring the amount of cod by-catch within the Irish Sea Nephrops fishery by using CCTV.
Data holder:
Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS)
| Other details | ||
| Internal code | Internally assigned metadata identifier | 9828 |
| 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. | CCTV development on Western Irish Sea nephrops vessels 2009/10 - Fisheries Science Partnership |
| Alternative title | The purpose of alternative title is to record any additional names by which the dataset may be known. | FSP CCTV development on Western Irish Sea nephrops vessels |
| 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. | CEFAS6572f29a-8054-4226-8e27-29b966eb9108 |
| Resource Identifier | This is the code assigned by the data owner. | CEFAS2944 |
| 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 | 2009-09-09 |
| End date | This describes the date the resource ends. This may only be the year if month and day are not known | 2009-09-22 |
| 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. | To develop a cost effective method in monitoring the amount of cod by-catch within the Irish Sea Nephrops fishery by using CCTV. |
| Lineage | Lineage includes the background information, history of the sources of data, data quality statements and methods. | Methods The fishing vessel “Supreme” (CN180) was selected to participate in the trials through an open tender process. It is a 16.16 m (LOA) wooden-hulled prawn trawler powered by a 229 bhp Gardner engine. The fishing gear used during the trial consisted of a 22 fathom dual-purpose single-rig net with 70 mm codend, fished off 30 fathom bridles with 8 fathom rubber legs. The trawl doors were 6 foot Dunbar design. Survey design The first part of the trial consisted of a period of three sea-days, during which cameras were sited in the most appropriate positions available to monitor catches. It also allowed the observer the opportunity to become familiar with the recording equipment and the vessels catch-handling procedure. During this part of the trial, there was a requirement of the vessel’s crew to record details of total catch weight, along with numbers and estimated weights for any cod caught, whether retained or discarded. This information will be compared with data extracted from the video footage to evaluate the potential for video footage to be used to validate additional records completed by fishers. Based on the findings from Part 1 of the survey, the second leg (Part 2) trial was modified so that the only requirement for the crew of the vessel was that all cod be placed in baskets and/or processed (i.e. no cod was to be discarded directly from the pound). This was done to test how effective the CCTV equipment and footage would be at assessing the cod catch independent of any modified crew behaviour. Sorting and processing the catch The aim of the project was to evaluate whether or not the CCTV equipment was capable of accurately assessing the percentage of cod in relation to the total catch, independently of any modified catch handling. As such, the only condition placed on the crew was that no cod was to be discarded directly from the pound (as is common practice in many fisheries where fishers believe that returning the fish to the sea in a timely manner will increase the chances of the fish surviving). The observer was also given the opportunity to sort through baskets to identify and measure cod where present before rebasketing and processing by the crew as normal. CCTV monitoring equipment Several camera positions were trialled during the trips, as were a variety of lenses (ranging from 2.1 to 12 mm) on the cameras. The most suitable locations for cameras were determined through trial and error through Part 1 and the early stages of Part 2. Catch Assessment In order to fulfil the requirements of the project, an estimate of total catch per fishing event, along with estimates (by length) for all cod (Gadus morhua) were required. During the first few days of Part 1 of the trial, all baskets were weighed, and the values averaged to provide a nominal average basket weight of 19.68 kg. This value was used for the remainder of the Part 1 trials, along with all hauls conducted during part 2 trials. As mentioned above, Part 1 trials involved a modified catch-handling regime, whereby all cod caught were to be passed over a fixed measuring board mounted on the sorting table prior to further processing and/or discarding. Actual basket counts, along with length measurements and the fate of all cod caught were recorded for all tows conducted during the trip. Video-footage was subsequently analysed on land (Part 1 trials by 1 person, Part 2 by 2 persons). The data collected included an estimate of total bulk (basket count + any observed discarding direct from the pound), presence or absence of cod, the fate of the cod observed, and an estimate of individual fish lengths. The length data were subsequently converted to a weight estimate by means of the conversion factor W = aLb, where W is the fish weight (g), a = 0.010752, L is fish length (cm), and b = 3 (derived from data collected on AFBI trawl surveys of the Irish Sea up to2000). Where discrepancies in video analysis were identified (for Part 2 trials only), footage was reviewed again by both analysts in an attempt to resolve them. Summary Irish Sea CCTV camera trials were conducted during September 2009, in the Northern Irish Nephrops fishery out of Ardglass. An array of 3 standard definition cameras and associated hardware were installed on the Nephrops trawler MFV Supreme, fishing a dual-purpose 22 fathom single-rig net with 70mm cod end, co-owned by Leo McGirr and Simon Wills (skippered by Leo McGirr). The aim of the project was to evaluate how effective CCTV technology was in assessing the cod bycatch as a percentage of the total catch in this fishery. In particular, the intention was to find a way of enhancing the monitoring of a sector of the fleet potentially excluded from cod recovery measures by virtue of that sector accounting for <1.5% of cod in the total catch. Results from the first series of trials (9–11 September) showed that, where crew catch-handling was modified, accurate assessments of cod live weights and hence percentage cod in the total catch could be made by video analysis in a cost-effective manner. Conversely, the initial trials also highlighted problems with species recognition of fish <30 cm total length. A second series of trials conducted from 23 to 27 September focused on whether or not the CCTV equipment could accurately assess the cod bycatch independent of any modified catch handling. Results indicated that video analysis failed to identify 81% of cod catches (by number). This was due to the small size of the cod being caught (mainly 12–20 cm), the presence of morphologically similar species (whiting, blue whiting, poor cod, haddock and Norway pout) in the catches, and the manual sorting and discarding procedures used on board. The findings show that CCTV technology is perhaps not the most effective tool for monitoring small-mesh fisheries, such as the trawl fishery for Nephrops. The results do, however, support further investigation of the utility of CCTV technology in fisheries where larger fish are encountered (e.g. otter trawls using 120mm+ cod ends) or more selective fisheries (such as gillnetting or longlining), where gear (and by default, fish) retrieval is at a steady rate. |
| 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 | Crustacean | |
| 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 | Water column | |
| 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 | -2 |
| South | The southern-most limit of the data resource in decimal degrees | 52.5 |
| West | The western-most limit of the data resource in decimal degrees | -7 |
| 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 | Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) | |
| 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/2944 |
| 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 | http://www.nationalarchives.gov.uk/doc/open-government-licence/ | |
| 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. | 2016-11-14 |
| Date of last revision | The most recent date that the resource was revised. | 2020-01-03 |
| Date of creation | The date that the resource was created. | 2013-10-23 |
| 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. | 2020-01-03 |
| 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 |