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Daily folders (17) of Simrad (.ek5 format) acoustic data. 17 Echoview format (EV) format analysis files. CTD data for 12 vertical dips. Continual AGDS data. Paper biological data for 19 pelagic hauls and 2 rod and line deployments. Objectives 1. To conduct an acoustic survey to estimate the abundance and distribution of mackerel in the northern North Sea (ICES division IVa). 2. To obtain samples of mackerel for biological analysis, including age, length, weight, sex and maturity. 3. To conduct a towed O.P.C./C.T.D. survey of the Fladen area of the North sea during transit.
Scottish Government (Marine Scotland)
no limitations to public access
Other details | ||
Internal code | Internally assigned metadata identifier | 6197 |
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. | 1503S- North sea mackerel acoustic survey- scotia cruise 1503 |
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. | Marine_Scotland_FishDAC_1748 |
Resource Identifier | This is the code assigned by the data owner. | Marine_Scotland_FishDAC_1748 |
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 | 2003-10-04 |
End date | This describes the date the resource ends. This may only be the year if month and day are not known | 2003-10-22 |
Spatial resolution | This describes the spatial resolution of the dataset or the spatial limitations of the service. | 55000.00 |
Spatial resolution unit | This describes the unit of spatial resolution which for distance must be metres. | http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/uom/gmxUom.xml#m |
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'. | Not Planned |
Abstract | The abstract provides a clear and brief statement of the content of the resource. | Daily folders (17) of Simrad (.ek5 format) acoustic data. 17 Echoview format (EV) format analysis files. CTD data for 12 vertical dips. Continual AGDS data. Paper biological data for 19 pelagic hauls and 2 rod and line deployments. Objectives 1. To conduct an acoustic survey to estimate the abundance and distribution of mackerel in the northern North Sea (ICES division IVa). 2. To obtain samples of mackerel for biological analysis, including age, length, weight, sex and maturity. 3. To conduct a towed O.P.C./C.T.D. survey of the Fladen area of the North sea during transit. |
Lineage | Lineage includes the background information, history of the sources of data, data quality statements and methods. | Scientific staff joined the vessel at 09:00 on 4 October and the vessel departed at 10:15. A small meeting was held with all scientists to explain the objectives of the survey and to describe general operating procedures. The vessel proceeded to Scapa Flow where calibration of the four transducers was carried out starting at 00:05 on 5 October. The vessel then proceeded to the Fladen area of the North Sea, where a towed body, fitted with an OPC, CTD and plankton nets, was deployed to sample concentrations of copepods. The vessel then made passage through areas thought to contain mackerel (close to the 200 m contour) to confirm the location of high intensity strata for the survey. The first fishing trawl was carried out during this prospective passage route on 6 October. The survey commenced on 7 October at 02:15 at approximately 61°48'N 001°54'E. Transects progressed southward along lines of latitude, at spacings of 15 or 7.5 nautical miles (nmi) as planned; although transect design was altered slightly due to delays from gale force winds. The vessel docked into Lerwick harbour on 12 October for 24 hours to enable a change of personnel and to give staff their rest day in line -. with working time directives. The survey resumed at 06:05 on 13 October. On 17 October the vessel headed back into Lerwick to pick up a pump for the third engine to enable fishing with the larger (PT170) net. The opportunity was taken to carry out a second calibration of all four frequencies in Sandwick Bay. On 18 October, the vessel rendezvoused with the Norwegian FRV GO Sars as planned and the two ships carried out an interlaced survey in the area close to the 200 m contour: transect spacing for each vessel was 15 nmi giving a combined spacing of 7.5 nmi. At the end of this, the two vessels undertook an intercalibration exercise starting at 18:20 on 20 October. This lasted for approximately 3 hours (30 nmi) with each vessel taking the lead alternatively on two occasions. The intercalibration was completed at 21:40 and the vessels then broke off to continue their respectiye surveys. FRV Scotia completed its survey shortly afterwards at 23:25 on 20 October. The vessel returned to Aberdeen on the morning of 22 October. Results The survey was completed and, despite encountering some poor weather, only a small amount of time was lost due to weather. The total mileage surveyed was approximately 2450 nmi. A total of approximately 70 GB of acoustic data was archived and copied to DVD; this corresponds to 981 acoustic log intervals of 15 minutes duration. Successful calibrations were carried out of the four acoustic frequencies (18,38, 120 and 200 kHz): calibration accuracy of the principal integration frequency (38 kHz) was within 0.05 dB (ICES recommends accuracy to be within 0.5 dB). Echo traces from mackerel were distinguished on the basis of the difference in acoustic return between the 38 and 200 kHz frequencies, using the latest version of the FRS mackerel identification algorithm, which was displayed in real time (assisting the direction of ground truth trawl hauls). As expected, most of the mackerel were detected close to the border between EU and Norwegian waters, towards the east of the survey area around Viking Bank. Ground truth identification of the mackerel echotraces proved far more successful than in the previous (2002) survey: both the PT170 and PT160 (with the larger doors) were able to catch large quantities of mackerel. Of the 19 trawl hauls carried out, mackerel were caught in 15, giving a raised total of 16 569 kg. On two occasions, echo traces thought to be mackerel were fished on with rod and line for comparative purposes - these were logged as separate biological samples. 4732 mackerel were measured for length and 886 mackerel were sampled for weight, sex, maturity• and otoliths. Other fish caught include herring (3816 lengths measured from a raised total of 17 246 kg), saithe (118 lengths), haddock (31 lengths), silversides and a variety of small gadoids. No cod were caught. The deployment and recovery of the trawls passed, in most cases, without incident and no trawls were damaged. However, significant problems were encountered with deployment and recovery of the netsonde transducer: the cable was often damaged due to abrasion or parting from the transducer head. It is recommended that some action be taken to establish more robust procedures; perhaps in consultation with engineers from the Scottish pelagic fleet who operate an identical system on even larger trawls without such problems. Three tows of the multisampling towed body were successfully completed in the Fladen area. The towed body was fitted with an optical plankton counter, seabird CTD, pup nets and a Scanmar depth monitor. The tows were carried out to a depth of 130 metres at a speed of 5.5 knots. Plankton samples taken by the 200 µ and 95 µ pup ne |
Related keywords | ||
Keyword | 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 | Acoustics | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Biota composition | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Fish | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Water column temperature and salinity | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Acoustic backscatter in the water column | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Fish abundance in water bodies | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Fish biomass in water bodies | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Fish morphology, age and physiology | |
Geographical coverage | ||
North | The northern-most limit of the data resource in decimal degrees | 62 |
East | The eastern-most limit of the data resource in decimal degrees | 4 |
South | The southern-most limit of the data resource in decimal degrees | 58.5 |
West | The western-most limit of the data resource in decimal degrees | 1 |
Regional sea | 46F1 | |
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47F3 | ||
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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 | Scottish Government (Marine Scotland) | |
Phone | +44 (0)300 244 4000 | |
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 | Scottish Government (Marine Scotland) | |
Phone | +44 (0)300 244 4000 | |
Delivery point | Mailpoint 11, Area 1B South, Victoria Quay | |
Postal code | EH6 6QQ | |
City | Edinburgh | |
Country | United Kingdom | |
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 | Scottish Government (Marine Scotland) | |
Phone | +44 (0)300 244 4000 | |
Delivery point | Mailpoint 11, Area 1B South, Victoria Quay | |
Postal code | EH6 6QQ | |
City | Edinburgh | |
Country | United Kingdom | |
Role | The distributor is the person or organisation that distributes the resource. | distributor |
Organisation name | Scottish Government (Marine Scotland) | |
Phone | +44 (0)300 244 4000 | |
Delivery point | Mailpoint 11, Area 1B South, Victoria Quay | |
Postal code | EH6 6QQ | |
City | Edinburgh | |
Country | United Kingdom | |
Role | The originator is the person or organisation who created, collected or produced the resource. | originator |
Organisation name | Scottish Government (Marine Scotland) | |
Phone | +44 (0)300 244 4000 | |
Delivery point | Mailpoint 11, Area 1B South, Victoria Quay | |
Postal code | EH6 6QQ | |
City | Edinburgh | |
Country | United Kingdom | |
Resource locators | ||
Locator URL | Web address (URL) that links to the resource | https://www.bodc.ac.uk/data/information_and_inventories/cruise_inventory/search/ |
Locator function | Code that describes the function of the resource. ISO function code chosen from ISO 19115-1 Codelist | Reference info #0 |
Dataset constraints | ||
20 Limitations on Public Access - Access constraints | ISO restriction code chosen from ISO 19115-1 Codelist | otherRestrictions |
20 Limitations on Public Access – Other constraints | Any restriction on the use of the resource such as the need to agree to certain licence conditions. | no limitations to public access |
21 Conditions for Access and Use - Use limitation | Any restrictions imposed on accessing the resource such as the need to agree to certain licence conditions. | Open Government License (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. | 2016-05-06 |
Metadata date | The date when the content of this metadata record was last updated. | 2016-05-06 |
Metadata standard name | The name of the metadata standard used to create this metadata | MEDIN Discovery Metadata |
Metadata standard version | The version of the MEDIN Discovery Metadata Standard used to create the metadata record | Version 2.3.7 |
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