1996 - 2013, North Western Inshore Fisheries and Conservation Authority (NWIFCA) Mussel Surveys
The NWIFCA conducts mussel surveys across its district in order to inform the management of this fishery. Data is collected on the percentage cover of a bed in mussel and other habitat types. The relative proportion of different size classes of mussel is also recorded. Samples are often taken for production of length frequency tables. Mussel beds are usually surveyed irregularly, with an adaptive survey strategy focusing on those beds that are very important commercially or have specific issues around their management.
dataset
NWIFCA_MUS_ALL_QUAD
http://www.ne-ifca.gov.uk
eng
urn:ogc:def:crs:EPSG::4326
biota
revision
2008-01-06
revision
2009-11-16
-3.7147
-2.7698
54.9831
53.2512
creation
2009-06-18
Irish Sea
creation
2009-05-01
28E9
creation
1954-01-01
Irish Sea and St. George's Channel
revision
2010-01-01
benthic boundary layer
revision
2010-01-01
troposphere
1996-11-15
2013-10-08
publication
2013-12-04
revision
2013-10-08
irregular
Beds are surveyed using a series of survey points in a grid pattern of 50 m, loaded onto GPS. Beds must be mapped previously to a survey in order to create this grid. However, additional points can be added in the field. At each survey point a 0.5 m2 quadrat is placed randomly within 2 m of the point. Within this quadrat the percentage cover of the two must abundant mussel categories (below) is recorded. Other types of cover (e.g. mud, rock, algae etc.) are not recorded. Spat (SP) = 1 to 10mm, Seed (S) = 10 to 25mm, Small mature clean (SMC) = 25 to 45mm, Mature clean (MC) = 45mm + No barnacles, or only one or two, Mature, some barnacles (MSB) = 45mm + Majority of shell can be seen, Mature barnacled (MB) = 45mm + Most of shell covered in barnacles, and Old barnacled (OB) = 45mm + Almost none of shell can be seen. Samples of mussels found in quadrats are taken for analysis in the lab. These are measured using a digital calliper to the nearest .5 mm and a wet weight taken. Available outputs from these surveys vary. These include raw data, amalgamated data, GIS data, thematic maps and reports. For some surveys this methodology was not followed, instead sample were taken for analysis and a general inspection completed with comments recorded.
Data is freely available for research or commercial use providing that the originators are acknowledged in any publications produced. A charge may be applied to cover costs of compiling and sending data.
No restrictions to public access
North Western IFCA
Northwestern Inshore Fisheries and Conservation Authority
originator
North Western IFCA
Northwestern Inshore Fisheries and Conservation Authority
custodian
North Western IFCA
Northwestern Inshore Fisheries and Conservation Authority
pointOfContact
2017-09-21