Identification

Title

2015 - 2015 Centre for Environment, Fisheries & Aquaculture Science (Cefas) Fladen experimental fishing impact recovery data - Sediment profile imagery

Abstract

Biological (presence of infauna, tubes) and physical (apparent redox potential discontinuity (aRPD) layer, penetration depth, surface roughness) parameters measured, and a Benthic Habitat Quality Index assessment, from sediment profile images of the seabed with associated station information. The sediment profile images were acquired from a self-contained photographic system at sampling stations located within six experimental boxes (three treatments and three control) during a fishing impact recovery survey within the Fladen Grounds. Data were collected at three time points (before impact (time 0), immediately after impact (time 1) and 8 months after impact (time 2) during two research surveys on the RV Cefas Endeavour in April 2015 and November 2015.

Resource type

dataset

Resource locator

http://data.cefas.co.uk/#/View/19707/

function: order

Unique resource identifier

code

CEFASbecee742-66b5-4a4d-bbcc-cb4d62599359

codeSpace

http://www.cefas.co.uk/

Dataset language

eng

Spatial reference system

authority code

OGP

code identifying the spatial reference system

urn:ogc:def:crs:EPSG::4326

Classification of spatial data and services

Topic category

biota

Keywords

Keyword set

keyword value

Keyword set

keyword value

originating controlled vocabulary

title

SeaDataNet P021 parameter discovery vocabulary

reference date

date type

revision

effective date

2011-03-25

Keyword set

keyword value

originating controlled vocabulary

title

GEMET, version 1.0

reference date

date type

publication

effective date

2008-06-01

Keyword set

keyword value

originating controlled vocabulary

title

GEMET - INSPIRE themes, version 1.0

reference date

date type

publication

effective date

2008-06-01

Geographic location

West bounding longitude

0

East bounding longitude

0.5

North bounding latitude

58.25

South bounding latitude

58

Extent

Extent group

authority code

title

SeaVoX Vertical Co-ordinate Coverages

reference date

date type

revision

effective date

2010-05-18

code identifying the extent

Temporal reference

Temporal extent

Begin position

2015-04-18T23:00:00.000Z

End position

2015-12-03T00:00:00.000Z

Dataset reference date

date type

publication

effective date

2020-09-10

Frequency of update

notPlanned

Quality and validity

Lineage

The camera system is a self-contained photographic system used for collecting *in-situ* images of the sediment/water interface. The system comprises a Nikon D100 digital camera, 35 mm lens, water filled prism, a self- contained strobe light, adjustable penetration stops, adjustable fall rate, and a stainless-steel construction frame. The frame also possesses mud doors to facilitate the use of the camera in low shear-strength muds. The supporting frame lands on the seabed first, leaving the area directly under the prism undisturbed. As the winch wire is slackened, the prism cradle descends toward the seabed at a controlled rate, and as the wedge-shaped prism enters the muddy bottom, it is driven into the sediment by its weight. The piston ensures that the prism enters the bottom slowly and does not disturb the sediment - water interface. On impact with the seabed, a trigger activates a time delay on the camera shutter release and two photographs are taken. Once the images are acquired, tension on the winch wire raises the prism cradle to the up position, a wiper blade cleans off the face plate, the strobe is recharged and the system can be lowered for another image. The camera system was ‘hopped’ over the seabed providing a series of images along a transect (5 hops spaced 5 m apart resulting in 10 images per station) at a subset of three stations within each experimental box. From each of the three stations within the experimental boxes, five images (one from each hop) were analysed to determine penetration depth, surface roughness and aRPD, using the well-established semi-automated Java macro within *ImageJ* (Version 1.46r). Ten percent of the images were processed by two analysts to ensure quality. The average aRPD, penetration depth and surface roughness was then calculated for each station within an experimental box.

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply

Constraint set

Limitations on public access

Public data (Crown Copyright) - Open Government Licence Terms and Conditions apply

Responsible organisations

Responsible party

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

originator

Responsible party

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

custodian

Metadata on metadata

Metadata point of contact

contact position

Data Manager

organisation name

Centre for Environment, Fisheries & Aquaculture Science

full postal address

Cefas Lowestoft Laboratory

Pakefield Road

Lowestoft

NR33 0HT

UK

telephone number

+44 (0)1502 562244

email address

data.manager@cefas.co.uk

responsible party role

pointOfContact

Metadata date

2020-09-10T13:21:39

Metadata language

eng