Across Wales Drop-Down Video Monitoring: North Llyn Ground Truthing (2011)

A drop-down video survey carried out in North Wales. This work was carried out by former Countryside Council for Wales (CCW) and focused on the North Llyn area. Subsequent analysis of the video taken was undertaken by Marine Ecological Solutions Ltd on behalf of CCW. This work was conducted as part of a ground truthing exercise through which the extent and quality of Modiolus mussel beds could be assessed.

Identifier: NRW_DS114499

Alternative Title

2011 DRAFT CCW Towed Survey of North Llyn Modiolus (Additional Area) MRCCW31700000005
2011 CCW Towed Survey of North Llyn Modiolus (Additional Area).
Gwaith monitro cwymp-gamerau fideo ar draws Cymru 2011: Gwirio Gogledd Llyn

Metadata Language: English

Lineage: Drop-down video is useful for gathering large volumes of data across wide areas of seabed and often to depths beyond which diver observations can be safely made. Amendments to the previous methods include the addition of a HD video camera system manufactured by C-Technics in place of the SD camera previously used. A Cannon EOS 400D digital SLR was also used in a housing manufactured by Rovtech systems. Photographic stills were taken every 11 seconds along the tows to assist with species and habitat validation. Following methodological and equipment trial (Sanderson et al, 2001; Southeran et al, 2004) drop-down video survey methods were employed extensively in Welsh Special Areas of Conservation (SACs) in 2004 and 2005 (Axelsson et al, 2006). The 2004 survey work focused on Cardigan Bay SAC, while the 2005 survey work focused on Pen Llyn a'r Sarnau, Menai Strait and Conwy Bay, Cardigan Bay and Pembrokeshire Marine. Between 2007 and 2010 work focused on the Pen Llyn a'r Sarnau Modiolus reef. Additional work was carried out in Milford Haven (Crepidula and Seagrass beds) and St Bride's Bay to look at possible anchor damage. In 2011 DDV was also carried out around Puffin Island in Anglesey.

Additional Information: Detailed methods and site locations are described in CCW Marine Monitoring report 24a.

Dataset Reference Date (Publication): 2011-06-10

Temporal Extent

Begin date: 2011-06-09

End date: 2011-06-10

Topic category

Oceans
Biota

Owner

Natural Resources Wales (NRW)

Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://naturalresources.wales/?lang=en

Originator

Countryside Council for Wales (CCW). Marine and Freshwater Ecosystems Group

Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://www.ccw.gov.uk

Originator

Marine Ecological Solutions Ltd

Marine Ecological Solutions Ltd, 41 High Street, Menai Bridge, Ynys Mon, LL59 5EF, Wales

http://www.marine-ecosol.co.uk

Extent

Geographic Extent: Wales (WLS)

Vertical Extent

Medin Extent Keyword: benthic boundary layer

Vertical Extent

Minimum value (metres): 13

Maximum value (metres): 25

Vertical CRS: urn:ogc:def:datum:EPSG::5100 Sea Level depth is unadjusted and does not take into account tidal height

Format Type and Description

Documents Documents ()

Specification

[A] Recorded directly onto hard drive as .asf files. [B] Still images in jpg format. [C] Site details and video metadata data in excel spreadsheets. [D] A subset of the videos analysed and habitat and species data entered into Marine Recorder [MRCCW31700000005]

Data quality

Quality Scope: Dataset

Conformity: Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Explanation
Degree: false

Lineage: Drop-down video is useful for gathering large volumes of data across wide areas of seabed and often to depths beyond which diver observations can be safely made. Amendments to the previous methods include the addition of a HD video camera system manufactured by C-Technics in place of the SD camera previously used. A Cannon EOS 400D digital SLR was also used in a housing manufactured by Rovtech systems. Photographic stills were taken every 11 seconds along the tows to assist with species and habitat validation. Following methodological and equipment trial (Sanderson et al, 2001; Southeran et al, 2004) drop-down video survey methods were employed extensively in Welsh Special Areas of Conservation (SACs) in 2004 and 2005 (Axelsson et al, 2006). The 2004 survey work focused on Cardigan Bay SAC, while the 2005 survey work focused on Pen Llyn a'r Sarnau, Menai Strait and Conwy Bay, Cardigan Bay and Pembrokeshire Marine. Between 2007 and 2010 work focused on the Pen Llyn a'r Sarnau Modiolus reef. Additional work was carried out in Milford Haven (Crepidula and Seagrass beds) and St Bride's Bay to look at possible anchor damage. In 2011 DDV was also carried out around Puffin Island in Anglesey.

Keywords

GEMET - INSPIRE themes, version 1.0

Habitats and biotopes

Type: Theme

Citation

Date (Publication): 2008-06-01

Code: geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Keywords

NRW Thesaurus

Video survey
benthic marine habitats
drop-down video
towed video

Type: Theme

Citation

Date (Publication): 2023-12-31

Code: geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

SeaDataNet Parameter Discovery Vocabulary

Habitat characterisation

Type: Theme

Citation

Date (Revision): 2021-01-06

Code: geonetwork.thesaurus.external.theme.rdf+xml

Code: Latitude and Longitude (EPSG::4326)

Content Information

NRW Profile

Custom Elements

Constraints

Limitations on Public Access and Use

Restriction type: Other restrictions

Access Constraints Directive

Limitations: no limitations

Access Constraints Text

Other constraints: Part of this dataset is sensitive and restricted. The sensitive data is as follows Ostrea edulis, Palinurus elephas. Sensitive data must be kept confidential; general release is not permitted due to risk of harm to the environment or third parties. Sensitive data may only be released under an appropriate NRW Licence. Requests should be referred to NRW's Access to Information Officer. Data may be released freely if the sensitive records are removed in advance, or shown only at a coarser scale.

Use Constraints

Use constraints type: Other restrictions

Other constraints: © CNC/NRW 2011. Recipients may only re-use sensitive data in strict confidence under the terms of an appropriate NRW Licence. No publication or dissemination is permitted, except if sensitive records are removed in advance, or shown only at a coarser scale. wn only at a coarser scale.

Metadata

File Identifier: 4f4c4942-4343-5764-6473-313134343939 XML

Metadata Language: English

Parent Identifier: Natural Resources Wales (NRW) Marine Benthic Species and Habitat Collation Held in Marine Recorder
NRW_DS114501

Resource type: Dataset

Metadata Date: 2024-05-31T09:31:45.923Z

Metadata Standard Name: NRW

Metadata Standard Version: 1.0

pointOfContact

Natural Resources Wales (NRW)

Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://naturalresources.wales/?lang=en

Publishing Body

Access the portal

Full access to the portal and metadata.

Across Wales Drop-Down Video Monitoring: North Llyn Ground Truthing (2011)

Identification

Temporal Extent

Extent

Extent

Vertical Extent

Vertical Extent

Distribution

Quality

Data quality

Keywords

Keywords

Citation

Keywords

Citation

Keywords

Citation

Spatial Reference System

Content

Content Information

NRW Profile

Custom Elements

Constraints

Constraints

Limitations on Public Access and Use

Access Constraints Directive

Access Constraints Text

Use Constraints

Metadata

Metadata

Publishing Body