Sediment profile imagery - Surface shots
At each survey location during the HABMAP cruise, images of the
seabed were taken using an underwater camera mounted on a frame.
This folder shows a handful of these images from the different
sites visited. For a more detailed look at the characteristics of
each site, download ‘Station_summaries.zip’ from the downloads
All surface shot photos credited to Stiofán Creaven from
Site 5 Arklow.
Anemone (Urticina eques) and keelworms (pomatoceros triqueter) on cobbled ground.
Site 25 Caernarfon Bay.
Dead man’s fingers (Alcyonium digitatum) and a common brittle star (Ophiothrix fragilis), shell/pebble gravel & cobble on medium sand.
Site 35 Caernarfon Bay.
Dead man’s fingers (Alcyonium digitatum), common brittle stars (Ophiothrix fragilis) and horse mussel shells (Modiolus modiolus) on a sandy seabed.
Site 37 Caernarfon Bay.
Bryozoan species (pentapora) on a coarse shelly/gravelly sand substrate.
Site 39 Celtic Deep Transect.
Burrows and tracks (probably belonging to crab or lobster) on a mud/fine sand seabed.
Site 59 St George's Channel South Transect.
Sandy gravel seabed with shell fragments, and an old bivalve shell.
Sediment profile imagery – Profiles
Sediment profile imagery is an innovative technique to take
images of the top 25cm of the seabed using a specially designed
camera and prism which penetrates the seabed. The images show a
selection of seabed compositions taken from different survey sites
during the HABMAP cruise. For a more detailed look at the
characteristics of each site, download ‘Station_summaries.zip’ from
the downloads section.
Uniform fine sand substrate
22AII Caernarfon Bay.
Muddy fine sand substrate
Coarse sand with shell fragments
35A Caernarfon Bay.
Brittle stars (ophiuroidea spp) and Dead man’s fingers (Alcyonium digitatum) on a muddy sand substrate.
35B Caernarfon Bay.
Horse mussel (modiolus modiolus) shells on a muddy sand substrate.
35C Caernarfon Bay.
Horse mussels (modiolus modiolus), Brittle stars (ophiuroidea spp) and Dead man’s fingers (Alcyonium digitatum) on a medium sand – silty clay substrate.
37C Caernarfon Bay.
Bryozoan (Pentapora spp) on a coarse sand substrate.
41C Celtic Deep.
A mud and very fine sand seabed substrate
85A West of Anglesey.
A thin layer of medium sand overlying boulder clay with a hydroid turf.
Diagram showing the design of Aquafact’s sediment profile camera (www.aquafact.ie). A photo of the camera being deployed can be seen in the cruise images gallery.
Multibeam imagery – transects
This gallery shows the five areas of seabed which were surveyed
during the HABMAP research cruise.
Five areas of the southern Irish Sea were surveyed by multibeam echosounder as part of the HABMAP project.
Multibeam image of St George’s Channel North. This area is characterised by relict seabed features and sediment waves.
Multibeam image of St George’s Channel South. This is dominated by sediment waves. A straight crested ridge feature can also be seen in the west of the image.
Multibeam image of the Caernarfon Bay survey area. This includes sediment waves, horse mussel (Modiolus) beds and rocky outcrops.
Multibeam image of Celtic deep, one of the deepest areas of the Irish Sea. The area in the SW corner of the image is over 120m deep.
Multibeam image of Arklow. Sand waves and mega-ripples can be seen towards the south of the image.
Multibeam imagery – seabed features
This gallery shows a selection of interesting seabed features
which were observed in the multibeam echosounder data collected
during the HABMAP cruise. The Office of Coast Survey
has further information on how multibeam echosounder
Gravel ridges possibly colonised by epifauna.
Sand waves in the Arklow survey area.
Ripple-forming sand features in the Arklow area.
St George’s Channel North. Sediment waves and a straight crested ridge feature, approximately 460m wide and 15m high, showing scouring around the edges.
Straight crested ridge feature found in St George’s Channel South, approximately 570m wide and 17m high. Scouring around the edges is clearly visible.
The visible pock-marks on the seabed of Caernarfon Bay are exposures of gravelly sediment underneath a sandy veneer.
Horse mussel beds (modiolus modiolus) in Caernarfon Bay. These are clearly visible as patches of mottled ground between the sand waves in the centre of the image, and extending towards the northeast.
Clearly defined sand wave features in Caernarfon Bay.
Sand waves from the Celtic deep study area.
A ship wreck found in the Celtic Deep area. The wreck is approximately 100m in length and lies in water over 100m deep.