Cruise inventory

RV Prince Madog PD23/05

Cruise summary report

Cruise Info. 
Ship name (ship code)RV Prince Madog (74P2)
Cruise identifierPD23/05
Cruise period2005-06-27 — 2005-06-30
StatusCompleted
Port of departureMenai Bridge, United Kingdom
Port of returnMenai Bridge, United Kingdom
PurposeResearch
ObjectivesThe main objective of the cruise was to obtain shells (including shells from live collected animals) of the clam Arctica islandica (Bivalvia) from various sites in the Irish Sea. Sites were selected on the basis of previous catches of live A.islandica or were determined in situ by assessment of sediment type and were dredged with a custom designed anchor dredge. At most sites a 2 metre beam trawl was also deployed to assess the benthos and at one of the sites a sediment sample was collected with a Day grab.

The A.islandica shells will be embedded in resin and sectioned and the internal growth increments in the hinge section and along the axis of maximum growth will be counted and measured in order to establish an absolute shell-based chronology for the Irish Sea for a period of up to 1000 years. Some of the dead collected shells will be radiocarbon dated in order to approximate their position in the chronology.

In addition a small piece of flesh of A.islandica was preserved in 100% alcohol for genetic analysis by Dr. John Taylor of the Natural History Museum.
Chief scientistChris A Richardson (University of Wales, Bangor School of Ocean Sciences)
Ocean/sea areas 
GeneralIrish Sea and St. George's Channel
SpecificRegion around 53 30'N 5 28.8W; east coast of Northern Ireland; area SW of Isle of Man
Track chartsRV Prince Madog PD23/05 cruise track — pd23_05trk.pdf (00 MB) 
Measurements 
Geology and geophysics 
DredgeQuantity: number of hauls = 8
Description: 7 "Arctica" dredges and 1 2 m beam trawl deployed and recovered on 28/06/05, Site B. Analysis of growth increments in shell of A.islandica.
DredgeQuantity: number of hauls = 9
Description: 8 "Arctica" dredges and 1 2 m beam trawl deployed and recovered on 27/06/05, Site A. Analysis of growth increments in shell of A.islandica.
DredgeQuantity: number of hauls = 7
Description: 6 "Arctica" dredges and 1 2 m beam trawl deployed and recovered on 28/06/05, Site C. Analysis of DNA of A.islandica.
DredgeQuantity: number of hauls = 13
Description: 13 "Arctica" dredges deployed and recovered on 29/06/05, Site D7. Analysis of growth increments in shell of A.islandica.
DredgeQuantity: number of hauls = 10
Description: 9 "Arctica" dredges and 1 day grab deployed and recovered on 29/06/05, Site D3. Analysis of growth increments in shell of A.islandica.
DredgeQuantity: number of hauls = 4
Description: 4 "Arctica" dredges deployed and recovered on 29/06/05, Site D2. Analysis of growth increments in shell of A.islandica.
DredgeQuantity: number of hauls = 1
Description: 1 "Arctica" dredge deployed and recovered on 29/06/05, Site D6. Analysis of growth increments in shell of A.islandica.
GrabQuantity: number of hauls = 10
Description: 9 "Arctica" dredges and 1 day grab deployed and recovered on 29/06/05, Site D3. Analysis of growth increments in shell of A.islandica.