RRS John Murray JM1/81 (B/1/81)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM1/81 (B/1/81)
Cruise period1981-01-26 — 1981-02-07
Port of departureBarry, United Kingdom
Port of returnBarry, United Kingdom
Objectives1) To continue the series of 5 cruises designed to quantify nutrient cycling processes in Carmarthen Bay, including;
A) Nutrient excretion rates of the zooplankton community.
B) Nurtient demand rates by the phytoplankton in-situ
C) Nutrient regeneration rates by the Benthos
D) Nitrification/dentrification process by bacteria
E) Nutrient advecation and diffusion from surrounding regions to Carmarthen Bay
Chief scientistPeter H Burkill (Institute of Marine Environmental Research, Plymouth)
Cruise reportRRS John Murray JM1/81 (B/1/81) cruise report john_murray1_81.pdf (0.17 MB) 
Ocean/sea areas 
GeneralIrish Sea and St. George's Channel
Track chartsRRS John Murray JM1/81 (B/1/81) cruise track — trk2532a.html RRS John Murray JM1/81 (B/1/81) cruise track — trk2532b.html RRS John Murray JM1/81 (B/1/81) cruise track — trk2532c.html RRS John Murray JM1/81 (B/1/81) cruise track — trk2532d.html
Physical oceanography 
Surface measurements underway (T,S)
Transparency (eg transmissometer)
Current metersQuantity: number of deployments = 1
Description: 14 days
Chemical oceanography 
Total - P
Suspended matter
Biology and fisheries 
Primary productivityQuantity: number of stations = 4
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of samples = 50
Description: additionally,cont.recording in the surface
Particulate organic matter (inc POC, PON)Quantity: number of stations = 30
Dissolved organic matter (inc DOC)Quantity: number of samples = 100
PhytoplanktonQuantity: number of stations = 30
ZooplanktonQuantity: number of stations = 30
Description: survey:energy trnasfers,biomass determination,distribution
SestonQuantity: number of stations = 30
NektonQuantity: number of samples = 60
Pelagic bacteria/micro-organismsQuantity: number of stations = 20
Other biological/fisheries measurementQuantity: number of stations = 30
Description: nutrient cycling
Geology and geophysics 
GrabQuantity: number of samples = 30
Description: physical analysis of sediments
Core - soft bottomQuantity: number of cores = 100
Description: chemical analysis
Data held at BODC 
Discrete samples 
46  General station with STD/bottles/additional instrumentsChlorophyll pigment concentrations in water bodies
Silicate concentration parameters in the water column
Salinity of the water column
Nitrate concentration parameters in the water column
Temperature of the water column
Nitrite concentration parameters in the water column
Phosphate concentration parameters in the water column
Phaeopigment concentrations in the water column