RRS John Murray JM9/81 (B/3/81)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM9/81 (B/3/81)
Cruise period1981-07-15 — 1981-07-21
Port of departurePlymouth, United Kingdom
Port of returnPlymouth, United Kingdom
Objectives1) To study the relationships between light, chlorphyll, primary production and flourescence on a CPR route

2) To monitor the performance of the Bristol Channel to update the validation of ecosystem model GEMBASE

3) To carry out a double tow of a Continous Plankton Recorder at the same depth for at least 200 miles to compare their relative catching rates.
Chief scientistMichael B Jordan (Institute of Marine Environmental Research, Plymouth)
Cruise reportRRS John Murray JM9/81 (B/3/81) cruise report john_murray9_81.pdf (0.09 MB) 
Ocean/sea areas 
GeneralEnglish Channel
Irish Sea and St. George's Channel
Bay of Biscay
Track chartsRRS John Murray JM9/81 (B/3/81) cruise track — john_murray9_81track.pdf (0.04 MB) 
Physical oceanography 
Surface measurements underway (T,S)Description: cont.recording over 240nm approx.
Water bottle stationsQuantity: number of stations = 11
Description: surface only
CTD stationsQuantity: number of stations = 11
Transparency (eg transmissometer)Description: cont.recording over 240nm approx.
Optics (eg underwater light levels)Quantity: number of stations = 11
Chemical oceanography 
NitrateDescription: cont.recording over 240nm approx.
Suspended matterDescription: cont.recording over 240nm approx.
Biology and fisheries 
Primary productivityQuantity: number of stations = 8
Phytoplankton pigs (eg chlorophyll, fluorescence)Description: cont.recording over 240nm approx.
PhytoplanktonQuantity: number of samples = 66
Description: identification,distribution
Incident radiationDescription: cont.for 3d