This dataset comprises measurements of microbial uptake activities of betaine and choline, particulate phase osmolytes, amplicon sequencing of marker genese involved in Nitrogenous-osmolyte catabolism, and single cell genome data. Water samples were collected from at the L4 station of the Western Channel Observatory between April 27, 2015 to April 24, 2017 using Niskin bottles attached to a rosette sampler deployed from the RV Plymouth Quest. Nitrogenous osmolytes (glycine betaine, choline and trimethylamine N-oxide are essential components for most organisms in the marine environment. They enable cells to exist in a salty environment, but also have several other proposed uses. The aim of the project is to understand the seasonal cycle of glycine betaine, trimethylamine N-oxide and choline at Station L4. The water samples were analysed for the microbial assimilation and dissimilation activities using 14C labelled betaine and choline, respectively. The data will be incorporated to the European Regional Seas Ecosystem Model (ERSEM) coupled with the hydrodynamic model General Ocean Turbulent Model (GOTM) to simulate the N-osmolyte cycling at the L4 station. The data were collected under the project Biogeochemical cycling of N-osmolytes in the surface ocean funded by NERC Discovery Science grants NE/M002233/1 (parent), NE/M003361/1 (child), NE/M002934/1 (child). The grants were led by Dr Yin Chen, Dr Ruth Airs, and Dr Wei Huang respectively.

The dataset comprises a diverse set of physical, chemical and biological data including: bacteria, carbon, chlorophyll, dissolved gases, light levels, nutrients, phytoplankton, productivity, respiration, salinity, temperature, trace elements and zooplankton. Measurements were gathered from the North Atlantic and Norwegian fjord waters between 1971 and 1998. The data arise from three sources: biological and hydrographic data collected between 1971 and 1975 at Ocean Weather Ship (OWS) India in the North Atlantic; conductivity-temperature-depth (CTD) casts, water samples, net samples and meteorological data from the four week Bergen Mesocosm experiment at Espegrend Marine Biological Field Station (Norway) in 1995; and the six week RRS Discovery cruise 221 to the North East Atlantic in 1996, where physical, chemical and biological data were collected. The data were collected using a variety of methods including: more than 500 CTD and SeaSoar profiles; nearly 1000 water bottle samples; over 600 net hauls; over 450 Secchi disk deployments; nearly 4000 multisizer samples; 23 production experiments; four drifting buoy tracks and 40 days of weather observations. The PRIME programme aimed to lay the basis for mathematical models to describe the role of plankton in biogeochemical fluxes within the oceans which have implications for climate regulation. The project was hosted by the School of Ocean Sciences, University of Wales, Bangor. Data management was undertaken by the British Oceanographic Data Centre and over 95% of the data collected are now assembled on a CD-ROM. The data are accompanied by an extensive users' guide (covering sampling protocol documentation), the structures used to store the data, and the data interrogation tools.