5 years of plankton monitoring in Southampton Water and the Solent including FerryBox, Dock Monitor and discrete sample data

The Environment Agency (EA) has to make a eutrophication status assessment of the Solent and its harbours every four years. This requires a review of the frequency and magnitude of phytoplankton blooms. To assist with this process SOC has prepared this report to provide a "meta-data base" describing the relevant data sets collected by SOC between 1999 and 2003. It provides details of :- (1) methods used to collect the data (2) errors associated with the methods (3) calibration and quality control procedures used (4) changes in procedures (5) references to technical reports and theses containing detailed descriptions of the methods used. Changes in concentrations of chlorophyll in relation to concentrations of nutrients at SOC study sites in Southampton Water are plotted in graphs. The occurrence of bloom events and processes of bloom limitation are described. In particular observations of the variation of chlorophyll concentrations made using the FerryBox route between Town Quay Southampton and Cowes Isle of Wight are described and the development of the systems and associated problems are detailed. The information is presented as (i) graphs of the whole data set at all locations against time for each year (ii) 3D maps of the variation in concentrations with location and time (iii) time series for single locations along the FerryBox track

5 years of plankton monitoring in Southampton Water and the Solent including FerryBox, Dock Monitor and discrete sample data

The Environment Agency (EA) has to make a eutrophication status assessment of the Solent and its harbours every four years. This requires a review of the frequency and magnitude of phytoplankton blooms. To assist with this process SOC has prepared this report to provide a "meta-data base" describing the relevant data sets collected by SOC between 1999 and 2003. It provides details of :- (1) methods used to collect the data (2) errors associated with the methods (3) calibration and quality control procedures used (4) changes in procedures (5) references to technical reports and theses containing detailed descriptions of the methods used. Changes in concentrations of chlorophyll in relation to concentrations of nutrients at SOC study sites in Southampton Water are plotted in graphs. The occurrence of bloom events and processes of bloom limitation are described. In particular observations of the variation of chlorophyll concentrations made using the FerryBox route between Town Quay Southampton and Cowes Isle of Wight are described and the development of the systems and associated problems are detailed. The information is presented as (i) graphs of the whole data set at all locations against time for each year (ii) 3D maps of the variation in concentrations with location and time (iii) time series for single locations along the FerryBox track

Phytoplankton photosynthesis-irradiance parameters in the near-shore UK coastal waters of the North Sea: temporal variation and environmental control.

Chlorophyll-specific photosynthesis-irradiance (P-E) parameters of natural phytoplankton in the near-shore UK coastal waters of the North Sea were determined during six 2 wk surveys carried out from 1993 to 1995. The initial slope of the P-E curve (alpha (B)) varied from 0.02 to 2.44 mg C mg(-1) chl a d(-1) (pmol photons m(-2) s(-1))(-1) between winter 1993 and October 1994; the light-saturated rate of photosynthesis (P-max)(B) ranged from 8 mg C mg(-1) chl a d(-1) during winter surveys to 332 mg C mg(-1) chl a d(-1) during October 1994. Values of alpha (B) and P-max(B) determined during October 1994 were significantly higher than in other survey periods. Although phytoplankton cell biomass was significantly higher during the June 1995 survey (due to high abundance of Phaeocystis spp. at some sites) than in October or winter surveys, the October peak in P-E parameters coincided with a period in which dinoflagellates accounted for a high proportion of phytoplankton carbon biomass. Multiple linear regression analysis revealed that alpha (B) could be predicted from the total photosynthetically available radiation (PAR) incident at the surface during the daylight period, whilst P-max(B) could be predicted from a linear combination of total incident PAR and sea-surface temperature. Temporal variations of alpha (B) and P-max(B) did not result in significant temporal variation of the light-saturation onset parameter (E-k) and the overall mean value of E-k was 176 +/- 6 pmol photons m(-2) s(-1). The high turbidity of nearshore surface waters of the western North Sea appears to restrict penetration of irradiance to the extent that phytoplankton are not exposed to PAR levels at which photoadaptation of their photosynthetic apparatus is induced

Bacterial response to blooms dominated by diatoms and Emiliania huxleyi in nutrient-enriched Mesocosms

The bacterial response to two algal blooms dominated by the marine coccolithophoridEmiliania huxleyiand the marine diatomsSkeletonema costatumandLeptocylindricus danicusin nutrient-enriched mesocosms was observed. Bacterial abundance was determined using epifluorescent microscopy and bacterial activity using3H-thymidine and3H-leucine incorporation. There were significant differences in the bacterial response to the two blooms with the maxima in bacterial activity associated with theE. huxleyibloom occurring almost synchronously with the maxima inE. huxleyiabundance and the maxima in bacterial activity associated with the diatom bloom occurring about 1 week after the maxima in diatom abundance. It is suggested that this results from the greater tendency ofE. huxleyito release simple monomeric organic compounds compared toS. costatum. Levels of bacterial3H-leucine incorporation relative to bacterial3H-thymidine incorporation were significantly higher in the diatom dominated bloom compared to theE. huxleyidominated bloom. It is suggested that this is associated with the large scale exudation of complex polypeptides byS. costatum. In both enclosures bacterial3H-thymidine incorporation peaked rapidly relative to bacterial3H-leucine incorporation implying a bacterial demand for inorganic nitrogen at the peak of bacterial activity. Consequently, at the peak of theE. huxleyibloom algae may have been competing with bacteria for inorganic nitrogen, whereas during the diatom dominated bloom this competition probably did not occur until the diatom bloom had begun to subside. Following the collapse of both blooms the bacterial community regained its pre-bloom status as a small source of ammonium