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Falmouth 2017 - Group 12 7TITLE

Results

Discussion

Winnie the Pooh background information & aims

The YSI multiprobe was used to determine the salinity of the surface water. This, in turn was used to determine the sampling sites. Once the sampling site had been established a Niskin bottle was deployed into the water by hand and it was triggered 1 ft (0.3 M) beneath the surface. This water was then used to test the temperature and salinity using the multiprobe, following this water was taken to determine the concentrations of phosphate, nitrate, silicate and chlorophyll. A plankton net (50 cm in diameter and had a mesh size of 200 µm) was used to collect zooplankton in the surface waters. The plankton net had a bottle at the end that was filled up with seawater containing the plankton. Once the sample had been collected, the location, time and date were recorded on the bottle.

The aim of the work on Winnie the Pooh is to gather samples from further up the estuary, where there is a lower salinity. This will form a more complete dataset when looking at how biological and physical parameters change with distance down the estuary. The biological parameters that we measured were the species and numbers of phytoplankton and zooplankton and chlorophyll concentration. The physical parameters that were recorded were the temperature, salinity and concentrations of phosphate, nitrate and silicate.

It was expected that further up the estuary the salinity would be a lot lower and that because of this the concentrations of nutrients, such as silicate and phosphate, would be much higher than the concentration of phosphate and silicate further down the estuary and out to sea. This would be because of the weathering of the granite bedrock, so it would be more concentrated further up the estuary.

Group 12 collected data on the Winnie the Pooh in the morning of 07/07/2017 starting at 09:00 UTC and low tide was at 10:27 UTC. Therefore the data was collected on the ebb tide. The temperature remained around 19 °C and there was no cloud cover.