Home Pontoon Offshore Estuary Geophysics References

Hello! Welcome to the Group 7 website documenting studies at Falmouth that occurred from the 24th June until the 4th July 2014. The aim of this field course was to create a comprehensive database on the biological, physical and chemical nature of the Fal estuary and the surrounding coastline, boosting knowledge and understanding of this fascinating area. Surveys were conducted at four locations; the King Harry Ferry crossing, offshore using RV Callista, within the estuary using RV Bill Conway and around the Manacles on the MTS Xplorer, all of which aimed to expand our knowledge of the area using a variety of methods. Here is our team of undergraduates:




























At the King Harry ferry crossing, a YSI multiprobe was deployed, and the change in temperature, salinity, pH, chlorophyll and dissolved oxygen was measured over a full tidal cycle. Water samples were taken to analyse the chlorophyll, and a current-meter was used to observe how the current changes during the ebb and flow of the tide. Click here for more info.


On the RV Callista, the aim of the investigation was to collect data to observe the Deep Chlorophyll Maximum (DCM), the thermocline and fronts. A CTD rosette with six Niskin bottles, and a fluorometer, was deployed at eight stations along the coastline between Falmouth harbour and just North of Lizard Point. At some of the sites, where a DCM could be seen on the ADCP output, a plankton net was also used to take a sample of the local phytoplankton and zooplankton species. Back in the laboratory, the water samples taken from the Niskin bottles were analysed for Nitrate, Phosphate, Silicon, chlorophyll and dissolved oxygen. Click here for more info.


On the estuary, measurements were taken at seven stations heading up the Fal Estuary. CTD measurements were taken, along with a continuous record from the thermosalinograph, plankton nets, ADCP transects and Niskin bottle samples. The water samples were analysed back in the laboratory for concentrations of silicate, nitrate, phosphate, dissolved oxygen and chlorophyll. The purpose of this investigation was to observe how the measured factors changed as the vessel moved from saline to fresher water. Click here for more info.


Geophysical habitat mapping was also done on board the MTS Xplorer in the Manacles area, between Nare and Porthkerris Point. Here, a tow-fish  was used to produce a side-scan habitat map of seven transects. A video of the benthic ecosystem and geology was also produced, allowing an insight into that habitat. A grab was then used to sample the infaunal populations of the areas sediment. Click here for more info.


Fal Estuary Background

The Fal is a sheltered Ria type estuary1, meaning that it was a river valley that was immersed in water during the last ice age. It reaches the sea in Falmouth, the third largest deep natural harbour in the world2, with some areas such as Carrick Roads going up to 34m deep, with no parts more than a mile wide4. The total shoreline of the Fal is 127km3, with a variety of habitats including mudflats and saltmarshes, providing a strong ecosystem with numerous rare species9.

The area has been a busy shipping zone for many years, with Falmouth being a port since the 14th century4, and Truro being a port since 1170, transporting granite, tin and coal5. Falmouth has been heavily used for human activities and this, combined with natural sediment deposition, and has caused many of the creeks and tributaries feeding the estuary to silt up3. However, as the industry in the area increases, the port area continually expands and threatens rich ecosystems8, threatening numerous rare species, for example, plans for dredging to allow larger ships access to the harbour; threatening maerl beds, a species of rare coral found in Cornwall11.

Threats to this diverse ecosystem are not new however. The Wheal Jane incident in 1992 produced cassiterite (the main ore mineral for tin) but also produced pyrite and arsenopyrite at 450m depths. When operational, water pumped out of the mine but in 1992 the pump was stopped, resulting in the release of approximately 50 million litres of acidic (pH 3.1) and metal loaded water into the Fal. It also contained cadmium and arsenic, damaging ecosystems around the area6,7. Conservation of this area is in place as SAC includes Fal Estuary, Helford and Carrick Roads10.





Jack Sims
Captain Jack



Emma Whettall
Data Diva



Joanna Miles
Web Wizard



Henry Norris
Tea Wench



Olivia Yarney
Speedy Scribe


Megan Masters
Contour King

Rianna Vlierboom
Poster Princess


Sam Holmes
Geophys God


Connor Dunbar
Part-time PSO

Disclaimer: The views expressed above are the opinion of the authors only and NOT that of University of Southampton or National Oceanography Centre, Southampton.


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Falmouth 2014
Group 7