Falmouth: Group 2

Falmouth, 2014

Adam Lawrence
     Bsc Oceanography
     2014 Graduate

Aubrey Hetzler
    Animal Science & Oceanography
    From Penn State, USA

Aurelia Pereira Gabellini
    Bsc Oceanography
    From the University of São Paulo (USP),
         Brazil

Catherine Young
    Msci Oceanography
    Going to the University of Washington, USA

Emma Lofthouse
    Msci Oceanography
    Going to the University of Miami, USA

Laila Ecard
    Bsc Oceanography
    From the Federal University of Bahia, Brazil

Luke Storrie
    Msci Marine Biology
    Going to the University Centre in Svalbard
         (UNIS), Norway

Maisy Fuller
    Msci Marine Biology
    Going to the University of Western
          Australia, Australia

Ophelie Humphrey
    Msci Marine Biology
    Going to the University of Sydney, Australia

Vinicius Laghi
    Bsc Biological Science
    From the Universidade Federal de Santa
         Catarina, Brazil

Wladimir Fae Neto
    Bsc Oceanography
    From the Universidade Federal do Rio
         Grande, Brazil

Zoe Holbrook
    Msci Marine Biology
    Going to the University of Gothenburg,
         Sweden

Aim of Study

Through the collection of data including physical, chemical and biological parameters of the estuary, we hope to analyse this information to gain a better understanding of the Fal estuary and the surrounding coastal areas. Examples of topics for consideration include i) the controls on nutrient distribution, ii) the controls on plankton growth, iii) coastal dynamics and benthic habitat mapping, iv) time series of water column structures and v) stability and mixing in estuaries and coastal seas.

Background and Characteristics of the Fal Estuary

This page looks at:

• The characteristics of the Fal Estuary
• Special area of conservation
• The history of pollution events

Characteristics of the Fal Estuary

Special Area of Conservation

The Fal estuary in South Cornwall (the worlds third largest natural harbour), is comprised of a number of tidal creeks that feed into a central body of water, known as Carrick Roads (Williams et al., 1998 , Burlinson & Lawrence, 2007). It is an example of a ria; a drowned river valley, formed through a combination of tectonic subsidence and sea level rise. Rias have a low freshwater input, and the area therefore contains a diversity of marine habitats, including a range of species typically found in the South West (Natural England, n.d.). The estuary is macrotidal with a maximum spring tide of 5.3m at Falmouth, but is mesotidal at Truro with a spring tide of 3.5m. At the time of data sampling we were on a neap tide.

In England, European Marine Sites (EMS) are sites designated as Special Areas of Conservation (SAC) under the Habitats Directive. SACs are areas supporting rare, endangered or threatened species and important habitats. (Sites & Area, n.d.)

The Fal & Helford has been selected as a SAC for the following features (Natural England, n.d.):

• Saltmarsh e.g. top of Fal & Ruan Creeks at Ruan Lanihorne.
• Intertidal mudflats e.g. upper reaches of Polwheveral and Frenchman's Creeks.
• Subtidal sandbanks e.g. maerl beds in the Fal Estuary, particularly the live bed on St. Mawes Bank.
• Large shallow inlets and bays e.g. the whole bay from Manacle Point to Zone Point, within this area are habitats such as reefs and rocky shores.
• Estuaries e.g. the Fal Estuary and the Helford Estuary.
• Reefs e.g. St Anthony‟s Head and inshore around Manacle Point.

Due to extensive mining in the Fal estuay catchment area, heavy metal concentrations in the intertidal sediments are the highest in Britain (Warwick, 2001). In 1991, the last tin mine in the Carnon Valley (Wheal Jane) closed and the mine workings and Tailings Dam filled with acidic metalliferous water. A plug in the Nangiles adit gave way in January 1992 causing a massive discharge of this water, via the Carnon river and into Restronguet Creek and Carrick Roads (Somerfield et al., 1994). Over the centuries a marked gradient of metal concentrations has built up in sediments. In otherwise similar creeks (located in different parts of the estuary) have shown levels of heavy metals (including Cu, Zn, As, Cd, Fe) which differ by orders of magnitude (Somerfield et al., 1994).

In the more enclosed areas of the upper Fal Estuary chronic contamination and nutrient-associated water quality problems have resulted in toxic algal blooms. The most recent incidence, in 2002, also affected the Helford Estuary resulting in invertebrate mortalities (Sites & Area, n.d.).

On Friday 16th May 2014, the Food Standards Agency (FSA) downgraded the quality of the water at Ruan Creek and King Harry Ferry (Pontoon site) to a level C from a level B, due to the high concentrations of E.coli in the water (The Telegraph, 2014). Following the downgrading, a ban on mussel harvesting in the last two ‘clean’ sites on the River Fal (West Briton, 2014) was introduced; as consuming the mussels may cause a risk to human health. Oysters are also likely to be threatened in the future as they are based in the same waterways but take up the bacteria less quickly.

History of Pollution Events

References

Burlinson, F. C., & Lawrence, a J. (2007). A comparison of acute and chronic toxicity tests used to examine the temporal stability of a gradient in copper tolerance of Hediste diversicolor from the Fal estuary, Cornwall, UK. Marine Pollution Bulletin, 54(1), 66–71. doi:10.1016/j.marpolbul.2006.08.047

Natural England, n.d. Fal & Helford SAC Management Scheme. [Online]
Available at: http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCIQFjAA&url=http%3A%2F%2Fpublicatio ns.naturalengland.org.uk%2Ffile%2F3118614&ei=KMywU__yOsSSOOfPgTA&usg=AFQjCNEKDsokDXsFF6QqQbmX_-2vAKdR3Q&bvm=bv.69837884,d.ZWU
[Accessed 30 June 2014].

Natural England, n.d. www.sssi.naturalengland.org.uk. [Online]
Available at: http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCUQFjAA&url=http%3A%2F%2Fwww.sssi .naturalengland.org.uk%2Fcitation%2Fcitation_photo%2F2000174.pdf&ei=zdCwU-yYHoL2O_7dgMAB&usg=AFQjCNGRvxgyAY9bs1GljSNCOboBzmShdQ&bvm=bv.69837884,d.ZWU
[Accessed 30 June 2014].

Sites, E. M., & Area, S. (n.d.). The Fal and Helford, (8).

Somerfield, P. J., Gee, J. M., & Warwick, R. M. (1994). Soft sediment meiofaunal community structure in relation to a long-term heavy metal gradient in the Fai estuary system.

Somerfield, P. J., Michael Gee, J., & Warwick, R. M. (1994). Benthic community structure in relation to an instantaneous discharge of waste water from a tin mine. Marine Pollution Bulletin, 28(6), 363–369. doi:10.1016/0025-326X(94)90273-9

The Telegraph, 2014. The Telegraph. [Online]
Available at: http://www.telegraph.co.uk/earth/environment/10844357/Mussels-and-oysters-under-threat-from-pollution.html
[Accessed 30 June 2014].

Warwick, R. . (2001). Evidence for the Effects of Metal Contamination on the Intertidal Macrobenthic Assemblages of the Fal Estuary. Marine Pollution Bulletin, 42(2), 145–148. doi:10.1016/S0025-326X(00)00120-X

West Briton, 2014. West Briton. [Online]
Available at: http://www.westbriton.co.uk/Fal-River-mussel-pollution-crisis/story-21094285-detail/story.html
[Accessed 30 June 2014].

Williams, P. R., Attrill, M. J., & Nimmo, M. (1998). Heavy metal concentrations and bioaccumulation within the Fal Estuary, UK: A reappraisal. Marine Pollution Bulletin, 36(8), 643–645. doi:10.1016/S0025-326X(98)00044-7