Jessica Lytle University of Sussex

Survey of Pre-Season Bathing Quality on Cumbrae’s Beaches

SummaryWhether a beach fails guidelines or

not depends on where a specific sample is taken, the time at which the sample is taken and a number of other external vari-ables. This is due to each specific test site having extra environmental factors such as the positioning of sewage and freshwater outfall, weather, and tides that can affect results. Therefore results can be predicted and pre-meditated based on where sam-ples are taken from.

ObjectivesThe aims of this survey are to ascer-

tain whether the designated bathing beaches of Kames Bay and Newton Bay meet the criteria of EC Bathing Directives (2006/7/EC) for safe levels of Intestinal En-terococci and E.Coli as fecal coliforms. This survey also aims to take a general look at the bathing water quality on other beaches of the Isle of Cumbrae (for locations and identification of these beaches see Fig.1)In-troduction

It has long been the assumption that any waste deposited into the oceans of the world is automatically ‘taken care of’. In the ‘Tragedy of the Commons’ the ocean is a no-man’s land of waste, with no responsibility of ownership except when our effluent and its repercussions begin to interfere with our coastlines and settlements. This ejected waste of-ten also includes sewage and agricultural run-off (Jones, 2002). Potential problems from this pollution include possible eutrophication, general aesthetic problems in an area that depends on tourism (Hannah, 2011b), and more importantly bacterial risk to human health. This risk lies in the pathogens that can be present in human faeces, for example cholera, typhoid, and hepatitis. Monitoring the amount of waste in an area where potential health and environmental problems may arise would therefore be beneficial.

Escherichia coli (E.Coli) is a member of the family Enterobacteriaceae and has its habitat mainly in the intestine of humans and warm-blooded animals such as livestock and sea birds, where it survives as essential intestinal fauna (Feng, Weagent et al, 2002) which facilitates our synthesis of Vitamin K and sodium (Broga, 1991). It therefore is closely associated with sewage as we pass large amounts of it in our faeces, i.e.1010 E.-Coli in 1g of faeces (Jones and Smith, 2004).

In 1892 Shardinger began to use E.Coli as an indicator of fecal contamination by more dangerous pathogenic bacteria (e.g. Cholera, typhoid fever and hepatitis), as al-though it is abundant in animal/human faeces it is not so well associated with other niches (Feng, Weagent et al, 2002). It can also be easily, quickly (and cost-effectively) detected

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Fig.1

Fig.1. Aerial photograph of the Isle of Cumbrae with bays that contain bathing beaches in yellow and designated(Newton)/most used bathing beaches in red and white.

Cosy Corner

Sewage outfall

Jessica Lytle University of Sussex

by processes whereby it ferments lactose into glucose and is easier to isolate than other species of Enterobacteriaceae that are also associated with the presence of ‘recently passed’ faeces (coliforms)(Jones and Smith, 2004). A result for a sample test of E.Coli can be achieved in less than 72 hours (Hannah, 2011a).

EC Directives have been put into place, such as the Bathing Water Directives (and the Municipal Waste Water Directive (1991)) to provide guidelines to help protect human and ecological populations where excess faecal sewage effluent could cause harmful and undesirable problems, e.g. the risk of human infection by bacterial and viral pathogens. The Bathing Water Directive (76/160/EEC) currently test for the density of fecal indicators (FI) with a top threshold of 10,000 total coliforms (TC)/100ml and 2000 fecal coliforms (FC)/100ml (Jones, 2002) (Fig.2).

The Scottish Environment Agency takes 20 samples on the designated bathing beach of Newton Bay during the recognised bathing season (15th May-30th September). Out of these 20 samples, 19 samples have to pass the ‘mandatory’ directive (see Fig. 2)

which amounts to 95% compliance (Jones, 2002). Out of these 19 samples, 16 have to ad-here to stricter ‘guideline’ directives, although 18 have to pass on tests for enterococci (80% and 90% respectively) (Hannah, 2011b).

Now the standards are changing under pressure from groups such as Surfers Against Sewage (SAS) to become more strict from 2012 (DEFRA, 2011) (Fig.3.)

These new guidelines focus more on measuring the amounts of fecal streptococci or Intestinal Enterococci/100ml, which is a FC like E.Coli but one which can withstand longer periods of time in a saline marine environment than E.Coli and other fecal indica-tors, as it has been acknowledged that an absence of indicators may not mean there is no fecal contamination (e.g. the colifier has just died off) (NRC, 2004). There is also better correlation between illnesses after bathing and instances of IE compared to E.Coli, and IE is less susceptible to environmental stress than pathogens and therefore may be a better indicator of fecal pollution (Munn, 2004). There are also greater risks associated with hu-man infection from enterococci than other coliforms (Hannah, 2011a). Previous guidelines also include total coliforms which aren’t truly faecal and which can provide false positives in tests for total coliforms (Hannah, 2011b).

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The Isle of Great Cumbrae is in North Ayeshire in Western Scotland, within the Firth of Clyde. It has a central settlement of ‘Millport’, with a population of 1434 (2001) (GROS, 2008). The Island is very popular with tourists and can see its population more than double in fine weather in the summer months. Millport has a designated bathing beach of ‘Newton Bay’, as required and monitored by the Environment Agency and SEPA, although many visitors tend to use Kames Bay to the east of Newton Bay (See Fig.4).

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A new primary sewage treatment plant was built by Scottish Water in 2004/5 and all waste from Millport is pumped here and discharged into the estuary on the west side of the Island away from the designated bathing area (see fig.1). This building affects amounts of E.Coli found as dye studies have shown that released effluent can tidally make its way onto the designated bathing beach (See Fig.5). Freshwater mixing (Neill, 2004) and resul-

tant diffuse pollution, along with the amount of sunlight and differing in salinity due to evap-oration/precipitation may all change at different times of the day (other than the 11am-3pm time window that SEPA choose to sample).

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MethodologyRefer to handbook (Hannah, 2011a) for main methodology of survey.

Data

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Table 1. Amounts of E.coli, fecal coliforms (FC) and Intestinal Enterococci (EI) per 100ml found on Kames Bay and Newton Bay

Table 2: A table showing whether sample points at Kames and Newton Bays passed or failed new and old bathing water directives

Jessica Lytle University of Sussex

Kames Bay and Newton Bay

Each site within the data provides different results, and needs to be considered separately due to

ex- isting envi-ron-mental factors which may have

an influ-ence

on the

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Table 1. Amounts of E.coli, fecal coliforms (FC) and Intestinal Enterococci (EI) per 100ml found on Kames Bay and Newton Bay

Table 2: A table showing whether sample points at Kames and Newton Bays passed or failed new and old bathing water directives

Jessica Lytle University of Sussex

amounts of bacteria shown. The times at which the samples were taken and the tides may make a significant difference. Here, morning samples where taken at approximately 11:10 am, and afternoon samples were taken at approximately 15:30. High tide occurred at 17:15, with low tide at 10:35.

The lack of any E.coli colonies occurring at all at sites K2 and K1 (see Table 1) may be due to human error in the survey method and it may be advised to repeat the survey again as this is reasonably unlikely based on information from previous years. It is unlikely to be completely accurate especially as the number of total faecal coliforms is so high at point K2 and as K2 is a site of freshwater agricultural run-off. Agricultural land can often contain vast amounts of FCs from livestock, slurry and human feces which have been used for slurry (Jones, 2002) which could explain these high incidences of FCs, although potentially cooler freshwater is more of an ideal environment for E.Coli (Jones, 2002) which does not completely agree with the results in table 1. The tide was still quite far out at the time of morning sampling and the sun was shining (raising the temperature of the sample in the shallow more quickly-warmed water). E.Coli does not survive well in warm water (Neill, 2004) and can show magnitudes of instances lower in times of high amounts of sunlight where they are killed by UVB rays (Jones, 2002) due to disruption in their up-take of glucose and inhibition of biosynthetic processes (Barcina et al, 1989). This may ex-plain the lack of E.coli at this time at point K2. K1 is also near to the site of a public toilet and outflow which would theoretically give results high FC and E.coli, although the beaches were very quiet during the morning and the toilet would not have been exces-sively used.

Higher amounts of samples found at Newton may be as a result of tides (see Fig.5). The tide was flooding (after 10:35) which may have brought with it faecal pollution from the sewage outfall on the south-west of the island if it was released at high tide (where the ebb and then flood tide could bring it back into Newton Bay).

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6.

Jessica Lytle University of Sussex

In Graph 1 there is an apparent correlation between a higher salinity and higher amounts of FC and confirmed E.coli cases. This is odd as E.coli is also adverse to salinity (Jones 2002). As all FCs present at point N3 are confirmed E.coli, the explanation of other hardier FCs being detected instead such as Clostridium perfringens could also be dis-

counted.

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Type to enter

Jessica Lytle University of Sussex

Graph 2 is more as would be expected with lower salinity and a higher result for FCs. The salinity level is a lot more stable than at low tide which could be indicative of bet-ter mixing at a higher water level.

Graph 3 shows higher levels of E.coli in the morning at Kames and Newton Bays, but more stable levels at the afternoon. These stable levels could also be due to more diffuse pollution and turbulent water-mixing as the tide flooded the bays.

Graph 4 shows a higher incidence of IE at Newton Bay, similar to the higher levels of

coli in New-

ton Bay. New-ton Bay

is

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nearer to the Aelians, a group of small islands that are surrounded by a circulating tidal pattern. This pattern could potentially cause a cycling of tide-carried effluent both from the sewage outfall on the south-west of the island and from the agricultural run-off on Kames Bay which settles to the west of a groyne at sample point N3. This may explain a higher in-cidence of E.coli and IE at this point.

Around the Island: Other bays around Cumbrae.

There are other bays around Cumbrae that are used often by locals and tourists but are classified as ‘rural’ beaches rather than official ‘bathing beaches’ which are not moni-tored by SEPA. As these beaches are also commonly used, it is important to assess the bathing water quality for these areas in addition to Kames and Newton Bays for bacterial risk to human health.

We tested for Clostridium perfingens at these beaches as a different FC indicator species. Some Enterococcus species appear at low numbers in effluent but are still harm-ful to human health (such as E. faecalis) (Hannah, 2011a). Problems occur when these species have a longer active lifespan in the marine environment than some FC indicators that are used such as E.coli, as these hardier FCs may still be present long after the indi-cator has expired (Bonde, 1962).

Clostridium perfingens is common in human faeces at an incidence of 104 organ-isms per gram of faeces (Hannah, 2011a). It has endospores which have a longer survival time than most FC indicators and which are easily isolated and detected. As it survives for such a long time in the marine environment, it is more an indicator of long-term faecal pol-lution (Hannah 2011a). Although there are no actually implemented guidelines for Clostrid-ium perfingens as a faecal indicator, Bonde (1962) has written that an excess of 100 colonies per 100ml of seawater is indicative of faecal pollution.

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Table 3: Samples from beaches around Cumbrae showing incidence of Clostridium perfingens and Intestinal enterococci per 100ml

Jessica Lytle University of Sussex

The incidence of Clostridium perfingens is quite below the standards of Bonde (1962) and <100 colonies/100ml, except at ‘Cosy corner’, where the frequency of Clostrid-ium perfingens exceeds this (see table 3). This could denote a long-term problem of pollu-tion in this bay. Fintray bay also shows high levels of faecal coliforms.

Graph 5 shows high morning instances of faecal pollution at Fintray and especially Cosy

Corner. Both of these bays have an outfall of freshwater run-off which could explain the decrease in salinity in these areas, and also an increase in FCs. Fintray Bay may be af-fected by sewage outfall released as the tide is flooding from the south-west point of the is-land, but the shore is reasonably exposed there which could also explain a marked lack of long-term faecal pollution (Clostridium perfingens) due to mixing. This may be coupled with a south-westerly wind on the day of sampling which could have moved more effluent to-wards Fintray bay from the sewage outfall. Morning amounts of FC are consistently higher at Fintray and Cosy than in the afternoon (Graph 6). This may be caused by an outfall of sewage just before the morning sample was taken as the tide was just starting to flood.

Cosy corner consistently fails old and new guidelines for IE and Bonde’s guidelines (1962) for Clostridium perfingens. This is an area of agricultural run-off with a high inci-dence of macro-algae growth in a very sheltered cove which would probably see little mix-ing. It may also collect effluent in the same way that Kames and Newton Bay would due to tidal processes (see fig 5.) from the sewage outfall on the south-west of the island. Cosy is also close to a reasonably populated area and therefore may see extra waste from nearby residences of Millport, rather than Ballochmartin and White Bays which are not near any areas of human occupation.

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Jessica Lytle University of Sussex

Conclusion

Results varied considerably even on the same beaches, as can be seen in table 1 and table 2. Whilst sample point ‘K2’ failed all guidelines at all times of the day regardless of tides and time, sample point ‘K3’ - which is roughly 100m away- passed all directives (for a map showing sample points, please refer to Fig.6). Other sample points such as K1 passed directives in the morning, but failed them in the afternoon. Sites N2 and N3 failed the new directives and the stricter old ‘mandatory’ directives completely. This means that overall the beaches are more likely to fail the old directives, as although they pass at 80% on the ‘mandatory’ level, they also only pass at 16% of the ‘guideline’ level (not the 90% required). Only 5/12 samples pass the new directives. It should probably be made appar-ent that this is pre-bathing season before the number of tourists on the island increases and before the primary sewage system is put under stress with added population.

There may also be a need to test on Cumbrae’s rural beaches due to the building of a new sewage outfall that releases only primary treated waste which still contains active bacteria that can be distributed tidally. Many tourists and residents use these rural beaches as bathing beaches and there may be a risk to human health.

References

Barcina, Isabella, J.M Gonzalez, J Iriberri and L.Egea (1989), Effect of Visible Light on Progressive Dormancy of Escherichia Coli Cells during the Survival Process in Natural Fresh Water, Applied and Environmental Microbiology, p.246-251

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Bonde, G.J (1962), Bacterial Indicators of Water Pollution, Teknisk Forlag. Copenhagen

DEFRA (2010), Bathing Waters and the Bathing Water Directive, Department for Environ-ment Food and Rural Affairs, [Accessed from: http://www.defra.gov.uk/environment/quality/water/waterquality/bathing/ on 13/04/2011]

Feng, Peter, S.D. Weagent, M.A. Grant (2002), BAM: Enumeration of Escherichia coli and the Coliform Bacteria, Bacteriological Analytical Manual, Chapter 4. [Accessed from: http://www.fda.gov/Food/ScienceResearch/LaboratoryMethods/BacteriologicalAnalyticalManualBAM/ucm064948.htm#authors on 13/04/2011]

Hannah, F (2011) (a), Isolation of Escherichia Coli and Intestinal Enterococci from two bathing beaches in Millport, UMBSM Marine Biology Sussex University, 2011, p55-76

Hannah, F (2011) (b), Faecal Pollution of Bathing Waters Sussex April 2011, from a Pow-erpoint presentation made by Dr Fiona Hannah at the University Marine Biological Station Millport

Hannah, F (2011) (c), Map of Currents Around Island, from course materials provided by Dr Fiona Hannah at the University Marine Biological Station Millport during the ‘Marine Ecology’ course.

Jones, Keith, and R.J Smith (2004), The Use of E.Coli as a tool in applied and environ-mental investigations, Microbiology Today, Vol 31, p.120-122

Neill, M (2004), Microbiological Indices for total coliform and E.Coli bacteria in estuarine waters waters, Marine Pollution Bulletin, Vol. 49, Issues 9-10, p.752-760

Munn, C.B (2004), Marine Microbiology, Ecology & Applications Bios Scientific Publishers, p197.

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