Can archaeology save our seas? Borth coastal defence scheme and human adaptation

Landscape archaeologist and CAT MSc student Jemma Bezant looks at how messages from the past about human adaptation and resilience can resonate today in the face of coastal erosion and rising sea levels. 

Our changing seas

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Borth, Cardigan Bay coastline

Everybody loves the sea. A trip to the beach can lift our spirits and feed our souls.

But we have a complex relationship with our coastlines, our oceans: they are at once liminal places of danger and places that supply our needs.

The chance discovery of a child’s footprint, thousands of years old on the Borth beach in Cardigan Bay, led archaeologists to speculate on the nature of human’s relationship with the coast and sea.

Can the lessons of the distant past help us deal with climate change and catastrophic changes to our coast?

Footprints from the past

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A child’s footprint preserved in Bronze Age peat deposits on Borth Beach. Made at a time in the past when Cardigan Bay was a great wooded coastal plain with rich estuarine resources. Subsequent sea level rise and flooding killed the trees and forced communities into adaptive retreat.

In 1913, the geologist Clement Reid published his survey of Submerged Forests where former wooded areas were preserved in the intertidal areas of the British coastline. He deduced that sea levels had been much lower when Ice Age glaciers had locked up the northern hemisphere’s water.

Rapid warming from 1300 years ago had a massive impact on human behaviour, and sea level rise changed our coastlines (Lowe and Walker, 2014).

The animal and human footprints preserved for over 3000 years at Borth reflect the activities of Bronze Age hunter-gatherer and early farming communities.

During periods of flooding and inundation, they must have witnessed catastrophic flooding that devastated vast swathes of open woodland.

At the same time, they adapted, exploiting the rich wetland resources for a range of useful resources.

This seminal site and its hinterland have long drawn those studying human adaptation and response to dramatic coastal change over many millennia, taking archaeological Holocene data from peat deposits to reconstruct past environments (Adams and Haynes, 1965; Heyworth, Kidson and Wilks, 2008)

Wales’ coastal protection schemes

Increasing storm activity, sea level rise and floods are battering our modern coastlines again.

Welsh Government outlined their controversial policy (Royal Haskoning, 2011a, 2011b) of ‘managed retreat ’ (Pennington et al., 2015) and the village of Fairbourne in north Wales is to be abandoned to its fate and is facing serious erosion.

Borth coastal defence scheme

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Archaeologists recording archaeological deposits in mitigation during the Borth coastal defence Scheme.

Borth fared better – by the end of 2015, Ceredigion County Council were already in the second phase of a £39m coastal defence scheme that aimed to protect the town of Borth from flooding for at least the next half century – but noted that “Other community resilience actions to help the community adapt to climate change and reduce the impacts of flooding and erosion on the people and environment of Borth will also be needed.”(Ceredigion County Council, 2013).

The project aims to protect the 450 houses of the village from coastal erosion and Phase I of the scheme was opened by the Welsh Government Environment Minister in spring of 2012.

The consultants Royal Haskoning secured the contractors Bam Nuttall to model rock-built groins and breakwaters to provide defence, and University of Wales Lampeter Archaeological Services were appointed to supply archaeological mitigation during the second phase of the project.

The scheme recognised the threats to the village from climate change, sea level rise and increased storminess and aimed to minimise those adverse effects for the next 20-50 years. The People, Places, Futures: The Wales Spatial Plan (2004) comments that, “We must act now to protect our communities from the unavoidable consequences of climate change, such as flood risks and the consequences on land use, water resources, biodiversity and wildlife.” The 2008 update states: “Future flood risks and coastal erosion present a significant economic threat to some of the key economic centres of Central Wales.”

Catastrophe

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The stumps of prehistoric oak and pine trees at Borth, dating to the Neolithic and Bronze Ages and preserved in the organic sediments of former land surfaces, stretch out into Cardigan Bay. These were growing at a time when the coast was further out to sea and reflecting episodes of inundation via a dynamically changing coastline. Photo Nigel Nayling, (Bezant, 2014)

We can expect further radical change. Our sea levels are on the rise and storms increasingly batter our coasts.

The wisdom of the £39m Borth scheme was questioned when it was criticised in February 2016 when Storm Imogen forced overtopping of the new defences, causing flooding of homes along the beachfront.

IPCC estimates on sea levels have recently been revised upwards (Bamber and Aspinall, 2013) and we could expect a dangerous 1-2m rise (Hansen et al., 2016), even if we keep to the Paris Agreement’s target of no more than 2°C above industrial levels.

Critics of the Saffir-Simpson scale (Simpson, 1974), which measures the strength of hurricane storms, say that flooding rather than wind speed is the biggest threat after storm surges – hurricane Matthew caused extensive damage to North Carolina, and saw over 1000 dead in Haiti (von Meding and Forino, 2016).

 

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Borth project GIS – mapping archaeological evidence and using terrain modelling to reconstruct prehistoric human adaptation to climate change. Palaeoenvironmental data will allow us to reconstruct responses to coastal changes – settlement patterns, diet and changes in belief systems and cosmologies.

Archaeology

Catastrophic storms and coastal flooding are nothing new if we look at the longue duree of human past.

At Borth, Geographical Information Systems (GIS) are mapping archaeological material in order to provide precise environmental reconstruction of former land and sea surfaces.

Archaeological evidence can reveal the way that past human populations have adapted to new opportunities in the past, both economically and as communities in a state of disruption and disaster.

These new insights can help policy makers seeking to mitigate coastal erosion and direct scant resources in a post-Brexit scenario.

 


Dr Jemma Bezant

me3Archaeologist Jemma Bezant has worked in academia for over fifteen years as a senior lecturer, practitioner and consultant in landscape archaeology and heritage.

A large section of the heritage industry in northern Europe is driven through mitigation for large energy projects such as assessments and impacts for wind and Jemma worked as a consultant on the OREIN (Offshore Renewable Energy Impact Network) knowledge exchange project that assessed the impact of offshore renewables development on costal heritage assets. Her more recent involvement with the Welsh Government’s £29m sea defences scheme at Borth, Ceredigion allowed her to start connecting human prehistory with a sustainable future.

While she continues her work at Borth and elsewhere, Jemma hopes that studying for a masters degree in Sustainability and Adaptation Planning at CAT will allow her to put archaeology and sustainability together. She says: “The international reputation of CAT and the Zero Carbon Britain team was irresistible. Although it’s a daunting prospect, I’m really enjoying being a student again.”

Read Jemma’s archaeology blog at http://archaeologistica.blogspot.co.uk/

 


 

References

Adams, T. D. and Haynes, J. (1965) ‘Foraminifera in Holocene Marsh Cycles at Borth, Cardiganshire (Wales)’, Palaeoentology, 8, pp. 27–38.

Bamber, J. L. and Aspinall, W. P. (2013) ‘An expert judgement assessment of future sea level rise from the ice sheets’, Nature Clim. Change, 3(4), pp. 424–427. Available at: http://dx.doi.org/10.1038/nclimate1778.

Bezant, J. (2014) Flood myths reveal our changing coastline and climate, The Conversation. Available at: https://theconversation.com/flood-myths-reveal-our-changing-coastline-and-climate-25056.

Ceredigion County Council (2013) Report of the Director of Environmental Services and Housing on the proposed development of phase 2 of the Borth Sea Defence works. Application A13.0533.CD.

Daw, T. and Gray, T. (2005) ‘Fisheries science and sustainability in international policy: a study of failure in the European Union’s Common Fisheries science and sustainability in international policy: a study of failure in the European Union’s Common Fisheries Policy’, Marine Policy, 29(3), pp. 189–197. doi: http://dx.doi.org/10.1016/j.marpol.2004.03.003.

DEFRA (2009) UKCP09, Marine and Coastal Projections.

Gray, T. S. (1998) ‘Fishing and Fairness. The Justice of the Common Fisheries Policy.’, in Gray, T. S. (ed.) Fishing and Politics. Macmillan Palgrave, pp. 228–250.

Hansen, J., Sato, M., Hearty, P., Ruedy, R., Kelley, M., Masson-Delmotte, V., Russell, G., Tselioudis, G., Cao, J., Rignot, E., Velicogna, I., Tormey, B., Donovan, B., Kandiano, E., von Schuckmann, K., Kharecha, P., Legrande, A. N., Bauer, M. and Lo, K.-W. (2016) ‘Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous’, Atmos. Chem. Phys.  16(6), pp. 3761–3812. doi: 10.5194/acp-16-3761-2016.

Heyworth, A. A., Kidson, C. and Wilks, P. (2008) ‘Late-Glacial and Holocene Sediments at Clarach Bay , Near Aberystwyth, British Ecological Society http://www.jstor.org/stable/2260487’, 73(2), pp. 459–480.

Khalilian, S., Froese, R., Proelss, A. and Requate, T. (2010) ‘Designed for failure: A critique of the Common Fisheries Policy of the European Union’, Marine Policy, 34(6), pp. 1178–1182. doi: http://dx.doi.org/10.1016/j.marpol.2010.04.001.

Lowe, J. J. and Walker, M. J. C. (2014) Reconstructing Quaternary Environments. Routledge.

von Meding, J. and Forino, G. (2016) Hurricane Matthew is just the latest unnatural disaster to strike Haiti, The Conversation. https://theconversation.com/hurricane-matthew-is-just-the-latest-unnatural-disaster-to-strike-haiti-66766 (Accessed: 11 October 2016).

Pennington, L., Wales, N. R., Marshall, L. and Council, G. (2015) ‘Wales Coastal Flooding Review : Learning from Fairbourne’, (June).

Reid, C. 1913 Submerged Forests. Cambridge University Press: Cambridge.

Royal Haskoning (2011a) West of Wales Shoreline Management Plan 2, Introduction and Glossary.

Royal Haskoning (2011b) West of Wales Shoreline Management Plan 2 Section 3, Background.

Simpson, R. H. (1974) ‘The hurricane disaster potential scale’, Weatherwise, 27, p. 169.