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Department of Geography


Splash and Squelch – Science Festival 2015 event

14th March 2015, Department of Geography

Splash and Squelch poster

The Geography Department event at the Cambridge Science Festival 2015 was a great success, with more than 150 visitors enjoying a range of activities from the study of salt marsh mud, to the measurement of waves in shallow water, playing a computer game to find out how to use the natural environment to protect against coastal flooding and looking at the weird and wonderful invertebrates that inhabit our tidal flats under the microscope, to reading about invasive species and learning about the habitat and behaviour of crayfish. The Cambridge Coastal Research Unit (CCRU) of the Department’s Environmental Systems and Processes research group and the University of Cambridge Conservation Research Institute (UCCRI) presented the activities together – much fun was had by all!

Read more below about the current research projects of the Cambridge Coastal Research Unit and find out about UCCRI below.

Photos from the event

Splash and Squelch - Science Festival 2015 event Splash and Squelch - Science Festival 2015 event Splash and Squelch - Science Festival 2015 event Splash and Squelch - Science Festival 2015 event Splash and Squelch - Science Festival 2015 event Splash and Squelch - Science Festival 2015 event

There are more photos available on Flickr [].

Cambridge Coastal Research Unit (CCRU) and the University of Cambridge Conservation Research Institute (UCCRI)

The CCRU carries out fundamental research on coastal, estuarine and nearshore processes, as well as environmental monitoring in the coastal zone. CCRU is also part of the University of Cambridge Conservation Research Institute (UCCRI), the interdisciplinary conservation hub for the University. As part of the conservation community, there is ongoing research to protect the environment using a variety of methods and interdisciplinary approaches including physical and social sciences. Recent focus has been on salt marshes in Europe and the vital role they play towards protecting coastlines. On a more global level, research has addressed the role of mangroves as another natural coastal defence, and has concentrated on how these areas are paramount to protecting coastal and marine life from future global warming.

Salt Marshes

Salt marshes have been found to provide a vital defence for our coastlines, protecting coastal areas in times of severe weather. They can act as natural flood defences and, at a width of only 40 m, can reduce (by almost 20% ) the height of damaging waves in storm surge conditions. One of the most noticeable effects of climate change is the increasing frequency and severity of storms, such as the series of storms which battered parts of south west England last winter. As the climate continues to warm and sea levels continue to rise, the effects of these storms could be devastating, putting these and other coastal communities worldwide at risk. Salt marshes are found throughout the world, particularly at middle to high latitudes. In addition to their role in protecting against coastal erosion and reducing flooding, they also act as nurseries and refuges for many species of marine animals, and protect water quality by filtering runoff.

While the important role of salt marshes in protecting against coastal erosion is well-known, their effectiveness in mitigating the effects of extreme weather, when water levels are at their maximum and waves are at their highest, had not been understood or definitively quantified. CCRU have recreated a salt marsh in a large wave tank and by subjecting it to realistic storm conditions, they have found that it significantly ‘buffered’ the effects of the waves. Similar to wind blowing through a forest, the plants reduce the energy of the water as it flows through and around them. Even when the waves flattened and broke the marsh’s vegetation, the soil surface beneath remained stable and resistant to surface erosion. Given increased rates of global sea level rise, there are concerns about losing salt marsh on many coasts, particularly where there is insufficient sediment and space to allow marshes to build upwards and landwards.


Mangroves are another natural coastal defence to communities globally. Despite fears that mangrove areas could be lost in the coming decades as higher sea levels due to global warming increase their flooding frequency, they have also been shown to be able to trap sediment and grow in height to ‘keep pace’ with sea level rise. It is thus human activity on land – such as the damming up of rivers or the felling of trees to create shrimp ponds – which is currently a far greater threat to many mangrove habitats than the effects of climate change on sea level.

It is vital therefore that they are managed and conserved so that they can continue to provide this protection. Mangroves – trees and shrubs which grow in saltwater, coastal environments – play a critical role in protecting thousands of shoreline communities in tropical and subtropical regions from floods, storms, and other hazards. Their densely-packed, overground root systems can absorb wave energy and reduce the velocity of a sudden surge of water. In the 2004 tsunami, for example, mangroves were sometimes the difference between life and death for people whose homes lay in the path of the giant waves which crashed into shorelines around South Asia. Despite this resistance to changes in sea level, however, the future stability of mangroves is by no means guaranteed. Threshold rates of sea level rise are likely to exist, beyond which mangrove surfaces can no longer keep up. Perhaps more urgently, in some regions human activities like agriculture and construction are being authorised regardless of their impact on the ecosystems which enable mangroves to thrive. Another common threat is aquaculture: in Indonesia, and other South Asian countries, mangroves are often cut down without restriction to make way for shrimp ponds. Mangroves may need room to expand landward, especially where conditions are such that sea level rise may still be a threat to their growth. Communities which rely on them for coastal defence need to leave space to ensure that this can happen.

Current coastal projects


Mudflats and salt marshes support a wide range of economically valuable animal and plant species and act as sites of carbon storage, nutrient recycling, and pollutant capture and destruction. Their preservation is of the utmost importance, requiring active and informed management to save them for future generations. The UK Natural Environment Research Council’s call to help understand the landscape-scale links between the functions that these systems provide (ecosystem service flows (the ESS in CBESS where C stands for ‘Coast’) and the organisms that help provide these services (biodiversity stocks (B in CBESS)) offers an important opportunity to move beyond most previous work in this field, which has been conducted at small or laboratory scales. Coastal managers require evidence to understand how ecosystem service flows operate at much larger spatial scales, e.g. entire salt marshes or regions of intertidal flat and salt marshes. The CBESS project will help deliver this understanding.

FAST (Foreshore Assessment using Space Technology)

Marine foreshores deliver several services, such as increasing sedimentation, reducing erosion and attenuating waves that mitigate flood risk by improving the stability of coastal and river defences but they are currently not included in flood risk assessment.

The FAST (Foreshore Assessment using Space Technology) project aims to develop a new assessment to gain spatial information on foreshore and floodplain characteristics. As part of this project, there are four study areas across Europe (Spain, Romania, United Kingdom and the Netherlands). FAST provides the first standardised tool for integrating flooding-landscape interaction into cost efficient and safe flood risk management strategies.


EU RISC-KIT [Resilience-Increasing Strategies for Coasts – toolKIT] is a major EU-funded research project which will deliver ready-to-use methods, tools and management approaches to reduce risk and increase resilience to low-frequency, high-impact hydro-meteorological events on European coasts. This new toolkit will comprise a coastal risk assessment framework, early warning system and decision support systems for hot spots, a web based management guide, and a coastal risk database.

The toolkit will be tested using data collected on ten diverse case study sites along each of Europe’s regional seas and one international site. The toolkit’s performance will be evaluated with an End-User Board of coastal managers, civil protection agencies and local governments with a vested interest in each of these case study sites.

The Hydralab Experiment

To build coastal vegetation into coastal protection schemes, the dynamics that control the sustainability of such an approach need to be fully understood. The Cambridge Coastal Research Unit (CCRU), with collaborative partners in Germany and the Netherlands, used a real salt marsh in one of the world’s largest laboratory wave flumes to observe how waves reduce over marsh surfaces during storm surge water levels. The data obtained from this experiment now provides a sound basis for upgrading engineering models and for the development of new design and safety concepts for vegetated foreshores as storm buffers.