Tracer Pebble Studies, East Solent Phase I

Minor funds contribution

Havant, Portsmouth & Gosport Coastal Partnership: £1,500 (2010-2011)

The Havant, Portsmouth and Gosport group (now the Eastern Solent Coastal Partnership, or ESCP) has developed a new shingle tracer study technique using Radio-Frequency Identification (RFID) technology to track pebbles moving around the East Solent coastline.

The pebbles were collected from the study area, drilled and a tag inserted, before being measured and deployed back onto the beach. Each tracer pebble has a unique identification number, and can be detected up to a metre deep within the beach without the need to dig up the pebble. The tags do not rely on battery power and should work for 50 years.

Further detail on the technique used can be found at Tracer Pebble Studies

The study was carried out to supplement the South West Hayling Island Beach Management Study. £1,500 was provided by SCOPAC to assist with the preparation costs of the tracer pebbles.

Sediment Tracer Report (PDF, 2Mb)

Clive Moon reported…

“A total of 2,300 tracer pebbles have now been deployed around the Hayling and Portsea Island open coast as part of an ongoing study to confirm the long-term sediment pathways in the East Solent. The deployment locations include the nourished beach at Eastoke, either side of the Langstone Entrance Channel and the Southsea frontage (Figure 1).”

  • At Eastoke the tracer pebbles were used in conjunction with volumetric analysis to improve the understanding of losses from the nourished frontage.
  • At the Langstone Harbour entrance the tracers were used to identify the rate and direction of material from the open coast of Portsea and Hayling Island, into the channel.
  • At Southsea Memorial the tracers were used to confirm the path taken by material placed on the upper beach to counter coastal erosion. 

A towed RFID antenna array was constructed to assist in the detection of a larger number of tracer pebbles in one sweep, and the handheld antenna had additional batteries installed to increase the survey duration between recharges. Tracer pebbles can be detected up to a 1 metre depth; those pebbles not recovered will either be buried too deep in the beach or will be taken offshore.

Further studies

This study ended March 2012. SCOPAC awarded the Eastern Solent Coastal Partnership a further £4,000 to undertake additional sediment tracer study trials in 2012-2013 (East Solent Phase II).