A recent botanical survey on the beach by the Sussex Botanical Recording Society identified an incipient invasion of Hottentot Fig (Carpobrotus edulis) which is  an invasive, non-native plant which is quite easy to distinguish with its 3-angled succulent leaves and large yellow flowers that fade to pink.

https://en.wikipedia.org/wiki/Carpobrotus_edulis
Why is this a problem, you ask?? Well, once established, this plant  forms dense, impenetrable mats that can carpet warm, sunny coastal areas to the exclusion of all other species. It has spread either from discarded garden material or has been used in some places to stabilise sea defences and then spread from these areas . The major problem is a rapid spread when It then outcompetes native species. A single plant can dominate an area up to 50m across
FoSB will be combining with Port Authority Rangers to try and remove this plant from 8.30 on 14th Sept. at Winterton Way entrance . The plant is about 9-10 houses to the East from the Winterton Way entrance BN43 5 HA.
The SBRS said get it up asap as it spreads rapidly and it needs to be removed before the seeds have set.. 

This species is listed on Schedule 9 of the Wildlife and Countryside Act in England and Wales therefore, it is also an offence to plant or otherwise cause to grow these species in the wild.