According to NASA, the bridge consists of natural sand dunes and coral reefs (partially submerged giant tombolos - a constant sediment source and a strong unidirectional or bi-directional long shore current).
The BJP, Visva Hindu Parishad and many Hindu organisations claim that Adam's Bridge should not be removed for deepening the Palk Straits during the implementation of the Setu Samudram Project.
The Archaeological Survey of India, an organ of the Ministry of Culture, Government of India, initially filed an affidavit indicating that the Adam's Bridge is not man-made. I have tried my best to obtain a full text of the affidavit filed by the ASI in the Supreme Court, but could not succeed. (Not) strangely enough, the ASI.nic.in or the NIC.in have become absolutely silent about Ramayana and Ramasetu. I could find nothing about them in a keyword search while there are thousands of other unnecessary things like Rutu Samhara and Rasa Krida.
Here are some quotes from the first affidavit of the ASI, which I could obtain in news media.
" ... The petitioners while seeking relief have primarily relied upon the contents of the Valmiki Ramayana, the Ramacharitamanas of Tulsidas and other mythological texts… which cannot be said to be historical record to incontrovertibly prove the existence of the characters or the occurrence of the events, depicted therein. ..."
"...Whereas it is submitted that the ASI is aware of and duly respects the deep religious import bestowed upon these texts by the Hindu community across the globe, it is also submitted that the study of human history, which is the primary object of the ASI, like other sciences and fields of study, must be carried out in a scientific manner...."
This blogger's personal comments: Unfortunately both the ruling party and the main opposition party seem to be more motivated by electoral considerations. The industrialists who finance their election costs also drive them. There is always a possibility that all the parties may ultimately - silently clear the way for the Setu Samudram Project driven by the commercial lobbies. After all, the Project was conceived during the NDA rule.
Notwithstanding the mythological nature of the Valmiki Ramayana, Rama may still be a historical figure. While the monkeys, the monkey-made bridge, the all-accommodating-Pushpaka aircraft, etc. may be fantassies. The Ravana's Lanka may not be today's Sri Lanka. It may even be an island in Central India or on the Orissa / North Andhra Coast. There was an Ikshvaku 2c. A/D dynasty which ruled the Krishna Godavari delta region of Andhra Pradesh which may represent the seeds sown by Rama during his exile. (Some historians classified these Ikshvakus as hailing from Bihar Vaishali Lichavi clan).
The present utility of Valmiki Ramayana: The book can help us to know the socio-economic environment prevailing during the consolidation of the Ramayana scripture (say Gupta period).