Boats line up off the Bet Dwarka coast.

New Delhi. Oct. 1: Excavations on Bet Dwarka island in the Gulf of Kutch have revealed the remains of an ancient shell industry that might have provided artefacts to the Indus Valley civilisation, marine archaeologists have said.

A collection of some 3,000 shells, strewn across a southeastern tip of Bet Dwarka, suggests that the island hosted a big shell industry during the late Harappan period, archaeologists at the National Institute of Oceanography (NIO) in Goa have said.

Some of the excavated sites on the island are 3,800 years old and correspond to the late Harappan period. The shells probably represent an artefact-making industry for Indus settlements, NIO archaeologist Aniruddh Gaur said. Marine shells appeared to be more popular than ivory or bone ? two other contemporary raw materials for artefacts and ornaments ? in the Indus Valley.

Excavations in the past have turned up bangles, beads, ladles and feeding cups among various shell-based artefacts at Harappan sites, including Lothal, Mohenjodaro, Nageshwar, Surkotada and Rangpur.

“The presence of cut and unfinished pieces and waste pieces on the island tells us that this was an industry site,” Gaur said. The NIO team found fragments of bangles, beads, a seal and unfinished ladles from the Bet Dwarka site.

While archaeologists have suspected that the shell artefacts for the Indus people came from the Gulf of Kutch, only one site for an ancient shell industry had been identified 15 years ago ? Nageshwar, a Harappan site on the Gujarat coast. The studies by the NIO scientists on Bet Dwarka, conducted during 2000-01, show that the island’s shell-industry might have been one of the largest enterprises of its time.

In a report in the latest issue of the journal Current Science, scientists have documented similarities between the shells at Bet Dwarka and artefacts recovered from Harappan sites. A unique late Harappan seal constructed out of a conch shell with a short-horned bull, a unicorn and goat engraved on it found during underwater excavation near the island is similar to a seal recovered from Mohenjodaro.