GIGLIO, ITALY—More time and money will be needed to remove the Costa Concordia cruise ship from the rocks off Tuscany where it capsized last year, in part to ensure the toxic materials still trapped inside don’t leak into the marine sanctuary when it is righted, officials said Saturday.

As shipwreck survivors and relatives of the 32 killed began arriving on the island of Giglio to mark Sunday’s anniversary of the grounding, environmental and salvage experts gave an update on the unprecedented removal project under way.

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They stressed the massive size of the ship — 112,000 tonnes — its precarious perch on the rocks off Giglio’s port and the environmental concerns at play in explaining the delays and problems in rolling the ship off its side and towing it intact from its resting place.

The pristine waters surrounding Giglio are part of a protected marine sanctuary for dolphins, porpoises and whales, and are a favourite for scuba divers. Already, tourism was off 28 per cent last year, thanks in part to the eyesore in Giglio’s port.

Franco Gabrielli, the head of Italy’s civil protection agency, told reporters that officials are now looking at September as the probable date to remove the ship, taking into account conservative estimates for poor weather and rough seas. Originally, officials had said they hoped to tow it from Giglio’s waters by early 2013.

In addition, Gabriele and Costa officials said the cost might now reach $530 million, up from the $400 million originally estimated.

The Concordia slammed into a reef off Giglio on Jan. 13, 2012, after the captain took it off course in a stunt to bring it closer to the island. As it took on water through the 70-metre gash in its hull, the Concordia rolled onto its side and came to rest on the rocks off Giglio’s port. Thirty-two people were killed.

The captain, Francesco Schettino, remains under house arrest, accused of multiple manslaughter, causing a shipwreck and leaving the ship before all passengers were evacuated. He hasn’t been charged. Schettino maintains he saved lives by bringing the ship closer to shore and claims the reef wasn’t on his nautical charts.