"After the big spill, when we were having large amounts of oil washing on the beach and we didn't know how much more was going to come, it was pretty depressing," he said yesterday.
"I've got a relationship with the dotterels here - I go out and monitor them each year - and the thought of them covered in oil was very unpleasant."
Fortunately, only a few of the captured dotterels were found with oil on their feet and plumage and all were cleaned and kept in a quiet area of the oiled wildlife facility at Mt Maunganui.
Mr Fitter said the birds were so fragile that a small fright could cause fatal heart attacks, which meant the birds were strictly off limits to journalists visiting the centre.
The birds were held individually in purpose-built aviaries, and each was tagged with coloured leg-bands.
"We don't know how it's been for them keeping them in captivity for a month but all indications are that they've fared quite well.
"We're not sure how many they are going to release on Friday, but the sooner they're back, the better, as they'll have a better chance of re-establishing their peer bonds and getting breeding again."
Mr Fitter was confident their capture will have caused only a "brief interruption" to the breeding season.
"While they might have a lost a bit of the season, all of their eggs seem to be intact, and generally we've got out it far more cleanly than it could have been."
The release of the dotterels at Maketu is a special moment for the small seaside settlement east of Te Puke, which was one of the worst-hit spots in the spill.
The birds were released last week to areas they had come from and which had now been declared free of oil.
Dr John Dowding, a shorebird specialist who led the release, was also hopeful the freed dotterels would be able to breed.
"The breeding season for New Zealand dotterels is from late August through to March. Dotterels can continue to lay eggs through to January and there are 17 very happy dotterels out there."
CALM WEATHER ALLOWS REMOVAL OF MORE CONTAINERS
Twenty more containers were lifted from the Rena yesterday, bringing the total removed from the stricken ship to 116.
After windy weather kept salvors at bay on Saturday, the crane barge Sea Tow 60 was back in action with forecast conditions looking favourable for the next few days.
Maritime New Zealand was continuing to investigate why Rena's charterers, the Mediterranean Shipping Company, did not declare a further 21 containers holding dangerous goods until last week.
The 21 containers contain 490 tonnes of cryolite, which is considered low risk unless ingested or inhaled in its dry powdered form.
Twenty of those were inaccessible and stored below deck in hold 3, which suffered considerable damage in the grounding.
Seventeen were understood to be submerged, but all were likely to have been submerged at some time as the ship had moved.
Tauranga MP Simon Bridges said while it was worrying the containers were not declared in the original manifest, he was "not overly concerned" after receiving expert advice they posed little risk.
