It could be years until the full impact of a 570,000 litre oil leak off the Californian coast is known.
Thousands of people are continuing to clean up and assess Orange County’s once pristine beaches, with many popular holiday spots remaining closed.
Heartbreaking images shared by a network of dedicated rescue teams, show oil-soaked birds coming into care and being treated by specialists.
More on the oil spill: 'Travesty': Pristine California beaches face environmental disaster
Experts are particularly concerned about pods of dolphins seen swimming through the area during the spill.
They are more likely to present with internal exposure to the toxicity, according to Dr Michael Ziccardi, Director of the UC Davis Oiled Wildlife Care Network.
“Inhalation of oil right at the surface of the water, or ingestion and the food items and oftentimes those things are more chronic," he told Yahoo News.
While the impact on fish and seabirds has not been as severe as expected, the effect on the wider marine ecosystem is yet to be fully understood.
"(We're) looking at the ecosystems, the plants, the invertebrates, and then the vertebrate species like we're caring for, and combine that all into an injury determination to see what the overall damage is," Dr Ziccardi said.
"That's going to take months to years before we really have a good understanding for what the impacts are."
Threatened snowy plovers among birds impacted by California oil spill
Speaking from the the cleanup command centre this morning, Dr Ziccardi said wildlife teams are still in “full flight”, covering the entire area of the spill which now stretches from Los Angeles County to San Diego in Southern California.
A partnership led by UC Davis and the California Department of Fish and Wildlife is managing a network of 44 organisations that respond to oil leaks, with 13 sent to the cleanup area on this occasion.
Teams have combed through the affected areas on foot, in all terrain vehicles, four wheel drives, as well as on the water.
The bodies of 24 birds have been recovered, and 26 survivors have been taken into care at a specialist facility for assisting oiled birds.
Along with a variety of species including gulls and a brown pelican, seven federally threatened western snowy plovers are being treated.
Dr Ziccardi said the tiny, secretive shorebirds are being "cared for very carefully" and recovering well.
A small field hospital has been set up on the beach to stabilise oiled birds with warmth and fluids, before they taken to the primary care facility.
For legal reasons, evidence has been collected from all incoming birds with feather samples taken and images snapped.
To reduce stress, most birds are given two days rest before they are washed repeatedly in tanks of warm soapy water and then rinsed.
Once they are deemed to have fully recovered, the birds will be released back into the wild.
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