An oceanographer and biologist, she was the first Spanish woman to participate in an international expedition to Antarctica, together with Marta Estrada. She was also the first woman to direct the Spanish Antarctic Base on Livingston Island, between 1989 and 1997. Close to where the Antarctic base was established, which CaStellví participated in 1986, is the Castellví Peak, named in her honour. She studied Biology at the University of Barcelona and Oceanography at the Sorbonne University in Paris, where she specialised in marine microbiology.
In 1994 she received the City of Barcelona Gold Medal and in 2003 she was awarded the Creu de Sant Jordi (St George’s Cross). In 2007 she delivered the opening speech for the Mercè festivities, where she called for a Barcelona nearer to the sea. She was the first scientist to receive the August Pi i Sunyer Medal from the UB Faculty of Medicine, in 2015. In 2019, a plaque was placed at the Institute of Marine Sciences in recognition of her scientific career.
An oceanographer and biologist, she was the first Spanish woman to participate in an international expedition to Antarctica along with Marta Estrada. Between 1989 and 1997, she directed the Spanish Antarctic Base on Livingston Island.