Asimilarity between ellis island and angel island is that both

Immigrants had to pass medical inspection at both stations.

Explanation:

Medical examination of the newly arrived happened at both stations. The immigrants were inspected by two doctors and the inspection was often quite unpleasant. Many Asian immigrants saw it as intrusion on their privacy as they were not used to taking their clothes off in front of strangers.

Men and women were inspected separately. They were examined for certain physical defects, their eyesight was checked and they were tested for parasitic infections.

Immigrants with minor health defects were allowed to register to receive an alien's card, people with contagious diseases were put into hospitals first, and their fate was decided later on.

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.