A short walk from the Oakwood Heights Station, south on Amboy Road, three packages of herring sit on the shelf at Net Cost Market, one of the Russian supermarket chain. The store, in a shopping center south of Amundsen Circle and Trail (named for the Norwegian polar explorer) and just north of Frederick Douglas Memorial Park (honoring the African-American abolitionist leader) is a great example of Staten Island’s ethnic mix. Even the herring are diverse, available in Swedish, Italian and Spanish styles.