Religious reading: "fish" is a Christian symbol. "Lambs of God." "the black fella" is an angel. "The river" can be seen as a symbol for spirituality, cleansing, and the holy spirit. "the beautiful, the river" is apparently a hymn- intertextuality. The religous reading highlights the concepts of faith and fate and destiny throughout the text.
Feminist reading: A feminist reading suggests that the males are weak and defeated by their circumstances, while the women battle on- such as Rose supporting her family and oriel keeping it all together. The men also take on typically female characteristics, such as Lester and sam are the "nurturers" of their children, and Oriel and Rose are the providers for their families.
A post colonial reading: the vernacular language of the text and the context of it suggests a reading in reference to post colonial Australia, and implies political and social connotations.
Hope that helps a little.