Marshall's most significant contribution to science was his work on coastal erosion and volcanology.

Marshall was born on 22 December 1869 in Sapiston, Suffolk, to Emily Louisa Merielina Rogers and her husband, John Hannath Marshall, cricketer and vicar of Sapiston.

After his father's failing health the family emigrated to Kaiteriteri, New Zealand in 1876.

[2] Marshall won the men's doubles at the New Zealand national tennis championships with his brother Joy in 1893–94.

[4] Articles by Patrick Marshall published in Transactions and Proceedings of the Royal Society of New Zealand: Books: The World Register of Marine Species lists 38 marine species described by P. Marshall.