Disclosed are methods and systems for using an impact-activated device for repelling sharks from marine geophysical survey equipment. An embodiment discloses a marine geophysical survey system, comprising: marine geophysical survey equipment configured to be located in a body of water when in operation; and an impact-activated device coupled to the marine geophysical equipment, wherein the impact-activated device comprises a circuit configured to release a shark repellent in response to a pre-determined impact on the impact-activated device.