If you have an old car, don't just scrap it. Think of the benefits to marine life. It could provide a new home for all kinds of creatures. Providing them with protection from fisherman and other predators.
Shopping trolleys make great animal traps. You will find trolleys lying around just about anywhere. Most of them are free, but the better ones cost a pound. If you are any good with a screwdriver you may even get your pound back.
Remember! Used engine oil makes great garden fetiliser.