What objects are needed to induce an electrical current?

There are two ways

Inducing current on a coil by moving the coil in a magnetic field.

Inducing current on a coil by by changing the magnetic field across it.

So you would need a coil and a magnet

If a coil of wire is placed in a changing magnetic field, a current will be induced in the wire. This current flows because something is producing an electric field that forces the charges around the wire.

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.