Was the resource present in abundance earlier?

Natural resources are present in abundance but do we really manage them properly ?

Name the resources present in unlimited quantity in nature :

Name the element which are present in abundance in earth's crust

Name the resources present in limited quantity in nature :

Both sodium and potassium are present in equal abundance in the earth's crust, but sodium is about 30 times as abundent as potassium in oceans. Give reasons.

Both sodium and potassium are present in equal abundance in the earth's crust, but sodium is about 30 times as abundant as potassium in oceans. Give reasons.

When feeding efficiency of one species is reduced in presence of the other species even if the resources are abundant , it is called -