Aqua-man can breathe underwater, swim at tremendous speeds, and telepathically communicate with sea life. Being able to withstand ocean depths, he gets bonus points on land with his superhuman strength, enhanced senses, and nearly impenetrable skin.
Aqua-man is loyal to the sea life and they are as well to him. Since he is loyal to him the are at his dispose for at least a 1 minute.
Aquaman had to come into contact with water at least once per hour, or he would die (prior to this story Aquaman could exist both in and out of water indefinitely.)