How to Survive in the Loch Ness

The Loch is only 22 miles long and a little more than a mile wide. As a result, there need to be one and a half monsters for every mile of the link. Since they'd be reptiles, they would need to regularly surface to breathe. They'd also need to find enough food in the Loch to sustain themselves with enoughFish breeding in each mile of the Loch without getting caught and eaten by the monsters.