For those of you who think Hamilton harbour is an abominable mess where nothing can live – think again.

Buoyed by recent successes with fish stocks in the bay, the Ministry of Natural Resources is sending a truck full of 50,000 walleye to Hamilton Monday to introduce more of the popular sport fish to the waters.

"The reintroduction of a top native predator is a really big deal," said Chris McLaughlin of the Bay Area Restoration Council. "The fact that re-introduction was even considered in 2013 was a story, but the successful growth of those individuals is even better news."

Pre-industrialization, walleye were a common sight in the harbour, as they were historically near the top of the food chain in the bay.

But bit by bit, atrocious water quality and a loss of natural habitat meant they disappeared from the area like many fish did. By the 1950s, they were all but gone.

However, in recent years water quality in the area has improved, said Colin Lake from the ministry. So officials took a gambit, and decided to start introducing hatchery-grown fish into the bay.

- Colin Lake, Ministry of Natural Resources

There were 100,000 young fish introduced to the water in 2012, followed by 10,000 in 2013 and another 950,000 in 2014.

This past winter, ice fishers started catching adult fish, meaning they were surviving. "Provincial fisheries officials were elated this winter when people out on the ice in Hamilton harbour began emailing them with selfies of them and their catch," McLaughlin said.

"Field work is showing that those little fish stocked in 2013 are doing exceptionally well, but we won't know for another year or two whether reproduction is taking place."

Though reproduction would be a real boon, the fact that the fish are surviving in the harbour is still great news, Lake says.

"It has really gotten people excited about the harbour," he said. "That's difficult to do when you're just talking about water quality tests and phosphorous levels."

Excessive phosphorus is one of the biggest cleanup tasks the harbour faces. It's a nutrient that increases productivity in water, causes algae to grow excessively and disrupts the food chain and the ecosystem.

Thankfully, phosphorus levels have been dropping steadily. But the current level in the harbour — 40 micrograms per litre — is still twice the accepted level.

Many of the fish currently living in the harbour have a resistance to poor water quality.

Still, the ministry says if the walleyes in the harbour can start reproducing, it would be huge for the area.

"Things certainly are getting better," Lake said.