As lobster condos, these were a flop.

"Never did we have more than five lobsters out there," said Glyn Sharp, a marine biologist trying to lure the lucrative shellfish to take up residence in 20, specially-designed concrete balls in 10-metre waters off McNabs Island.

"If you were renting these things, you wouldn’t be making too much money, would you? . . . And it’s not that there aren’t lobsters around McNabs. There are. There’s a lobster fishing industry right here on the doorstep."

Led by Mr. Sharp, researchers at the Bedford Institute of Oceanography began looking at ways artificial habitat could be created for lobsters in 2004, prompted by the need to find ways to compensate for activities like infilling, dredging, putting in underwater cables or pipelines, or even wharf construction in coastal waters.

Using artificial reefs to enhance fish populations isn’t new. The Japanese began doing it in the 1950s. And over the decades, artificial reefs made of everything from concrete and ships to cars and tires have been tried worldwide — with varying degrees of success.

While the 500-kilogram reef balls, with their Swiss cheese-like holes, didn’t draw lobsters in Halifax Harbour, the scientists found them no more attractive to tasty crustaceans in the more pristine waters of St. Margarets Bay.

Sure, a few of the old guys — hefty two-kilogram bruisers that could fill an oversized dinner plate and the like — settled in comfortably. But the juveniles that researchers really hoped to attract to the reef real estate stayed away, even as other species of underwater life took hold.

It seems nothing suits a crusty critter like a random pile of rocks, as the researchers first noticed inside tanks in their BIO laboratory.

Piles of different sized rocks placed around McNabs Island attracted lobsters within a couple of months — more lobsters than had ever been found in the concrete balls.

Researchers then set their sites on Sambro Harbour to see what would happen if they put similar rock piles in a place young lobsters weren’t likely to be found.

"We don’t just want to move animals around," he said. "We want to create new production."

Piles of different sized rocks were carefully put in place. Within a month, species such as snails and starfish had moved in, and so had the lobsters.

It’s too early to reach conclusions about how well the rock piles will work in the long run, but the research team is hopeful.

"We’re hoping eventually these will become normal lobster habitat and eventually fishermen will be able to put their traps where they’ve never put their traps to catch lobster. They’ll see some direct benefit and years of information will come out of the project," Mr. Sharp said.

And although Mr. Sharp says he’s convinced concrete balls aren’t the way to enhance lobster populations, he’s not prepared to write them off completely.

Results so far indicate that the reef balls may be very useful in creating kelp beds and more complex underwater communities since all sorts of other creatures are using them.

In fact, researchers will continue to monitor them regularly — every two months at this time of year, every month beginning in the spring — just as they plan to monitor the rock piles, for at least the next three years.

"Write them off as far as lobster habitat is concerned. I wouldn’t put any more out for that purpose," he said, adding the scientists have already advised Department of Fisheries and Oceans officials of their findings.

"But we know they are good for other plants and animals to come on. We get a good diversity and they enhance the productivity of the area. . . . We’re learning so much from them that really they’re very useful."

( kshiers@herald.ca)