With the populations of almost all large marine predators down to 90% of their pre-1970 numbers, conservation groups and responsible fisheries organizations need to quit talking and start doing something concrete to conserve and rebuild our dwindling marine resources.

In this regard, Captain Paul Watson of the Sea Shepherd Conservation Society was on the right track last year when he did something concrete to put an end to bottom dragging off the coast of Newfoundland. He dropped concrete blocks onto the bottom to snag and destroy the cursed drag nets.

But the concrete blocks do much more than just create a fishing obstacle. They create a new safe habitat for the creatures that live in the areafishing lure. A place where they can re-establish their numbers free from the terrors of bottom draggers.

Concrete disposal is a big problem in the US and many companies are capitalizing on it by offering costly removal and recycling services. The material is removed, broken up, separated from metal re-enforcement materials, and then crushed for recycling into clean land-fill and aggregate. It would be much simpler to load large sections of building foundations, road beds, septic tanks, and other material - concrete, metal, fiberglass, or wood - onto barges and scatter it onto ocean beds that have been decimated by draggers and trawlers.

The financing could come from 'bycatch' - the dead and dying creatures that longliners, seiners, trawlers, and draggers are required to throw back, dead or alive. Most of the bycatch could be sent to local government plants for processing into food for human consumption, or conversion into fish or animal food. A percentage of the profits could then be used to rebuild fish and crustacean populations.

It's not a new idea. Very successful artificial reefs have been constructed by sinking decommissioned ships and building concrete or rock breakwaters. There are a number of artificial reefs in some areas along New Jersey's 127-mile Atlantic coastline, tmade up of small sunken ships or piles of tires. And now engineers are preparing to install a concrete reef system off the coast of Cape May County to demonstrate how to counteract beach erosion. If successful, the project could be duplicated elsewhere and save taxpayers in the state millions of dollars a year in sand replenishment and beach restoration - and provide additional habitat for fish.

A concrete reef designed to make "fish ranches" off the west of Scotland has been an outstanding success. Scientists built 12 reefs in an area not previously been used for fishing said they were now teeming with fish and shellfish.

The Scottish Association for Marine Science, in Oban, began the experiment a year ago in an attempt to discover whether large-scale reefs would be viable for commercial fishing. Since then, 600 tons of concrete blocks have been sunk to the seabed. The reef provides sealife with shelter and and safe breeding areas in the blocks and already large numbers of juvenile cod and other cod species have taken up residence. They will only stay there the first year of their life but they have a chance to grow before they move away to other areas.

The group plans to have a million blocks of concrete, donated by a local firm, sunk to the bottom of the sea within two years. Dr Martin Sayer, Director of the project, said: "Reefs such as this are very widespread in places like the United States, Australia and Japan but they have never been attempted on this scale before. The overall objective is to see whether these reefs on a large scale will make any impact as a commercial fishery or if they could act as providers for commercial fisheries."

The thing is that artificial reefs can be made from everything from sunken cars or ships, concrete blocks, sandbags,culverts, railroad ties, light poles, and other large concrete or metal objects -- even offshore oil platforms. Anything that can attract and provide shelter for marine life. The fact is that such structures don't just attract the fish that live in the area, they actually increase the amount of sea by providing safe breeding areas.

There's an old saying "one man's garbage is another man's treasure' and a concrete building that is condemned for human habit seem like a palace for thousands - even millions - of sea creatures. Instead of being a pollutant, much of what we think of as garbage would actually serve to enhance the environment.

What do you think? Instead of worrying about the disappearing reefs that we can't do anything about, let's build some reefs that are impervious to climate change and acidification. If you'd like to participate please contact me. Maybe together, we can do something worth while.