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Keeping the Fish Safe - Dredging doesn't harm fish

According to scientists Claudia Wise and Joseph Green of the US Environmental Protection Agency, suction dredge mining does not harm fish and may actually improve the fish habitat.

Wise, a retired physical scientist and Green, a retired research biologist have done extensive research on the topic and have concluded that no evidence exists to substantiate claims made by environmental activists that dredging harms fish. In fact, they have found that dredging benefits the habitat of salmon and other species by improving rivers and streams.

"Any negative effects of suction dredging on fish or fish habitat are insignificant. The benefits definitely outweigh any of the negative effects in any of the studies I've ever seen," Wise said in recent interview.

In almost every study, the environmental impact of suction dredge mining on fish - including salmon - and fish habitat has been proven to be "less than significant," Greene said.

Dredging creates ideal environments for fish and marine life by creating pockets in the bottoms of riverbeds and streams. These give places for fishes like salmon to spawn where there are naturally limited areas of gravel (called refugia).

In the absence of dredging, the gravel on the stream and riverbeds has become so compacted that fish cannot always find a natural place to spawn.

When suction dredging creates small pockets (or manmade refugia), they are creating spawning areas where none had previously existed. After a year of dredging tailings settling, the areas become more stable and attractive to salmon, and they safely spawn - helping to increase the salmon population.

Even one nest of salmon eggs (called a redd) can create thousands of new salmon - a significant improvement in some rivers. Both Wise and Greene concur that most, if not all, the media coverage of the suction dredging debate has been one-sided in favor of environmental extremist groups.

The facts - backed by science and nature show that with controlled dredging (never in spawning season), in five or ten years from now the salmon population in Oregon and Washington could increase to surpass that of Alaska and British Columbia.


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Featured Project

Hurricane Damage Restoration

Florida Keys


  • Remote Island Location 3 miles from mainland in FL Keys
  • Hydraulic Dredging to Geotextile tubes
  • Automated Polymer Injection System for Material Dewatering and Clean Effluent Requirements
  • Dewatering site constructed on sectional barge at island location
  • Dredging, Dewatering, Hauling and Disposal all simultaneously
  • Geotextile tubes transported by barge back to mainland daily for offloading into trucks
  • Sensitive Marine Benthic Resource avoidance and protection integral part of project requirements


C&M Dredging performed an environmental restoration dredging project to reverse impacts caused by hurricane damage to an island resort in the Florida Keys. A canal system and basin system that was in place for barges and vessels that serviced the island resort daily had been filled in by hurricane-force winds and tidal surge.

The difficulty was that the project site was 3 miles from the mainland, on an island.

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