How Marine Dredging Affects Wildlife: A Comprehensive Study — 3R Incorporated

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How Marine Dredging Affects Wildlife: A Comprehensive Study

Marine Dredging How Often - Coral Reef

There’s no way around it: marine dredging affects wildlife. What you may not be aware of is that it often affects the wildlife population positively over the long term. Although dredging may negative effects during the actual act of dredging, these can be minimized and are often very short term while the work is being performed. The key is to hire a professional marine dredging consultant to ensure you’re minimizing the impact.


So what exactly happens during and after marine dredging? How will wildlife react? What can be done to minimize the impact? We’ll take a look at all these questions to get a better understanding of what dredging does, and does not do, to affect wildlife.


How Marine Dredging Helps Protect Wildlife

The reason for the dredging is just as important as the dredging itself. If you’re dredging to remove contaminated soil, or if you’re doing it to restore depth to a lake that is disappearing due to erosion, the benefits to wildlife are fairly obvious: you’re repairing or maintaining an environment that they require to survive and stay healthy.


Marine Dredging Affects Wildlife - Saltwater Fish


What may surprise you is that in most cases dredging doesn’t even affect fish levels. Although it can be disruptive during the actual act of dredging, the issue has been well studied. California has studied the issues extensively and have noted these studies in dredging laws:


“…the Department finds that suction dredging subject to and consistent with the requirements of Sections 228 and 228.5 will not be deleterious to fish.”


Dredging doesn’t start and stop with the act of removing material. Consideration must also be given to all aspects of dredging – including what happens to the dredged material. Simply moving the problem around won’t solve anything.


Although dumping dredged material in the landfill won’t hurt anything, it could be more more effectively used to promote wildlife elsewhere. The US Army Corps of Engineers have actually studied the issue and found that there are many uses for dredged material that can benefit the environment and wildlife beyond the dredging site itself.


Minimizing the Impact of Dredging

It’s important to take every step possible to ensure the type of dredging you’re looking to employ. We’ve already talked at great lengths about the differences between mechanical and hydraulic dredging, but there are positives and negatives depending on what you’re looking to accomplish.


When done properly, dredging can have almost no impact on wildlife. This is why it can often be accomplished in very sensitive environments. It might seem obvious that no dredging would ever be allowed in a national wildlife refuge, but it may surprise you to know that’s not the case. Dredging is one activity that has constantly been permitted by governments in these sensitive areas when done correctly.


“Negligible displacement could potentially occur during dredging, but no significant migratory waterfowl patterns would be impacted as a result of dredging.”


This is why: it’s important to hire firms that provide quality dredging services. Firms with a track record of environmental protection will have a much better chance at getting approval to perform the work. Having the right experience and tools can make all the difference in your dredging project.


Potential Negatives to Dredging

One major way in which dredging can negatively impact wildlife is when it’s done incorrectly. One study showed that even with the best intentions, dredging can have negative consequences:


“Technical constraints, like underwater obstacles, can prevent dredging equipment from accessing sediments and dredging can uncover and re-suspend buried contaminants, exposing wildlife and people to toxicants.”


It’s important to note that even with the best preparation and most experienced contractors, there are always unknowns. Of course the more experience you hire, the more likely you are to eliminate surprises, but this can never be entirely mitigated.


In other cases, dredging is necessary, but it is altering the wildlife landscape. In one case outside of New York City, the Hudson is being dredged to clean contaminants from the riverbed. Although most people would say this is very important work, it’s not entirely without consequences:


“Dredging and capping/backfilling activities in the Upper Hudson River are destroying mussel beds and mussel habitat, which are not being replaced as part of the remedy for the Hudson River PCBs Superfund Site.”


The best way to mitigate the potential impacts is not to stop dredging, as removing contaminants is clearly the priority, but to find a way to restore the environments as required. This is where the short-term impact of dredging can be a real problem, but the long term benefits far outweighs these short term concerns.


Working with Experienced Professionals

We can’t stress this enough. Experience can do wonders to protect wildlife during the dredging process. If you destroy an ecological area, it can take decades or centuries to recover. It’s important that you do your research first, to ensure you’re making the best decisions possible to minimize the impact of dredging.


Marine Dredging Affects Wildlife - Crane Dredge


If you have any questions about dredging or what’s involved, contact our team to find out the options available to you. We take the environment very seriously, and have been involved in many environmental cleanup disasters, so we know how fragile wildlife habitats are. Safety and wildlife protection are our top priorities. For a free consultation, fill out our brief dredging quote form today!


If you’re interested in having a conversation, pick up the phone and call us at (864) 848-1312 or email us at

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