ACBDA: Measures In Place For Sediment Plume

October 28, 2015

The depositing of dredged material from the North Channel into the South Basin in Dockyard has, expectedly, created a sediment plume that may have some in the community concerned about the impact on the marine environment, the ACBDA said today.

The ACBDA, as facilitators of South Basin infill project, said they want the public to know that this “sediment plume was anticipated and measures have been put in place to both contain the deposited material and monitor the turbidity in the water.”

The Niccolò Machiavelli dredging ship in Bermuda today:

NICCOLO MACHIAVELLI Dredger

“Bermuda Environmental Consulting Ltd. [BEC], the environmental advisors for the ACBDA, were on site from the start of the deposition as part of the monitoring plan,” the ACBDA added.

“As a result of some leakage, caused by unexpected high winds and moon tides, additional protection around the new bridge has been added and will be further reinforced as the winds ease.

“The steps taken to mitigate the environmental impact of this project include a sophisticated monitoring system in the waters around the South Basin.

“Contractors have also installed turbidity curtains around the area where the dredged material is being deposited, including both “silt curtains” and a “bubble curtain” that allow the scows to access the area and deposit the dredged material.”

“Just like we experience similar conditions after a period of high wind or waves, short-term spikes in turbidity are not highly threatening to marine communities. As long as these plumes are not allowed to persist it is unlikely that detectable harm will occur,” says Jack Ward, president of BEC.

“Over the short term this is more of a ‘visual insult’ than a real environmental concern. This milky water is caused by very fine particulates that are slow to settle to the bottom.”

“It should also be pointed out that we had previously relocated 130 coral colonies from the landfill footprint within the South Basin as well as a number of fish of various species,” says Mr Ward.

“We’ve been monitoring turbidity in the area for some time now and see higher levels of turbidity when the cruise ships arrive or depart Dockyard than those recorded today,” says Mike Winfield, CEO of the ACBDA. “But we are obviously committed to minimizing the impact.”

“This is a situation we anticipated,” says Mr Winfield. “Now that the dredged material has started arriving we are making further refinements to the containment system and will continue to do so throughout the process, as necessary.”

Last week the Ministry of Public Works said the widening of the North Channel — to accommodate the new generation of cruise ships — will commence at the end of this month, and the dredging will be a 24 hour, seven day a week operation and will take approximately one month to complete.

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Comments (26)

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  1. We thank you and others Jack, for the updates and insights as progress is being made…

  2. Watching says:

    The fact that the plume was expected does not mean that our precious coral reefs are going to weather this dredging event successfully.

    BEC needs to ensure that the dredging is adequately spaced out such that tests can be carried out to evaluate damage done/amount of sediment collecting on the reefs per unit of sand removed. This will be key to evaluating whether our natural environment can withstand this operation.

    Based on the devastation that the lionfish are wreaking on our coral reef systems we need to remain vigilant and ensure that our reefs are going to thrive in future. If the trade-off is to import the fill required for the AC village, then this option should be presented to the public.

    We know from Dr. Sarkis’ report that our coral reefs our extremely valuable. On this basis, we should take very seriously potential impact of the current dredging operations.

    • Terry says:

      Garbage.
      Once again you take the high road.
      Those large Cruise Ships that transit the channel stirrup more **** than you do.

      Have a name ‘Watching’?

      I am no fool.

      • That’s so true Terry…But of course, certain people like to lean towards making thing, “political” without calling names. Too bad they aren’t willing to accept it all for the betterment of all and not just a few.

    • bermy says:

      They have survived the other times dredging has taken place

      • cole says:

        How do you know that the reefs were not substantially degraded when the channels were first dug? There were no reef surveys done in the 1940s or before…

    • Build a Better Bermuda says:

      Have you ever seen the waters during storm, the turbulence and materials that are stirred up? Just yesterday you couldn’t see more than 10′ into the water from the rough weather on north shore. Our coral reef system has survived millennia of sand plumed waters. Unless there is a major containment failure, the Eco system will survive just fine.

  3. Hmmmm says:

    Those moon tides can really sneak up on you. It’s not like their predictable or anything.

  4. Legalgal says:

    So is the dredging really a way to do the AC landfill? What is the position with BEST’s representations?

    • Build a Better Bermuda says:

      The dredging was a planned event outside of the AC, it just presented an opportunity for materials needed to accommodate the AC plans

  5. paperboy says:

    I appreciate this communication and would welcome more information and metrics with respect to this project and in particular clarification with the following statement:

    “Just like we experience similar conditions after a period of high wind or waves, short-term spikes in turbidity are not highly threatening to marine communities. As long as these plumes are not allowed to persist it is unlikely that detectable harm will occur,” says Jack Ward, president of BEC.

    How do you define not highly threatening and unlikely? Would it not make more sense to stop the project in high winds and eliminate the risk entirely? How will you manage and measure the harm this is causing?

    • Build a Better Bermuda says:

      Why, if the high winds produce normal spike of sand plumes and turbidity, what does the dredging/filling add to… ultimately nothing. the dredging produces little pluming as it vacuumed up anyway, and the fill is being deposited in a confined area and any leakage plumes would not have any worse effect than Mother Nature already does, in fact turbulent conditions would merely accommodate a wider distribution of the plume.

  6. sage says:

    “It should also be pointed out that we had previously relocated 130 coral colonies from the landfill footprint within the South Basin as well as a number of fish of various species,” says Mr Ward. You or I would be fined $50,000 for removing any live coral, BEC digs out 130 colonies, no problemo. Relocated fish too? Hmmmm.

    • Person who knows a little says:

      Would you rather they are dredged and die?

      • sage says:

        They aren’t dredging the landfill footprint area where the corals were moved from genius.

  7. cole says:

    Castle Harbour was dredged for the airport in the 1940s and the reefs have still not recovered over 60 years later. Sediment from dredging is not the same as sediment from storms. Bacteria and toxic compounds from deep in the sediment kill coral and other marine animals. A basic google search for sediment impacts on coral reefs paints a clear picture that dredging is to be used as a last resort. The reefs provide valuable services we often take for granted, while the cruise ships are looking out for themselves, not Bermuda, and may change their long-term plans and leave us wishing we had instead invested in local hotels or enhancing international business.

  8. cole says:

    From Ward’s website:
    “The dredging needed to upgrade the channels as well as shipping activity itself can harm marine life:

    by destroying or burying it,

    by creating sediment plumes which can smother animals and plants,

    by the noise which can affect marine animals such as whales, turtles and fish by disrupting their behaviour, harming or killing them.

    Organisms that need light and are easily smothered by sediment falling on them are most likely to be harmed by sediment plumes. Corals and seagrasses are particularly vulnerable as they need both light and clear water to survive.

    They are important to the health of our island as they provide important habitat and food for fish and other marine life, help buffer our island from storms and provide an important service by filtering the water to keep it clear for other
    marine life. “

  9. Dr Thad Murdoch says:

    I recommend that folks google the following for a scientific evaluation of the impacts of sediment from cruise ships in Bermuda:

    ENVIRONMENTAL EFFECTS OF THE CRUISE TOURISM BOOM: SEDIMENT RESUSPENSION FROM CRUISE SHIPS AND THE POSSIBLE EFFECTS OF INCREASED TURBIDITY AND SEDIMENT DEPOSITION ON CORALS (BERMUDA) Jones R (2011) Bulletin of Marine Science, Vol. 87, No. 3, 2011, p. 659-679

    • sage says:

      That would only reinforce what I have been watching happening since the 70′s in the harbour, and the car ships are as bad or worse.

  10. Truth is killin' me... says:

    KEY POINT FROM THE ABOVE STUDY…keep all cruise ships below 10–12 kts while entering and departing the island through the shipping channels. The corals will thank you for it. While at sea go as fast as you want. If the cruise ships don’t abide…FINE THEM!

  11. Flash says:

    “It should also be pointed out that we had previously relocated 130 coral colonies from the landfill footprint within the South Basin as well as a number of fish of various species,” says Mr Ward.

    Sure….. has anyone actually dove the area prior to the filling? Well, tons of fish, lobsters, and healthy corals are still there (as least a couple of days ago). So what was removed? – no signs of removals of anything. This whole thing is an environmental disaster.

    • Mucho gusto says:

      So you’re calling them liars? Just file a PATI request to see for yourself what has been done instead of shooting your mouth with no evidence to back it up.

    • sage says:

      Careful, talk like that can make you public enemy #1.

  12. Sincerious says:

    Well for all the “axperts” on this thread I would just point out a fact not a guess or a theory. The decision to build the US base ( and our airport) resulted in a dead space for decades within castle harbor. All destroyed by the silt. We see the area has come to life but it has taken literally decades to occur. Now if we have no issue killing off more coral reefs in the desire for expedience (rather than necessity ( as to where it is dumped) than so be it , our great , great maybe great grandkids can see the coral life come back if the island is not already underwater from the other ignored issue climate change.
    The issue of the silt deposit was known and the concerns were raised and basically ignored.
    The question you need to ask is what are the mitigation strategies and what happens if we get a hefty winter storm while this crap is contained and the containment fails.
    How will that be dealt with? You may be surprised there is no answer I won’t.