Sediment destroyed reefs in Miami during dredging

| 03/05/2016 | 36 Comments
Cayman News Service

Coral killed by sediment from the Port of Miami Deep Dredge Project (Photo courtesy Florida Department of Environmental Protection)

(CNS): Over 80% of coral reefs near to the area of large-scale dredging at Miami’s port were damaged by sediment, despite a plan by the Army Corps of Engineers to minimise the damage, a new report by the National Oceanic and Atmospheric Administration has found. The revelation will fuel fears in Cayman that the planned direct destruction of reefs in the dredging footprint for the proposed cruise berthing facilities in George Town will only be a fraction of the loss, as much more of the reefs will be killed by sediment.

The report found that as much as 81% of the reef near the dredging site was buried in sediment, and up to 93% of the partial coral death was due to sediment, regardless of mitigating features that were meant to minimise the damage.

Environmentalists said that this shows the sediment spread much further than anticipated from the dredge site in Miami. Underwater monitors to measure the sediment also failed to work, according to the report.

See New York Times report: Dredging of Miami Port Badly Damaged Coral Reef, Study Finds

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Category: Marine Environment, Science & Nature

Comments (36)

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  1. Anonymous says:

    The crucial ‘small detail’ everyone seems to overlook: ocean acidification, which causes coral to die, is coming. It is too late to stop it. The world’s oceans are absorbing global warming’s CO2 and the corals are de-calcifying, losing their calcium, their structural substance. Dock or no dock, it don’t matter. World wide greed will win, we will lose.

  2. Anonymous says:

    The reef area represents an important part of the cultural heritage of the Cayman Islands. The famous 1932 wreck of the Balboa sits in the berthing facility’s way as does Devil’s Grotto and Soto’s Reef, the latter named after the pioneer of recreational scuba diving, Caymanian Bob Soto.

    Many coral reefs in the world are remote and inaccessible. The George Town reefs are among the most accessible reef systems in the world. Their vitality is important to many Cayman Islanders and as such have been protected by dedicated civil servants who work for the Department of the Environment. An example of one protective measure is that divers are not allowed to wear diving gloves as this can encourage people to touch the sometimes sharp reef surface and potentially damage the coral. If a diver is caught wearing gloves it can result in a custodial sentence. This is how seriously Caymanians take the protection of their coral reefs.

    It therefore seems unimaginable that the current Government should be supporting the construction of the berthing facility which requires reef dredging. On a first read the environmental law relating to reef damage seems clear: Damaging coral by anchor, chains or any other means anywhere in Cayman is prohibited… Violation of any of these
    laws is an offense carrying a penalty of CI$500,000 fine and one year in jail.

    It transpires that the National Conservation Law (dated 2013) allows permits to be issued, by the Government itself, which allows infrastructure developments to impact on coral reef systems. This said, and with further reading of a multitude of official documents, it appears that the proposed project is in breach of: its own Terms of Reference; International Conventions; and as such does not comply with the stated National Conservation Laws.

    This all adds up to the plans for the berthing facility flying in the face of the Island’s Biodiversity Action Plan which states that by 2015 all coral reefs in the Cayman Islands are fully protected and that anthropogenic stressors will be eliminated.

    How do we misinterpret this?

  3. Anonymous says:

    Absolutely no comparative “apples to apples” application to Cayman whatsoever. Let’s put things into perspective and be truly open minded and totally impartial and unbiased in the analysis of the facts comparing dredging in Miami to Cayman.
    1. The geology and marine environment of Miami harbour is totally different and has no comparison to Cayman.
    2. the duration of the dredging of Miami harbour was two 2 years or 104 weeks duration compared to 10-14 weeks estimated for GT harbour.
    3. the volume of dredging in Miami harbour was multi millions of cubic metres of material compared to the revised new dredging plan for GT harbour which is now only 167,000 cubic metres of dredging.
    4. The cost of the Miami harbour dredging was around US$200 million similar in cost of the entire construction and development of Cayman’s Cruise Berthing Facility.
    Now really can anyone be intellectually serious in making this comparison in the first place.
    The public can be honestly now be informed of the truthful facts to be able to form their own opinions whether this is a fair comparison to use and apply to Cayman’s Cruise Berthing Facility Project..

    • Anonymous says:

      Now can someone crunch the numbers and revise the estimates proportionately, so we can have the real, real answer? Its still relevant, even if disproportionate.

  4. Anon says:

    everyone posting against this dock have and still is enjoying something that part of the environment had to be destroyed to build , it’s the way the world works now we stopped living in caves a longtime ago

    • Anonymous says:

      Yeah, and that’s going so well for the world. Let’s keep destroying our earth until we are forced to extinction.

  5. Anonymous says:

    It would be nice if they would release the environmental impact statement. Everyone is making up their own facts.

    • Just Askin' says:

      Any thoughts as to why they might not want to release it?

    • Anonymous says:

      Mott MacDonald’s Final Draft EIA from Nov 2013 has been out for some time and identified a catalog of serious “not-to-be-dismissed” scientific risks. The new EIA has not been released – and we wonder why not? Perhaps because the science and risks have not changed by paying a different firm another fee?

  6. Anonymous says:

    When all the banking is gone, just as you see daily new pressures on that industry, the only things left bringing money into Cayman will be Cruise and stayover.
    We need both and to have both for the future, WE NEED A DOCK

    This Miami garbage example was dismissed as not relevant months ago.
    The anti dock group only has made up irrelevant stories to push from the start.

  7. Anonymous says:

    My God, with the truth staring them in the face, the Kirkbots stick to their position of greed. This project will never get off the ground due to the lack of the very thing the pro dockers think it will produce…money. It will obviously only produce the death of the coral and theGeorgetown harbour and stay over tourism.

  8. Cheese Face says:

    You reading this Alden? Stick your dock where the sediment don’t shine! Or sun, maybe it’s the sun? Yeah, the sun too!

  9. Anonymous says:

    The Miami project is a thousands times bigger than anything proposed for Cayman!

    Miami dredging took 2 years
    Miami Project cost $200 Million in dredging alone
    Miami project was 2.5 miles of dredging down to 52 ft

    Cayman port is like comparing a grain of sand to the hole sahara desert.

    • Anonymous says:

      Just as the Miami project is thousand times bigger, so it the land mass above and underwater, 12:13…. Get your head “out of the sand”!

  10. Sharkey says:

    I wonder if people could ever change to see the difference between
    greed and self- intrest and destruction ? Have anyone seen and monitor dredging in the north sound, when the wind is mostly from the northeast the silt from the dredging still be taken out to the reef.
    No one can tell me that the dredging that had been done in the north sound has not caused significant damages to the reef in the north sound and is killing the reef / corals.
    I have seen all the reef when it was all alive and in pristeen conditions before and after any dredging was ever did in the north sound .

    George town harbor is a worse spot to do dredging because the wind and currents would be against any silt containment , which then the silt would be taken out to Southwest point and down to seven mile beach / environment because of currents .

    I think that the government need to stop thinking about the cruise ship dock , because it looks like Cuba is the one that would need a cruise ship dock.
    I think that the government should be thinking about how they are going to keep tourism and economy alive for the future of the Islands.

  11. Anonymous says:

    Tender owner supporters (including the editor) are in full defense mode again! Let’s see all the old biased articles written by environmentalist “scientists” popping up now! Hilarious effort!

    • Anonymous says:

      And here come the ignorant comments from those who choose to ignore the facts.

      • Anonymous says:

        Exactly, all the environmental crazies that are ignoring how important this project is for Caymanians and Cayman are the few that are making uneducated comments. Push on with the piers, keep Caymanians employed!

        • Anonymous says:

          Do you think Caymanians are going to build this dock and then apply for the security guard positions? hahaha, surrrreee, get ready for more work permits bobo.

  12. Anonymous says:

    Hey, hey, hey … we have a member of our esteemed richer, Whiter Caymanian society pitching the port proposal to us, the UK and the wider world – so all of this malarky about sediment and reef destruction will just have to take a backseat.

    Never mind the glaringly obvious conflict of interest.
    Never mind the curious reality of previous administration being cursed to hell for the same proposal – but it is now mysteriously worthy of serious consideration.

    Unna jus hush and try let de progress proceed. Cha!!

    • Anonymous says:

      So you obviously are black and racist with the way you seem to resent white people. Racism goes both ways, I’m not sure you understand that. Stop being a hypocrite, leave race out of it, you’re selling yourself short.

  13. Anonymous says:

    This study is absolute utter hogwash. The coral reefs are booming in the florida keys in fact just south of miami’s governor’s cut. Which happens to be just south the intracoastal. The silt results from Florida’s shelf, with currents moving northward along the coast is the cause of depositing slit not dredging! The intra coastal also dump massive amounts of everglades water into that stream. The keys are dredged everywhere and the reefs are perfectly fine. Florida’s shelf is 1000% different than Cayman very deep reefs very close to shore. Silt cannot accumulate for any long periods of time on that side of the island. Also the north sound is also full of silt, The north snound barrier reef is perfectly fine.

    These “Scientists” are a complete farce.

  14. Anonymous says:

    XXXXXXX I am sure this will never be printed and will be censored as so many people are afraid of the truth because it does not support their agenda.

    CNS: Read the CNS Comment Policy regarding pet hate of moderator. No comment that ends with this sentiment will ever be published.

  15. Anonymous says:

    Move the dump to BTown with that money Alden, please. Forget about the homo haters.

  16. Anonymous says:

    Won’t ever get built just like the tip no one has the balls to make a decision. And if and it is a big if still 6-10 years away with this countries building record.

  17. Anonymous says:

    Cost of living is going above and beyond any other island country in the caribbean. Medical insurance covers nothing your sick of. People are losing jobs, homes,can’t pay electricity bills, water. We are going to lose more tourism jobs. You worried about the smallest amount of coral reef to be dredged. Why weren’t you worried about 2000 feet of coral reef on the drop off for the last 45-50 years? Every time a cruise ship dropped an anchor to put the ship in place was never a concern or protest by newbies.
    We are not the same dredging foot print like Fla in the least . They took out over 2 miles of bottom it had to affect the coral reefs. Their bottom is flat for miles out to sea. Ours on the other hand drop to 1300 feet from shore where the gangways open ,when the ships are perpendicular from shore. Get the pier built we are wasting time.

  18. Anonymous says:

    Kirkbots unite! Do not allow the antiberthers to dredge up this type of anti-pier sediment…, sentiment.

  19. Anonymous says:

    Of course the coral and sponge suffocating sediment was written about in the PEIA, the EIA and every report and discussion on the topic since it began. Suspended particulate will change the temperature, clarity, acoustics, and density of the surrounding water for miles. This is not new info. Pick any of the dozens of worldwide port dredging operations, and few to none are on the scale of destruction and recklessness still contemplated in Cayman.

    • Anonymous says:

      False and uninformed comment…yet again. The Cayman project is a drop in the bucket compared to the Florida project. Turks and Caicos’ number 1 dive spot is their cruise pier. The fish life under it is astonishing. There will be more fish life under that pier than the few pieces of coral rubble that is left there now.

      • Anonymous says:

        True, the Cayman project is a drop in the bucket compared with the Miami project, but Cayman is a drop in the bucket compared with Miami so it seems the ratio of destruction will be at least the same, if not worse here. Thanks for making the point.

      • Anonymous says:

        Dear Dismissive Kirkbot,

        Some of us keenly read the PIEA and the Mott MacDonald’s Final Draft EIA (Nov 2013) – maybe those that portend to care about Cayman should too? Or ask someone literate read it to them?

        Cayman’s stratigraphic conditions are totally different than Miami or T&C. Forgetting that Cayman is the summit of a submarine mountain ridge on the tectonically active “Orient Fracture Zone”, the island has a granodiorite base, followed by a cap of basalt and topped with 1300m of porous and highly fractured tertiary carbonates (lithified coralline limestones and dolostones interspersed with hard and soft lenses and calcareous sand). This hardpan “crust” of young white powdery deposits conceals porous calcified limestone coral and subterranean caves – like the ever popular and magical Trinity Cave dive site just meters away from proposed development.

        The Mott MacDonald report cautioned that they have no idea what’s under the hardpan or whether it can support the weight and stress of the piling structures contemplated to support the pier, the weather, and the mechanical torque of ships attached to it (localized piling collapses are not good when there is a >$200mln structure above with people on it – that is CNN headline news stuff). The weathering of existing fractures through water funnelling below the surface and chemical dissolution of exposed minerals are also pointed out. The calcareous sand/soils are more susceptible to particle breakage and crushing and extend approx 1200 ft off GT Harbour, beyond which the bathymetric relief declines quickly (edge of mountain ridge) all the way down to the Kirk Pride and beyond. Many of us have been down there and perhaps can better visualize the terrain challenges.

        Here are some extracts:

        Chapter 3 EIA Considerations

        3.1 Introduction p13
        3.2 Natural Hazard Assessment p13
        3.3 Geology and Soils p19
        3.4 Coastal Processes p22
        3.5 Sediment Transport and Water Quality p26
        3.6 Stormwater p31
        3.7 Air Quality and Greenhouse Gases Emissions p34
        3.8 Noise and Vibration p41
        3.9 Terrestrial Ecology p47
        3.10 Marine Ecology p51
        3.11 Cultural Heritage p54
        3.12 Traffic and Pedestrian p62
        3.13 Cruise and Cargo Operation p66
        3.14 Socio-Economic Assessment p71
        3.15 Business District – Impact Evaluation p76
        3.16 Landscape and Visual Impact Assessment (LVIA) p77

        3.3.2 Potential Impacts

        Potential impacts from the proposals are likely to include:

        Dredging and Extraction
        * The dredging of material for the berthing facilities may result in the
        mobilisation of sediment into the water column leading to increased turbidity (considered again in detail in Section 3.5). It has
        been noted that “in the presence of coralline limestone, the cutter
        head invariably generates considerable fines in the 10 micron range
        that are difficult to settle” (Sciortino, 2010).
        * The stratification of the bedrock, especially the presence of hard
        lenses may cause problems for the cutting equipment.
        * Potential de-watering impacts during the extraction process
        (considered again in detail in Section 3.5).

        * Steel piles for the suspended deck are to be bored into the bedrock;
        however the presence of subsurface caves and voids within the
        limestone has been noted. If the stability of these caves is
        compromised this may develop into local collapses.
        * The superficial materials are susceptible to breakage and crushing
        which may lead to increased turbidity levels.
        * The release of sediments in the dredging process will lead to
        alterations in the superficial material.

        * The dredging of the area will lead to permanent changes to the
        erosion regime within the harbour area.
        * If piles are drilled into the bedrock they may weaken the bedrock,
        and lead to the development of localised failures.
        * Increased ship operations may lead to disruption of the seabed.

        The UK Admiralty Pilot indicates that westerly equatorial currents
        predominate along the northern coast of Grand Cayman. However,
        George Town harbour is protected from these currents by the mainland.
        Direct measurements of local currents have been recorded by both
        Halcrow Inc and the Department of the Environment of the Cayman
        Islands Government (DoE). The results of the measurements show a
        directional trend generally parallel with the western coastline of Grand
        Cayman, with a tidal flow oscillating between northerly and southerly
        directions. The northerly flows were recorded as being more
        predominant than southerly flows, and local directional variation was
        apparent due to variations in local bathymetry.

        Permanent changes to water levels, flows and flow directions and
        sediment deposition and erosion regimes within the intertidal
        harbour/tidal areas could occur following the completion of the
        berthing facilities and dredging activities.

        Further data on waves and currents within George Town Bay will need
        to be collected to supplement existing data from Halcrow (2008).
        Bathymetric surveys were carried out during 1999 and around all three
        Cayman Islands in 2005/2006 however, these may not be of sufficient
        resolution. An up to date survey is recommended.

        …and on and on…not uninformed at all.

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