Coral-List: Coral Morphologic presents “The Endangered Elkhorn Corals of Fisher Island & Miami’s Deep Dredge (Part 1 of 3)”

May 26

With so many dredge projects being proposed on reefs around the world, here
is another reminder of just how negative the impact can be.

The massive Army Corps of Engineers’ Deep Dredge of Port Miami has now been
ongoing for 18 months nearly non-stop (with several more to go). Not only
have the Army Corps failed to transplant a large number of
federally-protected staghorn corals (*Acropora cervicornis*) living within
the offshore dredging area, they have also produced copious amounts of silt
that has smothered acres of adjacent reef area outside where they claimed
would be impacted. We have documented multiple corals having been
improperly transplanted by their paid contractors, in some cases not even
bothering to use adhesive to reattach them. In other cases, corals that
were transplanted still wound up smothered to death due to their horizontal
attachment on boulders which collects falling silt on their tissue and
doesn’t allow for easy sloughing off.

After our most recent health survey of several highly unusual elkhorn
corals (*Acropora palmata*) living on a coastal seawall along Fisher
Island’s marina here in Miami, we have decided to bring their plight
public. While staghorn is not particularly uncommon offshore Miami, elkhorn
is so extremely rare that is almost absent. It is quite possible that these
are the most ‘coastal’ of all of Florida’s elkhorn colonies… they are
literally growing along the shoreline in knee-deep water adjacent to a
marina and a wastewater treatment plant. The fact that they have persisted
for so long in man-made urban habitat is a testament to their resilience.
However, it is clear that over the past year and half of dredging, the
health of these colonies has declined precipitously. Coral Morphologic
proposes that these elkhorn corals, which are receiving the full brunt of
siltation stress, should be given special protection to ensure their
survival before the summer heat adds to their stress. Given that there are
multiple independent elkhorn branches as a result of past white pox die-off
(that caused them to become discontinuous sub-colonies), we propose that
they are ideal for in-situ mariculture in a coastal coral nursery here in
Miami where they can be carefully propagated into large enough numbers for
subsequent laboratory research and local reef restoration.

Video of the elkhorn coral and improperly transplanted corals on Fisher
Island can be found here:

http://coralmorphologic.com/b/2015/05/21/fisher-island-corals-the-saga-of-the-deep-dredge-part-1-of-3

Stay tuned for Part 2 follows up with the fate of two different hybrid
fused-staghorn (*Acropora prolifera*) corals living alongside the elkhorn
corals on Fisher Island.

Cheers,
Colin Foord
Coral Morphologic coralmorphologic@gmail.com via coral.aoml.noaa.gov

Coral Morphologic: Bad Year for Coral Bleaching & Sediment on Miami coral reefs

Coral Morphologic

12:09 PM (3 hours ago)

to coral-list
A combination of hot weather and sunny days in summer 2014 has resulted in
very a bad year for coral bleaching in South Florida. Recently, we surveyed
the natural reef (‘first reef tract’) just offshore Fisher Island here in
Miami. Unfortunately, the water has been kept exceptionally silty from the
Army Corps’ ongoing dredging of nearby Government Cut. The water is 10-15
feet deep here, and nearly all of the coral heads on the reef were
bleached. However, the most alarming thing we observed, was the prevalence
of black band disease infecting many of the brain corals. As evidenced from
the video, the dredge silt has settled on the corals, and seems a likely a
culprit in causing this disease outbreak. Prior to this summer, we have
never observed BBD as prevalently on Miami’s corals. Currently, the dredge
ships are operating just outside the mouth of Government Cut jetties,
resulting in plumes of silt that smother corals on the natural reefs in
every direction.

See the video of the bleached and diseased corals here:
http://coralmorphologic.com/b/2014/09/14/miami-coral-bleaching-report-september-7-2014

Fortunately, the water temperatures have steadily decreased since the start
of September, so we are hopeful that the bleached corals throughout South
Florida will begin to recover soon. However, up here in Miami with the Deep
Dredge ongoing, our corals may be too stressed out, diseased, or smothered
to survive. We will be monitoring the situation closely, and will continue
to update as necessary.

Cheers,
Colin Foord
Co-Founder Coral Morphologic
www.coralmorphologic.com
________________________

Why I am Still Opposed to Widening and Deepening Key West Harbor to Accommodate Larger Cruise Ships by DeeVon Quirolo

Points to consider in the discussion of whether to vote for a feasibility study to widen and deepen Key West harbor:

The science has been indisputable for a long long time on the negative impacts of siltation and dredging on or near coral reefs. Corals are living permanent structures on the ocean bottom comprised of colonies of living polyps that need clear, clean nutrient free waters to thrive. Dredging creates fine sediment and silt that covers corals, preventing photosynthesis and resulting in massive mortality, especially for Elkhorn and Staghorn corals–which cannot slough it off as can other corals. Such sedimentation also reduces the ability of all marinelife, including tarpon and other fish that utilize this area for habitat, to survive.

Episodic storm activity may stir up sediment but the wave action of those storms can also remove loose particulate matter from areas of the ocean bottom. While storm activities have historically affected visibility in the harbor and at the reefs, they do not compare in scale to the massive, chronic, intense effects of outright removal of habitat and the smothering of living formations by tons of dredge sediments that would occur immediately in the harbor and at nearby downstream coral reefs if additional widening and deepening of Key West Harbor were to occur.

It is incredulous to me that anyone associated with protecting coral reefs would dispute this elementary fact of coral ecology. In addition, the health of sea grasses and myriad other marinelife that depend upon this habitat would be severely impacted, including endangered sea turtles and dolphins.

The Key West Harbor Reconnaisance Report published November 2010 noted that the harbor is included in the “critical essential habitat” for both Elkhorn and Staghorn corals under the Endangered Species Listing for them. There has not been one case of allowing removal of critical essential habitat from the Jacksonville Corps of Engineers office in the last 15 years.

It states: “Under the Endangered Species Act (ESA) of 1973; the threatened coral Acropora cervicornis (staghorn coral) and Acropora palmata (elkhorn coral) could be located adjacent to the channel in the areas proposed for expansion as this area is designated as critical habitat for these species. While it is possible to relocate the actual colonies of coral, the critical habitat would be permanently removed. It is highly likely that the removal of several acres of occupied designated critical habitat (habitat where the species has been shown to be able to flourish under baseline conditions) could be considered an adverse modification of critical habitat under Section 7 of the ESA. This would be Jacksonville District’s first adverse modification of critical habitat determination in the last 15 years. It is also unknown what reasonable and prudent alternatives and measures National Marine Fisheries Service (NMFS) would include in a biological opinion to avoid the project adversely modifying designated critical habitat, as required under Section 7 of the Act.* It is expected that resource agencies would oppose any channel modifications outside the existing footprint.”

So this whole feasibility study could be a huge waste of money because there are good reasons why a permit would never be issued for the project thereafter. Surely we can find a more sustainable use of $5 million dollars—how about some stormwater treatment for the island of Key West to improve water quality?

The feasibility study is an effort to calculate the possibility of further widening and dredging in a harbor that was deepened just five years ago. Underneath Key West lies a fresh water aquifer. There are upwellings of fresh water in the harbor today. A massive deepening and widening may have severe unintended consequences on the aquifer, that at a minimum could result in salt water intrusion of that fresh water lens.

The last harbor dredging project just a few years ago included a mitigation plan by the Florida Keys National Marine Sanctuary to remove corals from the harbor with the purpose of restoring the damage. Despite their best efforts, there have been only a few of those corals planted in an offshore boat grounding site. For the most part, there has been no successful effort to restore the extent of coral colonies that existed in this area prior to the last dredging. It is therefore highly unlikely that another dredging project will succeed in restoring the habitat removed via mitigation this time either. It is just a false hope that the loss of biodiversity will be anything but an ecological disaster for this otherwise already stressed part of Key West’s coral reef ecosystem.

Often these dredge projects result in in-filling thereafter due to storm activity. Key West may be saddled with a harbor that produces chronic sedimentation without regular repeated environmentally destructive maintenance dredging. This will in turn affect the downstream coral reefs with additional chronic smothering contaminated sediment.

The greater question really is: How much more can the surrounding coral reef ecosystem of the Florida Keys handle in terms of human impacts? Isn’t it enough to have a thriving hotel, tourism and real estate industry? Can’t we draw a line in the sand and say “enough is enough”? Already the hoards of cruise ship visitors denigrates the downtown section to the exclusive benefit of a few businesses while high-end resorts and guesthouses hold their breath that this low-end massive impact to our quality of life will not repel their key markets. What about those who still hope that Key West can be a magic island home–don’t they deserve consideration?

Craig and I would encourage every voter in Key West to vote NO on the feasibility study to dredge Key West harbor….. again.

DeeVon Quirolo

Marine Pollution Bulletin: Environmental impacts of dredging and other sediment disturbances on corals: a review by PL Erftemeijer, B Riegl, BW oeksema and PA Todd

http://www.ncbi.nlm.nih.gov/pubmed/22682583

Mar Pollut Bull. 2012 Sep;64(9):1737-65. doi: 10.1016/j.marpolbul.2012.05.008. Epub 2012 Jun 7.

This is another study available only for a price, but the abstract is instructive to the issue of how dredging harms corals. DV

Sinclair Knight Merz (SKM), P.O. Box H615, Perth, WA 6001, Australia. perftemeijer@globalskm.com
Abstract

A review of published literature on the sensitivity of corals to turbidity and sedimentation is presented, with an emphasis on the effects of dredging. The risks and severity of impact from dredging (and other sediment disturbances) on corals are primarily related to the intensity, duration and frequency of exposure to increased turbidity and sedimentation. The sensitivity of a coral reef to dredging impacts and its ability to recover depend on the antecedent ecological conditions of the reef, its resilience and the ambient conditions normally experienced. Effects of sediment stress have so far been investigated in 89 coral species (~10% of all known reef-building corals). Results of these investigations have provided a generic understanding of tolerance levels, response mechanisms, adaptations and threshold levels of corals to the effects of natural and anthropogenic sediment disturbances. Coral polyps undergo stress from high suspended-sediment concentrations and the subsequent effects on light attenuation which affect their algal symbionts. Minimum light requirements of corals range from <1% to as much as 60% of surface irradiance. Reported tolerance limits of coral reef systems for chronic suspended-sediment concentrations range from <10 mg L(-1) in pristine offshore reef areas to >100 mg L(-1) in marginal nearshore reefs. Some individual coral species can tolerate short-term exposure (days) to suspended-sediment concentrations as high as 1000 mg L(-1) while others show mortality after exposure (weeks) to concentrations as low as 30 mg L(-1). The duration that corals can survive high turbidities ranges from several days (sensitive species) to at least 5-6 weeks (tolerant species). Increased sedimentation can cause smothering and burial of coral polyps, shading, tissue necrosis and population explosions of bacteria in coral mucus. Fine sediments tend to have greater effects on corals than coarse sediments. Turbidity and sedimentation also reduce the recruitment, survival and settlement of coral larvae. Maximum sedimentation rates that can be tolerated by different corals range from <10 mg cm(-2) d(-1) to >400 mg cm(-2) d(-1). The durations that corals can survive high sedimentation rates range from <24 h for sensitive species to a few weeks (>4 weeks of high sedimentation or >14 days complete burial) for very tolerant species. Hypotheses to explain substantial differences in sensitivity between different coral species include the growth form of coral colonies and the size of the coral polyp or calyx. The validity of these hypotheses was tested on the basis of 77 published studies on the effects of turbidity and sedimentation on 89 coral species. The results of this analysis reveal a significant relationship of coral sensitivity to turbidity and sedimentation with growth form, but not with calyx size. Some of the variation in sensitivities reported in the literature may have been caused by differences in the type and particle size of sediments applied in experiments. The ability of many corals (in varying degrees) to actively reject sediment through polyp inflation, mucus production, ciliary and tentacular action (at considerable energetic cost), as well as intraspecific morphological variation and the mobility of free-living mushroom corals, further contribute to the observed differences. Given the wide range of sensitivity levels among coral species and in baseline water quality conditions among reefs, meaningful criteria to limit the extent and turbidity of dredging plumes and their effects on corals will always require site-specific evaluations, taking into account the species assemblage present at the site and the natural variability of local background turbidity and sedimentation.

Marine Pollution Bulletin Report: Lethal and sublethal effects of dredging on reef corals by Rolf P.M. Bak

Marine Pollution Bulletin, Volume 9, Issue 1, January 1978, Pages 14–16
Caribbean Marine Biological Institute (Carmabi), Piscaderabaai, Curaçao, Netherlands Antilles Netherlands

http://dx.doi.org/10.1016/0025-326X(78)90275-8,

The full article is only available by paying $39.95, but the extract ends with one very strong statement for those who think that the sediment from storms compares to the avoidable impacts of dredging on corals. DV

Purchase $39.95

Abstract

Effects of dredging on a coral reef are described. Under water light values at a depth of 12–13 m were reduced from about 30% to less than 1% surface illumination. Colonies of coral species which are inefficient sediment rejectors (Porites astreoides) lost their zooxanthellae and died. Calcification rates in Madracis mirabilis and Agaricia agaricites were observed to decrease by 33%. The period of suppressed calcification exceeds that of environmental disturbance.

Science Network: Offshore dredging severely impacts coral reefs

http://www.sciencewa.net.au/topics/fisheries-a-water/item/1684-offshore-dredging-severely-impacts-coral-reefs.html
Thursday, 13 September 2012 06:00

Murky coral
The study found that sediment accumulation on coral tissue was a “strong and consistent cause of tissue mortality” and resulted in the death of whole coral fragments over prolonged periods.

Murky_coral

Image: Dan Derret RESEARCH by the Australian Institute of Marine Science has discovered that proposed dredging works along the WA coast could severely impact certain coral species found in local waters.

Scientists from the Institute along with the Australian Research Centre of Excellence conducted laboratory tests to develop lethal and sub-lethal benchmarks for coral exposed to dredging-generated sediments related to offshore developments.

The researchers tested two species of coral found in offshore locations to six levels of total suspended solids for 16 weeks, including a four week recovery period.

They tested the horizontal foliaceous species Montipora Aequituberculata and the upright branching species Acropora Millepora, both of which are found along WA’s coast.

Montipora Aequituberculata proved to be more susceptible as after 12 weeks all coral tissue under the sediment had died, exposing white coral skeleton.

Australian Institute of Marine Science senior principal research scientist Ross Jones says the sediment can affect coral by impacting their ability to feed as well as settling on the coral’s surface, causing it to expend energy cleaning itself.

“It can also attenuate light—light attenuation is a key thing because a lot of these habitats are primary producer habitats so the corals and sea life need light to photosynthesise and light is attenuated by the sediments,” Dr Jones says.

“It is like having permanently cloudy weather all the time, so it has the potential to have an effect on the marine environment.”

The study found that sediment accumulation on coral tissue was a “strong and consistent cause of tissue mortality” and resulted in the death of whole coral fragments over prolonged periods.

“What the study showed was that one species which was generally a flat plate-like coral was affected more so that the branching Acropora species because the sediment began to pile up on the coral,” Dr Jones says.

“That happened to an extent and rate at which it couldn’t clear itself, so it gradually became buried because the sedimentation rate was faster than its ability to clear itself.”

Woodside Energy funded the study and was cited as the operator of the proposed $30 billion Browse liquefied natural gas development at James Price Point, north of Broome.

Dr Jones says Woodside commissioned the study because it was investigating the effects of dredging at Browse.

“This study was initially commissioned by Woodside to try and come up with some numbers to build an environmental assessment of the project,” Dr Jones says.

He says this report is only a small amount of the research that will be conducted in the next few years into what sediment does to corals and other marine life in response to the proposed dredging.

Key West Harbor Reconnaissance Report by US Army Corp of Engineers

key_west_harbor_excerpt

Perhaps most importantly, this brief 7-page report ends with the following: DV

Under the Endangered Species Act (ESA) of 1973; the threatened coral Acropora cervicornis (staghorn coral) and Acropora palmata (elkhorn coral) could be located adjacent to the channel in the areas proposed for expansion (Figure 2) as this area is designated as critical habitat for these species. While it is possible to relocate the actual colonies of coral, the critical habitat would be permanently removed. It is highly likely that the removal of several acres of occupied designated critical habitat (habitat where the species has been shown to be able to flourish under baseline conditions) could be considered an adverse modification of critical habitat under Section 7 of the ESA. This would be Jacksonville District’s first adverse modification of critical habitat determination in the last 15 years. It is also unknown what reasonable and prudent alternatives and measures National Marine Fisheries Service (NMFS) would include in a biological opinion to avoid the project adversely modifying designated critical habitat, as required under Section 7 of the Act. It is expected that resource agencies would oppose any channel modifications outside the existing footprint.

Academia.Edu: Dredging and shipping impacts on southeast Florida coral reefs by Brian K. Walker, et. al.

http://academia.edu/1258184/Dredging_and_shipping_impacts_on_southeast_Florida_coral_reefs
Proceedings of the 12th International Coral Reef Symposium, Cairns, Australia, 9-13 July 201219A Human impacts on coral reefs: general session

Authors: Brian K. Walker 1, David S. Gilliam 1, Richard E. Dodge 1, Joanna Walczak²
1 National Coral Reef Institute, Nova Southeastern University, Dania Beach, FL, USA
² Florida Department of Environmental Protection, Miami, FL, USA
Corresponding author: walkerb@nova.edu

Abstract.
Many coastal regions have experienced extensive population growth during the last century. Commonly, this growth has led to port development and expansion as well as increased vessel activity which can have detrimental effects on coral reef ecosystems. In southeast Florida, three major ports built in the late 1920’s along 112 km of coastline occur in close proximity to a shallow coral reef ecosystem. Recent habitat mapping data were analyzed in GIS to quantify the type and area of coral reef habitats impacted by port and shipping activities. Impact areas were adjusted by impact severity: 100% of dredge and burial areas, 75% of grounding and anchoring areas, and 15% of areas in present anchorage. Estimates of recent local stony coral density and cover data were used to quantify affected corals and live cover. After adjusting for impact severity,312.5 hectares (ha) of impacted coral reef habitats were identified. Burial by dredge material accounted for 175.8 ha. Dredging of port inlet channels accounted for 84.5 ha of reef removal. And 47.6 ha were impacted from a large ship anchorage. Although the full extent of all ship groundings and anchor drags associated with the ports is unknown, the measured extents of these events totaled 6 ha. Based on the adjusted impact areas,over 8.1 million corals covering over 11.7 ha of live cover were impacted. Burial impacts were the greatest. The planned expansion of two of the ports would remove an additional approximate 9.95 ha of coral reef habitat.Ongoing marine spatial planning efforts are evaluating the placement of large ship anchorages in an effort reduce future impacts from ship anchoring. However, increasing populations and shipping needs will likely continue to be prioritized over protection of these valuable natural resources.

Full text and tables at:
Walker_et_al_ICRS2012_Proceedings_SEFL_Shipping_Impacts_Revision