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Author Topic: Black Mayonnaise Impacts to Blue Crabs & Oysters 1972 to present - T.Visel  (Read 4273 times)
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« on: October 16, 2014, 11:55:48 AM »

The Sound School
Inter-district Marine Education Program IMEP #31
Black Mayonnaise Impacts To Blue Crabs and Oysters
1972 to Present
Black Mayonnaise Deposits
Identified in Narragansett Bay Coves 1974
Capstone Question: Can Black Mayonnaise Deposits Be Located?

The Conowingo Study

Habitat Information For Fishers and Fishery Area Managers
Understanding Science Through History
(IMEP Habitat History Newsletters can be found indexed by date on
The BlueCrab.Info™ website: Fishing, eeling and oystering thread
And Connecticut Fish Salt Water Reports)
Tim Visel, The Sound School
October 2014

I struggled a bit to include this as an IMEP habitat newsletter or environment/ conservation series but after reading some of the comments regarding the Conowingo Pond case history, I felt it might be of interest to some oyster fishers as well. Perhaps the Blue Crab Forum will allow posting both threads.  “Black bottoms” have been found in core samples of Connecticut coves and in high heat linked to rapid bivalve shell lost from aragonite dissolution.  Organic deposition acidic sulfide waters has now been linked to toxic sulfide habitats in Norway, Denmark and Australia and potential acidic loss of estuarine shellfish on the US West Coast.

In 2010, I wrote up a report for the Louisiana Sea Grant folks who were desperately trying to save oyster bars following the BP Gulf Oil Spill. To keep oil from the Louisiana marshes, dikes were breached and allowed to fresh waters flood out to oyster reefs and bars and with the flooding of fresh water came the leaves and bits of organic matter with them. I don’t know for certain but I suspect rushing waters created a deadly sulfide wash as well with very low salinities. What I did know is that very productive oyster bars were now covered with foul smelling black mayonnaise material and perhaps Sapropel and now suspect sulfuric acid shell digestion must have occurred.  Shell seemed to last long periods before this 2010 event from oyster fisher accounts in the media. The hint of some acidic conditions was oyster shell was now disappearing at an alarming rate; entire oyster bars were dissolving under this “black mud.”  The comments seemed too similar to ignore.  We had the same thing happen here a century ago in Connecticut, right in New Haven Harbor. The colder storm filled 1870s saw huge storm damage along Connecticut’s coast.  Connecticut as other New England states asked the Army Corps of Engineers for help such as breakwaters. The third wall (breakwater) was completed in the 1904.

Oyster growers here at the turn of the century during a very hot New England period (1880-1920) noticed the same thing. “Black bottoms” seemed almost to consume oyster shell (George McNeil, personal communications, T. Visel, 1980s). This was very noticeable behind the recently finished New Haven breakwaters. Bottoms that were once firm or hard now turned sticky or soft. The breakwaters had altered the energy profile; they acted like a dam-- no longer did strong storms come in and remove deposits of leaves, they collected,  turned black and covered oysters. As fast as they shelled (some habitat modification, some bed cultivation), it seemed to disappear. Some oyster grow out grounds were just abandoned; no amount of shell could reclaim this habitat, a black ooze now formed in these areas.  No one had predicted what a lack of energy after the breakwaters would do to near shore habitats back then. But the New Haven oyster industry did and at first oyster growers blamed illegal mud dumping for these growing deposits, but eventually the amount of black leaves coming up in oyster dredges could not be ignored (George McNeil Conversations, Tim Visel 1980s).  Oyster companies now had to rake off leaves called “stirring” and dislodge mayonnaise in setting beds.

That is why when I read about these Gulf oyster beds, warm temperatures and riverine organics in low oxygen, acidic conditions possibly were dissolving (“melting”) the oyster reefs, it brought to mind some familiar sulfide habitat conditions. Although it was easy to see the damage down south (some oyster reefs had several feet of organic debris, after the flooding) extreme heat and low energy could allow these organic deposits to eat away at what little oyster shell remained in other areas. This is a Sulfur – Sapropel cycle and storm related event in northern areas as well; cores of our estuaries now show layers of organic matter and estuarine shell. I suggested to Louisiana Sea Grant that they equip as many boats as possible with Venturi lifts (similar to Fletcher Hanks clam lifts) and try to get these sulfides/acidic composts off oyster bars as quickly as possible, but I have no idea if it was ever attempted. What was certain was that the breach of the dikes had carried with enormous quantities of organic matter and most likely low salinity acidic waters over these oyster bars, killing them and perhaps bathing the oyster bars in sulfide waters for months.

In high heat I suspect acidic organic conditions that not only suffocated living oysters but started to eat away at the bars shell base as well.   That is why I suspect similar sulfide acidic washes occur downstream of the Conowingo Pond and not only is it toxic to blue crabs, but dissolves oyster reef base shells.  Deep cores of the Conowingo deposits should have sulfate acidic soil or in European terminology Sapropel. Comments from blue crabbers and the oyster industry make me suspicious of a much larger environmental event down stream after periodic floods.  The Saugatuck River here in Connecticut, after Irene, Lee and Sandy seems especially hard hit by organics and now sulfide formation. 

The last section is from a Megalops Report just released: The Conowingo Pond Cores (deep cores are especially valuable for checking on Sapropel formation). This case history could be huge for providing information to other states now investigating Black Mayonnaise (Sapropel) such as Arizona, New York and Florida.

If anyone wants a copy of the paper for reclaiming oyster reefs with Venturi equipment, just drop me an email at [email protected]. I am happy to send it, but I include a caution, many states do not as yet recognize Sapropel-sulfide deposits (reduced Black Mayonnaise organic deposits) and therefore removing it by any means may require “dredging permits.”  Some states are still undecided on the existence of Sapropel. It is understandable because for so long most estuarine policies promoted “natural bottoms” as very good and the fact that they can damage estuarine fish and shellfish is just being talked about now.  One advantage of Venturi lifts is that you reclaim native shell while putting oxygen into the organic material to prevent oxygen reduction collapse. Once the sulfur cycle begins it kills most veligers larval forms of oysters and blue crabs upon contact.  Eelgrass meadows are very good to fish larval stages in cold waters and in high heat becomes sulfides killing fields.

Capstone Question: Can Sapropel Black Mayonnaise Deposits Be Located?

As many states continue to grapple with high heat, organic-filled habitats, New York, Arizona, Florida and a Connecticut (NGO) have started to investigate these organic deposits for ammonia sulfide production and poor habitat conditions for many species including acidic shell erosion for bivalves, and now, sulfide toxic events for blue crabs (perhaps lobsters, but still too early to tell) and even winter flounder. We may be able to estimate Sapropel deposits and coverage, but this is just a moment in time and no policy discussions should result as a basis for habitat cover.

However, the presence of Black Mayonnaise (Sulfate acidic soil) and its sulfur-reduced end product, Sapropel, are still very controversial and are not generally studied as it relates to habitat change. For example, Tampa Bay, Florida’s estuarine program has determined that sulfide is harmful to sea grass (submerged aquatic vegetation), but has not identified reduced energy or heat as a indicators even though the first such example was detailed many years as the Tampa Bay Effect (a series of causeways crossed Old Tampa Bay) in an oceanography class I had while attending the Florida Institute of Technology at Jensen Beach in 1973.

When I returned to Connecticut it did not take long to come face to face with the Tampa Bay Effect here at home. By 1974, it had suffocated most of the oysters in a tidal creek close to my home in Madison. But black mayonnaise also appears to be cyclic and some researchers have found shell layers that indicate habitat reversals caused by “energy” events many years ago. It may come and go in long natural cycles governed by temperature and storm frequency.  For many estuarine studies sulfide toxicity was missed and its impacts to larval forms of fish and shellfish.

First Black Mayonnaise Sapropel Found by Accident in Narragansett Bay?

Deep clear cores could identify past Sapropel/shell layers. One Rhode Island core study apparently found out that by mistake. In a reprint from Estuarine and Coastal Marine Source (1977) Rhode Island. In these rivers the organic source materials is leaves.  Pages 549-561, Goldberg et al (Scripps Institute of Oceanography) contains this segment.

“Cores were frozen from Narragansett Bay September 1974 (two from the Providence River and one from the Pettaquamscutt River) and shipped back to the Scripps Institution of Oceanography. It was noted that freezing the cores did expand the pore water, however, authors noted did not appear to disturb the strata such “that annual valves, if present, became unrecognizable.”

Although researchers had agreed to a sedimentary rate of 1 cm each year of organics, it appeared as though some cores showed 11 centimeters of organic material came at once! (p. 551).  They reasoned that perhaps it may reflect an “episode” of extremely rapid sedimentation such as a “slump” or even more perplexing was the occurrence of shell layers, that is abrupt changes in the core material itself “from 15 to 22cm there is a layer of gastropod and some bivalve shells.” Plate 1 “NAR-740-2813- the clearly visible shell layers are at 15 to 22 cm and below.”

The authors suggests and I feel correctly that hurricanes have occurred in 1954, 1944, 1938 and 1893 (pg. 551) in the Narragansett Bay region may have a role in the shell layers. Core studies in Connecticut (1990-1994) found much of the same layers as the 1974 study layers of bivalve shell sandwiched between organic materials.
Many papers refer to leaf fall as a spring “flush” of phosphate and nitrogen. Some of the first research to documents the impacts of fall leaves upon water quality was done in the Cacapon River, West Virginia (1964). Keith Stock (US Geological survey, Professional paper art 161-D181-185 describes the impacts of leaves (organic matter) although short in duration (eventually stream energy (flow) would break up leaves – “the condition seriously degrades water quality and can result in the death of aquatic organisms.” Pg d-181. And, in severe cases the water acquires an inky appearance which gives rise to the name “black water”. D-182 and indication s of sulfate metabolism into sulfide D-183.

If large scale temperature and energy changes were responsible for large scale habitat shifts then the first places organic material would first accumulate would be areas of high heat and low energy such as shallow near shore coves and bays and it did.  One of the areas I first experienced this was the Pattagansett River system in East Lyme, Connecticut 1987-89.  Oyster shells were clean but not set. However, the few living oysters all very old and had no lip or mantle sets. I believe now that the lack of mantle sets on the adults was due to sulfide levels that were toxic to veligers. The black mayonnaise deposits shed so much sulfide that it killed oyster spat before it could set.

If a sediment sulfide wash occurs it can prevent oyster setting for years around such deposits and is how I was introduced to its impact upon oyster setting. But others along the coast had noticed similar events in coastal coves, John Scillieri Jr., found the same situation in the Town of Waterford Coves by 1983. In an article about Waterford’s coves, filling in with organic debris behind road and railroad causeways Mr. Scilleri is quoted as stating:

“The town has an obligation to maintain its coastal resources. The problems experienced are due to various acts by man –therefore, man should intervene in some of these cases to reverse a process he certainly has played a key role in,” said John A. Scillieri Jr., chairman of the Flood and Erosion Control Board.
Among the man-made creations affecting the coves are railroad bridges, roads, filled in portions to support building and dams. (“Waterford Studies Urge Action On Coves,” New London Day, December 3, 1983).  One of the things that Chairman Scillieri noticed was “nutrient imbalances that lead to foul cove odors warm weather.  Other towns noticed the same thing.  The Town of Branford after Hurricane Gloria (1985) felt the impact of just one large tree – how it could alter deposition, collect leaves and in hot weather start the sulfur cycle in the Branford River as mentioned in this article below..

New Haven Register, Friday, August 5, 1986

Engineers to remove fallen tree from river
Huge oak tree snares debris floating in water
By Catherine Sullivan
Register Staff_______________________________________________

BRANFORD –Since hurricane Gloria, residents on Riverside Drive have watched debris and eve dead fish pile up on a fallen oak tree that stretches across the Branford River.
“It’s a huge oak tree and it’s practically across the whole river,” said Marie Wall, a Riverside Drive resident. The tree is lodged in a section of the river near her property. “There’s just enough room for the boats to go by,” Wall said.

Saturday, the local unit of the Connecticut Army National Guard and the fire department plan to remove the tree.

“The tree has caused so much debris and grass to block up, it’s actually giving off an odor,” Fire Chief Peter Mullen said.

Mullen said the area will become passable again for boaters.

And it will appease the neighbors, who have been complaining to town officials since the oak made its grand fall.

“The first year, we had fish heads out there and everything,” Wall said.
At first, Mullen said Branford Company C, 242nd Engineer Battalion, was going to try to get a helicopter, so the tree could be air-lifted out of the river.  But a National Guard spokesman said that idea was dropped for safety reasons.

Instead, the National Guard will send several engineers to chop up the tree.  The tree will be removed between 8:30 and 9 a.m. The National Guard will use the event as a training exercise, Mullen said.

Spectators are not encouraged in the immediate area, Mullen said.
Marie Wall hopes to catch a glimpse of the tree being removed. Otherwise, she lamented, “I am going to miss the whole show.”

Rekeyed by Susan Weber for The Sound School, October 2012

If one tree could do this imagine what a coastal reservoir dam could do?  Or millions of cubic yards of leaves washed downstream from a tropical system. That is why core studies are so important to more fully understanding the impacts of organic matter in high heat.  We do have some excellent case histories, one of which overseas is “The Great Stink” a period of hot weather and drought brought hydrogen sulfide smells so strong it caused the suspension of Parliament in England in 1858, Élisée Reclus, writing in 1873 mentions perhaps the first toxic sulfide waters with Thames River tides – he certainly picked up on the sulfide smell, this is an excerpt from his famous book.

The Ocean, Atmosphere, and Life (Being the Second Series of a Descriptive History of the Life of the Globe, By Élisée Reclus, Author of The Earth,” Etc. New York: Harper & Brothers, Publishers, Franklin Square, 1873) in which he describes the Thames (and killing sulfide wash) two decades later noting in areas of the “mud” nothing could live was in fact describing a sulfide wash – I believe so a very early version of the sulfide black waters that was to occur here later 1880-1920.

“At the ebb of the tide, when the current of the river, with its slow and dark stream, flows on toward the sea, beds of semi-liquid mud filled with putrefying rubbish are gradually laid bare, emitting into the air their nauseous exhalations: inspired by a sentiment of instinctive disgust, one is almost surprised to see the blue sky and clouds reflected in these beds of moist filth. At the flow of the tide, when the body of water, being arrested in its progress, gradually rises and ascends the Thames, the islands of mud cease to be visible, but most of the unclean rubbish which has been borne down by the ebb is again carried up by the flow of the tide; a kind of to-and-fro motion is constantly shifting these impurities up and down stream under the eyes and noses of the inhabitants.*” 

Tampa Bay Submerged Aquatic Vegetation – Another Estuarine Core Study

From what I can recall, three causeways crossed the “Old Tampa Bay” reducing tidal exchange and most likely a reduction in energy.  There is little doubt that these causeways reduced energy and in low energy high organic input areas, submerged aquatic vegetation will fail – die off as a habitat type from sulfide toxicity.  Tampa Bay researchers had already found that high sulfide levels was toxic to larval urchin eggs but failed to make the connection to growing deposits in an area of once higher energy before the causeways to high acid volatile sulfides. See NOAA Technical memorandum NOS-ORCA-78 Magnitude and Extent of Sediment Toxicology in Tampa Bay, Florida, June 1994, pg 60. 
I suspect a “habitat history” lies shoreward if these three causeways in sediment cores and they will lead to sulfate reduction acidic sulfate marine soils. And the source of all of this estuarine sulfide trapped in low energy areas, terrestrial organics in high temperature and low energy conditions. Researchers have known sulfide extinction for eelgrass (again) Denmark and Australia is researching the impact of leaves currently upon the health of fish habitats is also finding a sulfide link.  In the research conducted by Carlson et al The Influence of Sediment Sulfide on the structure of South Florida Sea Grass Communities State on 216 2000 Tampa Bay Estuary Program technical publications 04-02-215-229-mentions the following, “We suggest that sediment porewater sulfide concentrations also influence the species composition survival, and growth of sea grass beds in South Florida.  If this is the case two important ramifications for sea grass management should be considered 1. Human activities which affect organic matter and sediment accumulation in sea grass beds might increase sea grass sulfide stress; 2. Sediment sulfide levels might affect the survival and growth of transplanted sea grass beds,” and also on page 216).
“We draw on data from four projects to examine the role that sulfide plays in determining the species composition, survival and growth of South Florida sea grass communities. Sediment sulfide data collected in studies of Florida Bay sea grass die-off over the last 12 years provide powerful, albeit circumstantial, evidence that high sulfide concentrations kill turtle grass.”    And in conclusion pg 226 : “Any process which causes elevation of sediment sulfide increases hypoxia or sulfide toxicity in sea grasses. Sulfide toxicity can also be increased by factors which decrease sea grass photosynthesis. If the balance between the internal oxygen supply of sea grasses is shifted slightly, sea grass species with higher sulfide tolerance might replace less tolerant species over a period of years.”
Researchers here have long known for many decades about volatile acid sulfide impacts to eelgrass. (Kirsten Kusel et al Applied and Environmental Microbiology, 1994).
The appearance and digestion of organic matter in estuarine areas has been studied for over a century.  Exposed to sufficient oxygen levels organic matter is “mineralized” or consumed.  To coastal observers it appears to melt away.  Add stream or coastal energy and it is often quickly dispersed.  In a 2001 paper (Marine Ecology Progress Series Vol 215-13-22 2001 Douwe et al describes the tendency for organic matter to accumulate in oxygen poor waters – “Effect of Oxygen On The Degradability Of Organic Matter In Sub Tidal And Intertidal  Sediments Of The North Sea Area” (Coast of Netherlands to the German Bight) finding that aerobic (oxygen) mineralization is of marine sediments is faster than anaerobic – oxygen poor.  In oxygen poor regions organic matter could accumulate as anoxic reduction is far slower – in particular aromatic structures and highly polymeric compounds (complex cellulose) including lignin have been found to be poorly degradable under anoxic conditions. A huge source of cellulose and lignin is leaves in lower rivers.

Black Mayonnaise May Indicate Habitat Failure for Blue Crabs

More and more attention it appears to be gathering around the country as it relates to terrestrial organics and possible roles in habitat failures. High heat can be just as habitat damaging as very cold. It is ironic that energy (storm strength) and duration has huge implications for habitat quality in each temperature range. One of the areas now receiving attention is the accumulation of black mayonnaise in southern areas. Florida recently commissioned several studies regarding the Indian River lagoon, similar organic deposits have been noted on Cape Cod, Boston Harbor and in the Saugatuck River in Connecticut. More recent news about the Saugatuck River conditions seems to have improved. New York Harbor has been looking at black mayonnaise deposits for over a decade.  Western states are looking at it as well. Sapropel formation found on page 22 of CAP Arizona project contains this section.

Arizona is finding that organics behind reservoirs here already formed Sapropel and accumulating waxes ruining irrigation drip equipment:

“The oxygen deficit conditions at the lower depths may cause sediment nutrient release through the process of reduction. If the sediment/water interface is exposed to prolonged periods of anoxia, reducing conditions allow the formation of nutrients previously unavailable for organisms that cause taste and odor changes in the water. This reduction may lead to Sapropel formation, a compound that is high in hydrogen sulfide and methane, and has a shiny black color due to the presence of ferrous sulfide. This compound is responsible for the occasional “rotten-egg” odor associated with releases from the hypolimnion layer through the lower portal on the intake towers.

Nutrients, such as nitrogen and phosphorous, become unbound from their ionic association with metals, such as iron, and manganese. This process may free up nutrients, which contribute to algae blooms in the canal system. Precipitates of iron and manganese cause discolored water and treatment problems” (P.22, 2011 Annual Water Quality Report, Prepared by the Water Control Department contributing efforts by Arizona State University, July 2012, Central Arizona Project).

With studies on Long Island (duck farm organic residues) New York, Florida’s Indian River and Cape Cod’s Buttermilk Bay, we are finding more and more about the black mayonnaise – Sapropel relationship. As we learn more about it and its ability to seal circulation within it (waxes), many habitat pieces that have so long perplexed biologists are now falling into place. Black mayonnaise is the building material of Sapropel when deprived of oxygen. With oxygen it is a benefit to some; with thin deposits nourishes eelgrass patches and good flows, it helps the blue crab Megalops but take away the oxygen and those same eelgrass meadows now become sulfur-killing fields, except near ground waters upwelling on shore fronts

It explains why in the early 1980s sections of Buttermilk Bay on Cape Cod and Eel Pond heavily loaded with black mayonnaise still had surviving populations of Mya, the soft shell clam along tidal edges (shellfish surveys conducted by the Bourne/Sandwich Shellfishers Association). At low tide a reverse hydraulic pressure would release tidal ground water and keep soil pores open to exchanges of oxygen (if this sounds like a sand/bead backwash cycle on a filter system, it is, only a natural one).

Organic patches were backwashed out keeping this “thin band of life” between mid-tide and the low tide line. Below the low tide, the soft shell clams were dead. But just a few feet above they were doing fine. Soft shells are a favorite food for blue crab Megalops. So a light sandy organic matter soil mixed with shell fragments with soft shell clams and eelgrass is prime blue crab star (past Megalops) habitat. Take away the oxygen and crabs move out, and if sulfides increase fast enough, kills crabs through contact (during test pits on the beach detected upflowing ground water; it is cool even on hot summer days).

It is the sulfide layer in winter that kills crabs in place. Cold water allows deep sulfide layers to leach out. Sulfide levels tend to rise to the top of black mayonnaise under ice and crabs now in a hibernated state cannot escapes as they can in the summer. “Sulfide jubilees” here the sulfide kills the minute the Megalops touch the bottom, hundreds of thousands of crabs at a time (Green pond EEL pond observations, Cape Cod, 1982) and the crabs have no defense. It gives the appearance of “winter kill” but freezing did not do it. On the contrary, crabs benefit from the heat in these composts and temperatures directly in them (not exposed tidal flats) rarely drop below 35 F. Even on winter days the black color of these deposits absorb heat as a solar bank to be released at night.

Charles Beebe of Madison illustrated the power of the winter sun to me in 1978. Our 16-foot Brockway skiff was locked in ice in Clinton Harbor and chopping it out each day, well it was taking its toll. After about a week of heavy complaints, he arrived in his green pickup truck with half a bag of rock salt and orders for Ray (my brother) and I to get a bag of charcoal briquettes, a tall order in February. We found some and placed the bag down on the ground. Mr. Beebe proceeded to jump on it. Soon we were circling the skiff in a mixture of ground up charcoal and rock salt. Within minutes (it was noon) crackling and popping happened. The ice sagged and then broke; the skiff was free. He left muttering something like “I need to teach you both everything.”

In 1988, George McNeil of Clinton gave a similar account of saving the oyster boats at City Point, New Haven, Connecticut (then Oyster Point). In 1931, several oyster boats were locked in deep ice, only this time it was coal dust at the end of South Water Street from a coal business, mixed with rock salt. The heat plus the salt did the trick; he chuckled when he heard of Mr. Beebe’s charcoal briquettes – same idea. The point is, black mayonnaise can absorb tremendous amounts of heat, and if deep enough, kick start the Sapropel process. Eelgrass at the end helps in developing these killing fields (sorry to all the eelgrass reports, but the eelgrass habitat history is very mixed as much good as bad in our area).

This is a quote from an article last February investigating mysterious die-off of eelgrass from the University of Copenhagen (Jens Borum) and Marianne Holmer from the University of Southern Denmark:

“The biologists explain that ‘eelgrass plants trap the mud’ that is washed away from chalky sea beds, and they also trap the poisonous sulfides. The high concentration of sulfides that is trapped in the midst of the older eelgrass that is less capable of withstanding the effects of the poison gets killed off, leaving only eelgrass that encircles the deposits of sulfide-rich mud. They state that the fairy circles of eelgrass (death) caused by the build up of sulfides is also found elsewhere in the world’s oceans.”

At the turn of the century, during intense heat, David Belding, a renowned shellfish biologist then, gave an account of the impact of organic matter upon marine soils and his 1910 report is just as valid today. He found many other biologists during this period the habitat change aspects of sulfide:

 “Organic Material: Clams are usually absent from soils containing an abundance of organic material. Even if the slimy surface does not prevent the set, the clams that take lodgment soon perish. Organic acids corrode their shells and interfere with the shell-forming function of the mantle. Such a soil indicates a lack of water circulation within the soil itself as indicated by the foul odor of the lower layers of soil, the presence of hydrogen sulfide, decaying matter, dead eelgrass, shells and worm. If such a soil could be opened up by deep ploughing, or resurfaced with fresh soil to sufficient depth, it would probably favor the growth of the clam. 

 Soils in which organic acid caused by vegetable decay, are present prove unsatisfactory for the catching of seed and interfere to a slight extent with growth by destroying the shell, often giving to the clam a black appearance which makes it less suitable for marketing.” (A Report Upon the Soft-shell Clam Fishery of Massachusetts Including the Life History, Growth and Cultivation of the Soft-shell Clam (Mya arenaria), David Belding, MD Biologist, 1910)

Several crabbers have noticed bubbles coming off leaf deposits (mostly methane) (Megalops #7, August 16, 2013) and deep leaf accumulations as poor crab habitat. In high heat the gas becomes hydrogen sulfide; the rotten egg odor of coastal areas when it is hot. That is why most large fish kills are preceded by accounts of smells of sulfur and mostly occur during hot and low energy periods. When oxygen is low, the toxic sulfur cycle resumes and the first toxic impacts are to the benthic bottom dwellers and dead crabs. John Hammond, a retired oyster grower on Cape Cod, used to say this stuff is bad for the fish and fishers; it is. When sulfur levels get high, blue crabs may walk out of the water, most benthic organisms can’t do that. Down south in the historical literature, they were called “jubilees.”

But even here they happen in extreme heat in New England Niantic Bay had a small jubilee accompanied by sulfur smells [Crabs Pick Land Over Niantic Bay, August 7, 2009, WTNH, Jamie Muro] and the infamous August 1898 die-off of Narragansett Bay, Rhode Island contains similar accounts. I agree with Dr. Scott Nixon who in 1992 said that a century before the account of A Meade could not be improved. I also agree and repeat Dr. Mead’s account here as it first appeared in 1898 after a long heat wave.

“On the 8th and 9th of September the water became extremely red and thick in various localities from East Greenwich to Providence, and the peculiar behavior of the marine animals attracted much attention. Myriads of shrimp and blue crabs, and vast numbers of eels, menhaden, tautog and flatfish came up to the surface and to the edge of the shore as though struggling to get out of the noxious water. Indeed, the shrimp and crabs were observed actually to climb out of the water upon stakes and buoys and even upon the iron cylinders which support one of the bridges and which must have been very hot in the bright sun…”

 When you read these accounts, they often share the same features within case histories: 1) a sudden or severe period of rain during extreme heat, 2) chocolate, purple or red waters, 3) algal blooms, 4) sulfur smells, 5) fish kills and 6) black waters. The smell of hydrogen sulfide or the rotten egg smell is mentioned in 9 out of 10 cases. Sulfur compounds are highly toxic and over time can be the source of “natural pollution” that kills finfish and shellfish.  Black mayonnaise, fresh organic marine compost is deprived of oxygen and turns deadly into Sapropel, creating sulfide waters.

A sulfide block is now suspected of impacting some coastal alewife runs. Although a Sapropel bottom has become in many areas a dominant habitat type and may signal a massive habitat reversal; we know very little about recent deposits. It just has not been a process of habitat change, which until recently focused almost entirely upon man-made pollutants. Anyone who has noticed an increase in leaves over previously firm bottoms or deposits that give off sulfur odors, drop me an email. All bottom habitat type observations are important as we learn more about habitats that may or may not support Megalops (blue crabs).

Black Mayonnaise Can Lead to Sapropel and Toxic Compounds

As mentioned in Special Report #8, the first accounts of the toxic impacts were from the agricultural community with older Sapropel, the built up organic matter behind dams. The New Haven Agricultural Experiment Station tested several sources of marine mud used as fertilizer and found it contained a high sulfuric acid content, four times that of “regular” stable manure (Report of the Connecticut Experiment Station, 1879).  As this organic matter collected deposits above effectively sealed it from oxygen in the water column. In time as the deposit deepened, the bottom layers became Sapropel and sulfur rich. Dredging in the coastal zone frequently removes these Sapropel deposits and is much of the reason after dredging projects local fishers often report improved fish catches and firmer bottom conditions after the source of sulfide waters are removed. Sapropel builds behind dams in high heat, or in in the marine zone behind blocked coastal inlets or above bridge and railroad tidal restrictions. It was the winter flounder fishers of eastern Connecticut in the 1980s who first grew concerned over deepening deposits of black mayonnaise (IMEP#15, 1and 2, April 2014) over bivalve flounder nursery habitats, which eventually signaled a huge winter flounder habitat failure. European organic matter pollution a century ago created an entire habitat classification system, the Saprobien System, in 1909.

One of the best current case histories of Sapropel (called sludge) is regarding the Long Island, New York duck farms which discharged into small creeks and bays collected on the bottom (Long Island Duck Farm History and Ecosystem Restoring Opportunities, Suffolk County, Long Island, New York). Here these bottom sediments become Sapropelic and shed sulfide and ammonia, nutrient for harmful algal blooms (HABS).  They rot in high heat and lower oxygen conditions and when sulfate bacterial reduction shed hydrogen sulfide gas (H2S). The presence of this “benthic flux” has been associated with the increase of the brown algal strains, which can directly utilize area (ammonia) nitrogen compounds. Descriptions of the benthic flux follow the patterns (descriptions) of fisher observations a century ago described by Mead, Narragansett Bay 1898 and later, Gaines for the Narrow River in Rhode Island, (1988). Sapropel and its impacts to bottom habitats has not been discussed for decades.

This description of page 16, Appendix D, February 2009, U.S. Army Corps of Engineers Duck Sludge fits the description provided by Stevens of Essex nearly a century before (North Cove, Essex, Connecticut, Marine Mud Harvests, 1879).

    “These organic rich sediments, often several feet deep, became soupy, black, clayey silt that had a rich odor of hydrogen sulfide, so potent that home owners adjacent to Moriches and Great South Bays complained that the paint on their homes were being discolored (Nichols, 1964, O’Connor, 1972)”

 And with decreased habitat energy (tidal flows, restrictions) smells got worse as experienced by other barrier split/ inlet systems, further descriptions (I bid) is provided by the comment below:

“Ecological degradation that was associated with the accumulating of nutrients throughout the estuarine bays continued throughout the history of the duck industry, and was heightened when the Moriches inlet was closed (Nichols, 1964 Lively et al, 1983) in the early 1950s.”

Sapropel habitat concerns are just not marine; the original classification of organic pollution, both natural and man-made, was developed in fresh water rivers (IMEP #23, August 29, 2014 – All IMEP Habitat newsletters can be found on the Blue Crab Forum™ – Eeling, fishing and oystering thread and CT Fish Talk™ Saltwater Reports, 1909). Sapropel can accumulate and show the basic characteristics in fresh water as (Megalops Report#8, 2014).

This is a description of Sapropel from a 1997 Arizona CAP study of reservoir and canal irrigation system. System managers were concerned with “organic rain,” organic matter that forms a sediment that when disturbed releases hydrogen sulfide, changed the odor and taste of water. In summer heat these water reservoirs have periods of anoxia and organic matter reduction occurs in the bottom sediments. It is a natural condition enhanced by high heat and increased biomass (organic) rains. Releases of Sapropel slurry into water distribution systems led to water customer complaints (odor and taste) and were implicated in filter system failures and clogging (waxes) agricultural drip irrigation equipment.

Water system operations soon launched “investigation” studies seeking answers to these complaints. Eventually the problem was linked to bottom water releases. In summer large bodies of water tend to stratify, surface warm water on top and colder water below (visitors to lakes in Maine will identify with this while swimming). The colder water below will become anoxic (oxygen limited) while organic debris inputs are now (grasses, leaves, woody residues from forest soils) and washed into water bodies. When that happened, waxes formed a byproduct of “leaf digestion” and the waxes clogged irrigation equipment.

Results from sampling trip to Lake Pleasant (Arizona):

“The anoxic conditions that occur in the hypolimnion during summer thermal stratification in most lakes are a result of high epilimnetic biomass that “rains” through the metalimnion and thermocline becoming trapped in the hypolimnion. This may lead to increased BOD in the hypolimnion and, therefore, an oxygen deficit. The oxygen deficit may have profound impacts on water chemistry and composition. If the sediment is exposed to prolonged periods of anoxia, reducing conditions may prevail. This may lead to the formation of Sapropel. Sapropel is high in H2S and CH4 and has shiny black color due to the presence of ferrous sulfide. This has been anecdotally referred to as the “rotten-egg” odor associated with high levels of discharge from the hypolimnion into the Waddell forebay. During the fall overturn, large amounts of sediment may be disturbed and entrained in the outlet ports of the towers.”

This is the report of Robert DeGoursey describing of black mayonnaise deposits in the Pattagansett River in August 1988 of East Lyme, Connecticut (Shellfish Survey with Gasoline Jet Pump):

“Robert E. DeGoursey, UCONN Dive Team Leader
Diver/ Video Survey of the Upper Pattagansett River Estuary, East Lyme, Connecticut

16 August 1988      UCONN Marine Sciences Initiative

Transect 3- 50 meters north of the Amtrak bridge

Area Surveyed: Approximately 25 meters in the center of the river proceeding west to east.   Depth: 1 meter

Sediment type: “All sediments observed were very fine grained, soft, unconsolidated and easily re-suspended. Divers could easily penetrate the bottom by hand to 1 meter with little resistance. No hard substrates were located. The surficial layer of sediment was oxygenated to approximately 1 cm. Characteristic H2S odor was produced when sediments below the redox layer were disturbed.”

A further second examination with the use of a hydraulic gasoline water jet pump revealed a buried oyster bed at 2 meters depth. The relic oyster shells were brought to the surface with glass shards, coal cinders and clinker chunks (thought to be remnants of steam trains coal refuse), an old bottle and the leather remains of an old shoe. Closer to the Amtrak causeway water high pressure fluidization did not allow divers reaching down far enough to pick up oyster shells. The UCONN dive team (Peter Auster, Bob DeGoursey) estimated that the high pressure water jets had removed about 1 meter from the surface, the pipe held into the hole had allowed divers to pressure fluidize about another meter with additional lead weights had penetrated another meter and the arm thrusts that had perhaps added about another meter. Any shell debris or relic oyster habitats had to be at least 3 meters and deep or more. Efforts to further examine this habitat history were suspended by high amounts of hydrogen sulfide gas being suspended in the immediate area (T. Visel personal observation).  This organic substance had most likely putrefied in high heat and then formed a layer of Sapropel.”

We were looking at black mayonnaise not realizing that at about 6 feet of depth it was Sapropel, the bacterial reduction of organic matter created without oxygen; the sulfur cycle and generating all the sulfide gas. Elizabeth Craig of the Norwalk River Watershed Association in her article “Good News From Norwalk Harbor: Flounder Population Recovers” (In the Mainstream newsletter, Fall 2013) sums it up for the rebound in winter flounder in Norwalk Harbor:

“Residents and homeowners in the Norwalk River Watershed, especially those living along river or stream banks, continue to play an important role in keeping Norwalk Harbor and the Sound healthy, so here is your friendly fall reminder not to dump leaves into the River or storm drains and wetlands. While this leaf litter is ‘natural,’ organic and biodegradable, in excessive amounts, as it decomposes, it uses up most of the dissolved oxygen in deeper water and makes the bottom water uninhabitable for fish and other animals. Leaves and yard waste blown into the river and wetlands form a black gooey paste known to boaters as “black mayonnaise.” When black mayo forms and becomes thick enough, it destroys spawning areas of bottom dwelling (benthic) fish such as flounder. Unlike many fish that spend their time swimming, benthic fish are very dense and have negative buoyancy, which allows them to lie effortlessly on the ocean floor or bury themselves, like flounders and sole who can remain hidden in sand because of their flat body shape.

Leaf litter is known to gardeners as “Black Gold.” Used in your garden to enrich soil, it is black gold, but dumped into the river, these same leaves settle on the harbor’s bottom and become the notorious ‘Black Mayonnaise,’ destroying important fish habitat.”

The sulfur cycle and its deadly habitat impacts are not found in many estuarine studies (a bias reflected perhaps in the not so nice eco-biological services of such deposits), but black mayonnaise exists and its deeper more toxic counterpart Sapropel does also.

Conowingo Dam Study and Blue Crabs

 The Conowingo Dam study offers a unique opportunity to examine the long-term organic digestion of leaf material (contrary to many published studies, leaves form most of the nitrogen sinks in estuarine waters) in the sulfur cycle. This dam no doubt trapped leaves coming down the Susquehanna River and with tannin signatures (See IMEP #23, #26 Blue Crab Info™, Fishing eeling and oystering thread), we might be able to distinguish the organic source material fingerprints of what comprises this organic deposit.
The Conowingo sediments should have leaf paraffin that seal these deposits with increasing depth. Cove profiles (deep cores) below 12 feet should show elevated sulfur levels. The sulfide problem was described by oyster farmers here a century ago who noticed that the teens oyster shell was dissolving quicker in these “black bottoms” (George McNeil) and this material may signal increased shell loss for the oyster industry. * Blue crabbers are justified in their habitat concerns; the Conowingo sediments may tell us more about Sapropel formation than the Indian River Florida Black Mayonnaise Study currently underway. Due to the fact that the Conowingo has unconsolidated sediments (loose), some exceptionally deep cores are possible (no boulders). Since we know the age of the dam, we can tell how quickly Sapropel can from and such deep cores could tell us much more. Dislodged Sapropel deposits release sulfur compounds that quickly turn into sulfuric acid. A sulfide wash is toxic to most organisms including blue crab Megalops. Acid bottoms in high heat dissolve bivalve shell and may explain sudden soft shell clam failures as well; a favorite food of young blue crabs. Acid waters could be part of the loss of shell on oyster bars as well.
This Chesapeake Bay habitat study of Conowingo Pond could be the most important review to date. It could tell us much more about how sulfide impacts blue crab habitats. Next newsletter will detail cold-water habitat failures.

*Some of the first export organic matter studies from estuarine marshes were conducted in Chesapeake Bay. David Correll in Estuarine Productivity (Chesapeake Bay Center for Environmental Studies, Smithsonian Institute, 1978) reported export from tidal marshes of 200 grams of organic carbon per year per meter (p. 647). The Conowingo is watershed source entirely and tannin signatures (source) from organics not mixed with marine source organics. Therefore identifying sources should be all terrestrial, etc. – a clear look at Sapropel formation.

Thanks again for your interest and support.
Tim Visel

Every observation is valuable as we learn more about our blue crab and oyster habitats. I respond to all emails at [email protected]
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« Reply #1 on: October 16, 2014, 02:11:56 PM »

good read , thanks


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« Reply #2 on: October 16, 2014, 08:02:08 PM »

How many threads do we need about this :/




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