IMEP #148: Eelgrass Monocultures Fail in High Heat 1897

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IMEP #148: Eelgrass Monocultures Fail in High Heat 1897
The Danger of Marine Composts in High Heat 1880-1920
"Understanding Science Through History"
Viewpoint of Tim Visel, no other agency or organization 
March 2019 Revised to January 2022
This is a delayed report - March 2024
Tim Visel Retired from The Sound School June 30, 2022
Thank you, The Blue Crab Forum^TM for posting these 
Habitat History reports – 350,000 views to date



A Note from Tim Visel


Shallow waters obtain the most direct solar heating – they (bay bottoms) can absorb heat and become even hot with temperatures over 100oF on cloudless days.  This heat changes the biochemistry of collected plant tissue into a marine compost that also gets hot.  Although much has been written about controlling the temperature of terrestrial composts between 140oF to 160oF almost nothing has been published about what happens when marine composts get too hot.  In high heat, marine composts can become toxic.


Terrestrial composters monitor the heat of compost piles carefully and turn them to keep composts from becoming too hot – killing off oxygen requiring bacteria the ones that shed nitrate for those that produce ammonia.  This is a segment of a Rodale Institute "Turning Compost by Temperature" from a decade ago (2012).    


"National Organic Program (NOP) guidelines require compost to be turned a minimum of five times within a 15 day period, during which time the temperature must be maintained between 131 – 170 degrees F."


A sign that a marine compost is too hot is that it smells of sulfide (rotten eggs) and a shortage of oxygen to support oxygen requiring bacteria.  In simple terms, bacteria that live in no or low oxygen conditions have taken over the composting process.  The other sign is that the land compost is too wet – here the sweet smell of ammonia leachate is a sign of low oxygen as well.  Marine composts often shed ammonia in large amounts into water below a thermocline – a sharp water temperature division layer.  This layer can cause oxygen poor waters.  This sea water compost is covered with water not unlike deposits in lakes and ponds.  They both can produce a high organic ooze, a sapropel.


The only time sulfide is released on land is just after a major flood.  Here, organic matter is often buried and sealed from oxygen.  When that happens, it may purge hydrogen sulfide.  Heavy rain can also, at times, produce foul earth odors.  In some texts, it is termed "petrichor," which also has a bacterial connection.


When reviewing the literature about marine composts and heat purging ammonia, I often find reference only to my papers.  Although the ability of eelgrass (as with land grasses) to concentrate organic matter is praised in high heat and stagnant water, this often is a harmful process.  That is missing today, the action of bacteria in marine composts and the heat that bacteria can produce in forming eelgrass peat.


That was not always the case.  Parker P. Trask (1955) Recent Marine Sediments contains several articles that mentioned the ability of eelgrass to gather organics (composts) in shallow water.  Earlier Irving Field in 1922 "The Biology and Economic Value of the Sea Mussel" talks about the same process. 


Irving A. Field was a Special Investigator with the U.S. Bureau of Fisheries, US Fisheries Biological Station, Wood Hole, MA.  His 1922 bulletin contains a very detailed description of eelgrass composting by measuring sugars beneath eelgrass growths – pg. 210, contains this section:


"Petersen and Jensen (1911) tried to show that, in all probability, the plants of the eelgrass belt and not the plankton organisms should be regarded as the main sources of the organic matter of the sea bottom in Danish waters.  Their reasoning is based on the fact that the quantity of carbon in a series of bottom samples is directly proportional to the amount of Zostera vegetation and not to the quantity of plankton present." 


 And further – Jensen (1911), (my comments, T. Visel):


"By chemical means, however Jensen was able to determine the source of eelgrass matter in the sea bottom.  He found that the eelgrass cells contain a considerable quantity of starch like substances known to chemists as pentosans (sugar, Tim Visel), whereas those of diatoms are composed mainly of silica and those of peridineans (algae) of fairly pure cellulose.  By comparing analysis of various bottom samples of organic matter with those of eelgrass and diatoms the following conclusions were reached, 

• In the more sheltered waters the organic matter of the sea bottoms to a preeminent degree is formed by eelgrass.
• In the more open waters, at least half of the organic matter is probably formed by eelgrass.
• In the deepest waters the organic matter is probably formed chiefly by plankton organisms."

The ability to form a marine compost was not praised by shellfish researchers a century ago.  Field (1922) highlights this perception by listing eelgrass as a "passive enemy" of the blue mussel, pg. 219 contains this section:


"Eelgrass, Zostera marina, is one of the most destructive weeds which grows in profusion on the sheltered beds.  It not only intercepts the currents which bear the food supply of the Mollusk but causes very often such a heavy deposition of silt that the mussels are smothered or even completely buried beneath it.  Their decomposing bodies then form richest kind of fertilizer on which the eelgrass thrives."  (This is often called "mussel mud" in the historical agriculture literature when used as a soil amendent, T. Visel).


David Belding a State of Massachusetts shellfish researcher shares similar comments about the eelgrass ability to build a marine compost.  His research mentions negative impacts to the bay scallop, quahog and softshell clam from eelgrass in his studies of Massachusetts shellfisheries (A reprint of his works was made available by my old employer The Cape Cod Cooperative Extension Service in 2004.)  His research time period was 1905 to 1920, a time in which eelgrass attained massive habitat coverage.


Swimming and Eelgrass - 1890's


One of my first "paid jobs was for the Neptune Beach Association (Madison, CT) as a "beach raker." An early morning visit to the beach meant raking the wrack and burying seaweed in holes above the high tide line.  In June, it was usually an hour to two to rake the seaweed and bury it.  Beach goers came to the beach around 10:30am or so, leaving time to "clean the beach."  It is here that I was first introduced to an eelgrass wrack.  For some reason, as it dried in heat, it attracted flies and "no see ums" or gnats – biting flies.  For some reason, eelgrass wrack attracted the most flies.  When touched, you could see the flies jump.  So, eelgrass really didn't interfere with swimming at least for the early part of the summer.  However, by mid-August, I dreaded easterly winds, especially after a storm.  Then, the eelgrass was thick and at high tide no place to bury it (this beach was indented and a place that naturally collected a seaweed wrack).  On several occasions, we just raked the seaweed (eelgrass) back into the water.  It is then that swimmers complained that there was so much eelgrass in the water that it was like "swimming in corn flakes."  The wrack on the beach attracted flies – complaints poured in.  This job was for one season only.  I guessed that the eelgrass was coming from the eelgrass flats along the northern edge of Cedar Island at the mouth of the Hammonasset River – that was the closest source but no way to determine the exact source.


The Cycle of Eelgrass – 1900's   


It was at a family outing many years ago that the subject of eelgrass came up.  I don't recall why but I do recall the reaction.  My wife's grandmother, Evelyn Nalchajian, had vivid memories of eelgrass from the 1920's.  She had vivid memories of the "eelgrass problem."  This increased growth of eelgrass was to confront the public's use of cooler water during the intense heat waves of the 1900's.  Eelgrass coverage increased as interest (public policy demands) increased for more beach/bathing opportunities.  This put more beach use in conflict with eelgrass.  Revere Beach in Revere, MA was first opened in 1895.  This beach, just north of Boston, reopened as a public beach in 1895 and a state public beach in 1925.  Mrs. Nalchajian insisted its first and true name was "crescent beach."  She recalls that on many mornings horse teams would scrape the eelgrass off the beach as it was, at times, more than a foot high (likely after a storm, T. Visel).  The opening in 1895 occurred before the great heat wave of 1896 and online reports mention tens of thousands of people came to the beach to escape it.  Eelgrass was a problem as that "it attracted flies" and was considered a nuisance (personal communications, T. Visel, 1980's).  A photograph from the Arthur Goss 1912 photograph series (online) clearly shows an immense seaweed wrack "Revere Beach Rests."  (This account also appears in IMEP #80 Part 1, posted December 16, 2020, The Blue Crab Forum^TM).  A 1909 picture of "Revere Beach Swimmers" from the Nathaniel L. Stebbins' photographic collection details an immense seaweed wrack – See Historic New England, Stebbins' negative #19545.


The impact upon beach use (large growths of eelgrass) is rarely mentioned by researchers today.  It might be because eelgrass is suffering from sulfide discharges in high heat – it is at a low point of abundance.  In the cooler and storm-filled 1950s and 1960s, eelgrass is mentioned as causing stagnation.  Shellfishermen felt the eelgrass growths in the Niantic River were causing stagnation (think reduced flushing, T. Visel) and efforts to restore tidal exchange utilized explosives to clear a channel for tidal exchange (See US Army Corps of Engineers, 1997, The Environmental Effects of Underwater Explosions) (Ludwig, M., 1977, Environmental Assessment of The Use of Explosives to Remove Eelgrass – Niantic River, CT) (Department of Defense Materials Research Laboratories, Commonwealth of Australia, 1980, pp. 3-5, The Effects of Underwater Explosions on Marine Life). 


David Belding, who wrote several state of Massachusetts shellfish industry reports in the early 1900's, mentioned negative eelgrass impacts to its clam fisheries (1905 to 1920).


Other shellfish researchers mention eelgrass reducing bay scallop meat size (eye) and suffocating quahog (hard clam) beds.  But direct suffocation is the least of the concern around eelgrass – its role in marine composting by bacteria that produce sulfides or ammonia has been often missed and is far more significant (my view, T. Visel).  


A deepening marine compost is the result of organic matter (land or sea) undergoing bacterial digestion in warm sulfate-rich, oxygen-poor shallow (and often poorly flushed) seawater.  It is here that a black (sometimes a blue tint) compost purges ammonia in such high quantities it is toxic to marine organisms.  The chemistry of this marine compost is so toxic it kills scallop larvae upon contact.  The toxin attributes is from a blue green algae toxin to many organisms who consume it.  It is a composting organism that thrives in nutrient-rich waters – lyngbya, a cyanobacterium.  It lives in high pH conditions assisted by ammonia – a compost bacterial discharge.  Toxic blooms frequently start near or over eelgrass/marine composts.  High ammonia levels signal a marine compost chemistry – bacterial break downs of plant tissue, that eelgrass over time helped collect.  This should be a great concern as much has been published about a warming planet – additional heat can turn eelgrass composts into potential toxic substance-producing regions.     



The Dangers of Marine Compost – Chemistry 


One of the ways that media has been able to confuse cause and effect in public perception has been the creation of new terms – nowhere has this been more successful than the term "cultural eutrophication" – the premature habitat aging process accelerated by human pollution or human coastal (development) activities.  The declines and reported negative values of estuarine health are most often directly linked to some sort of human activity and now as a culture – that is environmentally inherently negative.  This approach is so biased and at times and so extreme it fails most scientific analysis – as it offers no control trials free of human contact over time.  It does not include climate change or cycles, it has no natural history but portrays a moment in geologic time.  It is a concept not a scientific fact.  This concept tends to draw conclusions from any coastal development to declines in fish and shellfish at or during the same time period.  The problem is that some fisheries have rebounded or increased in areas of coastal development – such as the surge in Connecticut's blue crab post-1998.


The connection to human development was so broad based its weakness can be easily seen in increases in some species with heat with or without development.  Connecticut has seen a huge spike in blue crabs between 2006 to 2012, black sea bass has increased to a point they are beginning to stunt (reach sexual maturity at shorter lengths) and Maine lobster production has increased from 30 million lbs to 132 million lbs in the 2000's.  If this argument is now reversed then coastal development was good for these species?  Oyster setting grew stronger in New England as waters warmed in the 1990's even with coastal structures?  You can quickly see the errors in this conclusion but it is often found in many coastal studies.  Eelgrass responds to climate change with or without human impacts.  These changes are often claimed as new or novel when in several instances it is only a repetition of previous events.  Some may term this a "natural" resource history.  Resource natural history means different things to different people. 


For lack of a better term, I call it "recycled as new science" a restating or reinvention of previous terminology – hunting or fishing for example becomes "provision services" a link to the fact that hunting and fishing can and does provide food.  A review of the literature has become "meta analysis" and abstract as word "smithing."  A bias is often found in grant supported  recent scientific literature, a complaint that even has been raised in the scientific community itself (See 2016 JSR article, Vol 35, #1 "Debasing The Currency of Science").  Nowhere would "new" science be utilized than in building a culture of importance surrounding eelgrass – as an important habitat type with numerous "environmental services."  A review of how eelgrass became such an important environmental indicator is worthy of discussion (my view, T. Visel).


The amount of funding made available for eelgrass study was dependent upon its elevation as first a species of concern – an estuary health indicator that could provide a basis of regulatory authority.  It was in a way of Trojan Horse, an envelope that wrapped around it the real intent of the Clean Water Act revisions transitioning into Submerged Aquatic Vegetation estuary policy as a way to regulate nitrogen.  A negative nitrogen aspect to shallow water clarity is from algal blooms.  This grant funding was subject to confirming the importance of eelgrass connected to nitrogen public policy outcomes.  As a factor of this significance is the absence of any historical reference to when eelgrass reviews were mixed at best and many instances were considered habitat negative regarding eelgrass monocultures over extended periods of time.


As for "The Funding Effect" the "science" is subject to a type of bias evident in some medical research (See Sheldon Krimsky School of Medicine Tufts University of Boston, MA 2005) – that is very evident in some eelgrass/nitrogen research.  This eelgrass positive research findings nearly always mirrors the "guidance" information in highly structured request for proposals (RFP).  If often follows grantor expectations of grantee research areas.  Most of the research (although gives an appearance of independence) is perhaps compromised by expectations of further grants.  This is easily seen in eelgrass research, rarely if ever receives a negative mention so prevalent in the 1950's and 1960's.  Much of the negative historical eelgrass impacts to shellfish are missing today from recent reports.  Many eelgrass habitat histories start from the 1980's. 


We may need to expand the concept of peer reviews to a structured legislative response that includes natural history and broader review of scientific published articles.  (My early work with the University of Massachusetts Cooperative Extension had me come face to face with that concept – regulatory agencies funding education and developing research that then supported regulatory responses to it. I recall several conversations with Robert Light, then UMASS Cooperative Extension Associate Director at the time about this topic).


The eelgrass research is perhaps compromised by a contractor/client consulting relationship (conflict of interest) that delivers research that once used to be agency housed.  The outsourcing of "science" outside of civil service both insulates the funding agency and develops a relationship of future funding potential.  Many federal agencies published this type of research, which often included a broad disclaimer stating that it is not the official position of said agency, etc., but is printed on agency mastheads with agency publication numbers and containing agency logos.  


Such disclaimers often appear under federal agency logos or mast heads.  One June 2014 disclaimer for Improving Eelgrass (Zostera marina) Restoration, Conservation, and Protection contains this on pg. 2:


"This report was prepared as an account of work sponsored by an agency of the United States... The views and opinions of authors expressed here in do not necessarily state or reflect those of the United States Government or any agency thereof."


The problem is that these types of reports later appear as reference or citations but readers of other works rarely know about the presence of disclaimers but rely on agency representations or federal recognition.


Something similar happened decades ago with salt marsh research.  To prevent filling and dredging of salt marsh habitat numerous studies were untaken to counter beliefs and values that considered these habitats as worthless and also disease causing.  John M. Teal in a Fish and Wildlife Service report titled "The Ecology of Regulatory Flooded Salt Marshes of New England – A Community Profile (1986)," US Fish and Wildlife Service, Biology Report 86 (7.4) mentions a fine line of science and a growing concern of research guided by grants.  The preface contains this section:


"Note his comment on the inadvisability of trading "our credibility for political advantage."  It is all too early for a scientist believing (he) has achieved a new way of understanding some natural phenomenon to promote his idea for some management purpose.  This has certainly happened in relation to salt marshes."


In The Funding Effect in Science and its Implications for the Judiciary Sheldon Krimsky (2005) on page 59 has this segment.


"One Yale University research team pooled all of the studies available in a type of meta analysis on the impacts of financial conflicts of interest in biomedical research.  Based on eleven independent studies, the research team determined that "strong and consistent evidence shows that industry sponsored research tends to draw pro industry conclusions."


And further: 


"The data from the studies tells a convincing story that commercial affiliation of researchers has a biasing effect – not simply on each investigator but also on the general population of investigators.  It imposes a kind of evolutionary pressure that steers the research toward the interest of the sponsors." 


This helps explain the absence of negative eelgrass composting chemistry or the suffocation of oysters, clams, blue mussels, and food limitations to bay scallops from eelgrass in the most current eelgrass literature.  The return of eelgrass to many New England estuaries in the 1950's and 1960's was not met with delight but often distain.  This is an excerpt from a State of Massachusetts marine bulletin series (several of which mention the "eelgrass problem") funded by the Department of Natural Resources – Division of Marine Fisheries – Commonwealth of Massachusetts (1968) titled "A Study of the Resources of The Westport River" Frederick C. Wilbur Jr. Director, Division of Marine Fisheries – pg. 43 contains this section under Eelgrass:


"Although eelgrass is favorable to the setting of juvenile scallops it has been noted that mature scallops growing amidst eelgrass tend to be smaller in size than those growing in adjacent open areas where the current is unimpeded and the scallops receive a constant new food supply detriment to shellfisheries."   


Detriment to shellfisheries also occurs when deal eel grass accumulates in dense mats and smothers beds of shellfish.  Because of the increasing growth of eelgrass on shellfish beds, considerable research is presently being conducted to find an effective method of control" pg 44.


And many states did look into reducing eelgrass growth as did Canada but those citations do not appear in today's almost totally positive accounts of eelgrass assisting shellfish – when in actual fact the opposite is often true.  Reporting negative accounts would go against the current positive message so they were forgotten.  This is a type of science/research misconduct called "citation amnesia."  Assisting in this lost portrayal of eelgrass is that the shellfisheries who once reported on eelgrass concern no longer existed.  While eelgrass suffocated shellfish beds, a much larger negative impact can be found in its composting chemistry in shallow waters.  This negative impact is made worse by global warming and the increase of sulfate bacterial metabolism.  This is noticed in shallow bays subject to high heat and non-limiting amounts of sulfate dissolved in seawater.  This use of sulfate as an oxygen acceptor releases deadly sulfide.



The Compost Soils of Eelgrass and Habitat Succession 


Eelgrass, like most submerged aquatic vegetation, lives along coastal margins – its habitats also exist in areas, which contain shellfish and finfish.  As such they share habitat space within biological parameters of light, nutrient level and temperature.  They are from their proximity to land subject to similar environmental conditions necessary for many fisheries.  It was these shallow waters that are the most biologically significant that obtain carbon and nitrogen from land (open ocean waters are generally "nitrogen poor" and often labeled "biological deserts" from low productivity – overall poor in fisheries) shallow near coastal areas are rich in shellfish that now feed upon algae nourished by abundant nitrogen compounds.  It is how those nitrogen and sulfate compounds react in high heat that governs species dominance and the expansion and contraction of eelgrass meadows.


In the 1920's at the end of multi-decade warm cycle as icebergs invaded Southern Atlantic shipping lanes, eelgrass had a widespread die-off termed the "wasting disease" which is a slime mold infection.  It was a signal event marking the end of habitat succession period since the late 1880's.  As the eelgrass die off was worldwide (beginning in 1898) no specific action could be applied to explain this loss except that it signaled the end of a long period of eelgrass habitat expansion.  It was now in decline.  The ability of eelgrass to expand into a greater habitat coverage and in the process transition its retreat to different habitat types by the accumulation or organic matter (marine compost) did not go unnoticed.


A study of Norway's North Sea habitats (2019) was published (June 24, (3), pg.  410-434, titled "Distribution, Structure and Function of Nordic Eelgrass," Frontiers Marine Science, April 2019) that included observations and measurements on this aspect.  In high heat the habitat successive characteristics come into view and its role in enhancing anoxia and localized anoxic events.  Reduced depths narrowed hydraulic capacity the exchange of cooler generally richer oxygenated waters.  This is also termed flushing capacity – retained (slower) moving waters are most vulnerable to thermal hydrogen sulfide generation related to the sulfur – sapropel cycle.  Anoxic events and the generation of hydrogen sulfide in sulfur bacteria biological cycles of plant tissue have been studied for about a century.  See "Occurrence and Activity of Bacteria In Marine Sediments – Claude E. Zobell, Scripps Institution of Oceanography – University of California (1939).


In a few months, researchers from Australia, Norway and Denmark will examine to the impacts of terrestrial organic matter in high heat upon estuarine habitat quality.  It has also signaled a review of the Saprobien System developed in 1909 for organic high heat digestion in Europe's rivers (See Deninger and Frigstad (2019), Re-Evaluating The Role Of Organic Matter Sources For Coastal Eutrophication, Oligotrophication And Ecosystem Health edited by Marianne Holmer).  Norway's study of fjords and the accumulation of black muds was documented by Kaare Munster Strom, University of Oslo in 1938 (See Recent Marine Sediments: A Symposium edited by Parker D. Trask, US Geological Survey, 1955, 736 pages).  Strom's research focused upon areas with restricted tidal exchange and the gathering marine composts, Norway's coastal fjords, noting the tendency of fjords with tidal restrictions to become stagnant and contain a black mud rich in hydrogen sulfide.  Strom also describes nearly a century ago, which is today referred to as the sulfide deadline and toxic conditions in marine soil then called sediments.  From Strom (1938) reissued in 1955, page 361 "Land-locked Waters and Black Muds" has this segment (my comments, T. Visel):


"The biological effects of stagnation are mainly a sterilization of the bottom sediments and the open waters from a certain depth (Sulfide deadline, T. Visel) downward.  If a total renewal of the bottom waters occurs (now called "overturn," T. Visel), those containing hydrogen sulphide are sometimes lifted to the surface and cause a catastrophic death of the fauna (rotten egg – fish kill, T. Visel) that normally lives in the upper waters.  In localities with nearly fresh surface waters, a saltwater fauna may have a precarious existence between the fresh waters of the sulface and the poisoned waters (high in hydrogen sulfide, T. Visel) of the deep." 


And further (same page):


"Sounds with two outlets easily become stagnant, as in them there are relatively feeble reaction currents set up by the tides.  Extreme stagnation in bottom waters is found in some fjords with salt surface waters but with little salinity difference between surface and bottom."


Parker D. Trask mentions iron sulfide although the first study was done twelve years earlier by researchers in the 1920's (Recent Marine Sediments, 1955).  These studies (1926) mentioned that climate and energy levels influenced habitat conditions close to the continent and had focused upon organic matter.  This was known as the Treatise on Sedimentation was first printed in 1926.  Trask highlights the current questions about marine sediments on page 4 of his preface To Recent Marine Sediments, Washington, DC, July 27, 1939:


"The organic constituents form an essential through small part of sediments.  This organic matter offers many problems, some of which are the conditions of accumulation: changes that take place after sediments are deposited, the chemical composition of organic matter, the variations in the nitrogen and oxygen content of the organic matter under different conditions; the modes of formation of reduced sediments, of iron sulphide, and of dark-colored deposits that ultimately may become black shales, the effect of bacteria; the relation of texture to organic content and the origin of petroleum."


Many of these marine compost questions/"problems" remain today – my view, Tim Visel. 

Marine Compost Salt Marsh Peat Sinks in High Heat

Climate Change and Public Opinion – The Mosquito Habitat War in Greenwich CT 1901-1914

For those interested in climate change and diseases of the human race within habitat vectors might want to review this case.  Climate Change and Public Opinion, a 2008 report (revised in IMEP #16, posted May 29, 2014), looks at almost a full century of public policy changes as we today value coastal habitats.  The Greenwich Connecticut Mosquito Habitat war traces the desperate attempts of State and Greenwich citizens to quell a huge outbreak of Malaria blood parasites that neared 1,000 cases in 1911.  As panic broke out state and local health agencies allowed the filling (some under emergency orders) of Greenwich coastal ponds within one mile of the coastline.  Many subtidal salt ponds and nearly all salt marshes were filled as swarms of vicious salt pond mosquitos made Greenwich residents head for shelter in fear at dusk.  Recently discovered papers from Guilford detail efforts in the 1950s, 1960's and early 1970's of State officials discussed way of changing previous public opinion about filling them towards salt marshes conservation.  As the Great Heat ended by 1938 Malaria outbreaks were few and by 1942 gone with the return of colder temperatures.  A rare memo written by Ann Conover of Guilford is referenced and the early foundation of salt marshes as valued habitats detailed in the late 1950s to 1960s (See IMEP #16: Mosquito War Claims Connecticut Marshes 1901-1915).


In the late 1950's, the State of Connecticut desired to change the public's perception of salt marshes as dangerous disease filled habitats.  In an April 17, 1958 letter, Arroll L. Larson of the Connecticut Board of Fisheries and Game wrote to Paul Galtsoff at the Bureau of Commercial Fisheries (then part of the Fish and Wildlife Service) asking for help in saving Connecticut's salt marshes, which includes this first sentence:


"Dear Dr. Galtsoff – Here in Connecticut we are fighting the seemingly loosing battle of saving our tidal marshes." 


This effort to save the marshes came after a period of 64 years as in 1894 Connecticut had passed regulations to drain and or fill salt marshes to kill mosquitoes by eliminating habitat (Connecticut had Malaria outbreaks during this period of extreme heat in the 1890s).  A great description of this change of public policy can be found in a David Casagrande (Yale University report) The Full Circle: A Historical Context for Urban Salt Marsh Restoration (1997).  The late 1950s were known to have cold long winters – a negative NAO and Malaria outbreaks had disappeared by 1938 along Connecticut's shore as the climate then turned colder.  That climate feature ended in 1972 as heat returned to New England.  So would mosquito disease.


Climate Change and Public Opinion was first written for the EPA – DEEP Long Island Sound Study in 2008 and released as a regional habitat newsletter in 2014.  It is available free to all interested (See IMEP #16: Mosquito War Claims Connecticut Marshes 1901 to 1915, posted May 29, 2014, The Blue Crab Forum™ Eeling, Oystering and Fishing thread).  It looks at how gathered composts salt marshes responded to decades of high heat.


Salt Marsh Habitats Fail in High Heat - 1898 


One of the perplexing habitat events was the 1898-99 die off of Southern New England lobsters was followed by the immense New England oysters sets at the same time.  The 1899 oyster set was the set of the century –oysters it seemed were everywhere as reports from oyster literature are filled with pictures of set on shell – sometimes even on crockery – clay tiles and bricks.  Brick waste actually became a great setting substrate slightly porous oysters seemed to be able to "latch on" the best.  Bay scallop shells had been a cultch of choice as the first oyster grounds became cultivated but in the 1890's bay scallop shells became scarce.  As oyster planters were thrilled with the oyster sets inshore lobster fishers searched for any lobsters – the heat had been harsh to them (bay scallops as well) and the last large quahog beds – north east of Nantucket gave out a decade later.  Soft shell clams, oysters and blue crabs now dominated the shallows, where bay scallops, lobsters and quahogs had been before.  The decrease of cold water species and those that prefer warmer temperature would increase and be reflected in small boat fishery landings (US Fish & Wildlife Service Catch Statistics).   


But the harvest of salt hay soon declined.  Salt marsh peat became soft and soupy.  To keep horse teams from sinking into the peat, horses were equipped with a snow shoe like "hay shoe" horse shoe.  These wide wood shoes were to provide a greater surface area (on display at the Farm Museum building at the Durham Fair) but with ditching and soft peat conditions, Connecticut's salt hay crop was abandoned and production declined (See CT Agriculture Experiment Station reports).  New Haven Agriculture researchers were dismayed by this lost crop but in conversations with Charles Beebe of Madison in the early 1970s, Guilford farmers gave up because the marshes had become so soft.  These salt marshes, in many ways, were marine composts with a peat-turf cover.


It was the agriculture community who first detailed the wasting of ammonia in wet hot terrestrial composts.  Sealed from oxygen anaerobic bacteria produce hydrogen sulfide the rotten egg smell and excess nitrogen as a form of ammonia.  Ammonia is described as a "sweet smell."  A century ago in southern states marine compost was a soil fertilizer (called pluff or plough mud) and when harvested produced similar smells.


This loose marine compost is found in the Carolinas and the State of South Carolina issues "pluff mud warnings" to marsh visitors unaware of the danger of sinking into it (Hilton Head rescue personnel are equipped with special shoes similar to snow shoes – See The Island Packet – May 11, 2022 Sarah Claire McDonald – "Pluff Mud In The South Carolina Low Country Can Be Dangerous).  In New England and Canada, farmers harvested this marine compost for similar soil enrichment, called mussel or harbor mud.  In 2017 Suzannah Smith Miles – responds to questions about Pluff Mud – "The name originated in the early 1800s when coastal planters began using the nutrient rich substance as a fertilizer and would plow (then spelled plough) it into the fields."


And further:


"The mud is a mix of algae, decaying animal and plant matter and sediment.  Bacterial detritivores which feed on the dead and decomposing organic matter live within it, respiring without oxygen in a process that removes sulfate from the water and releases hydrogen sulfide into the mud.  Thus, the "rotten egg" smell."


(Charleston – The City Magazine – October 2017 "Pluff Mud").
Farmers well equated with terrestrial composts recognized its potential soil nourishment (Sapropel is a valuable international soil amendment product).  In northern states Agriculture Experiment Stations tested samples of harbor mud for nitrogen content.


An 1885 Maine Agriculture Experiment Station report titled "Harbor Mud" (pg 35) has this section:


"This station (Maine Experiment Station was sent a sample by Fred Atwood of Winterport (Maine) the barrel of mud was received several weeks before being sampled and when it was opened it emitted a strong odor of ammonia." 


Heat Brings Marine Soil Chemistry Change for Eelgrass 


Having worked for two Cooperative Extension Services, and for a short time an Agriculture Experiment Station at three different Land Grant Universities I was amazed at the research and educational programs available for home gardeners.  Don't forget "to get your soil pH tested" which was part of my Cooperative Extension experience since 1967.  When I was in the Shoreline 4-H Club (1967) until 1990, UCONN Cooperative Extension soil testing was an annual spring message.  Few gardeners today will reply that they have not heard this soil message.


Information on soil, types, soil pore space, beneficial soil bacteria, pH, fertilizer information and later when I left Cooperative Extension employment for work on Connecticut's FFA –Agriculture Education aquaculture efforts new "Master Gardeners" programs were available to the public and were important to Cooperative Extension Systems.  It certainly was not the same for future farmers of the sea – they struggled with incomplete soil information, an absence of habitat succession laws, no knowledge of acid or alkaline soils or impact of soil cation exchange capacity (CEC) conditions upon sea life.  In many instances, nearly none of the basis agricultural cultivation principles carried over to the sea except perhaps for predator control.  


The oyster industry had learned the hard way about the monoculture of oyster beds – soon had oyster predators, oyster drills and starfish in larger numbers in or near cultivated beds.  Genetics also carried over as "spawner" transplants of oysters from different localities were planted to improve local sets.  Instead the knowledge of shellfish and finfish habitats would languish for decades – in fact the most habitat information and knowledge were from the fin and shellfishers, themselves.  


Observations of fishers provided the most useful information – the visual records of habitat observations and the statistics for fish catches.  Some of the first soil cultivation experiments were in fact carried on by farmers who had teams of oxen and horse drawn plows.  Bridgeport Connecticut has the distinction of being one the first communities to experiment with marine soil plows – local soft shell clams set heavily upon beaches after the energy of the 1870's stopped into these recently cultivated marine soils.  Soft shell clam production now soared and clam seeding experiments were well underway in Bridgeport by the 1890s and in Clinton CT in 1900.  It was difficult to miss the soft shells that now set heavily from New Jersey to Chatham Cape Cod.  So also, was the subtidal marine grass known as "eelgrass," the grass that holds eels and important to a winter hand held spear fishery.


Eelgrass like most grasses biological and habitat successional role was to bind loose marine soils and stabilize them much as terrestrial grass after a forest fire.  Instead this energy pathway is represented by strong coastal storms – hurricanes and powerful Northeasters.  As strong storm waves, currents and surges had a role in habitat succession as well, cold sea water is denser and more destructive than warm.  Coastal barriers and inlets during cold and stormy periods tend to breach – allowing coastal energy to cultivate, disturb organic deposits and clean such compost deposits down to sulfide stained "black sands."  


Warm periods was just the opposite, warm water is less dense and the offshore sand bars of the 1870s now moved to the beach – inlets tended to "heal" in the fisheries literature and coastal salt water farms who wanted cheap fertilizer, bait or salted food (salted alewife was a popular bar food – stripped salted or smoked) rushed to unblock closed off salt ponds – in heat and as time passed such closed ponds went "stagnant" and turned black.  This was a natural occurrence and many rivers and streams that obtained large amounts of leaves naturally had sulfide "black waters."  The names of black bay or black cove or just black water river are those areas high in tannins and subject to iron/sulfate reduction.  These areas of iron and sulfate from seawater would eventually create conditions for a shellfish or fish kill.  These conditions were to present themselves during the 1880-1920 periods of huge heat waves and few storms (See Appendix #1: The Blockage and Sand Burial of Mememsha Pond of 1912). 


Into this roughly four decade period eelgrass coverage would extend far up into bays – these hot periods amplify droughts and saline waters could reach up higher into rivers and coves.  To the disappointment of duck hunters the freshwater grass widgeon grass Ruppia maritima its nourishment for ducks including a duck called widgeon and known years ago "Boldpate" today as a species of dabbing duck died off.  It fed largely upon Ruppia and when it disappeared along with these ducks hunters often complained.  This occurred in the 1970's in a Connecticut cove called Mumford Cove, when Ruppia (also called duck weed in some localities) died off and then duck hunting declined (Ken Holloway personal communication, T. Visel 1980's).


Eelgrass would replicate the same growth pattern after the 1870's, by the 1890's most agencies considered eelgrass a nuisance, even a public health hazard.  Thick eelgrass growths, slowed tides, filled in navigation channels, had to be dragged off beaches permitting those who could afford to escape the brutal of the 1890's to reach the water.  During New England heat waves, long narrow cove passages to the sea often stagnated producing the smell of rotten eggs.  The 1930's would see these eelgrass monocultures succumb to fungal disease when that happened Brant starved to death by the thousands.


In an effort to improve duck hunting many US Fish Wildlife Service efforts included projects to impound fresh water on blackish marshes to enhance growth of Ruppia.  Ruppia declined on the east coast as salinities increased in marshes from sudden breaches, inlet breaks along barrier spits.  The influx of sea water would kill Ruppia but greatly increase the eelgrass (Zostera) coverage into the 1960's.             


The eelgrass problem often became severe in the shallows, it was everywhere listed on nautical charts as "eelgrass" or at times just grass.  It some coves it caused sedimentation restricting navigation, it grew so thick at times special propellers were designed to cut through it, (New York) in other areas it covered soft shell and hard shell clams habitats.  Where tides or currents were slow a sticky black and sometimes jelly like substance built up on the bottom, the beginning of sapropel.  It is here that shellfishers noticed how aggressive it (eelgrass) could be destroying shellfish habitat and now creating an eelgrass (Zostera) peat sealing organic matter from oxygen.


In heat, this eelgrass peat fostered the production of ammonia, in cold the production of toxic sulfides.  The bottoms that held few fish or shellfish and once disturbed shed sulfides, a kind of poisonous smoke that sent a "smell" into the water column.  Here next to dead bottoms that produced sulfides the first sapropel formed in or near eelgrass.  When New England fishers went to spear eels in deep holes or cut a hole in the ice they did so over "eelgrass" and near black "dead bottoms."  This is a 1920 account from the American Angler – pg. 498 (My insertions in brackets, T. Visel):


"The eels on the close approach of winter had worked their way up the creeks and marshes, and with the making of the first key nights (usually from a group or ball of eels, T. Visel) and literally buried themselves body and soil in the soft mud bottom.  I soon found that eels were not everywhere on the bottom for to simply put one's spear down and haul them forth.  For it seems eels is particular, if not quite fastidious as to the certain kind of muddy bottom he buries himself in for the winter months.  In fact, he does not seem to like soft and deep, black sticky mud (now thought to be toxic sapropel, T. Visel).  On the contrary, he will generally prefer what is known to fisherman as clean, or "live mud bottom."  It seemed this clean or live bottom is to be found near or along the edges of the channel, and while soft mud, it's constituted of rather a firm mud, and is apt to have patches or a scattering of eelgrass grow on it.  In such eelgrass bottom, where the ebb and flood of tide sweeps over it, the eel delights to bury or bed, and there while in a state of semi hibernation he waxes fat and sleek the winter long while snow and ice deeply coat the surface of the waters above him."  (The American Angler, Volume 1920, pg. 498-500, "We Go's A-Eelin" Through The Ice For The Slippery One by Will R. McDonnel.)   


And so at the end of great heat, it is the eelgrass next to dead bottoms that gave off sulfides kept larger predators away from the soft tissue unprotected eels.  Eels dug out depressions among the eelgrass roots because enough oxygen was available in this soil to keep them alive – they could survive in this low oxygen cold sulfide environment.  Only a few organisms can live in eelgrass/sapropel (peat) in winter as ice restricts oxygen exchange it is these bottom that purge deadly sulfides.  The eel of our coast Anquilla rostrata, lives in an acidic eelgrass peat (it secretes an ample mucous layer for protection against sulfuric acid) and can absorbed oxygen through their skin, giving a huge advantage by hibernating next to eelgrass roots.  When fishers sought out to spear eels they headed to "eelgrass" and areas close to dead bottoms.  Eels could not live in sapropel because it contained little oxygen and toxic sulfides.  If winters were long, sulfide levels could rise and kill eels, terrapin turtles, blue crabs and even fish in salt ponds, i.e. a winter kill under eelgrass growths.  In winter's cold and summer's heat eelgrass /sapropel became deadly places and eelgrass could provide some life support to various species as well as become a toxic habitat that supported the sulfur cycle.  The term eelgrass should have been a clue to its habitat type, beneficial if ample/flows existed – reduce the flows (energy) and increase the heat eelgrass become a bacterial and chemical battlefield.  When the EPA decided to go "all in" for promoting eelgrass as an important if not critical habitat type it was one that fishers knew in heat marked the edge of dead or toxic lifeless bottoms a century ago.


Sulfate-reducing bacteria, including the Desulfovibrio series or Vibrio for short, thrive in heat.  Perhaps the most infamous recognizable Vibrio bacteria is Vibrio cholerae or shortened to cholera) lives below eelgrass.  It is here in an eelgrass gathered compost that organic matter feeds bacterial that utilize sulfate for oxygen and create sulfide deadlines.  Similar to turn of the century studies that found terrestrial grasses held dense cultures of bacteria below them some research exists indentifying marine composts (soils) as bacteria rich (see Are We Fooling Ourselves??  Eelgrass and Subaqueous Soils As A Refuge for Fecal Indicator Bacteria – Jessie Dyer URI 2009).  Other research is examining bacteria below eelgrass and reports mention the vibrio species and several fungi.  The "wasting disease" of the 1930's was found to be connected to the marine compost slime mold - fungus, Labyrinthula zosterae.  As temperatures dropped in the 1920s, it is thought that this favored the growth of fungus while heat increased bacteria.  Similar attributes have been associated with terrestrial compost science.  Cooler composting temperatures often favor the growth of fungus.


Eelgrass on the Beach 


Daily walks on Hammonasset Beach I soon noticed this ribbon like plant – it formed a thin wrack along the high tide line.  After a storm, it was a different matter and, from time to time, it was a deposit of green fertilizer and my father made short work of this natural fertilizer free of charge and it would quickly go into our garden.  One of things I noticed that eelgrass would not rot or crumble quickly – instead it lasted a long time and we used it to mulch our strawberries.  Only later did I learn that researchers had discouraged the use of eelgrass as compost as it "would not rot" from its high silicon leaf content.  Severe storms left a wrack of eelgrass with roots still attached.  In our area of Connecticut's coast we had more kelp/cobble stone than eelgrass in winter, which was dense at the mouth of the Hammonasset River.  Kelp would come up along the beach but it was often attached to cobble stones that had patches we could see between reefs at low tide when the waters were clear.  Only the strongest of storms was able to cast up kelp onto the beach which if close to Pent Road also ended up in the garden.  There is a huge depression era mural in the Madison Post Office gathering seaweed at storm, which shows Madison farmers (formerly part of Guilford) harvesting seaweed with pitch forks and oxen carts.


In the high energy coast of Madison, Clinton and Guilford, it was kelp cobblestone that was productive habitats for winter flounder, small black fish, and lobsters.  The kelp formed a reef complex, slowed currents but because of its high energy area cobblestones did not move.  Eelgrass needed lower energy environments so when the energy levels change it is natural to see eelgrass expand and then retract.  In the lower Hammonasset River eelgrass could be found, and by 1974 it lived on the north side of Cedar Island in a thick meadow.  When we oystered in the lower Hammonasset River, it was a nuisance; if we went off the oysters, the dredge quickly filled with a loose mud eelgrass mixture.  It (eelgrass) often filled our hand hauled oyster dredge and stopped our skiff.  A 1983 National Fisherman™ article shows our Brockway Skiff with it but by 1983 the eelgrass had started to disappear, as more and more black mayonnaise covered seed oysters.  What was once a nuisance now was a problem, eelgrass plants were brown and slippery, they looked sick.  It was also hot.


When I met John Hammond on Cape Cod, I had learned more about climate change and eelgrass – the impacts of temperature and energy upon shallow water habitats.  Those meetings and references appear in many of my habitat reports but the overriding message that at the end of a two decade period 1960 to 1980 period eelgrass had destroyed many of the shellfish habitats on the Cape, he described as "the eelgrass problem."  The eelgrass problem was similar after the four decade period 1880 to 1920 (this is the period in which Mr. Hammond wanted me to look at weather and fish catch statistics) eelgrass was abundant and also a nuisance – it filled bays and was destroying shellfish habitat – in the 1940's and 1950's strong storms had reduced eelgrass the water being colder and the great sets of quahogs had occurred.  As the cold and storms faded eelgrass over ran these shellfish beds and suffocated them.  One of the items Mr. Hammond impressed upon me was the study the sulfur cycle of soil as he felt it was most important to the understanding of shallow water habitats.  He was somewhat discouraged by my admission that my FIT and URI class work did not cover the sulfur cycle – and one meeting consisted of him throwing down a chapter from a textbook on the sulfur cycle "learn it" as he tossed it on a table.


As he described the efforts to eradicate eelgrass as it overwhelmed shellfish habitats, grew thick slowed tides and trapped organics as a rising layer of eelgrass peat (found in State of Massachusetts shellfish reports from the 1920s and 1960s.)  In fact, shellfishers grew to despise eelgrass as its ability to trap organics had turned productive shellfish areas into black sour and smelly bottoms or a marine compost – containing marine fungus.


The is the compost chemistry that is missing from nearly all recent eelgrass reports – what happens to the organic matter under eelgrass in heat and then in cold.  Most terrestrial composting mention fungi as saprophytes – those organisms that live off the dead.  Many articles describe the fungal communities that exist in land composts, some tolerant even of high heat.  When it came to composts under eelgrass however little of that chemistry carried into explanations of eelgrass wasting disease of the 1930's.  The clean and green eelgrass of healthy plants in soil with little compost (mostly sand) or the "brown and furry" eelgrass of soft compost that often smelled of sulfide.  Sulfide kills eelgrass sometimes weakening it so other "opportunistic" pathogens can now attack it.  This fits (almost precisely) the impacts of colder water and storms that cultivate (think compost turning) sandy soils – great for eelgrass or the poor stagnant soft compost that purge ammonia and sulfide.  As the heat returned to New England in the late 1970s eelgrass over high organic content "composts" started to die – from slime mold fungus and sulfide root decay mentioned as "black layer disease" in terrestrial peat.


What I had noticed in the 1970's was happening it the 1980's on Cape Cod every storm it seemed sent a wrack of eelgrass onto the beaches and into the salt marshes – as most of these plants still had some root tissue attached to them – at the time I was unaware of the soil chemistry that damaged its root tissue.  Eelgrass was high in silicon which caused it not to be broken down quickly by oxygen bacteria.  The high silicon content did not support combustion and soon made it a packing material in ice houses and cold storage facilities.  Federal and state reports soon mentioned the good insulating properties of dried eelgrass.  Before ice houses used sawdust but when wet that would oxidize and produce heat (and sometimes fire) the winter compost steam contrary to ice house function.  The ice industry went to report ice "cold" storage designs as reported in this 1905 report from Canada.           

35th Annual Report 1905 of the Report of Marine and Fisheries – Ottawa Printed by order of Parliament

Report of the Deputy Minister Sessional Paper No. 22

The Canso Cold Storage Campaign (bait) plant has all these – and the result is something unique in cold storage plants.


"The insulation seems to be well nigh (near) perfect.  Six (inch) thickness of matched spruce boards, nine (inch) thickness of heavy insulation paper, a two inch air space, and six inches of eelgrass surrounded rooms, while the first floor has between 12 inch joist 25 tons of eelgrass and the second floor about 20 tons. About 60 tons of washed and dried eelgrass were used in the insulating and while the employment of it was somewhat of an experiment, its value as insulator has been finally proved.  Its non inflammable qualities add to its value for the purpose."  


In time the insulation properties would be known as "Cabots Quilt" and became the first paper backed insulation in homes.   



The NAO and Storm Intensity/Frequency 


The transitions from a long period of warmth with a stable positive phase to a negative phase one allows cold polar air (the polar vortex was detailed by Hurd Willet in 1954) to sink far to the south and collide with the sub tropical warm air jet stream.  This allows the frequency and strength of coastal storms to increase.  Cold polar air hitting warm rising air over the gulf stream creates this energy as these air masses produce stronger storms – and for New England summer hurricanes and in winter the Northeaster's.  It is not like a switch – it takes time for the impacts of energy and temperature to reverse fisheries habitats.  This is why John Hammond was keeping records of wind direction, duration and velocity, noting not only changes in marine soils on the Cape- Chatham Monomoy and the resulting clam sets.  In times of heat 1880 to 1920, Chatham was a leading producer of the softshell clam, in times of cold and energy the bay scallop fisheries flourished.  In times of eelgrass abundance, clam and scallop habitat quality actually declined and not increased – these observations can be found in federal and state reports.  


The change in energy and temperature would greatly influence inshore shellfisheries.  A decade before I came to the Cape shellfish areas that were closed collected black mayonnaise (a compost sapropel) often with a suffocating eelgrass crust.  It was now warming in New England and deep organic deposits with or without eelgrass started to smell of sulfide.  It would die off again as compost chemistry changed with sulfate bacteria metabolism as it had a century before.  Many areas held a black soft iron sulfide organic ooze – toxic to plants. 


We need to review climate factors and impacts upon coastal shallow water habitats - my view, Tim Visel.

Appendix #1

The Blockage and Sand Burial of Menemsha Pond Martha's Vineyard of 1912

Excerpt from Irving Field US Fish Commission Bulletin Vol 29, 1911

Pg. 215 (Note Agency was often a term for Nature – T. Visel)

Inanimate Destructive Forces

• The Blue Mussel –

"A slight change of current may cause a deposition of sand over the beds which maybe acres in extent and smother the mussels out of existence.  Some years ago such a wholesale extinction by this agency (Nature – T. Visel) took place in Menemsha Pond, Martha's Vineyard, MA.  The bed a photograph of which was published in a previous paper of the author (Field) 1911, but when visited in July 1912 nothing but a barren flat of white sand was visible at low tide.  Investigators revealed the presence of the decaying shellfish about 4 inches below the surface."  (Field Irving, The Food Value of Sea Mussel Bulletin, US Bureau of Fisheries, Vol. 29, 1911)