IMEP # 142 part 2 Warmer Temperatures May Poison Eelgrass Soils

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IMEP #142 Part 2: Warmer Temperatures May Poison Eelgrass Soils

Cooler Waters May Foster Fungal Disease

"Understanding Science Through History"

Was Eelgrass Spread by Sailing Vessels In Commercial Trade?

Viewpoint of Tim Visel – no other agency or organization

February 2021, updated December 2023

This is a delayed report

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Tim Visel retired from The Sound School June 30, 2022

 

 
 
A Note from Tim Visel
 
One of the most curious discoveries of George Nichols 1920's Connecticut Vegetation Investigations was a series of extensive marine cores (vertical borings or plugs) in New England coastal coves. The bottom of such cores of salt marsh had no eelgrass remains as he surmised should be contained in these samples.  It was a New Haven, Connecticut core that was most noteworthy.  It was the most perplexing to him, and on pages 543-544 is found this section:
 
 
"Assuming the vertical or historic order of succession during the development of the marsh to have been coordinate with the present day lateral sequence of zones, as set forth in the second paragraph above, the peaty and mucky deposits underlying a salt marsh should show approximately the following sequence of layers, from below upward: (1) a layer of silt, with remains of eelgrass, extending from a variable depth to low tide level; (2) a layer of silt, with but few vegetable remains, extending from low tide level up to the level at which the salt marsh grass becomes established; (3) a layer of muddy peat with more or less abundant remains of salt marsh grass, extending upward nearly to mean high tide level; (4) a layer of peat made up largely of the remains of salt marsh peat along the New England coast has revealed a very different state of affairs. Bartlett ('09), for example, describes a salt marsh near Woods Hole in which the salt marsh peat near the surface is underlain the remains of a former Chamaecyparis bog, the stumps of large numbers of trees (false cypress) being preserved in situ.  C.A. Davis ('10) reports that in the vicinity of Boston, the peat deposits underlying the salt marshes likewise consist, in many cases, of the remains of fresh water vegetation; in other cases peat deposits composed largely of the remains of salt meadow grasses extend from the surface downward to a depth below that of mean low tide level- in other words, to a depth many feet lower than that at which the plants which formed peat could possibly have grown. In no case, Davis emphatically states, does the peat show the hypothetical arrangement of layers specified above. The peat underlying a brackish meadow near New Haven, and sectioned during operations for brick clay, shows similar conditions: just beneath the surface (2) a layer of Distichlis peat and (3) a layer made up largely of cat-tail and fern remains, with (4) numerous scattered stumps resting in place on the underlying gravelly substratum, about five feet below the present mean high tide level.

 From the foregoing observations it is clear that any assumed agreement between the present-day zonation of salt marsh associations in relations to tide levels and the succession of plant associations which has ensued during the development of the marshes, along the New England coast, is not in harmony with the facts as recorded by the underlying peat deposits, in so far as these records have been made available."

 The absence of eelgrass from these cores nearly a century ago is today the subject of habitat questions today is our dominant eelgrass strain present today actually native to our shores?

 The first time I heard this theory I was meeting with John C. Hammond, a retired oyster "planter" on Cape Cod. He had been studying the impact of eelgrass and a more recent seaweed invader, Codium, upon cultured oysters for decades, they both don't belong here, I can recall him saying the Codium (also called dead man's fingers) invasion was easy for me to believe; I had never seen anything like it growing up in Madison, CT- eelgrass was different, I had seen it, after storms the Hammonasset Beach wrack line was full of it, and it would fill menhaden gill nets set for lobster bait.  It was 1982 and shortly after arriving on Cape Cod I would meet Mr. Hammond in Chatham many times. In reality I was sent by an organization of shell fishermen on Cape Cod to seek him out about shell fish habitat conditions and nitrogen concerns. It would be the first of many meetings.

 To put it bluntly, Mr. Hammond had no use for either eelgrass or Codium, both in his opinion had damaged shellfish habitats.  Mr. Hammond blamed eelgrass for ruining hard clam quahog bottoms (habitats) and Codium had caused much additional cleaning of harvested cultured oysters.  At the time, Codium (slightly buoyant) had grown so dense as to lift oyster pond oysters off the bottom, or at least had added so much resistance they were carried out on ebb tides to sea.  The issue regarding eelgrass and hard clam habitats raised by Mr. Hammond came to an open conflict with shell fisheries on Cape Cod.   Mr. Hammond reported to me that growths of eelgrass had overrun hard clam habitats in Pleasant Bay in the 1960's.  Pleasant Bay efforts to control the spread of eelgrass even then included the use of powerful herbicides. 

 It is at one of our discussions about shellfishing that green crab predation in soft shell clams (Mya) and that Mr. Hammond connected these two species – eelgrass and green crabs.  According to Mr. Hammond, green crabs needed eelgrass as a "habitat cover" to spread.  Not fully realizing the significance at the time of that habitat connection, I was however well acquainted with green crabs.  I had trapped them and seined them in Tom's Creek in Madison, CT for decades and I knew they liked shellfish. Our favorite early catching method was very simple—a strand of beach grass (now frowned upon, string works just as good) with a cracked mussel tied at the end. Even fishing in daylight among rocks off Webster Point, Madison, a cracked mussel was hard to resist. There seemed no end of the green crabs and it was Mr. Hammond who introduced the concept of night movements. I also had first knowledge of green crabs' predatory aspects on shellfish, such as quahogs and steamers (soft shell clams, Mya) also in Tom's Creek, but eelgrass was scarce. Despite trapping and seining, there seemed to be no end to the green crabs. On that topic, Mr. Hammond did agree with me.
The book "The Canadian Oyster" by Joseph Stafford, (Ottawa, The Maritimes Company Ltd, 1913) describes an excellent turn of the century oyster industry – green crabs had yet to reach the Northern Maritimes (1912), but by the late 1950s, they had. 

 During a term on the Madison Shellfish Commission (1981), I had discovered correspondence with commission members from Victor Loosanoff about the decline of soft shell clams and the increase in green crabs (1953).  Green crabs in the late 1950's and 1960's were now spreading north into Maine ruining soft shell clam beds in the process – so was eelgrass.

After reaching enormous densities during The Great Heat (1880-1920), eelgrass had declined after the 1938 Hurricane and the colder and stormier 1940's and 1950's in Southern New England.  In the 1960's and 1970's, however, eelgrass was back and so were the green crabs. Mr. Hammond had decades of shellfish habitat observations and mentioned that the green crab and eelgrass habitat histories to him were closely linked – some three decades later; it looks without any doubt he was correct.  A direct and positive habitat relationship appears to exist (now frequently termed habitat services); eelgrass and green crabs do seem to have a habitat relationship – one that did not begin here but perhaps on a different continent in Europe, the English Channel and along the Dutch coasts.

 At first, Mr. Hammond was a bit reluctant to show me his eelgrass research; he had collected eelgrass blade samples and carefully preserved them on that heavy biological paper.  I had seen other seaweed examples at the University of Rhode Island in the basement offices of Woodward Hall.  Here one day, I discovered the remains of a collection of seaweed prints, dozens of pressed preserved seaweed mounts on similar heavy "biological" paper.  I was later to learn that this was a popular activity- hobby actually after World War I.  The URI collection was in a box and looking back most likely on the way out to discard. But, I had seen it so he continued:  He had collected blade samples from the North Sea and compared it to those now on the Cape, he had concluded it didn't belong here, it being he felt a North Sea strain.  This was the first time I had ever come across this theory, but the most amazing piece of the puzzle was yet to come, people in this section of Europe apparently ate green crabs.  As Mr. Hammond continued to tell me about this, I immediately thought of these green crabs I had long used for black fish bait, hardly the size of something I would at that time consider edible. The transplanting aspect however seemed very real to me, having oystered and seen oyster drills laying their egg capsules on living oysters and crabs moved in burlap oyster bushel bags.  The concept of moving species across the Atlantic Ocean with shellfish was plausible, but eating green crabs - that was something I had not seen, not until 2011.  Mr. Hammond felt that green crabs came to our coasts wrapped in eelgrass to keep them fresh and moist on the voyage here. Now it appears Mr. Hammond was correct again.
 
The first time I mentioned this theory to researchers was during the 9^th International Conference on Shellfish Restoration in November 2006.
 
I was fortunate to be able to attend and present at this conference as it had been nearly two decades since being employed by a University Cooperative Extension Service.  The title was "Connecticut Shellfish Restoration Projects Linked to Estuarine Health" but that was not the original title – the first time had habitat in place of estuarine.  My experience with other journals and a history perspective were often not within the somewhat rigid categories of research disciplines.  I changed it and was placed on the agenda.  I was surprised and somewhat saddened by how much of the break conservations during the conference were about grant topics.  I left University of Connecticut in 1990 and my experiences were quite different as Cooperative Extension reports called NARS then (Narrative Accomplishment Reports) were focused on the economic benefits of the work - how many acres or bushels produced basically how University research helped primary producers with costs or food production.  I used the same agriculture report form but acres and bushels just reflected shellfish leases or shellfish catches, not acres of corn or bushels of potatoes.  (Cooperative Extension Service Narrative Accomplishment Report Form FY82 Section V).  In the time I left Cooperative Extension that had changed, instead much of the conversations (called net working today) involved grants – more specifically the need of grants to continue University work rather than the economic benefit of the work itself (my view).  I am certain that not all conversations were about the need of grants – so many were that my reflections on habitat history had one remark come my way "No one pays for old data" which I remember very well.  That hit a nerve as the basis of my paper reviewed history what had worked and what had not – the importance of knowing your "habitat history" something introduced to me while employed by the University of Massachusetts. 
 
To me, knowing what succeeded was equally important in knowing what did not.  I had seen many projects fail from a lack of habitat knowledge and I include some of my own which was the main point of my presentation.  The conversations about eelgrass were, at times, intense.  The conference in 2006 at the Double Tree South Carolina Conference Center had a courtyard small tables and trees next to a small restaurant.  I would go there to Palmetto Courtyard during the breaks and many conversations at other tables involved eelgrass.  Some of the eelgrass meetings took on the feeling of a stock market promotion as a new hot stock only in this case more of grant opportunity than capital investment.  I had seen this type of promotion before, with winter flounder and lobsters in the 1980's and 1990's.  Researchers would obtain grants but with mixed results often blaming coastal development or capture fisheries for population declines when really it was massive habitat change.  I had experienced this lack of history knowledge as I had been working for the University of Connecticut since 1978 and first stationed at the Noank Marine Lab which once housed Connecticut's Lobster Hatchery.  As the 1998 lobster die off happened, no one mentioned the previous lobster died off of 1898 nor the New England lobster hatchery effort (including New York's) that followed.  A lobster convention to discuss this die off was held in the fall of 1903 at Boston Mass but this was not mentioned for nearly a century.  (Since 2006, many US Fish Commission Reports have been put online, See Report Upon A Convention Held at Boston, 1903, To Secure Better Protection of the Lobster by Joseph William Collins). 
 
Winter flounder was more personal as I and my brother Ray, with a small Brockway skiff, trawled for them off Hammonasset Beach.  When we first started in 1971, the fish were large and firm – and none of the fish lesion – rotting trail fins that happened in the 1980's.  In 1971, we rarely caught a small winter flounder, they were in much shallow waters or in the creeks.  By 1979, we caught tremendous amounts of small flounder (so did blue fish) and in one study of New Haven Harbor conducted in 1981 for Schooner Inc. reported about a quarter of the fish sampled in Morris Cove (New Haven) had fish necrosis (fin rot).  Later, fish rot was associated with Vibrio bacteria prevalence in warmer water.  Many 1980 and 1990 reports blamed over fishing as the primary cause of the decline instead of a massive inshore habitat failure for winter flounder.  The same was happening for the lobster post 1998 and several management proposals were developed as lobster catches fell quickly.  I waited to see if the 1898 lobster die off or lobster hatchery initiative was mentioned.  Decades of environmental policy or resource conservation efforts had produced a soft spot for grant funding.  If human-caused grant funds were available, natural cycles or population changes in high heat or cold were simply not "grant worthy."  That is little funding was available for natural sciences unless it could be connected to human indifference or human pollution.  (No matter how weak or abstract it seemed).  
 
At one conference break, I could hear some attempts to strengthen the connection between eelgrass and seafood that the public sought information in this case lobsters and winter flounder both of which had serious declines (later linked to warming waters).  A discussion revolved around clear photographs of eelgrass with lobster and winter flounder together to identify the need of eelgrass to support lobster and flounder species.  The problem was clear pictures of lobsters (a nocturnal species) and winter flounder together in the same frame was not common.  Briefly, the discussion turned to dumping lobsters and winter flounder together and then taking the picture.  This was quickly dismissed as it was thought that lobsters in bright daylight would be questioned.  A picture of eelgrass with selected species would be used many times in the years to come – I recall a picture used in a Boston Globe™ article that simply placed a Jonah crab on a bed of eelgrass, linking them visually (See Eelgrass Could Save The Planet, Nov. 9,  2014).
 
I was surprised by these conversations around eelgrass protection as having worked on Cape Cod with several Massachusetts documents, which mentioned problems with eelgrass and shellfishers' negative comments, not positive.  That did not match conversations or habitat comments from the Cape or even Connecticut.
 
Always in my mind were the comments made by John Hammond that our eelgrass is not "ours" but Europe's.  He had mentioned this to me many years ago and had made the connection between cold and energy and periods of heat.  I was concerned to see so much effort with a plant species much like Phragmites might not be even native here but possibly an introduced strain aboard the first sailing ships.  This caused me to alter my introduction comments before my talk to include this caution.
 
"One final thought – sometimes the habitat you see today is the last type of habitat you want to use or protect."  I had put the history into the abstract and most of my presentation was about habitat succession or change over time.  Much of that I learned on Cape Cod.  In 2012, I mentioned that cores in a New Haven salt marsh did not have eelgrass as a successional series.  This raised the question that if eelgrass was not found it may have been introduced hundreds of years ago – missing the plant spectrum of thousands of years ago (Bulletin of The Torrey Botanical Club, Vol. 47, #11, Nov.  1920, George E. Nichols.  The Vegetation of CT Associations of Depositing Areas Along the Sea Coast, pg. 543-4).
 
In the years after the conference, I was reminded of my conversation about eelgrass with John Hammond who believed that this strain of eelgrass was a high energy cold water strain from Europe.  In November 2013, I inquired about this possibility that eelgrass was perhaps invasive with little new information.  This followed a rapid rise in Long Island Sound water temperatures had facilitated a surge in blue crabs 2010 to 2012 but also die offs of eelgrass.  (See The 2021 Blue Crab Season – The Search for Megalops NE Crabbing Resources Blue Crab Forum™ January 25, 2022).  The eelgrass die off was detailed by several studies including photography from aerial overflights between 2002 to 2009 (See 2012 Eelgrass Survey for Eastern Long Island Sound – Connecticut and New York US Fish and Wildlife Service, Hadley, MA, November 2013, 26 pages).  From numerous reports and shallow water observations eelgrass die offs were more pronounced in warmer shallow waters while deeper and cooler waters eelgrass seemed to stabilize and in a couple of areas even increase in size.  This seemed to support John Hammond's conversations (1981-1983) that eelgrass really did not belong in shallow water – it was in a habitat that had a very short habitat clock – preferring habitats that contained more energy – did not heat up quickly and connected this to a "sulfide deadline."
 
As more reports continued to confirm that eelgrass in higher energy areas (and cooler water) were healthy and even prospering (Fishers Island New York), patches of eelgrass in coves appeared to be weak and suffering from marine compost diseases slime molds (similar to terrestrial turf industry black layer disease, also a sulfide deadline) that coincided with warmer sea water and a bacterial species change in low oxygen conditions.
 
We may find that the dominant strain of eelgrass is what Mr. Hammond first proposed in 1982 that a strain from Northern Europe was brought to the Americas aboard some of the first sailing ships (See Appendix #2: Conversations with John Hammond Oyster Grower – from Do We Have The Correct Scallop Grass – pg. 65, 66).  According to Mr. Hammond, this strain did not do well in shallow water.  His words were to the effect – "it doesn't belong here" – here being shallow water in Oyster Pond River of Chatham Massachusetts.
 
After the die off eelgrass between 2006 and 2009 (shallow water and in the presence of a marine organic compost in low oxygen – as sapropel) I began to believe Mr. Hammond's statement about the transfer of eelgrass (once a packing material for seafood) to our shores.
 
By 2012, I started to think about conversations with Mr. Hammond about eelgrass and his theory that we have a European strain.  As more eelgrass transplants were conducted and some genetic work completed (see NOAA Restoration Center Community – Based Restoration Program (CRP), 8/31/2012, Fred Short et al., 93 pages – The Eelgrass Resource of Southern New England and New York Science in support of management and restoration success seemed to give credence to different habitat conditions.  Like all grasses, eelgrass have the ability to grow in low organic soils taking nitrogen from sea water and then over time deriving greater nitrogen from organics it traps.  This is evident in some terrestrial "first growth" grasses in low organic soils such as tall fescue – Festuca arundinacea.  This feature allows grasses to move into soils low in carbon or at times dry conditions.  (Tall fescues are an introduced species that have a symbiotic relationship with a fungus that allows them to live in dry soils.  Page 7 of the 2012 NOAA Report contains this segment:
           
"However, we did find that our most successful resilient eelgrass populations were part of the two most district meta populations from the north Outer Cape and New Hampshire, MA-NH) and the South (South Shore of Long Island NY)."
 
Although I mentioned the possibility that one or more stains of eelgrass was perhaps introduced informally in 2006, I did so publicly in 2012 six years later.  By that time, I studied the habitat features of the green crab Carcinus maenas and Mr. Hammond's comments that they needed each other.  As eelgrass grew thick, green crab populations increased in the Oyster Pond River, Chatham Mass (comments to Tim Visel – John Hammond).  Between 2006 and 2012, I found many papers that reviewed plant species introduced from Europe – many of which were termed "invasive" and had detailed negative species/habitat consequences.  From the amount of introductions identified from ocean commercial transit, the chances that eelgrass was spread the same way increased.  Today, I feel that it would be considered likely even probable.  This takes into the past practices of packaging seafood in wet seaweed for shellfish and crabs.  In fact the green crab is a desired edible crab in Europe – although it reaches a much larger size.  It is a popular seafood item in the coast of England and Denmark, even Italy has a history of shedding green crabs for use in soft shell crab sandwiches.  That seafood aspect is missing from many green crab reports along our coast – where it is termed invasive.  With the probability of both eelgrass and green crab transplants formed the background for one of the first IMEP Habitat History reports #5 titled "Did Green Crabs Come to America Wrapped in Eelgrass" posted February 24, 2014 on the Blue Crab Forum™ Fishing, Eeling and Oystering thread.
 
Many eelgrass transplants have failed because of a lack of soil knowledge, such as basic soil constituents of clay, organic matter and soil porosity – important to the many forms and growth of terrestrial turf species and careful selection of grass genetics for that soil type.  Almost none of that has happened with eelgrass planting experiments that I have reviewed (See IMEP #121: Why Eelgrass Transplants Fail, posted April 23, 2023, The Blue Crab Forum^TM, Fishing, Eeling and Oystering thread).

If you consider habitat constraints for other plant species, especially terrestrial grasses, different eelgrass strains may have developed specific genetic responses to habitat constraints and related to soil conditions.  Some terrestrial grasses, for example, do better during droughts, others perhaps more shade, still other plants can live in submerged soils, such as rice.  This appears to match specific genetic traits and why, perhaps, eelgrass can be found in arctic conditions as well as those in the tropics.  Soil characteristics and soil chemistry might be one of the ways we can review the eelgrass habitat that appears to be cyclic in southern New England.  Grasses thrive in stable habitats up to a point.  If the habitat remains stable for long periods of time, it may succeed to other habitats.  We can see that with "grasslands" when frequent fires (both natural and human-caused) hold succession to a particular level.  We can also observe succession in a farm field once abandoned for agriculture.  In time, different plant species appear and then dominate previous growths.

It was Mr. Hammond's conversation about sulfide and the killing of marine organisms on moorings in Oyster Pond River that introduced the toxic impacts of low-oxygen composting.  One example he detailed was the bacterial composting of buried organic matter in marine habitats, more specifically, the production of hydrogen sulfide.  The production of sulfide – hydrogen sulfide, most recognizable chemical form as H₂S, is a bacterial response to low or no oxygen.  Dead plant tissue is broken down to be recycled again by bacteria – and consists of two different pathways: (1) those bacteria that need elemental oxygen to complete its digestive process, and (2) others that utilize an oxygen compound known as sulfate.  This second pathway, although much slower and less energy wise efficient, persists in low-oxygen compost, most termed sapropels.  Its byproduct reaction releases sulfides as a waste of the sulfur not needed in the composting process.  Organisms that live in or near such composting processes must have a high tolerance to sulfide or they would perish.  If one examines the tolerance of the bay scallop, it is very vulnerable to sulfide, even minute traces will cause it to stop feeding (See FAO Training Manual on Breeding and Culture of Scallop and Sea Cucumber in China)

 
Some species, such as the saltwater-salt marsh killfish, Fundulus, are very tolerant of sulfide, and when exposed, turn toxic sulfide into less deadly thiosulphate.  Fundulus parvipinnis, a California killfish, can withstand sulfide levels of 700 µm (micromolar) for short periods of time while other organisms thrust into sulfide-rich waters soon perish.  Some sulfide mortality is sudden, which others present a slow absence – one observed in the shellfisheries as "dead bottoms" or "dead soils."  Similar to dredging lakes and ponds, the removal of dead plant material can delay or hold succession that supports greater sea life diversity.

During meetings and conversations while employed by the Cape Cod Cooperative Extension Service (a part of the University of Massachusetts), I learned about dredging organic matter from salt ponds.  It was during an extended drought and warmer weather ponds that during colder times turned sulfide-rich, and during the summer "smelled bad."  I had first witnessed this black, greasy compost in Tom's Creek, Madison, CT, but in a survey of Green Pond (Falmouth) this organic compost in some areas was measured in feet (1982).  When I mentioned this material as "black mayonnaise" to John Hammond, he produced a report titled "Some Aspects of the Estuarine Ecosystem of Oyster Pond" by David A. Gates and Herbert F. Pettengill, MAT Chemist.  This report was approved when a beach nourishment dredging project produced a loose, silty mud, which ran back into the dredge project area.  The dredging of the Oyster Pond channel first removed a sand bar that restricted navigation, but once into the pond area hit several feet of loose, silty mud.  Page 50 of the report contains this segment – (my comments, T. Visel):

"The decomposition of organic material (many areas were described as having thick eelgrass and sea lettuce growths, T. Visel) results in the formation of hydrogen sulfide gas, the rotten egg smell of marshes and mud flats.  This hydrogen sulfide dissolves in the water, forming a weak acid and the pH drops."

Of special note is the deepest areas of Oyster Pond and Stetson Cove held little sea life – with 1 to 4 feet of black mud.  The edges of these embayments held eelgrass along the shore where wave action kept these organic deposits from developing.  Authors reported that in areas of deep organic deposits no shellfish were found.  These areas were recorded to have acidic measurements.  In many coves, I observed similar low diversity of sea life found in such deep deposits.  In a 1980's survey of Alewife Cove between the Town of Waterford and City of New London, just upstream of Peninsular Avenue Bridge were found dead hard clam beds (Mercenaria) under about four feet of organic matter mixed with sand.
Tidal restrictions in areas in coves can occur from sand waves that can seal or close tidal exchange or bridges and culverts will block tidal energy.  Many coves and rivers in New England have tidal restrictions from roads and rail lines.  It is frequently observed that these areas have organic matter accumulations above these restrictions (See IMEP #133 Parts 1 & 2: Tidal Choking Destroys Coastal Habitats 1880-2000).
 
The Eelgrass Dead Soils and Marine Compost Chemistry
A historical review for eelgrass shows that it is cyclic and reaches peak densities many years after strong storms (See IMEP #78-B: The Cultivation and Chemistry of the Eelgrass Soils, posted November 6, 2020, The Blue Crab Forum^TM Fishing, Eeling and Oystering thread) .  A series or period of storms destroy mature meadows while cultivating marine soils for future growths.  It might be best to think of eelgrass doing better after storm disturbances.  It was John Hammond (1980's), who introduced me to the concept of habitat clocks (habitat succession).  He observed that cold to warm periods favored eelgrass to reach up into shallow waters where it trapped organic matter without storms.  It would rise and then reduce flushing and, over time, choke out bottom species such as the hard and soft-shell clams.  Mr. Hammond felt that such storms allowed eelgrass to live in areas that would naturally die off in high heat from a soil "sulfide deadline."  Eelgrass would, over time, also trap small soil particles, such as clays, and change the soil chemistry by reducing pore soil circulation.  His theory of soil circulation was largely confirmed in 2019 by Erin Aiello in a January 11, 2019 report titled "Factors That Affect Eelgrass Growth in Morro Bay #3 Sediment and Light Differences Part 1" (Morro Bay National Estuary Program).  Following is a segment that details this aspect – (my comments, T. Visel):

From Aiello (2019) –
"If sediment (think soil, T. Visel) is too fine, there is little room between the particles, so gas, nutrient and water exchange at the plant's roots is limited.  Essentially, this makes it difficult for the plant (eelgrass, T. Visel) to eat and breathe.  If your sediment (soil, T. Visel) is too coarse, nutrients wash out of the sediment (soil, T. Visel) quickly, and plants growing in the soil can easily be removed.
For example, clay has very fine sediment (soil, T. Visel) texture and can hold tightly to roots (eelgrass, T. Visel) while sand has coarse particles and cannot.  Different plants have their own sweet spot of sediment (soil, T. Visel) texture, and for eelgrass, that sweet spot is arguably between one percent and twelve percent clay.  There is a scientific consensus that fifteen percent clay is too much clay for sustaining eelgrass."
The ability of eelgrass to hold dead plant tissue also in heat provides a culture media for iron and sulfur bacteria – confirming Mr. Hammond's thought about the toxic impacts he witnessed during a raft culture study of oysters in Oyster Pond River in the late 1950's.
Mr. Hammond assisted William N. Shaw, Fishery Research Biologist, in a study titled "Raft Culture of Oysters in Massachusetts," Bureau of Commercial Fisheries, Fishery Bulletin #197, Vol. 61, 1962.  Mr. Hammond's participation in the study is mentioned on pg. 481 "J.C. Hammond, commercial oyster grower, whose help in construction and maintenance of the raft made this project possible."  Mr. Hammond detailed that raft oysters hung on wires that touched the bottom, died and were stained black.  Ice had formed on Oyster Pond, creating a "sulfur deadline" during the winter of 1958 (This winter is in the records as the Cold Wave of 1957-1958 that largely destroyed the Florida citrus crop).  The raft was moved by a storm onto an area of soft bottom.  Mr. Hammond had seen this deadline impact on recreational boating moorings and described in IMEP #128: Sulfur and Iron Bacteria Linked to Seafood Death, posted October 8, 2023, The Blue Crab Forum^TM, Fishing, Eeling and Oystering thread. 

Mr. Hammond cultured seed oysters (mostly from the Hammonasset River, Clinton, CT) on the firm sandy areas, but in the late 1970's, the bottom became softer.  Shaw notes on page 483 that in areas "the bottom is soft with a high percentage of silt and clay."

As the bottom became softer, sulfide (sulfur) smells increased and a 1970 dredging project was once halted because of strong rotten egg smells emanating from the spoils once pumped out on a beach (See IMEP #41: Shellfish Habitats Collapse on Cape Cod in High Heat 1974-1984," posted December 19, 2014, The Blue Crab Forum^TM, Fishing, Eeling and Oystering thread).

Mr. Hammond felt that eelgrass was dying from changing soil conditions from organic composting even though under water.  That created a sulfur-rich bottom and was studying the culture of rice in tropical regions as a comparison to eelgrass soil conditions.  In warm weather, the sulfide levels were so high that they became noticeable as the common reference to the smell of rotting eggs in the fisheries historical literature.
The impact of warm temperature, increasing sulfate-reducing bacteria strains and soil chemistry (iron compounds) upon eelgrass were reviewed in IMEP #121: Why Eelgrass Transplants Fail 1935 to 2020" posted April 23, 2023, The Blue Crab Forum^TM, Fishing, Eeling and Oystering thread.
In time, marine soils become "dead" to eelgrass in terms of survival.

 
"Marine Soils": A Need to Look at Soil Conditions for Eelgrass Growths
 
Because of a near absence of the sulfate/sulfur cycle we have a bias of cold high oxygen water quality conditions applied to research conducted in great heat.  In addition in cold we may not understand the change in habitat quality and long to rebuild warm water species when their habitat clock had long run out.  This bias continues today in many research reports that reflect snap shot ecology that define habitat conditions during the brief time period in which the research was conducted.  The best example (or worst depending upon point of view I suppose) is the eelgrass bay scallop relationship.  Here a snapshot, the presence of small bay scallops setting on clean green eelgrass blades, would be associated with bay scallop habitats.  However when you look at a longer time period and other habitat parameters other than just presence or absence, and compare habitat dominance and biochemical attributes of climate cycles one would exactly the opposite habitat relationship – high periods of eelgrass dominance occur in heat with little storms (habitat stability) and bay scallops just the opposite, they prefer much energy (storms) and colder seawater – unstable habitat conditions.
 
In the 1900's when summers were hot and eelgrass grew in immense coastal meadows, the bay scallop crop nearly disappeared although their habitat clocks overlap – at some point and lacking the real scallop grass coraline red scallops will set on eelgrass as a substitute but not perhaps the preferred plant spat collector.  As the heat continued into the 1910's, eelgrass meadows declined.  When the 1920's came, colder water and strong storms ripped out eelgrass as storms intensified.  Oxygen was driven into sulfide soils producing acid conditions.  That change alone could impact the chemistry of the soil and influence the growth of plants.  Plants are sensitive to sulfide, it is also a plant toxin that has an impact on salt meadow cordgrass, Spartina pattens, as well as the submerged grass we call eelgrass.  Terrestrial soils also exhibit the toxic impact of sulfide, frequently termed black layer disease.  Black layer disease is widely known in the terrestrial turf industry.  When this is found, air (oxygen) is commonly introduced into the peat.
 
The same is true for aquaculture soils, some soils sandy and containing mixed shell hash or bits of bivalve shell make a great soil for eelgrass.  In cold and in patches, it adds a habitat type that holds forage and prey species and often  both.  It has reef habitat aspects as well.  However, after a period of habitat succession and in heat, over time, eelgrass habitat services become negative to oxygen requiring life and directly changes the chemistry of aquaculture soils to those of acid sulfate soils having a vegetative crust.  If this eelgrass strain carried specific traits for energy and temperature, it could be damaged by long periods of heat and little soil cultivation.  This also explains why clams and eelgrass often were noted as impacting each other after storm events in the shellfish industry literature.
 
"If cultivating agricultural fields before planting a new crop of potatoes or corn is essential to the commercial success of an agricultural farm, wouldn't the same apply to clam seeding activities for an aquacultural farm? The benefits of cultivating and enriching the soils for agricultural activities are well-known and special treatment for specific crops are readily available. This knowledge and various applications have evolved from many decades of research, development and trials" (See Sea Bottom Treatment Helps Clams, Atlantic Fish Farming, July 21, 1997, pg. 18).
 
The chemistry of peat soils is frequently associated with the ability of oxygen to be at the surface.  Two options exist, draining peat or building mounds. 
 
Cultural Entities Denmark
 
The Marsh at Brede A. and VedAen by Charlotte Lindhardt and John Frederiksen describes "mound building."  In coastal sections of the North Sea, lowlands contained coastal swamps (polders), which early farmers heaped up peat above ground, allowing oxygen to enter creating conditions for bacteria growths.  Once this happened, they could be farmed as noted as an early Danish agricultural practice of "mound culture."
 
"In comparison to the rest of the Wadden Sea are the dwelling mounds are both small and recent.  In the Danish part (Husum in Germany) however, it is quite exceptional to have approximately limited area, as can be found on the Tonder Marsh.  Many of the mounds are no longer inhabited, but remain as proof of mankind's eagerness to exploit the fertile soil."
 
Placing organic matter as to allow air to enter it provided the bacterial growths that helped plants grow.  In the coastal coves and salt ponds, this aeration occurred hydraulically by the motion found in waves and strong currents.  While composts could build in tidal regions, especially those with reduced flushing, this could set in motion a habitat clock as described to me by John C. Hammond that eelgrass would not survive long in a low-oxygen, high-sulfide habitat.  After a storm or driven "new sand" in a barrier beach break on Monomoy, Cape Cod, eelgrass grew thick after a few years.  According to Mr. Hammond, good growing conditions existed for some years, but as eelgrass became thick, it started to rise and create a layer of organics below it.  In heat, this composting process smelled badly – the presence of sulfides increased and eelgrass soon began to die back or die off.  This habitat clock described a cycle that followed climate periods, such as the North Atlantic Oscillation (NAO).
 
Soil Composting And The Bacteria That Breaks Down Organic Matter

Having worked for three Cooperative Extension Services or Experiment Stations the concept of soil testing became second nature.  The "land grant" Universities and before them Agriculture Experiment Stations (The nation's first Experiment Station was here in New Haven.)  In 1875, the Connecticut Board of Agriculture organized a tour of Germany visiting a series of agricultural experiment stations.  (The farm community wanted an independent testing and research functions not supported by commercial fertilizer companies).

Within a decade, US Agriculture Experiment Stations were created before some of the land Grant Universities I worked for – University of Connecticut in 1977, The University of Rhode Island in 1979, and the University of Massachusetts in 1981.  All three had a soils research department of the College of Agriculture and Cooperative Extension Services, which provided through its field officers soil tests for farmers, and then later as County Agents, providing assistance to home gardeners.  During World War II, this program was intensified as a "Victory Garden" became more than an effort to have a home supply of fresh vegetables but an effort to win a war.

The first efforts at the creation of the Experiment Stations were in fact to help combat fraud in the fertilizer markets.  One thing that was certain about Connecticut's Agricultural history it contained "thin and impoverished" soils.  This need left Connecticut farmers vulnerable to fraudulent (fake) fertilizer sales and products without unbiased testing.

Coal dust mixed with animal blood or talcum powder passed as bone meal; even sand mixed with coal tar, at times, was marketed as beneficial soil nourishment to Connecticut's organic-poor "hungry soils."  The soil was "hungry" after all Connecticut's previous residents had learned (and taught the first settlers) that corn grew best buried with an oily fish we now known as herring.  Herring left out in the sun turned red (and gave off an odor – the term it's a real red herring still implies a stink even today) and tossed in the soil with a few seeds gave the best results.  Within a short time, intensive agriculture soon drained soils of carbon and a generous rainfall helped wash nutrients and metals into the sea.  Soils were often "thin and nutrient poor".  Connecticut farmers soon learned the pitfalls of planting English corn broom, which drained so much carbon from the soil to make these tough bristles that nothing could grow in them for years.  Vast areas in the Mystic area, laid bare by such plantings, now eroded into the Mystic River.  Shipyards that needed deep water soon moved closer to the river's mouth south of "Old Mystic" as perhaps a result.
Forest fires "burn" the soil killing the needed plant bacteria and entire departments were interested in rebuilding these forest soils to reduce erosion.  In time learning that these soils got so hot, it killed off the good bacteria that plants needed by their root systems (USDA Forest Soils Research) and left what is termed a sterile soil.

Much as terrestrial farmers learned more about "agriculture soils" we need to do the same for "marine soils" – these areas of study lag far behind those needing for understanding marine soil composts with or without eelgrass.

If we are to farm eelgrass, we need to know more about how it has adapted to different soils under different conditions.  Underneath soil research should be an investigation if we have an invasive strain or strains brought to our shores from other continents – my view, T.  Visel.
 
 
 

Appendix #1

Eelgrass and Green Crab Relationship Now Needs a Review

My view, Tim Visel

 After 1998, the habitat quality for blue crabs tremendously increased in Connecticut and the 2010 blue crab season was the best in decades.  In 2011, I started a newsletter for this population surge – The Search for Megalops – The Rise of the Blue Crab.  As such, I would talk to Connecticut blue crabbers about crabbing and catches.  My trip to Niantic Bay in August, 2011 would forever changes my views towards Mr. Hammond's earlier research.  I heard that early morning coast time crabbing in Niantic Bay had been good recently, so one morning I set off early and arrived at Niantic Bay Cini Park about dawn.  Parking and walking to a finger-shaped point, I saw several crabbers (This is now a great DEEP East Lyme public fishing area.)  I don't like to barge in, so I watched a small family crabbing – handlines and bait and the usual scoop nets, and after a few crab returns (I recognized as blue crabs, I approached a man who appeared to be the father and asked about the crabbing- he said "Very good".  At that point a family member scooped a large blue crab and then flipped the net returning it to the water (without a measure) so I asked if it was short.  He replied, "We don't keep them," so at this point I asked what he did keep.  He motioned to a five-gallon bucket and pulling off some rockweed, the bucket was nearly full of large green crabs; these were by far the largest green crabs I had ever seen, they were huge—I would say some were about the size of softballs; he seemed pleased with my reaction and my next question surprised me more, I said "Do they hide in rocks?"  He shook his head, "no" and reaching down he picked up a blade of eelgrass- too big for rocks, they live in weed.  I said, "Eelgrass."  He nodded, "Yes, they live in eelgrass but can catch only at night, the best fishing today was from 1 am to 4 am;" they were hoping to catch a couple more.  I asked about taste; they apparently were great and far superior to the blue crab which they discarded.  Well, it was more than one light bulb going off, how about a football stadium light?  This one visit brought back my conversations 30 years ago with Mr. Hammond; eelgrass was carried here with edible size green crabs, the strain here was introduced and eelgrass restoration efforts could be possibly helping what now is termed the worst invasive species in the world—green crabs.

 A few hours later at home I looked at English Channel crab fisheries and there it was, a giant green crab; it's still an edible crab species in the North Sea; there are many green crab recipes on the Internet.  Researching this further, I found that an aggressive coastal storm habitat species of eelgrass spread along the Dutch Coasts and that in the Middle Ages, 1500 to 1700 when green crabs were a favored food of the coast. Combined with the fact wrapping lobsters and crabs with seaweed for long voyages was a practice dating back to Viking exploration the scenario that Mr. Hammond described was falling into place.

 1. A strong eelgrass/green crab habitat association;
 2. The possible introduction of both species as edible food and storage wrapping together;
 3. Our strain – aggressive to shellfish habitats following storms is not native, but perhaps developed genetic strains that could live in these storm prevalent habitats.

 From the information I have been able to find, the storms in the North Sea resemble periods in the 1940's, 1950's and 1960's with brutal winter storms equivalent to our Nor'easters. In the southern section of the North Sea Basic where depths are less than 60 meters, (C. K. Luders, Sediments of the North Sea - March, 1938) found storms did influence coastal sediments especially along the Dutch coastline (pg. 336).  This reworked material can be overlain by fine deposits and absent the fine- grained terrigenous detritus.  Large scale movement was also mentioned, currents of two to four miles per hour able to move vast quantities of sand along the Dutch coast for instance, a 1871 cable laid on the flat bottom in 15 years was buried by sand 5 to 11 meters deep (pg. 337). Eelgrass living in this storm filled active zone would need to be an aggressive quick growing strain with enhanced soil holding abilities to live there.  And Jensen (1915) reports that eelgrass growing in the waters of Denmark (Trask, pg. 436) produced 100 grams of organic matter per square meter, making it one of the fastest growing strains.  It would be natural for such a strain became prevalent owing to the habitat conditions in which it lived.
 
The association of green crabs to eelgrass and the aspect of green crabs as an edible food species should cause review of the introduction of both here back several hundred years, perhaps even back to the first Dutch explorers themselves.  Green crabs the food of coastal communities would have been brought on long voyages as a familiar staple, preserved by the common practice of seaweed packing. There is no direct evidence to the contrary and perhaps explains the fact that "our" eelgrass spreads so quickly after storms.  Several Canadian studies are underway currently looking at eelgrass as a vector in the spread of green crabs, I believe that when concluded they will show a strong positive relationship between them.

 On November 1, 2013, I asked the Connecticut Invasive Plant Council about the process of investigating or declaring that our strain or strains of eelgrass are those of the North Sea.  In recognition of his early work in this area I have asked if our strain is found to be non-native, its name should be Zostera-marina-hammond.  As far as green crabs as food, it remains a significant fishery in landings in England as an edible crab.  Several green crab recipes are on the Internet. This summer I plan to fish for them and near sea grass beds in Niantic Bay and give them a try.  As for the time of the green crab's introduction to America in 1805, I think we need to review that.  I believe some of the New World explorers brought some of the Old World with them.

 

Appendix #2

Conversations with John Hammond Oyster Grower About Eelgrass

Bay Scallop Habitats – Eelgrass Questions

Tim Visel – January 2012

 

There was a time I felt the eelgrass/bay scallop connection was significant, and my first bay scallop transplant (1978) with Ed Rhodes of NOAA NMFS and Lance Stewart of NOAA Sea Grant, I sought out the eelgrass beds behind Cedar Island in Clinton Harbor to place seed scallops, I would not do that today. In fact, my conservations with John "Clint" Hammond, a retired oyster grower on Cape Cod, points to an entire new direction, a climate /energy relationship and serious questions about the plant eelgrass in general.

When I arrived on Cape Cod in 1981, I had already been exposed to the great debate about the scallop/eelgrass relationship by old timers who fished PT Judith Pond for bay scallops; they had much different views than my age group. At the Point Judith docks, "strong discussions" would often break out between older fishermen who towed directly over the eelgrass flats and those like myself who avoided it, believing at the time it was good for bay scallops. The older fishermen were trying to remove it; then in fact, there was too much and that angered the much younger crowd. I no longer feel that way; instead I believe red coralline algae to be the real scallop grass, not eelgrass.

I am writing up John "Clint" Hammond's account of his research regarding shellfish habitats including eelgrass which is summarized below:
1) That energy (storms) and climate (temperature) largely govern shellfish habitat quantity and quality and that such conditions can be defined as a "habitat history." He had made a lengthy study of the Monomoy System in Chatham after storms.

2) Fishermen strongly resisted eelgrass returning from the die off I believe was created by extremely warm temperatures and low energy period (1880-1920). It was not an isolated incident (as a NOAA NMFS dynamite experiment in Niantic Bay (1974) illustrates) but a determined state/town effort as eelgrass spread from Connecticut to Rhode Island north into Buzzards Bay Massachusetts. It included machinery, Cabot cutters and herbicides and on the Cape, even Agent Orange (I am seeking clarification from Massachusetts.) 

3) Mr. Hammond worked with several BCF researchers, namely Paul Galtsoff and William Shaw. Some BCF papers are on the Internet today and thank Mr. Hammond for this help. He was an expert farmer, headed some civic agricultural organizations on the Cape and was highly educated in terrestrial soil sciences. He was at the end of his oystering career fighting Codium fragile, an invasive plant on his oyster grant in the Oyster Pond River in Chatham. He had battled what he believed to be another invasive plant, he believed also to be "foreign" eelgrass. Its presence here was odd, he claimed, against the prevailing winds and currents and its impact to small coves and bays. He was convinced it hitched a ride with green crabs on the first ships here from England several hundreds of years ago. His theory was that eelgrass came over in the packing seaweed to keep shellfish fresh during the large voyage here. Once here, the seaweed was just dumped overboard. It was colder then so the eelgrass did not spread that much at first; later warmer temperatures helped it to grow. At this time, no evidence linking our Zostera to Zostera in England exists, but it does seem plausible; green crabs, he claimed, came over the same way (green crabs are an edible fishery in England.)

At the time, I did not fully understand what Mr. Hammond was talking about, but he kept referring to barrier beach cuts and the impacts that followed – smaller "Monomoys." He asked if they existed in Connecticut, and I replied Niantic Bay and Clinton Harbor were two. This is why, when I returned to Connecticut, I started shellfish surveys in Niantic and Clinton and found much of what Mr. Hammond described- a barrier beach habitat history in both estuaries.

The Westport River (Massachusetts) studies shed light on the efforts on the second point, so the third question remains. Now that his first and second points are largely confirmed, he might be right on all three. Eelgrass is perhaps an older, invasive plant carried here during numerous crossings, perhaps the first invasive plant to our coast?

It was an industry practice to pack shellfish and crabs/lobsters with seaweed to keep them moist – a practice that continues today. It could be that vessels leaving the Thames River estuary would gather native eelgrass, use and just dump it over here. He had gone to the effort of collecting pressed blades samples and comparing them. That was Mr. Hammond's last remaining eelgrass question.

Appendix #3

 

FINEST  QUALITY

J. C. Hammond

PLANTER AND WHOLESALE DEALER IN

CHATHAM OYSTERS

CHATHAM, MASS. 62633

"Home of Pedigreed Oysters"

106 Main Street

 
May 16, 1983
Mr. Timothy C. Visel
Connecticut Marine Advisory Service
UCONN Avery Point
Groton, Conn. 06340
 
Dear Tim:
                I have just returned this past week from a short trip to Long Island and Norwalk, Connecticut.  This is an annual event that I have been doing with a friend for the past several years.  We contact as many of our old oyster business people as possible that are still in the business.  This was a rather brief affair that we did in one day making contacts with Long Island Oyster Farms, Blue Point Company, and Talmadge Bros.
          We found that all have enjoyed a good market and have had a good season.  Oddly enough, the best season is in the summer for both oysters and clams.  While at the Long Island Oyster Farms plant, we were given a conducted tour of their suction dredge The Pitman.  Quite a different way to harvest oysters and seemingly quite successful. 
          You left in such a hurry that I did not have a chance to say good-by but I trust your move has been to your advantage. 
                                                          Sincerely,
                                                                                                Clint Hammond 
 

 

Appendix #4

 

FINEST                                                                                              QUALITY

J. C. Hammond

PLANTER AND WHOLESALE DEALER IN

CHATHAM OYSTERS

CHATHAM, MASS. 62633

"Home of Pedigreed Oysters"

106 Main Street

 
November 26, 1982
Mr. Timothy C. Visel
Regional Marine Resource Specialist
Deeds and Probate Building
Barnstable, Mass. 02630
 
Dear Mr. Visel:
Sorry to have missed you on your recent trip to Chatham.  I had hoped we might get together so that I could show you the great potential that I believe exists here for tremendous improvement in shellfish crops.  However, since I have now pulled out my boat, it is no longer possible to do this season.
I enclose for your perusal a copy of a recent letter written to the Chatham Board of Selectmen relative to the prospective scallop crop in Chatham for the 1983 season.
                                                          Sincerely yours,
                                                          Clint Hammond
                                                          John C. Hammond  
November 22, 1982
 
Board of Selectmen
Town Offices
Chatham, Massachusetts 02633
 
Gentlemen:
          During the year 1981, in letters to the Chatham Board of Selectmen, I have expressed the feeling that good management of natural shellfish crops can materially increase the size of harvests with no added expense to the town and with greater benefit to the shellfishermen.
          I am convinced that a case in point presently exists in Chatham.  You are all aware that the 1982 scallop harvest has been quite beneficial to the fishermen and to the town in general.  Not a bumper crop, but a valuable one.  It presently appears that the scallop crop will be largely caught by November 30^th.
          The writer has been scallop fishing in Oyster River, Oyster Pond, and the Stage Harbor Area this season and can positively state that the set of scallop seed there for the 1983 season is a complete failure.  There appears to be no possible chance for a commercial scallop crop in these areas in 1983.  In the 38 years I operated an oyster business in Oyster River, I have never seen so little scallop seed there.
          The 1982 scallop seed set in Pleasant Bay seems to be completely different.  There is a large amount of scallop seed in certain areas with a variety of sizes from 1½" seed to very small sizes of later setting.  Presently none of it is large enough to be poached and sold as adult scallops.  That temptation will be greater as size increases.  An early closing of the Pleasant Bay area would seem logical to protect the 1983 crop which potentially is large.
          Because of the absence of seed in Oyster River and Stage Harbor, these areas could be left open without damage since there is no potential 1983 crop there.  From personal observation, there is still some worthwhile scalloping in Stage Harbor.  The scallops there are underneath heavy eel grass and will take time to catch.
          In summary, I would close the Pleasant Bay area to dredging by January 1^st but leave the Stage Harbor area open for the winter.  The closing of any area should be advertised well in advance to inform the fishermen.  It would be nice if you could get the Orleans Selectmen to do the same.
          The Selectmen of Chatham have an opportunity to make an important decision.  If it is made in time, it can vastly affect and improve the general welfare and economy of Chatham in 1983.  Chatham can have a vastly improved shellfish program if the right steps are taken.
                                                          Sincerely yours,
JCH/c  
 

Appendix #5

Connecticut Magazine – reprinted with permission for the Sound School 
October 2005
Letters
 
Out, Out, [dang] Phragmites
 
"Marshes: Disappearing Edens" [September] brought back some great and some not� so-great memories. Like author William Burt, I grew up watching the salt marshes and witnessed phragmites battle with Spartina in several areas. The marsh and its features were often lost to this tall reed. And unfortunately, we often helped it win.

 When Connecticut changed its mosquito� control plan, it frequently let perimeter marsh ditches naturally fill with leaves and other organic matter. These perimeter ditches, when filled with salt water, had acted like a medieval "moat" to phragmites roots, which cannot take salt. When the ditches were abandoned in the mid-1980s, phragmites marched right across them. Not all marshes were the same, and some were overly ditched, but these perimeter ones provided that lethal saltwater wedge.
 
 
As for the hardiness of "our" strain of phragmites, it doesn't surprise me. I talked to many residents in coastal towns who gave similar reports to me of the aerial spraying of phragmites seed to control erosion along U.S. Route 95 (the Connecticut Turnpike) during its construction in the 1950s. Strands of phragmites appeared along the coast shortly after that. One Madison report described it as "seeds of an Asian plant that can control erosion."
 
 
Restoring tidal flow (salt) and cutting the marsh level down can kill phragmites. It takes time, but it works. The Connecticut DEP is catching on to this fact. Both it and Paul Capotosto deserve much of the credit here.
 
 
Timothy C. Visel
 Ivoryton
 

Appendix #6

INTERNATIONAL CONFERENCE ON SHELLFISH RESTORATION

November 15 – 18, 2006, No. 9, Charleston, SC

Improving the Health of Coastal Ecosystems through Shellfish Restoration

CONNECTICUT SHELLFISH RESTORATION LINKED TO ESTUARINE HEALTH

Tim C. Visel

The Sound School Regional Vocational Aquaculture Center

60 So. Water Street, New Haven, CT 06519

 
A series of CT Sea Grant/Extension shellfish restoration program for hard clams (Mercenaria mercenaria); soft clam (Mya arenaria); oyster (Crassostrea virginica); and bay scallop (Argopectin irradians) were coordinated with local municipal shellfish commissions in the 1980's.  Potential candidates for projects were identified by local environmental fisheries history, shellfish maps, natural beds and local shellfish surveys.  Several restoration projects were undertaken with federal, state and local agency assistance.  Results were highly site-specific, some yielded almost immediate positive results, and some were complete failures.  Estuarine health concerns as communicated by small boat inshore fishermen during initial site investigations correlated with project success.  Local environmental fisheries reviews were often anecdotal so whenever possible, fishing statistics and U.S. Fish Commission reports were consulted.  Methods to restore shellfish populations included spawner areas, reseeding, re-shelling, re-cultivating, shell base restoration projects and spat collection.  This paper reviews shellfish restoration projects in CT from 1979 to 1989 for the following river systems: East; Neck; Hammonasset; Oyster; Pattagansett; Poquonock; and Niantic.  These projects are reviewed in terms of "estuarine quality" which included water quality, siltation, sedimentation, tidal obstruction or barriers and upland watershed alterations.  Predictions/suggestions by the local residents and resource user groups were often confirmed; therefore, their importance and contribution should not be overlooked.  Environmental fishery history reviews can be an important tool in understanding the declines in shellfish production from near shore areas.  As much information as possible should be obtained before attempting shellfish restoration programs, in this way, scarce shellfish restoration resources can be maximized (pg. 83).