IMEP 142 Part 1 -The Eels Of Eelgrass And Winter Eel Spearfishing

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IMEP #142 Part 1: The Eels of Eelgrass – Winter Eel Spearfishing 1900's

Is Our Eelgrass Strain Native to New England?

"Understanding Science Through History"

Soil Types and Condition Might Be Critical to Eelgrass Culture Efforts

Viewpoint of Tim Visel, no other agency or organization

February 2021 update June 2023 – This is a delayed report

Thank you, The Blue Crab Forum^TM for supporting these Habitat History and Fishery reports – over 350,000 views to date

Tim Visel retired from The Sound School June 30, 2022

 
A Note From Tim Visel
It was four decades ago when I first heard that our eelgrass might not be native to our shores.  That suggestion came from a retired oyster grower, John C. Hammond.  It is on the Cape where I learned about the cycles of eelgrass in shallow water.  Some of what I learned did not match what was frequently suggested.  At first, I did not realize the observations on the Cape could be so different than those of other areas.  In time, I would learn that they were not.

Eelgrass has been reported to offset carbon emissions by its ability to gather carbon residues in shallow areas.  It has also been shown to moderate waves, stabilize loose soils and build meadows called seagrass monocultures.  It is often linked to reef habitats, providing habitat associations to crabs, bay scallops, fish species, as well as a waterfowl forage grass for Brant.  It, for the most part, is a shallow water true grass – it has flowers and produces seed packets.  It is these shallow habitats that are the most sensitive to and impacted by climate warming or, at times, cooling.

What is frequently missing from the current research literature is how eelgrass adapted to different habitat variables across its worldwide ranges.  Most eelgrass studies focus upon anthropogenic (human) influences but leave the natural plant selection process or strain development in different soils underrepresented in the current research.  Long a consideration in terrestrial agriculture science, certain plants have also adapted to different growing conditions.  Moving plants into different growing conditions does not assure culture success.  Some grasses, for example, grow better over certain soil types, others have adapted to low moisture or temperature.  Some plants need habitat changing events, such as fire or storm disturbance to reseed. 

The athletic field and turf industry had researched how different grasses respond to different soil types and report that some grasses do better in growth trials under different culture conditions.  These reports include soil constituents of sand, clay, rock flour (fines) and organic matter.  Other chemical aspects include buffering of pH, acidity, soil pore capacity and organic content.  Most likely, the most plant/soil research surrounds the ability of some grasses to live in low moisture conditions – a drought (look at base material (soil) considerations for athletic fields). 
That was happening on Cape Cod in the early 1980's, an extreme period of little rain, which caused much concern around saltwater intrusion into the Cape's mostly sand freshwater lens, or aquifer.  That caused Mr. Hammond to mention that planting a tree in dry – desert conditions will not make it rain.  This comment sets into motion concepts that long have influenced agriculture research – how local soil conditions guided plant growth.  The tree in the desert indicates what someone could do with this transplant with the result that this transplant was in opposition to growing conditions.  Eventually, this tree would die.  A mature oak tree, for example, during its growth period needs about 1,000 gallons of water each week.

Shellfishers in Massachusetts, particularly on Cape Cod, watched how eelgrass responded to different growth conditions.  Eelgrass would respond to "new soils" – those washed or moved by storms.  In time, an eelgrass meadow (monoculture) spread into areas and then reduced shellfish habitat and often shellfish catches.  Observations by John Hammond over a period of decades led him to believe that eelgrass, which grew along the Chatham shore, may have been introduced as it lived in soils unstable to its ability to form a meadow.  It would frequently die out.  He had observed several cycles of its growth in shallow water.  He believed it was an introduced strain transported here centuries before, likely aboard the first European sailing ships.  He proposed that as he had done with packing oysters that seaweed was used as a packing material, likely a practice that caused the first European introduction here centuries before.  Eelgrass has long been used as a packing material for crabs.
Looking back and his statement with other European introductions, such as the green crab and coastal reed Phragmites, such accidental (or deliberate) introductions here happened and linked to maritime commerce.

The green crab, often termed the world's worst invasive species, mirrors a direct habitat connection to eelgrass and is reported as such in European studies.  Phragmites, a reed capable of producing strong fibers, was introduced and used as a soil holding and erosion control plant material in the early 1900's.  USDA reports experiments with seed purification of Chinese hemp plant materials in 1908 (See IMEP #18-1: Phragmites Invades Coastal Habitats in the 1940's, posted June 19, 2014, The Blue Crab Forum^TM). 

In 1913, hemp seeds from China were undergoing tests at the Kentucky Hemp Agriculture Experiment Station in a program to identify potential hemp rope species.  The yearbook of The United States (1913) on page303 contains the following segment:
"Nearly all the hemp now grown in Kentucky is of Chinese origin.  Small packets of seed are received from American missionaries in China.  These seeds are carefully cultivated for two or three generations in order to secure a sufficient quantity for field cultivation ... new supplies of seed are brought from China to review the stock owing to the confusion of names the seed received is not always of a desirable kind, and sometimes juke, China juke or ramie seeds are obtained."

By 1918, a tall reed thought to have been an Asian Phragmites strain had escaped from the Kentucky Experiment Station as concerns were expressed about controlling it (See IMEP #18-Part 2: Invasive Phragmites Habitat War, posted June 19, 2014, The Blue Crab Forum^TM).  Later, Phragmites was used as ground cover (USDA Bureau of Soils) and also as a peat drying process of mosquito control in the New Jersey meadowlands in the 1940's.  It gained use as a quick growing plant to control erosion on steep grades on rail and highway grades (See IMEP #16: Mosquito War Claims Connecticut Marshes 1901-1916, posted May 29, 2014, The Blue Crab Forum^TM).  In 2013, I surveyed remnant patches of Phragmites still surviving along the Route 9 (CT) between exit 9 and exit 49 and observed 56 independent stands of Phragmites on steep grades.  In 1952, the Kentucky Hemp Experiment Station was closed.  It was reopened in 2014.  Observations of Phragmites and the genetic strain differences leads to consideration that eelgrass had done the same over time.  Different strains may have developed over thousands of years, giving some an edge over others.  The aggressive nature of New England eelgrass in newly washed, storm driven sand points to its superior growing and spreading ability in sandy "cultivated" soils.  Eelgrass grew thick in the 1950's as did the green crab. 

Rachel Carson describes the spread of the green crab during a climate period of cold and storms, the negative NAO.  This same period eelgrass in New England spread rapidly even into the Canadian Maritimes.  Reports from the Western Atlantic record the impacts of strong coastal storms, changing the soil constituents and dramatic changes in seagrass species.  Nichols (1920's) describes the end of a period of warmth 1880-1920 as few storms with diminished eelgrass growths.  The 1950's and 1960's would bring efforts to control eelgrass that was viewed as habitat aggressive, including to clam and oyster populations.  These efforts included New York, Connecticut and Massachusetts that had colder water with stronger coastal storms from 1938 to 1965.  These eelgrass control efforts are in numerous state and federal reports up until 1972.  In periods of heat and few storms, eelgrass has been shown to die off, thus leading to questions of soil succession and the buildup of organics in hot, stagnant marine soils.  Eelgrass may signal a soil change and a possible bacterial shift to composting organic matter by sulfate-reducing bacteria (sulfide purging) as well as assisting compost, fungal and mold disease.  We may need to identify first if our strain is native and whether hot, high organic soils are suitable for its cultivation or farming – my view, T. Visel.

Can We Farm Eelgrass?

Growing up along the shore, I never gave eelgrass much thought.  I had seen the eel spears in old barns and one was given to me by Byron W. Gardiner, a Pent Road resident.  In the early 1960's, I saw many old eel spears with long hickory pole handles.  It would be another decade or so that the eel spears would be fully explained to me by Alfred R. Wilcox of the fishing business known as the Wilcox Marine Supply (formerly George W. Wilcox Company).  I was interested in flounder spears rather than eel but each was very different.  Flounder spears pierced the flesh while eel spears pinched the flesh.  That is how eelgrass came up, that most eel spear fisheries were pursued in or near eelgrass during the winter.  To find eels, you needed to locate the "eelgrass" – "the grass that holds eels."  Since few of our fish and lobster customers rarely asked for eel, it never became an important part of our small boat fisheries.  Only when we started seed oystering in the Hammonasset River in 1975 we did see eelgrass.  It existed in a meadow on the south side of the Hammonasset River.  It was soft bottom/peat habitat, shallow and thick with eelgrass.  Getting off the channel ran the risk of getting stuck in this grass (it would fully wrap an outboard motor prop) and having to walk/pull a boat out.  At high tide, this site was a popular water ski site, at low tide a place with no crabs, oysters or many fish.  No one had eeled here with spears for many years.

Working at the University of Rhode Island from 1978 to 1981, I heard similar eelgrass/eel accounts from workshop attendees and visitors.  Virginia Lee 1980 – In her University of Rhode Island Report #73, she mentions these coastal salt pond spear fisheries on page 37 of An Elusive Compromise Rhode Island Coastal Ponds and Their People – my comments (T. Visel):

"Pots came into use around 1900 (likely because these winters were very warm and little ice, T. Visel).  Prior to that, eels were caught with spears or even seines.  They are still speared through the ice in winter time.  With a 16-foot long pole, a competent fisherman can spear about five eels out of a one-foot hole in the ice.  As many as 33 eels can be caught per hole in the ice if the fishermen are lucky enough to find a pocket of muddy bottom in which the eels are concentrated."

However, according to printed reports and accounts mention that each fall cove and salt pond small boat fishers sought out "eelgrass" in which to spear eels.  Discarded iron weights and wood floats were used to mark eelgrass as a "live bottom" in terms of eels in the ice/spear fishery.  This explains how eelgrass got its name for its shallow water pond and cove fisheries accessible in winter by ice spearing – the "grass that holds eels" – as part of a hibernation shallow water process.  Marking the eelgrass helped identify "live bottoms" those that could still support eels underneath.  Even a century ago, small boat fishers realized marine soil differences but used habitat associations rather than soil chemistry to describe them.  Today, this live bottom is associated with those low in sulfide a marine soil – composting chemistry from sulfate-reducing bacteria.  This bacteria thrives in hot, high organic, low oxygen sapropels – the organic carbon residues of underwater compost habitats.  Under ice, these high organic composts can have very low oxygen; the ice blocks sunlight and shuts down the natural algal "oxygen pump."  Once that occurs, sulfide levels can increase and poison the water above.  This can happen in lakes each fall as warm surface waters cool.  They then sink, forcing sulfide-rich bottom waters to the surface.  Waters may be dark brown-black or purple depending upon which sulfur bacteria were present.  Eelgrass was an indicator that sulfide levels were lower and provided "eel banks" a habitat edge.  Thus, the term "the grass that holds eels" in the historical literature (See Appendix #2: The Eels of Eelgrass.)

Habitat associations were often site-specific, such as a "clam bed" or "oyster bed" and usually named for dominant fisheries.  Colder waters could contain more oxygen and did not need eelgrass to define eel habitats although links to productive fisheries in terms of catch can be determined.  For example, The US Fish Commission Report on The Fisheries and Fishery Industries – Maine River Fisheries – Casco Bay and Tributaries contains this section on pg. 724 – (my comments, T. Visel):

"The principal eel fishery of this district is in Quahog Bay (this region in cooler times can support the quahog Mercenaria – T. Visel) where there was discovered in 1876 a most remarkable eel-bed, the most productive.  It extends over about 10 acres, on a muddy bottom, without grass, at a mean depth of 13 feet at low tide.  The eels are taken out by spears worked through holes in the ice, which commonly forms here in December.  The first and second winter from its discovery this bed yielded 2 tons of eels a day for the first five or six days of fishing."

As with many inshore small boat fisheries, a close relationship between habitat type and species was frequently mentioned.  This habitat knowledge was familiar because of observation – catch relationships.  This knowledge was often passed down in families and was often difficult to describe – they could just tell what was a productive habitat.  In The River Fisheries of Maine, page 697 (History and Methods of the Fisheries, US Fish Commission) provides a description of eel beds:

"At Dresden, in the mouth of Eastern River, are some beds much resorted to now and for the last 18 years.  The water there is entirely fresh.  The fishing is, as a rule, done on the channel banks, but sometimes quite out in the channel, so that at low tide the depth of water over the different parts of the beds may vary from 5 to 25 feet.  Some observations are led to the conclusion that mud meeting in all respects the requirements of the eels occur only in patches, and when they find one of these patches they will bed in it to whatever depth it may carry them."
And further mention of the Harpswell eel fishery occurs on the same page 697:

"Another locality for eel spearing is in Quahog Bay in the town of Harpswell.  Here in 1876 an eel bed was discovered, which is famous as being the most productive ever known in that region.  It lies in 13 feet of water at low tide, just outside the eelgrass zone, and extends over about 10 acres."
What is being described is that some soils or bottoms were different at times from others.  In later texts, this is mentioned as "live" or "dead" bottoms.  The bottoms that were "productive" were those habitats that signaled survival of a species.

The eel, however, is well protected from sulfide and acidic conditions in these organic composts – the formation of sulfuric acid with a thick mucus surrounding its skin.  The presence of sulfide displaces binding locations for oxygen on iron-containing blood proteins.  It is often termed an inhibitor of oxygen-requiring organisms by disrupting respiration.  Sulfide is deadly to us but most associated with bacterial breakdown in high organic soils or areas without sufficient oxygen.  Fish that live in or near marine peat (eelgrass or salt marsh) or burrow in sapropel (low oxygen marine muds) are much more tolerant of sulfide.  Marine worms, such as the milky ribbon worm, Cerebratulus marginatus, are extremely tolerant of sulfide.  This worm, a major softshell clam predator, is extremely sulfide tolerant as its primary habitat is high organic, low oxygen marine composts – it is the worm composter–predator of living tissue as soils "die" in terms of oxygen content.

It was a retired oyster grower, John C. Hammond of Chatham, Massachusetts, who first raised organic matter residues as a soil condition.  Mr. Hammond was also long involved in coastal plant research first as part of a Cooperative Extension (UMass) group, investigating the Beach Plum, Prunus maritima, with low organic alkaline soils of the sand dune soils.  One of the soil questions he investigated was why wind-blown branches of the beach plum bore more fruit than plants under culture away from the immediate shore.  He felt that oak leaf residues in the soil had an effect on the plant to bear fruit.  He was, in the early 1980's, studying the composting – soil qualities of storm-washed sands or soils for clam sets and growth.  That study, in time, included eelgrass, Zostera marina, and that he felt a strain prevalent on Cape Cod did poorly in shallow water in heat.  He also felt that what eelgrass we had was likely introduced here centuries before from European sailing vessels looking for trade routes.  His observations included statements to the effect that eelgrass did not belong in the shallows and that it needed cooler, more energy conditions to keep soil conditions from killing it (the eelgrass).  Key to his studies was how plants (including cultivated rice) reacted to soil sulfide formation.
Mr. Hammond, during several meetings, mentioned that he felt eelgrass from Europe had been introduced in our region but our climate was different and limited how long eelgrass could grow in periods of heat and sulfide formation.  At the time, eelgrass on Cape Cod was considered more a pest or danger to shellfish rather than something of value or benefit (See IMEP #30: Quahoggers Final Stand Against Eelgrass, posted October 9, 2014, The Blue Crab Forum^TM).  I first mentioned some concern about eelgrass during a 2006 International Conference for Shellfish Restoration.  During the conference, many break sessions involved the promotion of eelgrass as the primary habitat type.  My presentation titled "Connecticut Shellfish Restoration Projects Linked to Estuarine Health" included podium comments, which included habitat change over time – "sometimes, the habitat you see today is the last type of habitat you want to use or protect."

In 2012 as the eelgrass initiative seemed to be mentioned almost continuously, I mentioned in a report titled "The Trouble With Eelgrass" that its habitat value was not consistent over time and did, at times, exhibit negative interactions with shellfish (even including the bay scallop).  On page 6, item 6, I included the possibility that our strain may be invasive carried from Europe.  This is something that was mentioned to me four decades ago. 

The introduction of one or more strains was likely in packing material used to transport seafood.  Once on our side of the Atlantic, it was likely just dumped overboard.  This concept of plant material exchange is not new.  Many ancient and modern-day examples exist and continue to evolve even today.

A few years ago, the University of Connecticut conducted research on the spread of aquatic invasive seaweeds.  The report is titled "Multi Component Evaluation to Minimize the Spread of Aquatic Invasive Seaweeds, Harmful Algal Bloom Microalgae, and Invertebrates Via the Live Bate Vector in Long Island Sound 2009."  This study looked at bait worm packaging (live seaweed) as a vector for the introduction of invasive species.
A Long Island Sound Study EPA Estuary Program May-June 2009 Newsletter – Sound Update on page 4 contained this article "Recreational Fishers: Don't Throw the Packaging Material for Live Bait Overboard!" by Robert Burg.  The article starts with this segment:
"The seaweed used to pack both sand and blood worms in bait boxes may contain invasive marine algae (both seaweeds and potentially harmful phytoplankton) and animals."

Is Our Eelgrass Strain Native?

"It doesn't belong here" – a short statement made by John Hammond for the eelgrass now covering much of the oyster grant (culture) bottom in Oyster Pond River in Chatham, Massachusetts.  I was curious so I questioned his statement.  He responded that he had studied eelgrass blades (a type of seaweed mounts one popular hobby – collector hobby of the previous century - See Herbarium Collections of the Victoria Era) (See IMEP #5: Historic Eelgrass and Green Crab Habitats, 2013) and had them mounted on heavy, what I call, biological paper sheets.  He felt that "our" eelgrass was actually a high energy strain imported from Europe as packing material for shellfish.  This was an old practice that kept crabs and shellfish from drying out or cushioning the motion on sailing trips.  Once here, this packaging material was simply discarded over the side.  He felt strongly that green crabs arrived here in the same manner.  In Europe, green crabs grow larger and are a popular crab dish.  Only once have I seen large green crabs harvested as food in the Niantic River gut – the entrance of the Niantic Bay by the road-bridge causeway (these crabs were huge).  I did cook some of the small green crabs prevalent here – using a toothpick, I picked out some meat which was very good but took much time to get a small bowl full (bodies only).   

To Mr. Hammond, green crabs and shallow water eelgrass were both unwanted visitors to the Cape from Europe.  As his studied had progressed, he noticed changes in the leaf blade biology of eelgrass – short, thin blades and those with wider and longer blades.  He also mentioned that the collection of organics could undergo a composting process similar to land but just with different bacteria.  In the 1950's and 1960's, he had been involved in an effort to increase the yields of the beach plum fruit that grew along the dune lines of Chatham Cape Cod.  It was Mr. Hammond who witnessed beach plums at the beach subject to wind-blown sand having the greatest and heavier fruit yields than plants inland, and linked it to soil conditions.  We, today, recognize that soil condition as the Cation Exchange Capacity (CEC).  Sanding branches for the beach plum produced similar results as sanding cranberry vines.  Only, in this case, wind-blown sand was an act of nature – dune burial.

The eelgrass he studied, he felt, regarded as invasive as shellfishers noticed at times it would take over habitats of the soft clam, hard clam quahog and interfere with oyster culture.  Even with bay scallops, it was recognized that too much eelgrass was a problem, not a joy or benefit frequently mentioned in the environmental literature today.

In recent times, according to Mr. Hammond, seaweed continued to be used as packing material.  To keep lobsters and crabs alive, they were frequently packed in wet seaweed.  In winter if kept moist, crabs could last longer out of water, and the use of seaweed to pack/ship shellfish extended well into the 1900's.  Seaweed was also used as packing material for oysters and lobsters to keep shells moist to reduce drying out of water.  This is similar to packing oysters in wet sawdust.  A segment from the University of Wyoming Cooperative Extension Service article titled "Oyster Stew: An American Tradition" describes how Irish immigrants, who moved to the West, brought tradition and market demand with them of oyster stew in December:

"The tradition spread west despite a lack of refrigeration.  Wagon loads and train cars full of oysters in the shell, packed in wet straw, sawdust and seaweed, were transported west during cold months."

Because oysters could like long periods if kept cool and moist, packing oysters in damp sawdust in New England cellars provided a live food reserve for very cold, snow-filled winters.  That is how Mr. Hammond felt this strain of eelgrass in Oyster Pond River came to the western Atlantic, as packing material for oysters and crustaceans as both to keep shellfish alive and cushion the motion of ships while in transit.  Since sailing vessels did not have easy access to sawdust, he surmised that crews gathered what they could that could fulfill cushion and dampness, and that was seaweed – eelgrass.

Organisms with the seaweed could be transferred as well.  Many plant species were transferred across continents that way with many unfortunate results.  Sometimes, introductions were deliberate for ornamental or commercial purposes.  For example, the invasive reed Phragmites was thought to have arrived as a packet of smuggled seeds from Mongolia as a commercial product for the construction of hemp rope.  In the 1900's, hemp rope was a critical war material as it was needed for so many shipping uses.  China had a huge market share of hemp rope with most US supplies coming from then US Phillipines as "Manila" rope.  It was thought that a US hemp industry could break China's hold on this important product.  Unfortunately, Phragmites was cultured and seed purified in Department of Agriculture greenhouses before it escaped from the Kentucky Experiment Station, a research facility, which focused on hemp research.

Later, it was used, not as a hemp substitute (the fibers were too difficult to extract), but as a soil control erosion plant material in the 1930's.  Much later, it was the erosion material of choice for very steep grades, such as railroad causeways and banks along newly constructed road grades (highways).  That is why today this plant shares genetic material commonly found in Asian strains (See Saltonstall, 2002, Cryptic Invasion by a Non-Native Genotype of the Common Reed, Phragmites australis, into North America).

In time, this plant has become widespread and one of the most despised invasive aquatic reeds.  Although it wasn't native, it soon displaced other similar native strains as it was superior in rooting ability compared to other natural, less "aggressive" strains.  Mr. Hammond felt that our eelgrass was such an aggressive strain that out-competed other strains or other seagrass species.  He felt that it evolved in a more violent habitat that made it so quick or aggressive in our shallow water, in areas of Northern Europe, the shores of England, Denmark and the German Bight.  Here, he felt, is where this strain arrived and that its usual habitat is deeper, cooler water subject to greater storm energy.  As such, the only strains that could survive were those that could quickly root (spread) and provided less resistance thinner blade width.  He felt this to be an aggressive strain that needs energy to prepare soils but lives in deeper waters and could not be considered a constant or permanent habitat type.  I clearly recall him saying it does not belong here (shallow water) (personal communication, T. Visel, 1981-1983).

It's aggressive and soil-compost holding ability put it soon within conflict with shellfishers from the Carolinas to the Canadian Maritimes.  What made it so successful was its ability to quickly invade shallow soils, gather compost and form a peat.  This peat building would compete for shellfish habitats and many accounts detail how eelgrass would "take over" shellfish beds.

When the US oyster industry expanded in the 1880's, it was during a warmer, less storm prevalent climate period.  This was the time of the Great Heat waves of the 1890's when hot waters reeked of sulfides and sapropel first noticed on oyster culture beds.  Sapropel formed in shallow waters away from storm energy similar to that of ponds and lakes.  A shift in climate would destroy those soil building processes and clear out eelgrass meadows.  Many meadows were subjected to bacterial sulfate metabolism – the conversion of organic plant tissue to sugars by bacteria, which thrive in oxygen-poor seawater.  This is known as the slime mold Labyrinthula spp. that killed eelgrass when it was weakened by a soil/sulfide compost chemistry.  A series of storms and cold waves from 1932 to 1955 cleared out eelgrass meadows, cultivated marine soils and provided similar conditions that occur after terrestrial forest fires – habitats ready for habitat successional properties – eelgrass and shellfish clam sets.  As clams matured into a fishery and eelgrass growths buried shellfish, it caused widespread industry condemnation. 

The US west coast is dealing with a similar situation with the invasive eelgrass strain Zostera japonica or dwarf eelgrass thought to arrive on the west coast with shipments of seed oysters.  The US Fish Commission sent to the west coast barrels of Crassostrea virginica seed oysters in the 1880's with perhaps seaweed packing.  Its use as a packing material could explain the movement of seeds, which can live in cut seed blades (spathe) for weeks or months if kept cool and most around distant parts, having arrived or served its purpose in times of little concern merely dumped overboard.  This is opposite other crustacean transfers that form a megalops stage and can be moved in ballast water.

While the impacts of eelgrass damage to shellfish was widely reported, in 1965 Canadian fisheries' researchers established a team to investigate chemical control of eelgrass (MLH Thomas, St. Andrew's Biological Research Station, Report Manuscript Series No. 905, 1967). Other US state and federal reports detail similar efforts in the 1950's and 1960's but also in the 1890's and early 1900's.  Almost none of these reports are mentioned today, bringing questions to the objectivity of modern meta-analysis of the "current" literature.  Almost never discussed is the possible transmittal of multiple strains of eelgrass that developed unique responses to habitat characteristics and were brought to US shores post-1500.  It seems quite possible to John Hammond's association of green crabs and invasive eelgrass strains may have happened and similar to the reports of the US west coast oyster and clam growers (Final Environmental Impact Statement Management of Zostera japonica on Commercial Clam Beds in Willapa Bay Washington, March 26, 2014) with non-native eelgrass strains from the far east.  This is my comment, pg. 14 of the comment section (1):

            Tim Visel – (Interested Party) Comment #58
"Many turn-of-the-century shellfish researchers wrote about the negative impacts of eelgrass to shellfish – more current work (in this area) reflects a bias regarding sapropel – organic matter trapped by eelgrass that lowers pH.  These acidic, high sulfur bottoms are highly toxic to shellfish veligers.  Many such habitats are started by eelgrass during periods of high heat and few storms."
In 2008, the state of New Hampshire requested Comments for Methodology and Assessment Results Related to Eelgrass and Nitrogen in the Great Bay Estuary, Section 303(d) List.

My comment submission was mentioned on page 16 but not described.  I urged caution as to describing fixed habitat values to eelgrass as it was, at one time, described as a negative habitat quality for eelgrass – July 17, 2008 communication to Philip Trowbridge, then with New Hampshire's State Department of Environmental Services – that eelgrass had a mixed record in terms of shellfish and even the bay scallop.  When Niantic's eelgrass died out, bay scallop harvests actually increased.  The 2008 report did mention my comments but did not include them as submitted (referenced statements of eelgrass harming, not helping, shellfish populations).  I did not include references that this strain could be possibly invasive.  I was first introduced to this concept by John Hammond almost three decades before.  Mr. Hammond felt that the prevalent eelgrass strain was associated with habitats much colder and energy-filled than Cape Cod.  He even mentioned that he had observed that green crabs used eelgrass as a hunting ground.  He proposed that both the green crab and eelgrass had a close habitat relationship.  It was at this time he mentioned that long ago he would pack oysters in seaweed to keep them fresh and the practice of packing seafood with seaweed dated back centuries, perhaps to the first European sailing voyages to the "New World" and brought some of the old world with them.

It, therefore, is possible, if not plausible, that with widespread use of seaweed as packing and preservation process for seafood that, over time, exchange of marine plants between coasts did happen.  Reports of the US Fish Commission includes the use of seaweed in the lobster fishery as packing material for shipping lobsters from the east to the west coast.  In a US Fish Commission Report titled "The Preservation of Fishery Products for Food" by Charles H. Stevenson, pg. 357 has this segment about shipping softshell crabs from the Chesapeake region – "crabs are carefully packed side-by-side with their legs well folded up in rows between layers of cold seaweed," 1899, Washington GPO.

Even into recent times to keep bait worms from drying out, species such as sand worms and blood worms were often packed in seaweed.  I recall years ago helping to sort worms in Clinton Harbor after selling off "flats" of worms – seaweed was just dumped overboard into Clinton Harbor in the late 1970's (Holiday Dock Clinton Harbor).  No one thought about plant introductions then or where the seaweed came from.

After 2000, I began to think more about Mr. Hammond's theory as more coastal programs looked at other invasive plants along the coast – Phragmites, a tall tough reed, also shared a history of introduction, this time as a hemp rope substitute detailed in the IMEP Series #18-1 and #18-2.  It raises the question that our research into eelgrass is far from compete or even through to eliminate this possibly.  Much worldwide interest is recognized around the study of marine seagrasses, especially eelgrass.  Much of this research interest came at a time when US Oceanography research, funded by the Office of Naval Research (ONR), declined and environmental protection (conservation) gained significance.  Over many decades, research shifted from providing a useful product to that of useful policies.  In this funding transition, science at times became very political and motives moved from providing possible solutions to responding to public policy questions.  If it was perceived to be a problem, it was a problem.  In many respects, the foundation of policy change needed a face to galvanize public opinion in a conservation movement that approached a century-long effort.  The public was in need of information as to why some species were dying off and initiative rushed to fill this information void.  At first, eelgrass was used to explain the loss of the bay scallop.  Later, that was expanded to other fish and shellfish species, much later, to beach erosion and sea level rise and, more recently, as a compost builder of peat relabeled "blue carbon."  No one possibly thought that eelgrass could have been moved to other regions by commerce or how it responded to habitat change over time.  There was no attempt to develop a habitat history for eelgrass or how it succeeded to other habitat types over time.  This is quite opposite terrestrial study because you could see the transitions from grasslands and meadows after forest fires – the impact of hurricanes (storms) took much longer and was largely out of sight.  Observations and associations were presented as established habitat types and assigned constant or permanent habitat conditions that, over time, were impossible to guarantee.  Nature, itself, could change all of the assigned conditions in a matter of days or even hours.  There was to be no constant habitat conditions; as one region of eelgrass was destroyed, perhaps another was developing.  That is the concept for widespread seed dispersion – that out of the tremendous numbers of seed produced, some will land on soils that could provide growth, and it is here that eelgrass found its habitat niche. 

Its ability to broadcast seeds over huge distances quickly develops meadows for more seed.  Think of the thistle plant, Cirsium vulgare.  It develops a single seed pod – emits its light structure seeds that catch a ride on the wind, allowing seeds to travel aloft miles, if not tens of miles, in search of the proper soils in which to grow.  Eelgrass uses the water as its wind to spread seeds.  John Hammond, a retired oyster grower on Cape Cod, when faced with eelgrass covering his seed oysters, hired high school students to drag chain-link harrows in an effort to cut it and pull it out, only to discover that this helped distribute seed and opened the soil, enabling more of it to grow.  The more cultivation, the more eelgrass grew around or on the oysters.  In the early 1980's, it was a practice to grade hard clam aquaculture beds with pea gravel.  This soil grading and adding gravel often resulted in eelgrass growths where this preparation had occurred.  This was, at the time, an accepted industry practice (See Small-Scale Farming of the Hard Clam on Long Island, New York 1986 – pg. 35 and Manual for Growing the Hard Clam, VIMS 1981, pp. 40-42).

Other growers in New Jersey and the Carolinas reported the same effects, that jetting the soils and adding gravel were a positive growth factor for both the hard clam and eelgrass.  Light populations of eelgrass did not harm the clams.  Only when eelgrass forms a peat and gathers organics and clay fractions does it suffocate the clams (mussels and oysters also) over time.  The addition of clay particles "seals the soil" that was described several times to me by Mr. Hammond and other Cape Cod shellfishers (See IMEP #130: Quahoggers Final Stand Against Eelgrass, posted October 9, 2014, The Blue Crab Forum^TM)

Without any knowledge of the proper soils for eelgrass, hundreds of transplants were likely made into hot, sulfide-rich organic soils, which promptly died.  This had happened in the Niantic River in the early 1980's (See IMEP #110: Niantic River Case Study for Eelgrass, posted May 3, 2022, The Blue Crab Forum^TM).  If eelgrass is to be farmed, soil science study must be included – my view, T. Visel.
 
 

Appendix #1

Is The Long Island Sound Dying?

By Dick Harris

Long Island Sound Report

A Publication of the Long Island Sound Task Force of the Oceanic Society

Vol. 3, No. 1, Spring 1986

 
Continuing controversy surrounds the issue of water quality in Long Island Sound.  On the one hand, the public has some strong signs to indicate that the waters are in good shape; the lobster catch has increased dramatically and the oyster shells near the western end of the Sound are excellent.  Various municipal departments reassure everyone that water quality is improving, that recently installed secondary sewage systems are working, and that dissolved oxygen levels (a basic indicator of water quality) are increasing in many areas where routine sampling has been done for years.

On the other hand, the scientific community is worried about organic loading and the nitrogen buildup from sewage in the western end of the Sound.  Many feel the potential for eutrophication, a state of oxygen depletion caused by excess nutrients in the water, exists over large areas of the ecosystem.  All the elements for trouble are there and yet no scientific conclusions have yet been drawn as to how much effluent or storm water runoff can be tolerated before the Sound can no longer support marine life.  Information is fragmented and scientifically valid baselines do not exist.  Nevertheless, a renewed scientific effort to provide a basis for estimating water quality of the Sound is presently being formulated at Yale University by Dr. Donald Rhoads.  His approach is to map and analyze the sediments of the Sound's western basin in order to determine how organic loading and excessive nutrients have impacted the area, and to predict what the implications are for the future.

            The truth concerning Long Island Sound's water quality may lie in the sediments of the western basin, which runs from Norwalk west to the Throgs Neck Bridge.  Here, in about 60 feet of water, waste products from overcrowded shoreline communities have silently rained down on the bottom for decades.  Out of sight and out of mind, this collection of organic debris has slowly accumulated on the bottom, creating no apparent major problems – yet; but then Chesapeake Bay gave no evidence of massive problems either until it was too late.

            "Municipal agencies and health departments don't know how to take dissolved oxygen readings properly," says Dr. Donald Rhoads, a PhD in paleobiology and a leading scientific expert on marine basins in Long Island Sound.  "If you don't know how to take oxygen readings properly, you may miss the point completely – people get encouraged with readings off 3 ml to 6 ml per liter a few centimeters above the basin floor, and yet the sediments may be totally azoic (dead).  "The truth," he continues, "lies within a few millimeters of the sediment-water interface – not several meters off the bottom or in the shallow coastal waters.  Most measurements cannot be made that accurately with oxygen probes dangled off the end of a cable.  Besides, near the bottom hydrogen sulfide tends to corrode the probe of the most commonly used meter, which detracts from accuracy.  Oxygen levels of less than .3 ppm may be the norm for much of the bottom in the western basin."

            "All pollutants put into the Sound, organic matter from sewage treatment plants and surface runoff, go somewhere," explains Rhoads, "and my concern is that this stuff adheres to particulate matter and ultimately sinks to the bottom of harbors and the deeper basins.  "The result," he continues, "is the formation of a black, mayonnaise-like material (sapropelic mud) now all too familiar on the bottoms of many of our harbors at the western end of the Sound."

            He describes this black, colloidal paste in vivid terms, "This gook is free of oxygen and subsequently free of metazoans (higher invertebrates that help oxygenate sediments by burrowing)."  There is so much organic material and limited amounts of oxygen, that bacteria are unable to burn it off efficiently.  The small concentrations of oxygen are consumed in the process.  As the sediments become more reducing in character, sulfate reduction also takes place, producing hydrogen sulfide and methane, which further compound the problem by consuming even more oxygen.  
 

Appendix #2

The Eels of Eelgrass – Winter Eel Spear Fishing

By Timothy C. Visel

Connecticut eel spears are just reminders of a once popular winter spear/ice fishery.  Eel spears (many with no handle) can still be found today in antique shops along the coast.  These spears are often called gigs in the historical fisheries literature.  Gigging refers to an old term of a fast small row boat and its use for spearing flounder.  Flounder, eel and a rare "turtle hook" were all part of a winter fishing season.  Eels and Turtles in torpid states were caught in winter and at times under ice.  In open winters eels were sought in eelgrass – "the grass that holds eels" for spear fishing.  It is in this organic/ grass compost eels would dormant waiting for spring.  In this eelgrass habitat that was "alive" that spear fishers sought out.  We have a century old report that provides insight into this spear fishery.  Following is a 1920 account from "The American Angler" pg. 498 that describes an eel trip written by Will R. McDowell:

 "The eels on the close approached winter had worked their way up the creeks and marshes, and with the making of the first icy nights they had squirmed and latterly buried themselves body and soul in the soft mud bottom.  I soon found that eels were not everywhere on the bottom for to simply put ones spear down and haul them forth.  For it seems, Mr. Eel is particular if not quite fastidious as to the 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.  On the contrary he will generally prefer what is known in fishermen parlance 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, its constituted or rather a firm mud, and is apt to have patches or a scattering of eelgrass growing 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 out the surface of the waters above him" (The American Angler, Volume 5, 1920, pp. 498-500,  "We Go's a Eelin' Through the Ice for the Slippery One," W. R. McDowell).

 

Appendix #3

National Fisherman, March 1989, Vol. 69, No. 11

Page 73

Habitat degradation hurts flounder stocks

By Bob Bernstein

 "Everybody blames the fisherman (for the stock declines), but more and more evidence leads to habitat degradation," says Tim Visel, a marine resource specialist with the University of Connecticut.

What concerns Visel, and many other researchers, is the decline of estuarine and salt water marsh habitats due to development-related filling and the accumulation of both natural and manmade pollutants.  Because of their unique geological, oceanographic and biological properties, these areas are essential to the support and breeding of marine animals.

According to a report in a recent issue of the Sea Grant publication "Connecticut Currents," winter flounder spend the first year of their lives in shallow estuaries, coves and rivers with less than 4' of water.  They prefer protected waters with flat, hard, clean bottom and are rarely found in marsh creeks or areas with mud, rock or algae.

Research indicates that there is very productive habitat near the Pawcatuck, Poquonnock, Niantic and Connecticut rivers, and in Jordan, Morris and Greenwich coves.  However, the majority of estuaries sampled had little or no young flounder bottom.  Furthermore, many locations that were once suitable flounder habitat, are now covered with sea lettuce (Ulva lactuca), an algae that thrives in polluted areas and has been determined in the laboratory to kill juvenile winter flounder.

Another environmental concern among UCONN researchers is hypoxia (low levels of oxygen) which, according to data presented by Dr. Barbara Welsh in 1987, appears to be a major problem in western Long Island Sound during warm, stable weather.  As reported in "Connecticut Currents," hypoxia is caused when nutrients, augmented by sewage effluent, promote phytoplankton blooms that eventually fall to the bottom and decay, using up oxygen.  During the height of a hypoxia event one summer, scientists discovered that most of the fish had left their study area, and 80% of the invertebrates sampled were dead.

Tim Visel remarks on still another condition that affects flounder habitat – low pH.  According to Visel, a low pH, or acidic, environment causes fin rot in fish and also kills clam larvae.  Visel's concern here has to do with the accumulation of dead leaves (with a pH of 3 or 4) on local river bottoms in the fall.  He is encouraging further studies of rivers and estuaries where landfill has reduced water flow, particularly the areas where new expansion bridges and train trestles have been built. 

Visel cites Quiambaug Cove as a location where tidal flow is choked, in this case by the narrow Conrail bridge and the Route 1 highway bridge.  Dredging is seen to be the only solution for the rapid shoaling and the accumulation of "black mayonnaise," the name given to the mucky substance left by decayed leaves.

An 11-year-old United States Fish Commission Reports states that in 1892, there were 110 fyke nets in the cove, making it the site of the largest fyke net flounder fishery in the country.  And there were oysters as well: 4,000 lbs. of meats were taken every year.  "You'd work a long time to get that out of the cove today," says Visel.

He notes that the old oystermen knew the effects of the leaves on their oyster beds and used bedsprings to clean them up.  But ever since harvesting declined and local coves were closed to shellfishing, nobody has bothered.  One local resident, Franklin Rich, claims to have measured the black mayonnaise at 6'6'' deep off the dock on his property.

The Environmental Protection Agency has now recognized Long Island Sound as "an estuary of national significance."  As such, it will be guaranteed federal funding (about $1 million per year) for a study on water quality over at least the next three years.  This is good news to research scientist Dr. Jay Taft of Harvard University.  He is quoted as saying that conditions in the sound are "running a startling and ominous parallel to those that existed in Chesapeake Bay in 1960."

 

Appendix #4

INFORMATION FOR THE PRESS

 
                                                                                                           
 
RELEASE FOR PUBLICATION
FEBRUARY 24, 1935 (SUNDAY)
 

SEEK WILDFOWL IMPROVEMENT

IN STUDY OF EELGRASS SHORTAGE

 

Calling the disappearance of eelgrass one of the outstanding biological phenomena of recent times, Clarence Cottam of the Bureau of Biological Survey, yesterday (February 23) told the Biological Society of Washington, (D.C.) that conditions observed on the coast of the United States as a whole are beginning to show signs of improvement.

            Eelgrass, the staple winter food of sea brant, began to die out rapidly on the Atlantic coast in 1931 and by 1932 the disappearance was so widespread that a close season was provided for the protection of the brant.  The plant, a submerged salt-water or brackish water perennial of the pondweed family, Mr. Cottam explained, is also an important food for Canada geese and black ducks, and to a lesser extent for other waterfowl.  It provides a shelter and habitat for shellfishes, fishes, and many interdependent forms of minute life, some of which have almost disappeared with the eelgrass.

            Though emphasizing three indirect uses of the plant, Mr. Cottam also pointed out its many direct commercial uses.  Eelgrass is used as an insulator, in upholstering, in packing, in the manufacture of mattresses and other articles, as a compost for fertilizer, for bedding domestic animals, and as a soil binder and erosion preventive on farms and in coastal areas.

            Since November 1934, Mr. Cottam related, the Biological Survey, has intensified its close watch begun when the disappearance of the plant was first apparent.  Conditions, he reported, have been found extremely variable.  The general improvement observed is modified by the fact that some areas are decidedly worse than 6 and 12 months ago and characteristics of the disease are still in evidence in every section.  Yet in a few localized small areas, there has been a progressive improvement for two years and conditions are approaching normal. 

            Referring to the many theories advanced as to the cause of eelgrass destruction, Mr. Cottam has declared that none has been conclusively demonstrated.  Evidence at present, he said, seems to point to a fungus disease, though for a time it was thought that the shortage was due to a bacterial disease.  There are indications, he commented, that the degree of salinity of the water in which the plant grows is an indirect factor.

            Some workers, according to Mr. Cottam, have tried to correlate the periods of eelgrass scarcity with sunspots or with the periodic shifting of the moon's position.  Other hypotheses have attributed the disappearance to storms, to the changing nature of the substratum or water levels, to temperature changes, drought, or to oil or other pollution.

            Mr. Cottam's address was based on a report prepared by him recently and entitled "The Present Situation Regarding Eelgrass (Zostera marina)."  The report sketches the history and extent of eelgrass disappearance; discusses the cause of the malady, the effects of the plant's disappearance, and past periods of scarcity; and gives details of conditions in North America and in Europe.  Copies of the report are available at the Bureau.
 

1612-35

 

Appendix #5

FAO TRAINING MANUAL ON BREEDING AND CULTURE OF SCALLOP AND SEA CUCUMBER IN CHINA

 
CHAPTER 1
STRUCTURE AND BIOLOGY OF SCALLOPS
 
1.      Argopecten irradians, the bay scallop, has a wide geographical distribution along the Atlantic and Gulf coasts of the United States. After being transplanted into China in 1982, the bay scallop gradually became one of the dominant species of scallops cultivated in China.
2.      Furthermore, heavier mortality occurs with higher culture density and bigger sized individuals.
3.      An unsuitably high culture density may be the main cause of mortality. The reasons are: (1) the scallops cannot obtain sufficient food; (2) a greater amount of metabolic waste is produced, the decomposition of which will consume great quantity of dissolved oxygen; (3) the products of decomposition, especially sulphide, are toxic to scallops; some experiments have shown that when the sulphide concentration reaches 0.3 ppm, the filtration rate of scallop is reduced by about 30 %, and at 0.7 ppm, feeding and respiration stop; and (4) the weak individuals in a crowded and adverse environment are susceptible to disease.
4.      Other important factors that cause mortality are high temperature and high density of fouling organisms.
Oceanology of China Seas – Volume 1, Edited by Zhau Di – Kluver Academic publishers
"The decomposition of fecal pellets of parent scallops, food debris and dead scallops by enculture bacteria as well as metabolic wastes may produce toxic ammonia. When waste materials are sedimented and oxygen in the tank is exhausted, toxic hydrogen sulfide is produced. Aeration serves to replenish oxygen in the water resulting in converting hydrogen sulfide into hydro-sulfate and at the same time restricts the growth of anaerobic bacteria, thereby reducing the production of toxic ammonia. Lowering the pH of the water can have a diluting effect on toxic ammonia."
 

Appendix #6

Questions for The Connecticut Invasive Plant Council

January 2013

 

FROM: Tim Visel
Sent: Tuesday, January 08, 2013 11:06 AM
To: Murray, Nancy
Subject: Eelgrass Zostera Marina Questions
 
Hi Nancy,
This request may seem a bit odd but my research investigations as part of the Long Island Sound Study concerns the bay scallop and eelgrass habitat association.  A historical review does indicate that the red macroalgae and corraline reds contain setting and spawning stimulants important to scallop species worldwide (not eelgrass).

In fact, the habitat association between green crabs, Carcinus maenas, an invasive, appears to be strongest to eelgrass Zostera marina and the subject of my inquiry.  I raised the suggestion that the habitat association between eelgrass and green crabs is much closer than first suspected, that it is possible that our strain of eelgrass came over as seaweed packing material with adult green crabs, which several hundred years ago was an edible fishery in Great Britain.  My research has found that adult green crabs are still consumed as food in some English channel communities today – in fact, you can find green crab recipes on the internet.

EPA seagrass and SAV researchers were reluctant to take this up – mentioning that even if it is (eelgrass) invasive (the west coast has an invasive eelgrass species now) that it has been accepted here as beneficial – a "native invasive" because of its length of time here?  I'm not familiar with time as a criteria for this designation?

What is the process for proceeding for determining if a plant or strain is invasive?
I shall appreciate any information you can provide.

Thanks,
Tim Visel

 

 

Appendix #7

Grasses and Soil Types

 
Invasive plant species have long been researched as for specific phenotypes for habitats.  Some recent eelgrass research supports the concepts of particular strains and perhaps genotypes that for survival reasons adapted themselves for particular habitat constraints.  This is mentioned in a 2012 report titled "The Eelgrass Resource of Southern New England and New York".  On page 7 is a short but curious segment that mentions certain strains are perhaps more suitable for certain conditions than others.  In a study of genetic diversity, the report details that some populations were different – "However, we did find that our most successful (resilient) eelgrass populations were part of two most distant metapopulations from the north (outer Cape Cod and New Hampshire MA-NH) and the south (south shore of Long Island, NY)" (both areas subject to greater storm energy, T. Visel).

In terrestrial grass studies, we know today that certain grasses can grow in a successional pattern or when converted to monocultures prefer certain soil types.  It is possible that several eelgrass varieties have developed in response to habitat conditions.  Most of the 17^th and 18^th century nautical charts detail "grass beds" in much deeper water than the shallows.  The profusion of eelgrass is documented following intense storm activity (soil cultivation) and that one or more strains of eelgrass that can take advantage is one that can quickly colonize such "new" or washed soils, and, over time, as the soil chemistry changes, it "dies off" naturally.

The soils of estuarine shallow waters are subject to both heat and bacterial composting.  It is these warm to hot composts that show extreme soil chemistry change and influence upon eelgrass growths.  Researchers at the University of Connecticut have begun to investigate soil/bacterial population impacts upon eelgrass (See Appendix #7: Improving Eelgrass Restoration Success by Manipulating the Sediment Iron Cycle). 
Knowing the genetics (attributes) and soil conditions (chemistry) are two of the pillars of terrestrial agriculture.  If we are to farm eelgrass, both are key areas to successful cultivation – my view, Tim Visel.
 

Appendix #8

EPA Long Island Sound Study Research Grant Program

2020 Research Project Descriptions

Projects will take place from 2021 to 2023

Improving Eelgrass Restoration Success by Manipulating the Sediment Iron Cycle

 

Investigators: Craig Tobias and Jamie Vaudrey, University of Connecticut; Chris Pickerell, Cornell Cooperative Extension
Grant Award: $323,404, plus $161,786 in matching funds

"While many Long Island Sound embayments now have improved water quality that should make them suitable for eelgrass restoration, there is a difference between the acreage of habitat that could theoretically support eelgrass and where it has actually regrown or been restored successfully.  Sediment is a key component that may have been overlooked and is a potentially limiting factor for eelgrass restoration efforts to move forward, which is a key goal of the Long Island Sound Comprehensive Conservation and Management Plan.  To develop a new restoration management framework, this project will map sediment sulfide and iron gradients in relic eelgrass beds in the Niantic River Estuary, and correlate sulfide concentrations to other sediment variables to establish easy-to-measure proxies for sulfide for use in evaluation of potential eelgrass restoration.  The project will then conduct experiments to test the effects of adding iron-oxide pellets, a cost-effective tool, to sediments on porewater sulfide and solid phase iron-sulfide mineral content.  This method of iron amendments could potentially be easily integrated into existing restoration techniques."