CTFishTalk.com: The Role of Energy and Climate in Habitat Reversals IMEP #30 - Connecticut Saltwater Reports ( CT Saltwater Reports ) - A Community Built for Connecticut Fisherman.

BlueChip

The Sound School Interdistrict Marine Education Program
IMEP Newsletter #30

Quahoggers Final Stand Against Eelgrass in Chatham 1973-75 – IMEP #30
THE ROLE OF ENERGY AND CLIMATE IN HABITAT REVERSALS:
Updated Work Plan, Feedback, Input for the September 5, 2012 Habitat Restoration Committee Meeting
Quantitative Acreage Assessment – Habitat Quality Factors Assessment
And Historic Mapping Concerns
Timothy C. Visel
LISS Habitat Restoration Work Group Member*
Capstone Question – Did We Make the Case for Protecting Eelgrass?
June 2014

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

This paper was originally prepared for the Long Island Sound Study Habitat Restoration Work Group, but does not represent or reflect a viewpoint of the committee, nor has a consensus been obtained regarding the concept of a long term habitat history for eelgrass Zostera marina . This paper follows a 2009 effort to have the Long Island Sound Study explore the long term impacts of climate temperature upon habitat quality and species abundance. The concepts introduced then include long term climate (temperature) and storms (energy) influence on species as “habitat clocks” for marine habitat succession similar to such changes observed on land. Marine succession relates to the terrestrial parameters of habitat or “forest” succession. Habitat clocks are also “natural” for aquatic regions and as habitat quality for one species declines over a long period of time, another may often strengthen. The recent reversal of lobsters for blue crabs post 1998 here is a good example, and one that has happened here before.

This paper examines the habitat association between eelgrass and its long term successional habitat relationships to shellfish and fish species. It also details a scientific bias from examining time periods that often are far too short upon which to enact public policy discussions. Did we make the case for protecting eelgrass without a long term view?

Introduction

Eelgrass often provides a positive transitional habitat for winter flounder and juvenile stages for many fish and shellfish species during the first stages of a habitat reversal. As a structure (reef) habitat it is home to small crabs and fish and a productive place to fish. This is the “clean and green” eelgrass that is often in areas of modest current and cooler, oxygen sufficient waters. However, as the habitats begin to age (succeed) in warm water, eelgrass turns against many of the species it provided positive ecological services to earlier. In the shallows it slows currents, creating and assisting organic deposition and Sapropel formation (which in the hot sun rots), releasing ammonia from now an oxygen deficient benthic reduction cycle. Eelgrass now is often “brown and furry” with epiphytes that produce a slime on the blade itself. It is this stage that eelgrass smothers shellfish as the organic matter trapped below it becomes sulfide-enriched and toxic. It is also the home in periods of high heat to an entire family of sulfur cycle bacteria including a group that breaks down the complex sugars (cellulose) in terrestrial leaves. Due to its very high silicon content, eelgrass is protected from this bacterial decay except for its soft root tissue. It is also attacked by such sulfide reduction and explains why so often the floating blades often have some root tissue attached to it. Eelgrass because of its reproductive capacity soon displaces other submerged vegetation types. In some offshore regions in the Mystic River / Masons Island area below some eelgrass growths were once kelp / cobblestone habitats (Larry Malloy comments 1980s). On Cape Cod in the late 1960s it was documented in Massachusetts State reports to damage bay scallop and hard clam habitats.

Eelgrass has a very complex habitat history especially in the shallows and this paper reflects not so much on the positive but the fact that the negative (almost, if not just as significant) has not been mentioned. This conflict is perhaps part of a larger issue, the comparison of U.S. Fish, and Wildlife fish and shellfish catch (fisheries) statistics – with climate patterns and fisher habitat observations. In this comparison, habitat quality reverses in different climate and energy parameters over long periods of time. The habitat services of eelgrass greatly change from a structural reef (positive) to a suffocating toxic containing compost (negative).

This paper was first developed in June 2012 and does not in any way represent the viewpoint or position of neither the Citizens Advisory Committee nor the Long Island Sound Study. No consensus has been reached that climate patterns (long term) influence habitat quality or quantity in Long Island Sound. However without long term views a bias existing of promoting positive aspects but ignoring the dangers of Sapropel formation (my view).

Questions about our strain as being not native needs to be addressed. Not all eelgrass strains are alike, and like other plants, some strains evolved under different environmental conditions. In fact, we may have several strains of eelgrass (some not even native to our shores) and perhaps some of the more aggressive strains are from the North Sea. With numerous ocean voyages especially those originating at England, some mature “aggressive” non-native strains may have been introduced here. That possibility is also renewed discussions if like phragmites strains our dominate strain is also not native. A Chatham oyster grower John Hammond long felt that the strain running Quahog habitats on the Cape was in fact “not native.”

The scientific research surrounding eelgrass often contains an institutional bias created by insufficient data (time) – and also possible research misconduct practices by ignoring references that previously mention negative impacts of eelgrass habitat succession. Indeed as eelgrass habitat succeeds it often harms species that they are proclaimed to assist and this even includes the bay scallop.

Many of these research conflicts arise because of a failure to include climate (temperature) and energy (storms) as factors to eelgrass and habitat services. This is a perspective that has been mentioned before, some with a strong warning about short-term observations (Roberts 1985) (Pauly 1995). And it is not that this issue has not been mentioned before, in the 1980s it was a topic discussed at many state DEP Costal Cove and Embayment meetings. Then an organization called the Sounds Conservation with President Christopher Percy called on the state to investigate such long-term fish and shellfish studies. It was felt that a long-term view was the most important effort the state then could undertake. The challenge was daunting but important to our understanding of the baseline research habitat assessments. Many of the Coastal Cove and Embayment meetings had requests and suggestions to conduct such investigations into past habitat conditions.

Much has been written about eelgrass Zostera marina and it role as a habitat quality indicator. The trouble with eelgrass is that we do not have a good long term habitat history for it.

Mervin Roberts, a naturalist and writer in Old Lyme, was one of the first to raise the alarm bells about a bias in short-term surveys and makes this a part of his book in 1985.

A Tide Marsh Guide to Fishes

“Biological surveys and censuses are difficult to design and sometimes impossible to carry out so as to be free of bias. Examples of bias in science are sometimes found in collections of living organisms where population is in motion. To be without bias such a collection would have to be made over an extended period with no regard to inclement weather, ice, time of day or holidays. Consider the swallows at the Capistrano mission in California, how would a report on their habits look if no observations were made during those few days when they were all arriving or all leaving? Consider a fly hatch on a trout stream, all over in one day, only one a year. Consider a run of river herring, if you miss it, no one will be able to make you believe it… I submit that we have no business establishing rigid categories for the works of mother nature” from The Tide Marsh Guide to Fisher by Mervin F. Roberts 355 1985 The Saybrook Press.

The trouble with eelgrass as a process was outlined by naturalist Merv Roberts 1985 in this book The Tidemarsh Guide. A full decade before Daniel Pauly outlines similar concerns made famous in his “shifting baselines” report (1995) that continues to rock the scientific community. The real question is if the institutional bias around eelgrass is just a series of research mistakes, or a way to promote specific environmental public policy. And is the trouble with eelgrass as its role as an environmental indicator is presently under investigation.

This report below is from 2012 raises many questions about eelgrass and habitat reversals and it is my reflection – not the Citizen Advisory Committee of the Long Island Sound Study or The Habitat Restoration Work Group – both committees upon which I belong. The report was updated for a possible capstone project in June 2014.

Tim Visel – The Sound School

Introduction

Earlier this spring (2012), I sent three messages to regional EPA estuary research programs – Massachusetts Bay, Buzzards Bay and Long Island Sound. Those messages contained research cautions and warnings regarding the habitat services of warm/acidic bay bottoms and potential eelgrass restoration projects proposed for them. This update reiterates these concerns and offers feedback to the recent Habitat Restoration Meeting held on September 5, 2012.

My first caution concerned volunteer and civic groups planting eelgrass shoots (culms) into highly acidic low energy marine soils such as Sapropel.

It seems eelgrass has become a key marine policy indicator species worthy of conservation and protection. My second caution concerned doing so before an accurate long term habitat history for eelgrass has been published and reviewed. Such a habitat history would yield information that New York State, for example, is believed to be the first state to utilize eelgrass mowing machines in its south shore salt ponds a century ago. In addition, that several Massachusetts communities applied herbicides in a failed effort to keep eelgrass from over-running clam and oyster habitats in the 1960s. In Connecticut, explosives even were used in Niantic Bay in 1974 to control dense eelgrass growths there.

My third concern regarded a chance that our strain of eelgrass is perhaps invasive. There is a strong possibility that it was carried here hundreds of years ago from the lower Thames River in England with green crabs, an edible fishery that continues today. It was an industry practice to ship lobsters and crabs in seaweed to keep gills moist and prevent death/spoilage. This is still an industry practice today. As such as the edible green crab fishery and eelgrass wrapped in barrels provided the transfer opportunity for both species to have happened hundreds of years ago.

John Hammond Cape Cod Account – Chatham Mass

My employment with the University of Massachusetts Cooperative Extension Service on Cape Cod had me meet with Mr. John Hammond, a retired oyster grower from Chatham. In fact, he was more than “just” an oyster grower; he had once worked closely with US Fish and Wildlife Service researchers, Paul Galtsoff and William Shaw. His account of eelgrass is perhaps the most compelling on this possibility of eelgrass/green crab introduction from ships arriving here from England. The destruction the eelgrass caused in coves and bays to shellfish habitat was so extensive that he felt that this strain of eelgrass had to be not native or invasive. In 1982, I did not fully understand or agree with Mr. Hammond; I now believe it. Green crabs are still an edible food in England, and Long Island Sound Study’s own publications have highlighted seaweed as a potential invasive species vector. We should at the very least investigate this possibility. With a number of off-the-record comments, the potential for transfer was described as extremely possible, if not highly likely to the point of being impossible not to have had some type of exchanges like this to have occurred. His account of the eelgrass struggle with quahoggers three decades later included a herbicide attempt to arrest the spread of eelgrass into productive quahog habitats on Pleasant Bay Cape Cod. At the time it was hard to comprehend the extent of this habitat war. Some three decades has passed and this type of habitat succession is occurring, again on our pacific coast.

The West Coast shellfish interests have been exposed and currently battling a very destructive Japanese invasive eelgrass strain that threatens to dominate thousands of acres of clam and oyster habitat very similar to experiences of the New England shell fishermen here a half century ago. It is not that I am against eelgrass or pro some other species, far from it. What I support is a long term comprehensive environmental fisheries habitat history for Long Island Sound. Restoring what type of habitat to what period historically is key to our restoration work plan. I hope you might consider these comments for our work plan – especially the historic mapping component. Mapping short term is bound to be biased and misrepresent temporary values or benefits as permanent.

Quahoggers make last stand against eelgrass in Pleasant Bay

Unless some additional information is uncovered I will leave the 1973 date as the approximate time hard clammers (Quahoggers) asked for state assistance to keep a section of Pleasant Bay within the towns of Orleans and Chatham still free of eelgrass. That is trying to keep it away from quahog habitats free of eelgrass (Zostera marina). Several reports mention the loss of good hard clam habitat to spreading eelgrass growths in the Pleasant Bay. This request was made according to several Cape Cod shellfishers a “last stand” against the spreading eelgrass.

This account of herbicide use against eelgrass was told to me several times while employed on Cape Cod in the early 1980s. Shellfishers did not hold it eelgrass high regard in fact nitrogen issues had then been connected to suffocating growths of eelgrass over running productive hard clam habitats. But it was not just a nitrogen issue, it was a climate issue as well. What started out in the southern areas – possibly Connecticut finally reached Cape Cod by 1970. By 1980 was growing suspicious that eelgrass meadows could damage shellfish populations from some experiences in Clinton Harbor and Niantic Bay associated with a bay scallop restoration project.

Cape Cod quahoggers watched with dread as they heard accounts in southern areas as cove after cove “fell” to dense growths of eelgrass that soon increased siltation, slowed tides and grew so thick that it completely covered hard clam beds killing the shellfish below. They wondered how long it would be until they experienced this, but the cooler Cape waters did slow the advance of eelgrass but did not stop it.

From several fisher accounts what started out as scattered patches of eelgrass grew larger – after a while these isolated patches now joined in a continuous carpet of eelgrass. In the late 1950s “the eelgrass problem” had already alarmed some shellfish wardens in southern Massachusetts towns of Buzzards Bay. By 1965, Massachusetts shore towns had already tried underwater mowing machines, drags and finally herbicides. A Westport River report mentions herbicide 24-D experiments were already underway by 1965.

In Southern Massachusetts and in Niantic Connecticut old cabot cutters triangular metal plows connected with proof coil chain were put back into service. It had been years since the Cabot Corporation stopped buying eelgrass for insulation but the cutters were still available and quickly put to use. Some accounts mention “all we did was spread the seed around” leaving roots behind Niantic Bay 1968-69. On the Cape an oyster grants link fence drags were used to rip out roots but like mowing a lawn the eelgrass grew back. (John Hammond report) by 1965 some Massachusetts shore towns had tried underwater mowing machines, and as a last effort – chemical treatment of herbicides. As eelgrass growths spread north from Narragansett Bay – quahoggers on the Cape wondered if they would be next – they were.

When I arrived on the Cape in 1981 – shellfishers were still talking about their “habitat war” with eelgrass especially Mr. Hammond and John Farrington. By 1966 eelgrass had arrived on the Cape into and Pleasant Bay a large productive area for the regions hard clam fishery. Here according to John “Clint” Hammond a retired Chatham Mass Oyster Planter it was a habitat war the fishers could not win and by 1981 apparently had lost. Mr. Hammond described a “last ditch effort” to arrest the spread of eelgrass with 24-D herbicide which according to Mr. Hammond was the same substance “they used in Vietnam” (his words).

Estuarine Habitats Are Dependent Upon Climate (Temperature) and Energy Pathways

Few people realize that we are in the largest habitat reversal since the turn of the century (1900). Lobster habitats, for example, are essential to our Sound’s kelp/cobblestone matrix. The kelp/cobblestone habitat that is vital to lobster larval stage 4 has failed after four decades of high heat and low energy inputs. This failure precisely resembles the previous southern New England lobster habitat collapse of 1898-1905 which also occurred after a period of high heat and low energy. Rhode Island at this time closed its lobster fishery the only New England State to do so in recent history. (After two years they took off the seasonal restriction 1906 as it was generally accepted as not effective).

Bay scallops thrive in periods of cold temperatures and strong energy (frequency of storms). In the coldest of times (1870s) and more recently the 1950s, habitat reversals occurred, and bay scallop production soared. During those brutal winters, Long Island Sound freeze-over’s, coastal ice and damaging storms seemed to maintain a high habitat quality for bay scallops. In 1875, the most productive Long Island Sound community for bay scallops was Greenwich, Connecticut. By 1900, in the midst of The Great Heat and few storms, bay scallops disappeared in Greenwich, Connecticut – their habitats failed.
During the violent storm filled period of the 1940s and 1950s, in the face of bitter winters and a record number of coast damaging hurricanes, bay scallop production in Niantic Bay soared without the presence of eelgrass. Eelgrass was completely gone from Niantic Bay at this time. Local fishermen felt that red weed, a red macroalgae species (Agardhiella subulata) was the real scallop grass. It looks as though they may have been correct a worldwide habitat association between scallops and red algae species exists even today, especially to coralline reds, producers of Maerl, a substance with a known habitat advantage for scallops worldwide. The reds are known to contain scallop setting and spawning stimulates; eelgrass does not contain such chemicals, my research to date indicates.

My research into historical fisheries of Long Island Sound now points to two factors, largely out of our control, temperature and energy. Temperatures control tolerant species of both plants and animals. Energy inputs can alter depths, sediments constituents, pH and tidal exchange. During different temperature/energy periods, different “sea grasses” with their associated habitats prevail. During the colder, high energy periods, kelp/cobblestone and coralline reds predominately are found; during warmer, less energy periods, eelgrass becomes very prevalent. Other seagrass types besides eelgrass, such as the coralline reds and kelp/cobblestone may have habitat services equal to or surpass those of eelgrass. In fact, eelgrass seems to quickly colonize disturbed marine soils, following cold periods such as the 1880s and 1960s. Eelgrass colonizing and reproductive capacity is similar in fact to the terrestrial invasive plant, phragmities.

Other habitat examples exist that support this energy/climate pattern. Winter flounder habitat is improved after colder and stormier periods, especially in the presence of estuarine shell. Hard clams (Mercenaria) set well after the strongest of storms, in colder temperatures and hard clam sets in shallow areas following greater tidal exchange (energy) are tremendous as such recorded in New York bays.

My fisheries habitat research indicates when Mr. Hammond mentioned decades ago the presence of habitat “clocks” for many species. In Narragansett Bay, many species and four major habitat reversals since 1860 have happened for Long Island Sound and is much the same landing (catch) reversal. These habitat reversals appear to be entirely energy and climate driven, adding to the necessity of such events to be included in our historic understanding of habitat quality and quantity. Previous habitat acres are “reversed” as habitat quality is changed. This of course alters the number of habitat acres, etc., and future levels of abundance.

Jon Kachmer of The Nature Conservancy also strongly supported this effort at our July 21, 2010 meeting.

A long term environmental habitat history for Long Island species is critical to our efforts and work plan. I would be pleased to provide additional information or respond to questions.

Thank you for allowing me to comment on the proposed 2012-2014 work plan.

Tim Visel, Member Habitat Restoration Workgroup.
Sent to Kelly Hines and Harry Yamalis – Sept 10, 2012

Here I was to learn much from the shellfishers on Cape Cod and one who was very astute about climate impacts.

* Almost every day additional information and research is going on line which describes the potential fishery impacts of a negative or positive NAO shellfishers on Cape Cod were experiencing the heat during summers not seen in nearly a century. This “heat” is now associated with a positive NAO.

At first it was somewhat difficult to understand how herbicide pellets could be shoveled overboard on eelgrass meadows without some context of shellfish surveys in the late 1960s. A key report just recently obtained sheds some lights on what fishers observed a growing eelgrass monoculture which overran previous shellfish habitats. The report which was one of a series of historical reports made available by Bruce Carlisle of the Massachusetts Coastal Zone Office is titled A Study of the Marine Resources of Pleasant Bay by John Fiske, Clinton Watson and Philip G. Coates May 1967 – Monograph Series #5 Massachusetts Dept of Natural Resources – Division of Marine Fisheries. The report is very valuable in many respects but chiefly supports the positions of shellfishers on Cape Cod, see Appendix #1.

The Pleasant Bay Herbicide Incident Eelgrass Control Experiment
The Notes and Possible Files of Edmund Harding, Chathams Shellfish
Shellfish Officer 1967-75
Katherine Abreu 1975-1984?
Some Capstone Research Questions – June 2014

1. Question - When did Massachusetts communities apply herbicide to control eelgrass?

Incident – The granulated ester of 245-T commonly known as dioxin contaminated herbicide Agent Orange. It is now infamous for causing birth defects in Vietnam Veterans and citizens of Vietnam. The herbicide 24D was contaminated with dioxin during manufactures. The Eelgrass problem – Quahog fisheries Massachusetts Herbicide pellets distributed in Pleasant Bay to control growths of eelgrass over taking (Habitat Succession) Quahog habitats in Pleasant Bay 1973-74, John Hammond and Sherril Smith of the Division of Marine Fisheries also confirmed experiments did happen to control eelgrass. According to Mr. Hammond he watched or participated in loading bags of herbicide pellets to be shoveled over an eelgrass patch or area. Mr. Hammond may have assisted or used one of his oyster floats. He also described attempts to loosen it (eelgrass) with fence drags in Oyster Pond River (1981-1983) in the 1970s which did prevent direct (oyster) suffocation but did not eradicate growths.

A later report in 1974 Westport River does mention 2-4 D experiments were underway in one or more Massachusetts towns. Canadian studies also confirm 245-T experiments to control eelgrass growth s on commercial oyster beds. (Source – Gallagher 1965, Fisheries Research Board of Canada Manuscript Report Series #905 St. Andrew N. B. ML M. Thomas Experiments in the chemical control of eelgrass 1965).

Habitat History from shellfishers 1981-83

Oral accounts Phil Schwind, Author, Ron Ribb, a shellfish gear fabricator, John Hammond, Oyster Grower (retired), Sherrill Smith (DMF) and John Farrington all described that eelgrass overran and choked quahog beds during the 1945 to 75 period in Pleasant Bay. At first the increase of eelgrass was linked to an increase in bay scallops but later as eelgrass became so thick in rotted in warming summer temperatures bay scalloping declined in these thick growths.

Written accounts - eelgrass habitat succession (3 located all Massachusetts) can be found in three separate reports.
- Army Corps Report 1968 – yes, mentions eelgrass overrunning quahog beds
- Westport River Report State Mass – several reports mention eelgrass harming quahogs
- Pleasant Bay Report State or Mass – Several sections mention spreading eelgrass meadows into hard clam quahog habitats

Two State of Massachusetts reports courtesy Bruce K. Carlisle Massachusetts Coastal Zone Management Office
Pleasant Bay Report – May 1967
Five to eight years before eelgrass control experiment (estimated 1972-75) reference to testimony of John Hammond Chatham.

The Orleans/Chatham Pleasant Bay Report (1967) State of Massachusetts Marine Bulletin series mentions the observation of a transitioning habitat from cold, energy “hard bottoms” to those of soft organic filled eelgrass meadows which was a concern if not only hard shell clam (quahog) fishers but scallopers as well.
Pg 16 Extensive growth of eelgrass – several areas
Pg 25 Excessive weed growth
Pg 36 1931 Zostera blight absence of bay scallops
Improved after 1948
Pg 38 Eelgrass rapidly taking over quahog setting habitats
Pg 42 Sampling hampered by thick eelgrass handicap to scallopers
Pg 46 “A main problem facing scallop fishermen is the rapid spread of eelgrass”

“The eelgrass problem, which is not unique to Pleasant Bay, has become common in practically all bay waters on the south shore of Massachusetts – unfortunately there is no practical method of controlling eelgrass at the present time.”

And issued several recommendations on pg 55, one of which,

5. “That the shellfish officers or Orleans, Harwich and Chatham continue to record the volume and value of annual shellfish harvests from Pleasant Bay.”

According to Mr. Hammond nothing seemed to work eventually eelgrass over ran what little clam habitat remained. To him the climate had turned against the quahoggers it was just “too hot.”
One of the characteristics of the NAO (North Atlantic Oscillation) was a habitat reversal between alkaline marine soils and acidic eelgrass meadows. One of the ways acidic soils were extended and contaminated to catch bivalve sets was surface shell litter. The report also mentions that habitat observation now key to understand the negative aspects of eelgrass to the pH of marine soils.

Estuarine shell – sets increased Quahogs Pg 36 dramatically improved after 1938-1955 storm recultivation events. In 1957 excellent sets now returned – heavy sets were now thinned by a hydraulic clam dredge. Shell setting notes Pg 38 “In one area where diver biologists found to be exceptionally thick, the bottom was covered with great numbers of empty Quahog shells.” These shells function to provide structural relief and buffer acidic soils.

2. Question – Is there any evidence that a strain or strains of eelgrass came over from Europe? Yes, several possible vectors exist for introduction.

Mr. Hammond felt that the eelgrass strain “pushing out” Quahogs was not native to our shores. Mr. Hammond raised questions about specific strains of eelgrass he believed that were carried here aboard shops originating from the North Sea (Great Britain). He felt the aggressive nature of a strain now inhabiting Pleasant Bay was not native. He believed that it was an aggressive strain with an “abbreviated habitat clock” that was able to dominate previous habitat types – he was looking at the North Sea and had researched blade examples. He had made a collection and surmised that an aggressive strain from the North Sea had been carried here as packing and said barrels were the other mechanism for transport of different strains. Eelgrass was carried here as perhaps packing for green crabs or oysters. Mr. Hammond explained that seaweed acted to keep shellfish moist and absorbed the movement (shock) during transit. Bait was also used in fishing trips and that also was packed with seaweed centuries ago which today is a current industry practice (marine worms).

Some Possible Research Areas Include,

a. Live bait vector Vikings carried bait to catch fresh fish later fishing vessels had multiple chances for introduction. Early Newfoundland fishers had treaty rights not for fishing (open sea) but for landing to gather bait for fishing. Bait rights complicated custom and English tax agents as New England vessels sought to circumvent tax (stamps) and smuggled goods during “bait trips” along unguarded coastlines. Live bait could have originated in North Sea – it’s an old practice, see US Fish Commission Reports – also see baiting trips pg 173-179 Maine Sea Fisheries Wayne O’Leary Northeast University Press 1996.
b. Danish Coast green crabs edible species – live green crabs kept layered in seaweed old practice, see US Fish Commission Reports packing blue crabs. USFWS – packs lobsters used seaweed. See Recluse The Ocean 1873 – Several old Danish texts reference eelgrass/crabs – large eelgrass population 1600s, pg 154, 369, 421, and 476. Green crab “shore crab fisheries.” During this time of ocean transit North Sea fishers caught and consumed large quantities of green crabs. A European green crab fishery still exists today.
c. Shellfish shipments in barrels to prevent shell chips damage, layers of seaweed (Ostrea edulis) or edible crabs packing practice. It has been known that lobsters or crabs keep longer packed in seaweed. See John Hammond article Cape Cod – 1981 – Art of packing oysters in barrels.
d. Freshing adults (shellfish) before transit – long industry practice placing shellfish in saline waters, wet storage before ice. Mesh bags on bay bottoms could gather eelgrass shoots. Freshening for oysters and clams was an old practice to extend shelf life. Shellfish shipments linked to spreading oyster predators and a habitat link to green crabs.
e. No crab species that predate upon shellfish pg 97 to 103 (1913). The Canadian Oyster Jos. Stafford. Eelgrass smothers oyster beds beginning 1959 as green crabs arrive 1955-63, Dept of Marine and Oceans. Canadian researchers ran several trials with herbicides in an attempt to control eelgrass overtaking oyster growing areas (1960s) see Thomas St. Andrew Biological Station #905 Manuscript Report Series Fishers Research Board of Canada 1965.
Shellfish shipments linked to spreading oyster predators and a habitat link to green crabs.

Appendix I – Quahoggers Make Final Stand
The Eelgrass “Habitat War” Niantic Bay Connecticut
Accounts of Cape Cod Hard Shell Clam Fishers 1980s
Tim Visel

In the late 1940s Niantic Bay shellfishers noticed growths of eelgrass growing thickly on the river bottom. Nelson Marshall was studying the life history of the bay scallops and took note that bay scallops often set on long eelgrass fronds (blades) found there. There is no record of the comments by shellfishers but apparently they did not agree with some of his research mentioning red weed with the observation of bay scallops also setting on it but Dr. Marshall did make a note of it writing. “In this connection it is noteworthy that fishermen of the Niantic Bay refer to such algae as scallop grass.” In his 1960 study titled Studies of the Niantic River Connecticut with Special Reference Argopecten irradians to the Bay Scallop. The algae mentioned was a red algae highly blanched observed by him to be both very abundant in Niantic River and heavily laden with attached scallops Dr. Marshall concluded that this red algae or “red weed” was a adequate substitute for Zostera commonly known as eelgrass but what if it was the other way around – what if red weed was the preferred settlement vegetation and Zostera was just a second choice substitute?

That question is being answered overseas with research into the coralline reds but also here as we understand more about the habitat succession characteristics of eelgrass itself.

Eelgrass has a successive characteristic that has been reported by fishers and fishery managers in the 1900’s and again in 1960s. Eelgrass growths soon overwhelmed shellfish habitats and alarmed fishers and managers alike in the 1950s and 1960s. A 1967 report of the Westport River Massachusetts starts to detail the habitat conflict that soon developed into a full scale “habitat war” which included towed cutters, mowing machines, herbicides and in one case, dynamite in Niantic Bay Connecticut. It is doubtful that a plant once thought to be so beneficial to shellfish became so despised by so many shellfishers as a shellfish habitat benefit. This view was so contrary to the view generally accepted at the time – eelgrass “was all good.”

When I started working for the University of Massachusetts Cape Cod Extension Service in 1981 the shellfishers on the Cape were still talking about the eelgrass war which by all accounts they had lost. Conversations mentioned techniques and trials but had failed to stop eelgrass from covering good shellfish “bottoms.”

As the 1960s turned to 1970s eelgrass was to continue its growths overrunning quahog, oyster and even bay scallop habitats. One shellfisher John Farrington told of eelgrass ruining shellfish habitats – contrary to the prevalent public opinion. In 1983 he wrote a large letter to the editor of the Village Advertiser titled was “Too Much Eelgrass” and describes many of the negative comments about eelgrass made during the earlier 1880-1920 period in New England – dense growths suffocated previous habitat types and more recently in the 1980s.

As for the Niantic River comments about red weed (now thought to be Agardhiella subulata) studies overseas have identified two substances found in coralline reds that stimulant scallop setting. It, as the first studies indicate, releases chemicals from algae tears or breaks adding evidence to the belief that bay scallops set heavy after storms. The broken fragments of coralline red algae may have signaled settlement of bay scallops and why Niantic Bay shellfishes termed it “scallop grass.”

The observations of the negative eelgrass habitat impacts were real to the shellfishers and fishery managers and repeated many times in the 1900s and again between 1954 and 1974.

John Hammond, John Farrington and Conversations with Niantic Bay Scallopers, Recollections 1981-1983

Quahoggers (on Cape Cod) with dread as they watched as cove after cove dense eelgrass growths suffocate quahogs eliminating hard clam habitat. What started as scattered patches (Pleasant Bay) of eelgrass grew larger in the 1960s and grew so thick it buried productive dam beds in many towns starting with the southern Buzzard Bay region. By 1965 Massachusetts shore towns had already tried under water moving machines, and herbicides. In southern Massachusetts and Connecticut old “Cabot cutters” towed chain sweeps – angle weights with chains to pull free eelgrass growths for sale to Cabot Industries for insulation a decade before were put back into service in failed efforts to arrest the spread of eelgrass into quahog habitats. It was a habitat war that shellfishers could not win – I recall John Clint Hammond retired oyster plants from Cape Cod who lived in Chatham Massachusetts saying that to me in one long afternoon meeting over three decades ago. Eelgrass has become too abundant and now threatened the productive hand shell clam – quahog producing areas in Pleasant Bay itself. Here Mr. Hammond quahoggers would make their final stand and evidently they had support from the state also. Here he witnessed the shoveling of herbicide pellets suspected 245T – the same substance Mr. Hammond claimed “they used in Vietnam.” (Direct quote).

I had first heard negative reports about eelgrass growth from bay scallopers in Niantic Bay in 1977-78. They had told me the growths got so thick it stopped the tide and explosives had been used to try to clear a path in lower Niantic Bay. It was difficult to believe but published reports now confirm it. As more and more records became available and fisher accounts compared these accounts are true and give now a dark side to the eelgrass debate – it’s no longer if eelgrass destroyed Quahog habitats, it did and the habitat impacts can be found in several published Massachusetts state reports. A larger question is why this information was not fully explored in the recent eelgrass habitat quality debate? If periods of low eelgrass abundance are followed by habitat expansions – are natural then its selection as an environmental quality indicator would be needed to be indexed against these apparent fluctuations? It might be just as natural that over times we have periods of eelgrass declines. What the quahog fisheries experienced in Pleasant Bay is seems are not unique experiments with herbicides were well underway in Canada – not in response to intrusions into quahog habitats but impacting those of the oyster (Gallagher 1965 – Aquatic Weed Control in the United States).

The State of Massachusetts report about Pleasant Bay has recently been made available – I thank the Town of Chatham for making it available online – when I arrived on the Cape in 1981 eelgrass was still on the minds of shellfishers there.

The Pleasant Bay report confirms many negative habitats to shellfish habitats. It was published in May 1967 about 7 years before the reported herbicide experiments – conducted by the Massachusetts Division of Marine Fisheries according to Mr. Hammond of Chatham, MA.

Records and files on the Cape may shed some additional light on this habitat war, why it was fought for so long and what where the habitat consequences of this “defeat” that shellfishers called it.