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PostPosted: Wed Jul 19, 2017 11:04 am    Post subject: Temperature, Energy & Niantic CT Bay Scallop Fishery IME Reply with quote

Temperature, Energy and the Niantic Connecticut Bay Scallop Fishery
IMEP #60
Habitat Information for Fishers and Fishery Area Managers
Understanding Science Through History (IMEP History Newsletters can be found indexed by date – Title on the BlueCrab.info™ website: Fishing, Eeling and Oystering thread) The Sound School ISSP – Capstone Series - Do Climate Factors Lead to Habitat Failures?
“Bay Scallops, Temperature, Energy and Eelgrass”
February 1, 2017
Tim Visel

The Sound School, New Haven, CT 06519


Questions were raised at a recent University of Connecticut Sea Grant meeting of Connecticut Shellfish Commissions here at The Sound School regarding bay scallops, if they live in deep waters and whether it was suitable to reinstate bay scallops dredges. How important is eelgrass to the bay scallop fishery and what impact does temperature have upon bay scallop habitat quality in shallow waters. This is in part a response to those questions. After 2011 bay scallops have again returned to sections of Connecticut’s coast. Winters have been colder and sometimes with record snow falls.
The last two winters we have had warm falls and very cold springs. Bay scallops prefer deeper cooler waters – they need high amounts of nitrates (algae) and deeper water with moderate tides to provide good growth. They prefer cold and clean bottoms. The fall bay scallop season dates back to pre-1880s, when cold and stormy weather would then drive bay scallops into the bays and rivers. There, they could be caught by small boat fishers that would use deep water rakes called bull rakes or push pull (pushers) rakes to capture deep water scallops in channels. In bitter cold and often with strong storms that drove scallops into the shallow bays, sailing vessels that towed dredges allowed scalloping to occur in deeper water – such as in the once huge Narragansett Bay Deep Water Scallop Beds of the 1870s. Later outboard powered boats that towed smooth chain dredges allowed this fishery to flourish in 30 to 35 feet of water. In the fall and as waters grew colder – scallops moved into the shallows. Last year 2016 they arrived in the Mystic River, February, when waters cooled.
A warm, quiet fall means scallops can stay in deeper water longer (except for strong storms) and don’t come in the “regular times”, with water temperature being the deciding factor. Ben Rathbun, who once scalloped in the Noank area told me of offshore deep water scallops similar to the fishery of the deep water Narragansett beds- they would tow dredges and “follow the scallops in” as they moved ashore – they (scallopers) sought to seek them, and not wait for them to come into the harbor - which occurred following storms and was “hit or miss”.
Although much has been written about shallow water (spotter dip nets) bay scallop gear that is a successful method in the coldest and storm filled winters in the 1950s and 1960s. Winters were often bitter and storm filled and scallops were in the shallows and therefore “easy” to catch. The use of spotters only eliminated the deep water channel fishery which used push/pull rakes and the deeper “bar” offshore fishery that used scallop drags/dredges. They did not change the cooling of the water or number of strong storms. As the climate cycle moderated the decline of bay scallops was often attributed to over fishing but a warm period 1972 to 2011 did not favor bay scallop habitats.
Bay scallops, abundant during these cold and stormy periods fell to lower levels (catches) that were “poor” in warmer water that contained fewer storms. Several communities went to view box/spotters only (most often to protect eelgrass) but in actual fact, these inshore areas that obtain leaves and organics, bark, twigs grass, etc., it was a poor habitat decision to do this. Scallops prefer alkaline clean and clear “hard” or “firm” bottoms, and fall/winter scalloping helped “rake the leaves” and swept bay scallops habitat clear of this compost. Storms do this very well; of course naturally.
Warm and low energy periods mark expansive growths over time of eelgrass which traps more leaves as eelgrass meadows rise. This changes the bottom to a sulfide rich Sapropel deposits (commonly called black mayonnaise) with a rich eelgrass growth cover and actually hurts shellfish habitat quality – even for bay scallops.
The questions about shortening the season, it is of little biological/fishery consequences. Only a small percentage of scallops, (around two percent) live long enough to spawn twice. Most of the fishery are post spawned adults (raised growth ring) and saving them is of little management concern. The only time a shortened or suspended season might be necessary if scallops were freezing on the boats and to protect seed, the scalloping (season) is suspended and then returns with warmer temperatures.
Imports of seed scallops or moving seed to deeper water are the best management options at this point and eventually reinstating a deep water fishery (a return to towed dredges) in offshore locations and lessening Sapropel deposits if at all possible.
Many questions still remain about the habitat services of eelgrass to the bay scallop. In times of cool water and high energy seed scallops will set on clean, slime free eelgrass blades free of mold. In times of heat however eelgrass can form a peat Sapropel with organics and foster a deadly sulfur cycle which in time actually helps end a successional pattern that reverses with bay scallops. In times of the greatest eelgrass coverage historically coincides with low bay scallop abundance.
I respond to all emails/questions at tim.visel@new-haven.k12.ct.us
Tim Visel
The Connecticut Career and Technical Education System has issued Agriculture/Aquaculture Performance Standards and Competencies. These performance standards are from the 2015 edition issued from the Connecticut State Dept. of Education Academic Office. The IMEP #60 (The Blue Crab Forum™) has the following ASTE standards referenced.

AE #6 Identify environmental factors – temperature, salinity, ammonia, nitrate, nitrite, dissolved oxygen and pH.
AE #9 Define non infectious diseases, including those from environmental conditions.
A-17 Describe the function of Regulatory Agencies as related to Aquaculture
NRE #4 Identify ecosystems structure in terms of food web, biodiversity and carrying capacity.
NRE #9 Describe process of ecological habitat succession.
NRE #14 Identify water quality indicators pH, temperature nitrates, nitrites ammonia, dissolved oxygen and turbidity.

Capstone Questions:
1. For over a century, agricultural researchers had studied the formation of peat and the chemical characteristics of organic peat once sealed off from atmospheric oxygen. (This is the same reason why terrestrial composters even today “turn over” composts to introduce oxygen to assist bacterial decomposition). Eelgrass Sapropel seals the organic deposits below from oxygen helping the sulfur cycle form, which is toxic to sea life. The recent eelgrass literature does not mention Sapropel/sulfur cycle impacts – Why?
2. The U.S. Fish and Wildlife Service conducted numerous experiments to replant/restore eelgrass to assist some coastal waterfowl (Brant) that now starved as eelgrass wasted away in the 1940s. However, many of these eelgrass restoration efforts then failed, and now are suspected of replanting into “black bottoms,” those areas that contained marine Sapropel. Sapropel as a habitat type that is not mentioned today in recent research. The terminology “sediment” is used and not terrestrial soil classifications. Do you think marine soils should be classified?
3. The law of habitat succession pertaining to terrestrial plant dominance is accepted as a guiding principle and understanding of opportunistic characteristics and cyclic dynamics of ecosystem change. Plant dominance and the role of grasses in sustaining soil bacteria was also subject to agricultural research as “soil inoculation” from the high levels of bacteria living below grasses. Soil bacteria was crucial to the first plants under grasses that moved into soils once stripped of vegetation covers. This occurred slowly after very “hot” forest fires that burned the soil, itself killing off the beneficial bacteria. Once soil bacteria recovered plants could grow again. What is the foundation of marine habitat succession and what role (if any) does eelgrass have in a marine/peat bacterial successional process?
Nature hates a habitat void – this is something I recall from my oceanography and marine science classes at the Florida Institute of Technology at Jensen Beach, Florida. When a habitat niche opens, nature seeks to fill it. Although this is easy to see with the effort and energy needed to maintain a grass lawn monoculture (i.e.; lawn mowing) and what happens when that energy stops (i.e.; cease lawn mowing in August), grasses now grow until trees appear. I stopped mowing a section of my backyard in 2013 and the black locust trees are now over 20 feet high in the unmanicured section. Land habitat succession is still occurring and is quite noticeable. That is why the concept of constant habitats (mapping) in shallow estuarine areas not being subject to terrestrial climate patterns and energy from storms is not correct, and in some cases, false. This is why habitat maps are merely point-in-time reference pictures. Come back in 50 years with or without energy and the habitat picture (snapshot) will be different. Withholding energy actually quickens habitat succession for both terrestrial and marine habitats in many instances.
After a careful examination of the habitat for bay scallops Argopecten irradians, and a review of some historical reports, you get two basic parameters, cold and energy/storms. This is quite opposite from what farmers want – stable, dependable habitats with little energy, except rainfall, of course. It is different for the bay scallops, and cold helps explain why today the bay scallop’s genetic clock does not match its habitat clock. It lives beyond its first spawning event, competes for food and space in direct habitat competition with its young. This has perplexed scallop biologists and researchers for over a century, but I feel it is a climate factor that largely explains this bay scallop question – it is not cold enough. Cold conditions tend to saturate oxygen levels, allowing nitrates to nourish algal strains that live in very cold water. Cold water may have produced a longer hibernation period over the winter – a state of dormancy that allows it to live longer. Presently, adult scallops do not reach a second spawning period, and the fishery is sustained by post-spawned adults.
Cold and Energy
Bay scallops prefer cold, energized, cultivated habitats – soft, sulfide/ammonia discharges are not preferred (nor ammonia algae). Instead, scallops thrive in nitrate-rich cold waters, the nitrate that feeds nutritious algal strains rich in calories required to grow quickly and spawn when mature. It is the cold habitats that contain oxygen-requiring bacteria that reduce organic matter quickly and, in the process, add nitrate to the water column for marine plants. In very cold waters, the metabolism slows down and perhaps scallops would proceed to a dormancy stage, but unable to do so in warmer water and perhaps explains the difference in the life cycle. In extremely cold water, I feel more bay scallops could spawn twice (unconfirmed) when summers are short and winters are very cold.
Energy Periods Show the Highest Crops
It is difficult for most people to understand that storms that are so destructive to shoreline features produce more bay scallops. It goes against popular beliefs and values that such energy is only “bad.” This is not true for the bay scallop in southern New England. Cold and storms undoubtedly damaged structures, washed away beaches, and even killed people, but the highest catches of bay scallops occur during and after these events.
When you compare catches of Connecticut bay scallops, you see distinct peaks – the Portland Gale of 1898, the November 26 - 27, 1898 Hurricane that sank the City of Portland steamship, killing all 192 persons aboard. The Connecticut 1899 bay scallop crop was approximately 10,000 bushels. The Great New England Hurricane of September 1938 had a fall crop of 50,000 bushels. The 1955 hurricane season for Connecticut, which had two major hurricanes, Connie and Diane, only eight days apart on August 12, 1955 and August 19, 1955, produced a crop of 72,000 bushels (The Connecticut Commercial Bay Scallops Landings, 1887-1965, State of Connecticut Marine Research Management Plan, 1984, Blake et al.).
This matches accounts on Cape Cod as well. The coldest, storm-filled winters produced the best bay scallop crops. If the association of climate energy produces better crops in cold, one might ask if a cold/energy-filled period provides better habitat quality conditions for the bay scallop, and that fits as well. Bay scallop fisheries hold onto the northern ranges longer than those in more southern ranges and the warmer Long Island Sound. In heat and relatively storm-free periods, bay scallop catches diminish or stop. This has a chemical signal for habitat change and sub-tidal successional attributes as well as that of bottom cultivation. Two pathways for energy exists, hurricanes tend by the energy they create, clean, and re-cultivate marine soils. The “harvest” energy is similar to lawn care and comes from fishery practices. It tends to help keep habitats from succeeding by the energy used in the harvest process. It is ironic but the use of scallop drags (dredges) actually helps scallops’ habitats – they tend to prolong their habitat quality when a warm pattern occurs.
In many ways, hurricanes are forest fires in the marine environment, but necessary for habitat renewals. When bay scallopers tow scallop dredges, they act to help thin eelgrass, remove dead organic waste, loosen separated blades and any terrestrial debris, leaves, twigs, and bark. Removing this or disturbing this organic compost helps oxygenate it with alkaline seawater. This tends to “sweeten” marine soils. Reduce the harvest energy (or lawn cutting of terrestrial grass) and habitats tend to “grass over.” They become fouled, softened, and in high heat, black. Dense thick eelgrass is actually a negative habitat factor for bay scallops. Many fishery managers believe that minimizing harvest energy is a positive fishery management goal. In this case of low energy and warm temperatures, this has an opposite effect. It helps end bay scallop habitats.
Harvest Energy Can Be Positive
An example of this can also be seen in the hand-hauled otter trawl (small boat trawl nets in the salt pond winter flounder fishery) when winter flounder catches declined as waters warmed; otter trawling was prohibited and habitats succeeded faster against winter flounder. Otter trawls had, in fact, doubled as a leaf raking activity similar to “turning” terrestrial organic composts. When that energy stopped, salt pond bottoms that had been clear now became “foul bottoms.” Sticks, leaves and grasses accumulated sealed organics from oxygen, decayed and then soon formed a sticky blue-black organic compost Sapropel (called black mayonnaise) toxic to larval marine life. Rotten egg, sulfide smells increased from Cape Cod salt ponds in August, toxic to sea life forms (Visel, 1980s, Personal Observations of Green Pond, Cape Cod).
The banning of hand-held otter trawls in the 1970s and the 1980s in an effort to promote conservation actually helped winter flounder habitats fail faster. (It was the same energy impact of stopping lawn cutting to ensure that grass would not grow?). These banned areas soon contained eelgrass Sapropel, which in time, turned to an eelgrass peat when in high heat generated ammonia and sulfide from sealed Sapropel “composting.” Small boat fishers that before towed otter trawls and hand-hauled bay scallop dredges soon noticed that the amount of time “picking sea weeds” or sorting “rubbish” increased from the catch. What used to be clean or clear bottoms now held sea lettuce, and attached eelgrass blades now collected in areas of little current sometimes feet deep.
This change in the eastern Long Island salt ponds and coves was observed in 1975, When I presented at the New York Fishermen’s Forum in 1979, about small scale, in-shore fishing gears including trawls, I was surrounded by bay men who had noticed what I had been observing, a rise of Sapropel on bay bottoms. When otter trawling was banned, they noticed that these deposits now were growing rapidly, some in the remaining hard shell clam habitats as well (See Blue Crab and Marine Bacteria #12 Blue Crab Forum™ June 2, 2016 environmental/conservation thread).
A reduction in harvest energy (i.e.; scallop dredges) actually works against habitat quality. Although much has been written about the positive habitat services of eelgrass, in times of heat, the biochemistry of eelgrass peat (Sapropel) now favors the deadly sulfur cycle. The warm water now supports the sulfate, reducing bacteria below the eelgrass, and below its roots sulfuric acid. Sulfides build up sealed from oxygen to toxic levels and purge into the water column. This is the source (sulfur cycle bacteria) of the black water deaths of the last century and the source of ammonia that supports the often toxic, harmful algal blooms, called HABs.
Eelgrass has a very complex habitat history in New England. In times of cold/energy it moves into cultivated marine soils and suffocates bivalve shellfish, oysters, and clams. In heat it helps build a marine compost Sapropel which fosters a deadly sulfate sulfur cycle – the production of ammonia and periodic releases of sulfuric acid. When oxygen is available (cold periods) its habitat services are quite different, and positive to species that find shelter and forage in it. When oxygen is limiting (hot periods) it fosters the formation of Sapropel and what fishers term a “black mayonnaise.” It is in this “Acid Sulfate Soil” that occurs in peat and below eelgrass/Sapropel in the marine environment the sulfate reducing bacteria and the disease causing Vibrio bacteria (See the Blue Crab Forum™ Environment Conservation Series reports #1 to 14).
This information is rarely presented in the recent eelgrass literature, a form of research (science) misconduct termed “citation amnesia,” “the forgetting” of research that often does not support agenda-based outcomes. Most likely, the largest example of this, as evidenced in the current eelgrass literature, is the absence of the sulfur cycle below eelgrass peat meadows. This was known a century before that eelgrass could build a peat, and in warm temperatures, change the chemistry of the soils with sulfur as meadows rose in elevation. The association of peat building and the buildup of hydrogen sulfide and the potential for sulfuric acid has been studied for over a century. This is a turn of the century report of the New York State Museum (1902) that both mentions the role of eelgrass gathering organic material and forming a peat (salt marsh). It also mentions the same hydrogen sulfide and sulfuric acid formation impacts which it termed “harmful” even then.

Documents of the Senate of the State of New York 1902
55th Annual Report New York State Museum including the reports of Administration and Geology – Paleontology Botany, Entomology and Archeology
Report of the Director and State Geologist 1901
Vol. 21, No. 38
Albany J. B. Lyon Company State Printers
“Marine Marsh Soils – These form a special type, which is found to some extent along the seashore. They are formed by the accumulation of fine mud in sheltered or quiet waters long the coast.
On this mud flat there springs up a growth of eelgrass which serves to entangle more mud and organic remains, thus raising the general level of the flat and on this raised surface land grasses and plants spread out forming a marine marsh.
The task of reclaiming soils of this type is by no means difficult, as has been pointed out in a circular (No 1) recently issued by the Division of Soils of the Department of Agriculture.
These salt marshes are usually underlain by silt and clay, and may be covered by a foot or so of grass growth. Soils of this type are not usually in need of lime because they contain more or less shell fragments.
If this be lacking, the soil is apt to be too acid, this being natural or due to the decomposition of organic matter, such sourness may be counteracted by the addition of lime.
Iron sulfide may also be present, and by its decomposition may yield hydrogen sulfide, soluble ferrous iron compounds, or sulfuric acid, all of which are harmful. The hydrogen sulfide may be corrected by aeration, but the ferrous iron has to be changed by similar treatment, with the addition of lime.”
The knowledge of the sulfur cycle below marine grasses has also been reported by those researchers that attempted to restore eelgrass after the 1930s die off.
This is an excerpt from a bulletin (1980) U.S. Army Corps of Engineers titled “Planting Guidelines for Seagrasses” by Ronald C. Phillips coastal engineering technical AID No. – 80-2 February 1980 Coastal Engineering Research Center, Kingman Building, Fort Belvoir, VA 22060, 30 pages. Contact # DACW72-79-C-0030 released for the public Ted E Bishop Colonel, Corps of Engineers Commissioner and Director.
This section mentions the sulfur cycle and the results of sulfate (sulfur) reducing bacteria – (dead leaves, wood, tissue, yard waste, grass, and bacterial reduction without elemental oxygen – T. Visel, pg. 25).
“Seagrasses appear to maintain an active sulfur cycle (Wood, Odum, and Zieman, 1969). An accumulation of detritus leads to anaerobiosis below the sediment surface, and an abundance of sulfur bacteria lead to this cycle. The thin oxidized sediment surface promotes sulfate accumulation, but sulfides are produced in the lower layers. Fenchel (1973) found the decomposition of material in the underlying anaerobic sediments slow but favoring the release of mineral nitrogen phosphorous and readily assimilable organic constituents.”
It is the sulfate reducing bacteria which thrive in high heat below thick eelgrass growths. It is natural that in cold oxygen-rich waters after a storm, marine soils rinsed of sulfides sustain new eelgrass growth. It is also natural that in long heat, this process reverses and eelgrass dies off. In high heat, observations often mention the occurrence of “black spots” on eelgrass blades. This is a comment about a similar species turtle grass from (Phillips 1980). Wood and Ziemen (1969) reported about a similar species, turtle grass: “Blades of turtle grass formed large necrotic and discolored areas when stressed by high temperature. Persistent thermal stress resulted in the loss of leaves and eventually raised sediment temperatures by heat conduction. Higher sediment temperatures increased the respiration of rhizomes and caused the complete collapse of the stressed populations (pg.24).”
In other words, in times of high heat, it is natural to observe the “die off” of seagrasses, such as eelgrass. Alternatively, when the energy increases and waters cool, we observe the spread of eelgrass to the upper portions of bays and coves. In heat the retreat to habitat refuge of cool and more energy containing waters at the mouth of estuaries. If the heat and lack of energy continues long enough even these eelgrass populations will die out – leaving a blue-black deposit mentioned by Nichols 1920, (Torrey Botanical Club).
Bay scallops set heavily after storms, sensing perhaps the “bleeding grass syndrome” of ripped or torn coralline red algae. That is coralline algae provided a chemical scent that attracts scallops, signifying a more alkaline soil. Scallops may set on eelgrass, lacking any other suitable surface, because the eelgrass and bay scallops’ habitat clocks overlap. In fact, renewed attention is now being placed on the chemical and biochemistry of eelgrass/Sapropel in high heat as a distinct negative habitat factor, not a positive habitat factor now found in much of the eelgrass literature.
Some may feel that high bay scallop crops occurring in cold and storm-filled periods is just a coincidence; it is not – my view.
Tim Visel
The Niantic River Bay Scallop Fishery
In 2006, I presented a paper at the NACE conference about winter flounder habitats. I was researching the connection between temperature and energy for the rise and fall of several New England Fisheries, including winter flounder and a developing proposal to gather together records of historic fish and shellfish catches (USF&WS) habitat observations (largely from those in small boat fisheries), historical climate records from USDA and topic related state and federal literature. In the mid-1980s, I became aware of eelgrass habitat and replanting projects in the 1940s and 1950s, by the US Fish and Wildlife Service. They also ran into “black bottoms” and marine soils that were “unsuitable” habitat wise and many of these programs to transplant eelgrass failed during this period. These eelgrass efforts were largely supported by wildlife agencies that managed waterfowl as eelgrass was an important food for ducks, especially Brant. (USF & WS).
I was amazed as to the interest around this particular marine subtidal plant – eelgrass Zostera marina - that it was a premier habitat type worthy of special attention and protection – above that of bivalve estuarine shell or cobblestone kelp. On Cape Cod, I had participated in several habitat surveys (Buttermilk Bay) and on hot August days, eelgrass meadows had sulfide smells and fish fled from these areas (T. Visel) Eelgrass in high heat was a hostile habitat in shallow soft bottom growths and eelgrass frequently grew over previous habitat types including estuarine bivalve shell. Clinton Harbor, CT observations (1978)* See Appendix #1. After a bay scallop seed transplant into the Clinton Harbor near eelgrass on the north side of Cedar Island George McNeil told me that the area was once a soft shell clam bed about 3 feet below. Upon closer examination the eelgrass peat had accumulated over a once very productive soft shell clam bed. By the time, I started working on Cape Cod in 1981 I had a very different view of coastal energy and the opening and closure of barrier spits such as the one at Clinton Harbor called the Dardanelles (see Clinton Harbor and The Great Heat IMEP #24 Blue Crab Forum™).
My habitat research into estuarine habitats had come to the opposite view regarding the soil chemistry, Sapropel and sulfides associated eelgrass was at times toxic to sea life. These Sapropel sulfides had in my research negatively impacted winter flounder habitats as well. Although I had seen eelgrass in cold water in Maine, and in warm water in New Jersey, the habitat history of eelgrass in New England was very mixed and complicated. Eelgrass by its characteristic natural biology is an aggressive grass or peat building plant that stabilized marine soils and in the process changed both the physical and chemical characteristics of these marine soils. Over time, nearly one hundred percent of the time eelgrass meadows had, at some point, damaged shellfish habitats that is why I was so concerned with all the excitement around eelgrass. The New England history of its impacting shellfish habitats did not match the presentations or much of the emerging research literature. In fact, it was opposite much of the past historical records and shellfishing experiences / accounts given to me by those still or once involved in shellfisheries. In fact, as a whole, I would say that shellfishers despised it. This bothered Nelson Marshall who years later after his paper on the Niantic River Bay Scallop Fishery had doubts about eelgrass and its role in the Niantic River bay scallop fishery (Tim Visel, University of Rhode Island conversations). One of the best examples we have is to study previous habitat types and the impact of heat and energy (climate patterns) upon the bay scallop is the Niantic River Bay scallop fishery (my view). The Niantic Scallop Fishery is an outstanding case history study for the following reasons,
1. There is historical research available for the negative eelgrass impacts (tidal restrictions – changes in bottom substrates) (Nelson Marshall’s comments about bay scallop is returning after eelgrass had in fact actually died off).
2. Research and observations on scallop setting on eelgrass as well as “blade attack” from green crabs and starfish predation programs conducted by the Waterford East Lyme Shellfish Commission.
3. Some oral history exists from the bay scallopers themselves and perhaps more in the Waterford East Lyme Shellfish Commission files – state and federal projects to replant eelgrass at first in an effort to save the Brant population which as eelgrass died-off was then starving were conducted by the Fish and Wildlife Service with state assistance in the 1940s and 1950s.
4. The biochemistry of peat builders (marine grasses) including sulfide generation is now being made available to the public (mostly from overseas research in Denmark) US F W S – projects to replant eelgrass often with state cooperation in the 1940s and 1950s may provide important information. (Information obtained from State of Connecticut Marine Fisheries files).
Following the 2006 NACE conference, I was concerned with the “eelgrass hype” and wrote a report up for Dr. Sheila Stiles about a workshop I had in Niantic following eelgrass die-off’s in the mid-1980s. This write-up is now IMEP #7 posted on the Blue Crab Forum™ on February 25, 2014. I also want to acknowledge the help from retired Niantic area bay scallopers who provided information to me in the early 1980s about the 1940s, 1950s and 1960s Niantic River bay scallop catches and fisheries.
In the middle 1950s in the midst of a very cold and energy filled period, Bay scallop catches here soared while river bottoms were clean and free of eelgrass and bay scallops set heavily upon “red weed,” what Niantic River scallopers then called and mentioned to Dr. Marshall was the real “scallop grass” most likely a coralline red algae, not eelgrass. (This was the concern that Nelson Marshall mentioned to me at the University of Rhode Island. He tried several times that being from Connecticut and so close to Niantic, to point me towards my master’s work in the Niantic River bay scallops instead of oysters, but I was more interested in oysters at this time. So my primary study area would remain the Oyster River in Old Saybrook). At one of the marine advisory service shellfish workshops, I had a retired bay scalloper reach out to me for a “private meeting.” Curious I agreed. This is the write up for Dr. Sheila Stiles of the NOAA Milford labs in 2006. The account matches many habitat observations’ of historical reports in New England during 1880-1920 period - what I term the Great Heat . This climate period was to greatly impact coastal inshore fisheries, eelgrass overran deep water Narragansett Bay scallop habitats (detailed in US Fish Commission Reports) a die-off of the Southern New England lobsters around or between 1898 to 1905 and a surprising, sudden increase in blue crabs by 1912. Fishers told of black bottoms and black waters, shallow waters that smelled of rotten eggs and fish kills were common during this period. (See Blue Crab Forum™ IMEP #52 Narragansett Bay Deep Water Bay Scallop Habitats 1870s posted July 27, 2015 Fishing, Eeling, Oystering thread).
The colder and storm-filled 1920 to 1970 bay scallops returned to Niantic, Connecticut: climate patterns began to change in the 1920s, by 1922-1924 Rhode island fishery managers were shocked by the bitter winters and now a surging bay scallop population. They were surprised to see so many bay scallops, considering the severity of the winters. The problem was bay scallops thrive in cold and energy (frequent strong storms) and bay scallops “returned” to the Cape and Rhode Island into the 1920s as colder more storm prevalent cycle transitioned habitats in more northern cooler waters first. (See Blue Crab Forum™ The Rise of Sapropel – Fall of Bay Scallops 197-2005 IMEP #14 posted March 24, 2014, Fishing, Eeling, Oystering thread.)
I suspect that shellfishers here in CT were disappointed with New England’s climate, with bay scallops returning to the north (with cooler waters first) bay scallops were after all, an “inshore” fishery – making those fishers with small boats an income opportunity. On Cape Cod, Scallops were known as the “Christmas Crop,” arriving in late fall in time for seasonal gifts (despite what appears in current literature, scallops are good swimmers. The historical literature contains many mentions of “scallop schools” before and after storms. Each fall on the Cape, small boat fishers waited in anticipation for scallops to come – to swim into bays and coves and this was often sudden (strong storms or bitter cold, the best indicator signal) and often they would “leave” bays and coves just as quickly. This led to some strong conflicts on Cape Cod as overnight bay scallop populations moved to a different town or across a town boundary. Although fishery managers strived to convince fishers, bay scallop movements of this magnitude was not possible, actually perhaps to minimize conflicts over town “ownership” records and historical accounts prove otherwise. They can swim and move generally with tides and storm driven currents, but the historical literature is filled with reports of sudden arrivals, even the sound of closing shells “clicking” sounds at night during such moments on Cape Cod. (Many comments T. Visel including John Farrington, Cape Cod 1980s).
Bay scallops need cold water nitrate algae and some references maintain that perhaps the populations were at times so large they consumed all the food in an area, a type of marine locust in search of better feeding opportunities; they would move. Others felt storms drove them into safe harbors and such movement is also mentioned before a Nor’easter. These fisher reports were frequently “dismissed” by researchers until more recent studies of the filtering (eating capacity) of oysters. It is now thought that at times shellfish ran out of food which had prompted nitrogen studies in the 1890s. The movement of adults from deep waters to shallow was mentioned to me by several Niantic River scallopers in the 1980s and those also on Cape Cod. As waters cooled and the fall storms increased scallops with “clean” no bio fouling shells moved inshore.
The return of the cold and energy in the 1920s to 1930s was a climate cycle known as the Northeast Atlantic Oscillation (NAO). The 1930s led to a period of numerous hurricanes, sudden warming followed by cold spells and increased coastal energy. This created much “habitat instability” benefiting shellfish that can move and bay scallops now filled a habitat void as oysters and hard shell clams were buried by shifting sand, or cast upon the beaches. Seed scallops now washed upon sandy beaches filling with sand and freezing – hundreds of thousands of bushels of seed scallops perished this way. This period also coincided with a large national policy change, “Prohibition” (1920-1933) which made the movement, production and sale of alcohol against the law. i.e., the era of Prohibition. Within a few days of the act, some coastal coves suddenly became very busy places and many of the observations mentioned to me in the 1980s --seeing schools of scallops on the surface at night were made during this period.
As nighttime navigation increased to also the observation of scallops moving at night just before dawn, this matches some of the accounts on Cape Cod in the evening there was no scallops but by daylight the cove was now filled (many similar accounts).
These nighttime observations for obvious reasons were kept “quiet.” During that time nighttime observations of bay scallop movements wasn’t something you proclaimed for the neighborhood (enough said). Many small boat fishers often found “overtime” transit employment opportunities at night and soon seafood trucks began appearing to take “bay scallops” north to Boston, but on the return trip from time to time, a few tens of bushels of seed scallops on the return run back to the Niantic River. The seed program was to jumpstart a bay scallop fishery here as well, many fishers were aware of the seed oyster industry and the knowledge that oyster industry often mixed up adults from many areas and transplanted them as a mix to “help the set.”
[Oyster companies often collected and transplanted spawners from different locations to “improve the sets,” an early agricultural genetics effort – and mentioned to me by some retired oyster growers as “spawner transplants” including George McNeil, John Hammond and J.R. Nelson}.
It Wasn’t Eelgrass-
The special trucks from Boston keep coming until 1933 – and a few bushels of seed of and on for the same period. After 1933 these trucks stopped and so did the seed program restrictions of harvest seed). However, by 1933, the eelgrass had died off and circulation (flushing) in the Niantic River now improved and “scallops returned”. (Seafood trucks did continue for years beyond 1933 as now Niantic Bay scallop seafood popularity increased). This is a section of Nelson Marshall’s report on bay scallops in the Niantic River (who I would see at graduate student meetings at URI) - Bay scallops returned after the eelgrass died off – after a fifty year cycle which dated back to the 1880’s.
Nelson Marshall
Narragansett Marine Laboratory, University of Rhode Island, Kingston, Rhode Island

“The disappearance of the eelgrass, Zostera marina, with the epidemic of the early 1930s permitted better circulation near the river bottom. Apparently this was advantageous to the bay scallop, which thereafter became the predominant sessile grazer with a production calculated at 2.2g C/m2/yr. Anchorage previously offered by eelgrass for the early setting stages of scallops was subsequently available through the abundance of small branching algae.
In an earlier paper (Marshall 1947), I attempted to show that the local scallop population had been sparse and had suddenly increased to an abundance which supported a new fishery after the eelgrass disappeared. Doubts raised from the recollections of others as to from when the fishery developed prompted me to check the accounts of the early fishery in the archives of the New London Day, Write-ups of the fall of 1934 and to early 1935 emphasized the developing fishery. Consistent with these accounts and the dates thereof is the legislation of 1935 establishing the Waterford-East Lyme Escallop Commission. Thus the association in time between the development of the scallop fishery and the disappearance of eelgrass in the early 1930s is well documented. Well over half the take was in the first two months, October and November of the six-month season. The take was primarily from the shallows downriver.
Scallops are abundant elsewhere in the estuary and do well in the deeper water though restrictions against the towing of gear has made it difficult to fish much beyond the shallows.
In natural setting the scallops attached in quantities to most anything, including the frayed manila rope which had not worked effectively for the counts. It was evident that the small branching algae, observed to be very abundant throughout, the river, were heavily laden with attached scallops. In this connection it is noteworthy that fishermen of the Niantic River refer to such algae as scallop grass.”
Note- The use of spotters view box and dip (ring) nets had to rely upon water clarity to see scallops in the shallows, usually after the first two or three “killing frosts” around December. These were used to catch the shallow water scallops – too shallow to maneuver dredges. If waters were warm or (algal blooms) cloudy with the presence of storms this method could not be used. (Waters could not be cloudy and scallops generally prefer deeper waters absent of predators – seagulls and crabs) and here instead deep water “push pull” rakes were used. Towed dredges were for the offshore bars and the deeper channel bay scallops.* There was in fact two bay scallop seasons the deep water after spawning in October, and the late shallow season as cooler water happened and strong storms drove scallops into the shallows where the waters now clear – from algal die-offs (December). Seed scallops did live in shallower water and these storms were often the cause of seed driven up on shores and many accounts of this occurring in the historical literature can be found.
*Scallops often aligned east to west between the sand bars offshore – or edges. These bars often contained eelgrass meadows River beds (channels) the same way only north/south (Ben Rathbun, personal communication T. Visel 1980s).
Although much has been written about the damage to eelgrass from scallop dredges, they are, in fact, able to extend not reduce both eelgrass and bay scallop habitat quality – most of the negative viewpoints are based upon visual observations, they do in fact rip up blades and weak eelgrass plants, but this is the equivalent of thinning overgrown rows of carrots and other agriculture examples mentioned to me several times on Cape Cod – the problems of eelgrass is when it becomes too thick, as mentioned by John C. Hammond, a retired oyster grower in Chatham, Mass. According to Mr. Hammond the process of scallop dredging helped “thin out eelgrass” like a lawn grass monoculture, oxygenated its roots and provided some good space for healthy plants to grow while reducing toxic sulfides. (This thinning aspect happens in a dramatic way during storms of course). Mr. Hammond a retired oyster planter described an incident in Chatham, Mass, from the 1960s. I described this account in an IMEP newsletter found on the Blue Crab Forum ™ November 25th, 2014 titled: “Habitat Discussions with John Hammond and Cape Cod Shellfishers 1981-83” on the Blue Crab Forum™ Fishing Eeling and Oystering thread.
“The fact, Mr. Hammond stated, is that shell fishermen are the eyes and ears for the environment, while people see us harvesting shellfish, they don’t understand the habitats that provided it and that shell fishers do. Every time we breach (a new cut into Monomoy) we get great clamming. Why? because the ground has been prepared, cultivated for soft shells by waves, the flats set heavy and then slowly go hard, the soil gets packed and muck covered or “soft” –nothing is better than clean loose sand. He had seen this several times especially after storm caused breaches. Fishermen can only harvest what has set, as the ground will again go soft. But today, from the 1950’s to present, it was happening quicker, and heat was the reason the nitrogen was the result. He had seen it in Chatham and told me a couple of stories. Several years ago, we had a scientist from Woods Hole come out here and tell us that eelgrass was good. We agreed that some eelgrass was good*, clean sandy areas it would hold large quantities of fish, they liked the food in the coves and the structure. Scallops too, would be next, the eelgrass which he felt helped them from being swept out by the tides. Concerned about scallop dredges damaging the eelgrass, the town (Chatham) voted to conduct scalloping with “lookers” and nets, view boxes that were used at other areas. What they didn’t realize (the shell fishermen knew it) that the process of fall scalloping had become largely a grass cutting operation, as they picked through a larger and larger amounts of it, eelgrass searching for the prized delicacy. The overgrowth of eelgrass was removed as a byproduct of the scallop fishery (similar to mowing a lawn). The first thing they noticed after the change was that there was so much eelgrass and leaves, marsh grass, they couldn’t see any scallops, only the clear areas, those free of eelgrass were productive. Eelgrass which had been before cut free and drifted out with the tide, died off as usual but then stayed, piling into windrows (holding the bottom, by the second year eelgrass was so thick it stopped outboard motors, it was rotting over the bottom producing a whitish bottom which Mr. Hammond called composting). *(It is Mr. Hammond that described the “clean and green” eelgrass as he had watched it turn into the “brown and furry.”) By the second year, fishermen convinced town officials to reverse the no dredge policy and excess eelgrass was removed by the scallop fishing. What fishers had described was habitat succession and eelgrass is highly aggressive in shallow low organic marine soils.”
It is at the end of the Great Heat 1880-1920; that sulfides and sulfuric acid destroyed eelgrass roots and weakened that plants that now often had fungus and mold diseases. As eelgrass died off a long natural cycle, its Sapropel below was exposed to powerful storms. In actual fact, the publicity effort around eelgrass habitat services started in the 1940s by the US Fish and Wildlife Service when eelgrass died out in the late 1930s; it was at an end of a long habitat cycle started in the 1880s. After the brutally cold 1870s, when powerful storms scoured estuaries. Eelgrass moved “up” into estuaries. Eelgrass meadows now grew dense and dominated habitat coverage 1890-1910 often covering hard and soft shell clams, suffocated oyster beds, and causing bay scallops to starve into the 1890s. When the climate cooled, sulfides under eelgrass peat weakened it to point that it was open to fungal and mold infections. It “rotted” or “wasted away” (US Fish & Wildlife Service program personnel used the term in the 1930s ending a period of habitat dominance).
When that happened the thick eelgrass meadows in warm open waters that grew (1890-1910) now receded or wasted away. Brant (geese) populations rose along with its primary food- fodder eelgrass in the 1900s. When eelgrass died off from sulfide buildups to mold, and fungal disease, Brant by the tens of thousands starved to death as eelgrass died- off USFWS staff went in to detail how important eelgrass was to Brant (which is accurate) but with bay scallops, the opposite occurred, in times of eelgrass abundance was actually poor years for bay scallops –bay scallops thrive in cooler more energy storm filled periods. The dredging or dragging of scallops gear actually helps keep bottom clean or clear. The “cultivating” aspect of freeing organic debris helps prevent sulfide formation. Heavily fouled bottoms become these that contain an eelgrass Sapropel deposit that actually harms bay scallops habitats; gives rise to sulfide “black waters” and black water deaths (fish kills). The biochemistry of eelgrass peat in high temperature and low energy periods has not been fully explained to the public. However, the information about eelgrass peat and the sulfur cycle reactions in it have been known for over a century. This includes eelgrass as a peat builder, raising soft bottoms over shellfish, creating conditions for toxic sulfide and sulfuric acids. In fact after a review of the historical fisheries literature, bay scallops prefer bivalve shell, clean sand and clean pebbles with coralline algae to set not acidic eelgrass peat. It is the eelgrass habitats so important to the green crab that is a major bay scallop predator.
When eelgrass and bay scallops habitats reverse they overlap, and gives the appearance of habitat significance but period of peat eelgrass dominance is marked by low bay scallop populations /fisheries)
In scalloping on Point Judith Pond, 1978-99, I talked to a group of scallopers who were deliberately setting into eelgrass beds – when questioned they said very thick eelgrass growths were bad for bay scallops and at the time I disagreed, but now decades later I realized that eelgrass was a peat builder and had the ability to transition alkaline bay bottoms (high pH) to new acidic (low pH). In other words, these scallopers were correct, very dense eelgrass was in fact, a poor scallop habitat as mentioned in the historical literature. It will be very difficult for coastal residents, seafood consumers and even some bay scallopers to understand that thinning and at times, removing eelgrass/Sapropel is actually beneficial. Restoring tidal flows and keeping sulfide levels low is one of the few methods we use to restore bay scallop habitat. (IMEP #46 describes the Anthiers Pond, Edgartown (Clyde MacKenzie account Bottom Disturbance and Habitat Quality last history posted Blue Crab Forum™ February 5, 2015 Fishing, Eeling and Oystering thread).
For example, Clyde MacKenzie, Jr. a shellfish biologist, NOAA National Marine Fisheries discusses the bay scallop habitat preference of deeper channels. What scallop fishermen noted decades ago is described by Dr. MacKenzie in a 1989 Marine Fisheries Review article titled, A Guide for Enhancing Estuarine Molluscan Shellfisheries.
“Only one known attempt has been made to increase the abundance of the bay scallop through environmental improvement, and it occurred in Anthier’s Pond, Martha’s Vineyard, Mass., in the early 1970’s Bay scallops were relatively scarce over a section of the pond because the water was too shallow. The town dug a channel through the scallop bed 2 meters deep. In subsequent years, the bay scallops were relatively abundant in the channel as compared with the remainder of the bed. Although other options were available, the town chose the scallop bed as the site to take the sand for beach enlargement in an attempt to increase bay scallop production.” (See Town of Edgartown Shellfish Management Plan (1985) for a project description. [Many biologists have reported that the largest of Bay Scallops exist near edge channels or dredged areas – several reports in Massachusetts (1950-1960) mention the best scallops in deep channels – Westport River – Pleasant Bay, page 598 – Bulleting of the Bureau of Fisheries – James Gutsell – Natural History of the Bay Scallops 1930. U.S. Dept. of Commerce – Bureau of Fisheries Document #1100. “Thus in western Bogue Sound, scallops of good size were found along the edge of the dredge channel north of Loretts Marsh – A few rods away from the channel scallops were of diminutive size usual in this section of the Sound.”]
Energy and the Niantic Scallop Fishery.
The restrictions of scallop dredges have the potential to help eelgrass/Sapropel peat to form – and with that deposit harm bay scallop habitats. As eelgrass meadows rise frequently mentioned in the Massachusetts Fisheries Literature (Belding reports) they trap fall leaves and any organic matter. Eelgrass meadows grow thick in cool waters but that changes with temperatures. In heat over time eelgrass can accumulate vast deposits of Sapropel. Thick soft eelgrass meadows purge sulfides and ammonia in hot weather as they then become nature’s sulfur killing fields. My view, Tim Visel


Marine Advisory Service
University of Connecticut
Avery Point Groton, Ct. 06340

December 5, 1978
Mr. Charles Schroeder
Madison Shellfish Commission
790 Durham Road
Madison, Conn. 06443

Dear Mr. Schroeder:
This letter is to describe our scallop seeding procedure and interest in further investigations on general scallop ecology within the Hammonasset River estuary.
Approximately 10,000 juvenile scallops (5-30 cm. diam.) were provided by the National Marine Fisheries Service - Milford Laboratory, courtesy Mr. Edwin Rhodes as a result of intensive aquaculture efforts on the species. The planting was conducted 5 December 78 in two locations of the Hammonasset River - 5,000 individual Juvenile scallops were broadcast at a site approximately 250 yards WSW of the bulkhead at Cedar Island Marina, and another 5,000 broadcast at a site on the northern bank of the Hammonasset River 50 yards W of the junction with the Indian River. Attempts were made to select hard bottom with evidence of eel grass stands adjacent to the release sites. John Baker, Chief, Division of Aquaculture, Edwin Rhodes, N.M.F.S., Lance Stewart, UConn-Sea Grant Marine Advisory Service, Timothy Visel and Brian Sullivan participated in the seeding.
The cooperative scallop projects (UConn Marine Advisory Service, National Marine Fisheries Service, Division of Aquaculture) have included the coastal waters of Stonington and Groton and we would like to extend our efforts further west along the Connecticut coast to areas that indicate potential for introduction of scallop population. Our future interests would include: dive survey of the estuary to determine prime scallop ground and more general condition of river shellfish resources, attempts to recover scallop seeded in December 1978 for evaluation of survival and growth, future stocking of juvenile scallops (dependent on Ed Rhodes’ hatchery production), research on predator protection enclosure systems to optimize scallop productivity and increase chances of greater broad stock recruitment.
Our thanks for your support in these exploratory activities. I would be pleased to discuss any questions or provide more specific information on the nature of the work we intend to pursue.
Lance L. Stewart, Ph.D.
Regional Marine Specialist
CC: to Mr. Douglas McGuire
Re-Keyed by Susan Weber/Sound School 2016

Waterfowl Tomorrow
Editor: Joseph P. Linduska
Managing Editor: Arnold L. Nelson
Artist: Bob Hines

The United States Department of the Interior
Bureau of Sports Fisheries and Wildlife
Fish and Wildlife Service

Produced by the Department of the Interior with the assistance of officials and representatives of State, Provincial, and National Governments and Private enterprise in Canada, Mexico, and the United States.
L. C. card no. 64-60084

United States
Government Printing Office
Washington: 1964
Brant, Ross’ Goose, and Emperor Goose
The fast, agile, white-bellied Brant once were popular sporting birds along the Atlantic coast. In the early 1930s they became almost extinct because eelgrass, their chief food in winter, suddenly died off due to a disease caused by a Mycetozoan (Labyrinthula)The surviving birds changed foods and the number of Atlantic Brant slowly rose again. Then another untoward event happened. They lost prestige as a game bird because sea-lettuce, the chief item of their new diet, taints their flesh. Now eelgrass is slowly recovering, and Brant once more feed on it. We hope their meat in time will become more palatable.
Another remarkable thing: As Atlantic Brant changed their diet, they also changed their migration routes. By the mid-thirties, about two-thirds of them, no longer dependent on coastal eelgrass beds, were using overland routes in spring flights north, instead of following the seacoast. Most of our 150 thousand to 200 thousand Atlantic Brant today are their descendants; they fly directly to James, Hudson, and Ungava Bays before spreading out to their nesting grounds.
Because eelgrass on the Pacific coast was little affected by the die off, the black Brant suffered less, and they still provide excellent sport and tasty game. They continue their regular migration along the coast and follow the shores of Gulf of Alaska to Cold Bay before heading to the breeding grounds. Pacific Brant number 100 thousand to 175 thousand.
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