[BlueChip]

IMEP #41
Shellfish Habitats Collapse on Cape Cod in High Heat 1974-1984
Different Views about Nitrogen Pollution and Shellfishing,
Climate and Energy
Conversations with John C. Hammond, Chatham, Cape Cod

The Truth about Nitrogen, Part IV
December 17, 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
Shellfish Restoration and Water Quality Project Shellfish Proposal EPA/DEP Habitat Restoration Initiative
Meeting November 18, 2009*
Important Water Quality Issues for Habitat Restoration and Case Study Analysis for the Oyster River, Old Saybrook; Hammonasset River, Clinton and Oyster Pond River, Chatham, Massachusetts
Tim Visel, Committee Member, HRI
The Sound School, New Haven, CT


Preface
I would meet with Mr. Hammond three or four times regarding the Cape Cod nitrogen issue, but mostly talked about climate changes (his term: storm damage) and cold winters that would clear out Black Mayonnaise from shallow areas. Black Mayonnaise would destroy valuable areas of viable shellfish habitats, bring snail fever oyster disease and rot the fins from winter flounder. Everything that Mr. Hammond predicted came true and left a lasting impression upon me that it was vitally important to know about our shellfish history. Most of the interest in climate and temperature impact study today is the results of these Cape Cod conversations. But at that time his records were of storms and breaks in the barrier beach systems. Marine soils would be washed free of organics - “plowed” as he would term it by nature. Shellfisheries needed energy (storms) to renew the soils – similar to agriculture cultivation – storms were nature’s plows and temperature is what decided in the long run what species would win this habitat war. He had folders of papers and clippings that talked about Chatham’s turn of the century soft shell clam fishery (steamers in Connecticut). At this time, it was “hot” and steamers did quite well, Chatham became a high producer of soft shell clams, but in the 1920s, colder winters returned and strong storms soft shells retreated to the protection of coves, but quahogs and then bay scallops increased. It was Mr. Hammond who urged me to look at the 1880 to 1920 period “to catch” the most recent largest cycle. If I looked at the 1880-1920 period, he assured me I would find it. He was able to watch that carefully with (bay scallops) until it started to get hot. Shellfishers quickly¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬ then switched to bay scallops in the 1950s and 1960s as they were doing now with a surprise bounty of Icelandic Scallops on the Cape in several towns. In the 1960s, skiff fishermen fished the bays and coves for bay scallops which were at times extremely abundant – it was colder. Then in 1971, scallops plummeted and shellfishers went from harvesting “Nature’s Bounty” to over harvesting greedy destroyers of the sea. He had watched that happen he paraphrased the following: “We went from hero’s- harvesting scallops for the elderly who couldn’t’ go – restaurants who promoted the local seafood to tourists, or just fish markets to “villains” –the truth is, there just wasn’t any- not at all.” It wasn’t the shellfishers, there just wasn’t any at all. He blamed the decrease in eelgrass for producing sour bottoms and killing the small seed scallops (note this is some creditable reference that sour bottoms was describing deadly sulfide purging and shellfisheries didn’t know or have the language to describe habitat change in scientific terms. I am reviewing all my notes from New York Baymen 1978-79 (Long Island, New York) that “sour bottoms” was in fact the beginning of deadly sulfide purging. Sulfide in the marine environment is many times more toxic than cyanide, that is a bias that continues today- that all bottoms are “good” related to decades old anti dredging disturbance policies and continues today you can find articles that mention sulfide purging but do not mention any toxic effects to fry and shellfish larvae). .
In 1974 as it started to warm in Southern New England, Dick Nelson of Cotuit Oyster Company started purchasing Hammonasset River Seed Oysters; the oyster sets had improved that by 1978 Clinton, Madison and Guilford were drowning in seed oysters, 120,000 bushels of seed oyster from the Hammonasset River alone in 1978 much of it bound for Cape Cod. Several river systems had Black Mayonnaise deposits but some were removed (on outgoing tides) and some buried shell bases exposed – oyster sets were again obtained. For example with Oyster River in Old Saybrook (1981-82). It seemed for awhile that this Black Mayonnaise habitat war was “winnable” provided the correct hydraulic and cultivating equipment and despite the Tom’s Creek closure and Black mayonnaise deposits in other areas of Connecticut and now on Cape Cod I still was optimistic about inshore oyster culture. With equipment necessary to keep these areas clear of organics; it was still viable. By 1981, I would change these views once it wasn’t “people nitrogen” but climate and energy as well. I have Mr. Hammond for much of that viewpoint he wasn’t so optimistic—it termed it a Habitat War that his records showed shellfisheries would lose.
Part IV The Truth about Nitrogen
Shellfish Habitats Collapse on Cape Cod In High Heat, 1974-1984
Introduction
Increasing shellfish closures (from excess bacteria) had generated much public attention. Several people had already contacted the Cape Cod Extension Service about the decline in flounder in clear or clean areas where small boat flounder trawling and scalloping was occurring. This resulted in a letter to Arnold Carr (February 18, 1983) describing the loss of clear areas which were once productive for winter flounder:

“I thought you might be interested in some of the feedback I received after my presentation at the New York Fishermen Forum. I gave a short slide-lecture presentation on skiff trawls in a general “baymen's” section. The last time I had the opportunity to attend the forum in Riverhead was in 1979, just after an otter trawl closure for Great South Bay. At that time many fishermen were upset by this law, not only from the loss of income but also the need to “turn the bottom.” I know we have discussed this issue many times in reference to the inshore flounder fishery and hydraulic shellfish harvesting.

It seems that in the four hears of closure, some areas have gone “sour” after small trawls were forbidden. This was made known to me in the lengthy talk with a half dozen fishermen after my presentation. One fisherman described a “white film” over soft muck in some areas that had been previously hard bottom-productive in both fish and shellfish. The hard clams below the soft muck were all dead. I’m not certain, but I think he was explaining some of the problems that many salt ponds and estuaries have been subjected to.”

All of these issues compounded the basic problem for the Cape, who had water, who needed it and would there be enough for everyone--residential home builders were asking for regulations to keep the housing market viable. Residents were concerned with development and shell fishers saw widespread habitat failure, excess vegetation (sulfur smells) and now closures from bacteria. And the source of or reason for this decline – sewage- and now excess nitrogen. . Upon review of some Soil Conservation Service materials from the extension office, we decided to seek setback or buffer areas as part of the “Nitrogen Study.” The method at the time was to describe the impact zones, a 1000 foot buffer from creeks, salt marshes, bay, etc. The area in which it was felt could “impact” nitrogen levels sources were estimated from undeveloped land, housing etc. We used to look at street maps and counted the houses. We had the daily nitrogen load to freshwater bodies from houses so many grams/day. We used the same number to multiply it by the number of homes in the impact zone. We used two figures, one that 50% of nitrogen was removed by vegetation and soil, and one that calculated no soil retention occurred. (The new term is attenuation). Bacterial pollution it seemed was ready to become secondary to nitrogen which had a public policy land use edge. But what about Nature- – Mr. Hammond would frequently mention.
The Cape at the same time had a growing swan population that was starting to alarm shell fishermen and the cranberry industry used fertilizer also in the tidal zone. Any talk of fertilizer misuse or excess application was an industry concern. Several nitrogen sources could be identified including poor man’s fertilizer “snow” which could fix atmosphere nitrogen and deliver it into the water table. Determining the potential homeowner nitrogen source was the easiest. You could count them and use loading criteria for each system. The hard part was the other sources watershed, and nitrogen reserves bound up in the decayed plant matter itself the product of nitrogen. Shellfishers worried about that but it was Mr. Hammond who would bring this marine compost to the forefront. He described that shellfishing equipment was in fact the energy source similar to storms only on a much smaller scale, and it was beneficial to free the organic matter (leaves) from stagnant areas and help sustain in shellfish habitats rather than compost So you had this nitrogen on nitrogen impact in these small coves and bays. If this nitrogen “reserve” began to increase in the form of bottom organic matter, it would and did accelerate eutrophication processes. Evidence indicated extreme oxygen loss in the water column especially at night as several bays began to produce rotten egg smells during prolonged hot weather. This was especially evident on Green Pond where fyke net studies yielded numerous dead juvenile winter flounder thought to be trapped and unable to escape low oxygen levels (1982). No one, it seemed, mentioned natural cycles and processes of great warmth followed by cold except Mr. Hammond.
Source Pleasant Bay Chatham Orleans Harwich Massachusetts
But Mr. Hammond’s research looked at three issues, the number of storms, storm length and intensity, temperature of the ocean and bay waters. He produced a 1968 study of a proposed new inlet for the Chatham fishing fleet, while public comments included the Chatham Bar, how difficult the approach was for vessels, the possible drift of sand and the importance of the fishing fleet to Chatham. Mr. Hammond’s comments – he spoke about ocean temperatures. It was here on the Cape talking to Mr. Hammond that I realized the historical records of fish and shellfish landings combined with climate, temperature and observations is what Mr. Hammond was researching and he had been at it for a long time. He gave me a copy of the 1968 Army Corps Report *[This is his public comment. “Public Hearing Survey of Pleasant Bay, Chatham, Orleans and Harwich, Massachusetts, August 27, 1964. John C. Hammond, Interest Presented Self by page A-2. “As a property owner, he is in favor of a project to preserve the barrier beach. As a shell fisherman, cautioned on the adverse effects of cold water entering through inlet on shellfish, and he favors giving the fishermen (a) stabilized inlet. [(1) Survey Report Dept of the Army, New England Division 75 Corps of Engineers Waltham, mass. Nov. 1968 #527]
He spoke often about the long term impacts of energy and temperature upon shellfish. His best example was the closure of salt ponds during storms here. You didn’t need to wait years to see habitat change, you could see it in a few weeks and if it was “hot” – the fish and shellfish would quickly perish. He felt that Pleasant Bay had a fascinating “habitat history” over long periods of time locked in a historic record of “changed bottoms”.
That is why still on the Cape, people unblocked them (the inlets), allowing free exchange of the tides, he had seen that happen in other towns.* (Other accounts appear in previous IMEP newsletters especially numbers 14 and 5 so not wanting to repeat previous reports they are not included here.) Without restoring tidal change, the herring and shellfish perished. People who lived along the shore and bays know that because they watched it happen over tens of years. They had, in fact, an experienced based “habitat history.” That is something that had carried over from his agricultural experience that habitat change takes much longer in the sea than on land; he used mowing the lawn as an example, stop cutting (i.e. energy) you could see the difference in a few weeks in the marine environment it would take much longer. It may take years for a clam set to mature, but the time the clams are large enough to harvest and enter the fishery, people forget about the storm that first cultivated the soil. That is why he was concerned about hard nitrogen, marine humus or compost. It was hot and each summer more and more compost – I termed it Black mayonnaise- he liked the term. To him the mechanisms that were needed to clear it out, storms and colder temperatures were no longer happening and had been following the change since 1971, so by this time, a decade into this period. In colder times, quahogs did better and in warm periods, oyster; he had an example of this and provided a copy of a 1970 report about “Oyster Pond.” In it contained an example of an older bottom.
Mr. Hammond did like the term “Black Mayonnaise” and his account of a dredging project on Oyster Pond in 1970 gives some habitat history background information held by Cape Cod fishers of “many bottoms”, the current bottom and the remains of previous older bottom habitats. This was also confirmed by George McNeil in regards to oyster culture for the Hammonasset River a current crust of oysters and clams and below often had deep jelly-like mud. According to Mr. Hammond and confirmed in Oyster Pond Shellfish Study. Some aspects of the estuarine ecosystem of Oyster Pond, Chatham, Massachusetts with species on the Quahog (Venus mercenaria) the soft shelled clam (Mya arenaria) and the scallop (Pectin irradians), David A. Gato, Herber and Pettengill, 96 pages, November 1970), a dredging project in Oyster Pond hit a layer of blue black mud with a strong rotten egg odor** [The characteristic pungent odor given off by the purification of organic matter gave rise to the Miasmatic theory – widely held by the scientific community over a century ago. The so-called bad or night airs of the Thames River in England in the 1850s were called Maisma and that disease could be vectored by such pungent smells. Oyster growers for example were ordered to remove oyster stakes from the Poquonock River (CT) during the hot period here in the 1800s. It was thought that the smell of rotting organic matter was the cause of Scarlet fever in Groton linked to Miasma from oyster culture. Bad or night airs was linked to disease outbreaks to about 1915 in the United States).

Its consistency was unsuitable for beach sand and residents quickly had objected the project and had it immediately stopped. The blue black description and high sulfur smell was most likely a trapped Sapropel layer buried by a sandy layer. To complete the new channel into Oyster Pond, it had crossed an older channel and it was the older side of old channel that this very “different mud” was hit. Several storms had most likely deposited new soil (sand) burying previous bottoms. This was mentioned to me many times by Cape Cod shellfishers. Mr. Hammond’s view was a long term history would show a much warmer habitat here between 1880-1920, when oysters in fact oyster thrived here. Hard shell clams were scarce (1900), shellfish survey only located one oyster, but the name even bothered the authors of the study, where were all the oysters in Oyster Pond?”
But cooler water temperatures now favored the hard clam, which was prevalent over the entire Oyster Pond. Mr. Edmund Harding, shellfish warden of the Town of Chatham at this time, was concerned over the remainder of some 3,000 cubic yards of mud to be dumped in Oyster Pond itself. What was a concern according to Mr. Hammond, that this mud was not like the “regular mud” that bullrakers (hard shell clammers experienced- a gritty black sandy mud that contained shell fragments) instead; it was the consistency of mayonnaise. It was a hard clam fisher, Mr. John Linnell of Chatham, Massachusetts. That was concerned about this mud (he also participated in the shellfish survey). According to Mr. Hammond no hard clams could live in this material.
The dredging project was halted just short of bar separating the 8’ channel, the bar which reduced depths to only 2 to 3 feet (pg at low tides. Authors suspected that increased tidal energy would over time, reduce the bar. ”It is our feeling that the eroding force of this current may in time wear down the bar and provide a natural access to the pond.” pg 8 According to Mr. Hammond, this in fact did occur and with greater tidal exchange this material evaporated as if it had melted as if snow. I can still recall him mentioning that many felt this marine humus (Mr. Hammond’s term) had been carried out by the tides and he felt that was indeed part of the answer, but he watched it become “alive”. It was being dug into by shrimp and crabs and being exposed to colder more airy oxygenated seawater it had broken down into minerals, like terrestrial compost. He had also seen something similar following salt pond breaches. Once tidal circulation was restored this organic matter disappeared, except where eelgrass had colonized it. Here it held out the longest but it was in the still areas (these areas with minimal tidal flow). It was the eelgrass flats that trapped pieces of organic matter and made the water cloudy after a wave or wake. He had noticed that as eelgrass grew adjacent water quality decreased (called turbidity today). As it (eelgrass) grew upward it made particles subject to even the smallest waves. The sandy areas, these swept by tides were clear, the eelgrass flats always less so.
According to Mr. Hammond, by the time this study was completed, a couple of winter storms had blown a hole in the Oyster Pond Bar, the smelly mud had disappeared and the dredging may not have been finished (unclear local records of the Chatham Shellfish Office might have more details.
He felt (Mr. Hammond), that as it was the practice to turn organic compost to introduce oxygen for “soil makers” on land the same happens in the marine environment but it is rarely noticed (except by shellfishers). He felt that the dredging project had uncovered a habitat type of long ago, (previous bottom) created long ago when climate and energy patterns were different. Since the material was black, organic and similar composting features (accumulations) he estimated it had collected during a time of low energy and high temperatures. Its once habitat history was buried by storm sand until it was discovered by the dredging project. As it was organic, he felt (as land compost), it contained large quantities of plant nutrients such as nitrogen. The Oyster Pond report did mention that Stetson Cove Station was found the entire area is thick with Zostera (eelgrass and thick muck was found 2-3 feet deep and no Venus (quahog) found (page 26)
As for the odors researchers did include on page 40, that “the decomposition of organic material results in the formation of hydrogen sulfide gas (the rotten egg smell of marshes and mud flats- this hydrogen sulfide dissolves in water forming a weak acid and the pH drops.” Although researchers did mention oxygen compensation for organic matter reduction they found that the area (Stetson Cove and Oyster Pond was not limiting, “most tests showed the dissolved oxygen level to be near saturation levels.” Pg 42. Mr. Hammond felt that when it was disturbed, it created organic acids as older shells in it crumbled easily to the touch.
The report contains a series of location specific survey sites and although not a direct part of the study areas with Zostera and mud, containing the fewest number of quahog clams. It was noted that Zostera contained seed scallops on blades of eelgrass, usually in August but some shellfishers on the Cape felt Bay scallops set on eelgrass to escape “foul bottoms” now linked to sulfide purging (sulfide deadlines).-- George Sousa, shellfish officer, Falmouth, Massachusetts felt this was indeed happening. personal communication, 1982, Tim Visel).
When you examine Pleasant Bay and other shellfish surveys years later, you can begin to compile a “habitat history” of long term species abundance and habitat conditions. In areas that had deep mud, or mud with a Zostera crust held the fewest quahogs. On page 94 researchers also elude to the habitat aggressiveness of eelgrass (overtaking previous habitat types) and did reference the State of Massachusetts “Pleasant Bay Report (1967) which did contain long sections regarding the “problems of eelgrass.” At the same time, researchers did have a dilemma at certain times eelgrass appeared to have a significant biological role, so most reports listed the negative as well as the positive, but the ability of eelgrass to “move in” as Mr. Hammond would describe to me many times, was difficult to ignore. On page 94 under conclusion and recommendations contained one (number that mentioned the “eelgrass problem” it is repeated here as a complete recommendation from the 1971 report.
8. Eelgrass (Zostera) is a problem, particularly around the periphery of the pond, but it must be kept in mind that this vegetation also plays an impartial in the chemical (supplying oxygen) and biological (acts as a substrate for scallops) for aesthetic reasons, Zostera should be pumped out of the swimming area.”
When I arrived on Cape Cod only Mr. Hammond was talking about energy and temperature. As the 1970s turned into the 1980s, waters in New England started to warm, compliments of a growing positive North Atlantic Oscillation – what Mr. Hammond frequently mentioned that the climate had turned against the small boat shellfishers, as his research looked at similar conditions between 1880-1920. To him, the habitat quality for some species had collapsed and a mud filled soft bottom habitat for transition was occurring. Apparently according to Mr. Hammond during that period of warmth, Oyster Pond did contain oysters; by the early 1980s, it had turned “hot” again on Cape Cod.
Although nitrogen could enhance algal blooms and helped eelgrass and sea lettuce two of his less than favorite plants- he felt that cold and storms could take care of that just as it always had; he was much more concerned about organic matter, manure (which wasn’t that prevalent on the Cape as before) and leaves. He had noticed the leaf problem as well, just as Joe DiCarlo of the Massachusetts Division of Marine Fisheries had also in clearing Alewife runs as the temperature and energy had decreased (The Cape during this period was very dry). Alewife runs were now choked with leaves and it was the oak leaves that were the worst because they didn’t “breakdown”; he felt this leaf compost helped eelgrass “ruin” Pleasant Bay (see IMEP # 29 and #30) and supplied composting nutrients to feed it. He had noticed (as previous shellfish biologists) that eelgrass meadows tended to rise over time and on hot days, fish tended to stay away from them. * Knowledge of ammonia production (summer) and sulfide purging in winter from eelgrass beds that had bottom Sapropel (rotted Black Mayonnaise in high heat) was known in 1985 as “sulfur muds.”
Mr. Hammond reported that shellfish underneath in the eelgrass meadows were all dead and once shellfishers stopped working the bottom, it “died” and filled with Black Mayonnaise. He had seen that himself happen on the Oyster Pond River with eelgrass as he described as a crust grew over mud deposits. The shape of the oyster under these buried deposits held a clue for Mr. Hammond as he described an oyster’s struggle to keep ahead of this change; the shells would be long and thin. The Centerville River in Barnstable yielded these large thin oyster shells, hand baked bricks and fragments of steam engine coal, dating the productivity as nearly a century before. Galtsoff (1964) introduced the concept of shell shape as a “State of the oyster reef” indicator and has been found to provide important information about oyster reef ecology. Other indicators such as nitrogen loading (source analysis) bacterial water quality, and diversity (habitat associations) can provide important information as to current and previous habitat values. Oyster shells can provide important clues as long as proper sampling method is used. To be most effective you need several feet of the bed, just not the surface shells.
Several types of sampling surveying equipment should be employed. Whenever possible industry compatible sampling methods should be reviewed as often the same equipment utilized to harvest shellfish is seen to be the most effective to sample populations. Often non commercial methods provide hard to quantify or provide misleading results for example, a grab sample effort failed in 1981 to explain obtain any seed oysters for a river (the Hammonasset River) that would produce over 40,000 bushels that same year (1982 Shellfish sampling equipment should replicate commercial techniques). An excellent example is the DEEP Marine Fisheries Offshore Trawl Net Survey Program, i.e., the use of industry trawls. Seed oyster surveys in tidal rivers needs to be conducted with hand hauled commercial design seed oyster dredges).
Water Quality Monitoring
All Cape Cod communities have seen small declines in water quality as measured by nitrogen and bacterial water quality indicators. Long term studies can illustrate increases in bacteria but rainfall data is key to identifying watershed sources. A complete nitrogen source analysis is required to determine the largest inputs. On the Cape, residential nitrogen inputs were large in some towns watershed inputs appeared to be the most problematic in others.
The watershed impact was felt to be acute for example, in the Oyster Pond River after heavy rains, the river turned brown. A large bird population also fed in the salt ponds. He (Mr. Hammond) had urged local officials to examine runoff and not residential housing as the largest source of bacteria. I reviewed with him the Tom’s Creek Closure to shellfishing next to my home in Madison, Connecticut.
I think the reason “Clint” (Hammond) wanted to review so much of his material with me was that I covered a topic that also interested me, fisheries history and marine weather. Even though I had just skiff fished, it was the inshore experience that caught his attention. I had, growing up in Madison, CT, fished for most of the inshore fisheries with my brother Ray, we had lobstered, hand hauled small Wilcox otter trawls for winter flounder, oystered (again hand hauled dredges) tonged for clams, gillnetted for bunker (menhaden) and set conch pots. We had done this while still in high school. Our skiff was a Brockway similar to ones on the Cape including some Connecticut Brockway’s that made it to the Cape. Throw in some bay scalloping and soft shell clamming and the Cape fisheries resembled home.
But it was interest in weather that also had a part – looking back, I had also grown up watching the barometer, coastal lows” and powerful Nor’easter’s with my father. Who watched the weather just as closely as Mr. Hammond. But there was more, Mr. Hammond had made a connection between the two and looked at fish and shellfish habitats, and he had an excellent opportunity to do it in Chatham. His lab bench was the Monomoy Barrier Island complex, his notebook, the catches of Cape Cod fish and shellfish. He had kept records of storms, I had seen it but at the time was more interested in the “nitrogen problem” than storm events. All these years later I wished I had spent more time on the journals he kept.
At times he would describe great storms, barrier beach breaks and soils cleaned of “humus” as he used to call it and the results years later. One of his favorite topics was soft shell clam sets heavy in these “new soils” that wasn’t really new, but reshuffled in a constant changing habitat profile. In the 1950s and 1960s Bay scallops were “King” on Cape Cod– it was a colder and much stormier time.
It was the 1967 Massachusetts Pleasant Bay report that always was on the table, the weather patterns, strengths and duration of winds, storms and barrier cuts as old cuts healed all having an habitat impact years or decades later. That was one of the things he wanted me to know that it took time in the marine environment to see these things. He had seen soft shell clams set heavy on the flats after a cut, mature enter the fishery and “sets failed” as the soil became mucky and clams died off. Although many blamed the shellfishers for the decline overfishing, he had seen the effects of the cut “washing the soil” to prepare it for the set. As the cut “healed” the soil transitioned into sticky mud, and smelled of sulfur and that now was “acid” or sour and needed lime he compared to placing oyster shell (similar to his agricultural experiences). The soft shell sets had failed, but he had noticed that the turning of the flat had extended them. He had found as in other states that “working the bottom” was beneficial to keeping it viable for clam setting. If anything in the historical fisheries literature is consistent is small boat fisher observations of the benefits of marine soil cultivation, whether it is trawling for winter flounder, oyster dredging or clamming with hydraulic equipment appears in many Cape Cod Fishery at this time. (Some southern reports now include winter blue crab dredging as conversations benefitted to removing Black Mayonnaise.)
I was working with Sherril Smith, Massachusetts, DMF Extension Agent on a small hard shell hydraulic clam dredge as he had come to the same conclusion that some bottom cultivation was good- just as in agriculture and we would go on to do several small boat workshops together while working on Cape Cod about hydraulic clamming.
Even the hand hauled skiff trawls for winter flounder seemed to keep production areas free of leaves in a long conversation with Phil Schwind one morning.. But it was the hydraulic shellfish soft shell clam equipment that had caught my attention on Cape Cod and one that I focused upon for years. Although the nitrogen problem had appeared in local press reports and some shellfishers had implicated it also, Mr. Hammond’s research pointed me in a different direction that biologically available nitrogen was related to temperature aqueous nitrate for example was quickly utilized by green algae. While ammonia preferred by brown’s nitrate was cycled quite rapidly by green algae which preferred cooler temperatures. Any algae could be moved by tides bringing it into more oxygen sufficient areas. That is why these algal increases were so at first productive” they had nitrogen enhanced algae which is fed to shellfish which now grew “faster”. Shellfishers reported and I agreed that the poorly flushed areas were subject to Black Mayonnaise deposits first. They also, at the beginning of this transition showed rapid shellfish growth. That fit with my observations of the streams and creeks in the Madison, Guilford and Clinton, CT. I didn’t believe that all the dead algae created Black mayonnaise deposits, I still don’t. To me, it looked like the nutrient cycles had three areas, the nitrate quick growth for marine algae which required high nutrient levels and slower growing eelgrass, which can absorb nutrients into blades as well as through roots. This gives eelgrass an advantage of living in nutrient poor waters (like tropical waters) and related to water exchange rate flushing and temperature, an ammonia path, and an inert nitrogen gas, a growing marine compost now attributed to terrestrial leaves causes concern. In observation of black grass in Buttermilk Bay 1982 eelgrass blades was covered in secondary algal growths but again shallow very hot areas had more of “black grass” than the cooler better flushed areas. According to soft shell clammers, the black grass had started in the hot shallows first and spread out to the deeper cooler regions in August – that was also the pattern of Black Mayonnaise which had started to accumulate in the shallows first, nothing however was as dismaying as watching area productive shellfish beds close once they were closed to high bacteria events. Almost immediately Black Mayonnaise began to appear- shellfish then died.
To me, the early 1980s Cape Cod was beginning to experience shellfish closures and habitat changes that Connecticut coastal communities experienced a decade or more before. The heat that Mr. Hammond often described had finally reached Cape Cod. Fishermen were concerned about the impacts of the Hyannis Wastewater Treatment Plant, shellfishers were upset with shellfish closures, residents were concerned about access to scarce drinking water, and the environmental community was concerned over development as local businesses worried about new regulations. The residents of Cape Cod were coming to realize that the future, their future was going to be very different, a period of extreme heat and few coastal storms was just ahead and fisheries from other states would also report the deepening Black Mayonnaise deposits as New England had the largest habitat reversal in a century.
I respond to all emails at tim.Visel@new-haven.k12.ct.us
An Elusive Compromise
Rhode Island Coastal
Ponds and Their People

Virginia Lee



Eutrophication pg 42 Pollution from excessive fertilization is also considered to be a major problem in the ponds, particularly in coves where circulation is sluggish. It is thought that nuisance algae are increasing because of increased nutrients coming into the ponds from surrounding residential developments. Flounder fishermen report that algae are becoming more and more dense on the pond bottom and fouling their nets. Trawls come up with about 12 bushels of algae with each bushel of flounder even through most of the algae passes through the 4 ½ inch mesh in the net. The abundance of algae is not only an impediment to fishing. Then the temperatures rise in late summer, oxygen is used up by decomposing algae, making it scarce for bottom –dwelling organisms. When oxygen levels are very low, young flounder either leave the pond or die of suffocation. After oxygen levels are depleted, toxic hydrogen sulfide is often produced, causing the rotten egg smell that lurks over mud flats and back coves. The increased algal growth may be making the pond environment less hospitable as a nursery and spawning area for a variety of fish and shellfish. For instance, in the summer of 1978, Fosters Cove in Charlestown Pond went anoxic for so long that the oyster spat growing on the aquaculture rafts died.

Since there has been no monitoring of basic parameters such as nutrient and oxygen concentrations or primary production, it is difficult to know whether or not eutrophication is an increasing threat to pond life. Even through development is increasing around the ponds, which adds nutrients from septic leakage, road runoff, and lawn fertilizer there may have been low-level inputs of fertilizer from cultivated fields that surrounded the ponds in the 1940s and 1950s. Surveys of the general ecology of Charlestown and Green Hill Ponds were conducted by URI investigators in the late 1950s (Conover, 1961; Saila, 1961, 1966; Smayda, 1962, Fish, 1964). Comparison of these data with surveys done for NEPCO in the 1970s (Marine Research) and the URI pond research being conducted now may help answer the question at least for these two ponds. Present research will measure nutrient inputs from runoff, septic seepage, groundwater, tidal flushing, and benthic regeneration, as well as production of algae, eelgrass, and shellfish. These data will be used to assess whether or not eutrophication is increasing to the detriment of the pond fisheries.

[Benthic regeneration is the concept today called benthic flux or secondary source nitrogen. Excess organic matter in low flush areas collected and formed Sapropel deposits in many coastal coves in the late 1980s and 1990s. These deposits were frequently called Black Mayonnaise (Tim Visel Comments]

Rekeyed by Susan Weber for Sound School- 12/8/2014



Southeast Region
COOPERATIVE EXTENSION SERVICE

BARNSTABLE • BRISTOL • NORFOLK • PLYMOUTH COUNTIES

Cape Cod Extension Office University of Massachusetts and U.S. Department of Agriculture Cooperating
Railroad Avenue
Barnstable, Mass. 02630
Phone: 362-2511, Ext.201

February 18, 1983
Arnold Carr, Director
Fisheries Extension Service
Mass. Division Marine Fisheries
449 Route 6A
E. Sandwich, Massachusetts 02537

Dear Arnold:

I thought you might be interested in some of the feedback I received after my presentation at the New York Fishermen Forum (1983). I gave a short slide-lecture presentation on skiff trawls in a general “baymen's” section. The last time I had the opportunity to attend the forum in Riverhead was in 1979, just after an otter trawl closure for Great South Bay. At that time many fishermen were upset by this law, not only from the loss of income but also the need to “turn the bottom.” I know we have discussed this issue many times in reference to the inshore flounder fishery and hydraulic shellfish harvesting.

It seems that in the four hears of closure, some areas have gone “sour” after small trawls were forbidden. This was made known to me in the lengthy talk with a half dozen fishermen after my presentation. One fisherman described a “white film” over soft muck in some areas that had been previously hard bottom-productive in both fish and shellfish. The hard clams below the soft muck were all dead. I’m not certain, but I think he was explaining some of the problems that many salt ponds and estuaries have been subjected to..

I realize that such research on small trawls that could be fished in estuaries and near shore areas is a low N.M.F.S. priority (see enclosed proposal review), but I feel it is an important one in light of the heavy sediment and nutrient load now evident in many estuaries. I have found small trawls to be extremely conservation efficient with low or no mortalities of juvenile fish when hauled by hand. In addition, their use may be important in the maintenance of clear areas free of grass, silt, leaves and dead seaweed. Some evidence does seem to even correlate the existence of clear areas to good catches of scallops.

I understand that the use of small trawls should not disrupt the spawning of adult flounders, but with many estuaries and salt ponds suffering from oxygen depletion and over-enrichment, the use of small trawls would be beneficial and far outweigh negative impacts, if any. Seasons might be a good idea.

Perhaps the Division could undertake some experiments with the small 33 high rise skiff trawl. Any information you could provide me concerning the above would be greatly appreciated.

Sincerely yours,


Timothy Visel
Regional Marine Resource Specialist

TV/pd
enclosures

(rekeyed by Susan Weber Dec 8, 2014)