CTFishTalk.com: Salt Marshes-A Climate Change Bacterial Battlefield Part 1 - Connecticut Saltwater Reports ( CT Saltwater Reports ) - A Community Built for Connecticut Fisherman.

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[size=18]Salt Marshes - A Climate Change Bacterial Battlefield

Sea Level Rise, Climate Cycles and Salt Marshes
The Blue Crab Forum™ Environment and Conservation #7
Capstone Question: Will Salt Marsh Habitats in High Heat
Kill Fish and Shellfish Eggs
Will We Value The Salt Marshes of Tomorrow?
An ISSP/Capstone Proposal Series
ASTE Standards NRE #4, 5, 6, 9
Tim Visel, The Sound School – July 2015
{IMEP Fisheries Habitat Series can be accessed on the Blue Crab Forum™
eelgrass – oystering and fishing thread reports #1 to 55}
CT Fish Talk™ Saltwater Reports
This is a two-part report

Environment and Conservation #7– The Blue Crab Forum™ Part (1)

I want to thank the Blue Crab Forum™ for allowing me to post in a new thread – Environment and Conservation and also Connecticut Fish Talk™ for reposting these reports. This is my seventh report about bacteria and nitrogen cycles. Coastal habitats once praised for valuable habitat services are impacted by bacteria and at times become nature’s killing fields, eliminating critical nursery and spawning grounds for many inshore fish and shellfish species. Coastal fishers often observe these events, mats of bottom bacteria, chocolate or purple waters, brown tides, blue crab jubilees or just fish kills. Beyond these public events bacteria and nitrogen change the habitat qualities that we recognize today as “good” into something that is “bad” for inshore fish and shellfishing. Out of sight and rarely discussed, these conflicting bacteria strains have important implications for estuarine health and seafood production worldwide.

#7 Salt Marshes a Climate Change Bacterial Battlefield 9/10/2015

#6 Bacteria Disease and Warm Water Concerns 7/23/2015

#5 Nitrogen, Inshore Habitats and Climate Change 1/12/2015

#4 Black Mayonnaise Impacts to Blue Crabs and Oysters 1972 to Present 10/16/2014
#3 A Caution Regarding Black Mayonnaise Habitats 10/2/2014

#2 Black Mayonnaise, Leaves and Blue Crab Habitats 9/30/2014

#1 What About Sapropel and the Conowingo Dam? 9/29/2014

Fishers should follow this bacterial conflict as more and more information comes in regarding habitat quality and important recreational fisheries such as striped bass, winter flounder and blue crabs or lobster habitats are subject to bacterial impacts.
I respond to all emails at tim.visel@new-haven.k12.ct.us

Salt Marshes A Climate Change Bacterial Battleground

Capstone/ISSP Case Histories

Many salt marsh ecologists were unprepared for the 1982-2012 hot period which saw Long Island Sound water temperatures rise in response to this increasing heat. In high heat salt marsh surfaces were bathed in sulfate an important oxygen source for sulfur reducing bacteria commonly abbreviated as “SRB.” Sulfate reduction – (bacterial respiration) “consumes” organic matter when oxygen is limited and can cause collapse of salt marsh surfaces from sulfate digestion below. Sulfate reduction has a temperature element, the hotter it is the better the chance for sulfur/sulfate reducing bacteria to flourish.

At the turn of the century a famous botanist George E. Nichols described the salt marsh collapses at the end of the great heat – an extremely hot period (“hot term”) in New England’s coastal history 1880-1920. His description is quite accurate today a century later. The end product of sulfur reduction was often a barren expanse of sterile mud flat. “At ordinary low tides these tidal flats of the lower littoral present a surface of soft, blue-black, ill smelling mud an area in which, except for local colonies of eelgrass or salt marsh grass (Spartina glaba), (alterniflora) seed plants and attached algae are practically absent. At certain seasons these muddy flats may be destitute of visible vegetation of any description; but at others the bare mud at low tide is littered with loose sheets of Ulva and tangles of Enteromorpha, which may cover the ground so thickly that, when viewed from a distance, the surface appears verdant green. The failure of the eelgrass to flourish on tidal flats is probably associated with its inability to withstand the desiccation and extreme temperatures to which plants growing here are frequently subjected at low tide.” That is an excellent description of Sapropel – still valid today.

It is extreme temperatures that Nichols refers to an exceptionally “hot” period for New England even up into the Northern Maritimes. (Many New England shore villages and lakeside communities were built as the result of these 1890s killer heat waves). The heat (extreme temperatures) was horrific for city residents and NPR has a segment titled “The Heat Wave of 1896 And The Rise of Roosevelt” – August 2010 that provides vivid details to the hardship city residents faced. At the same time people rushed to the shore for cool waters and breezes – a habitat reversal occurred, helping blue crabs, oysters and soft shell clams but harmful to lobsters, bay scallops and the hard shell clam quahog.

In the 1990s however the very hot summers would again return altering bacterial respiration or pathways as bacteria that thrived in high heat low oxygen organic deposits soon dominated bacterial reduction. Their population is measured by their products – very acidic sulfide containing metal discharges that can be high in very toxic aluminum levels. In time our creeks and tidal flats contained the same blue-black ill smelling mud, described by Nichols more properly termed Sapropel today. We have a Connecticut example and warning that was written as far back as 1994 as part of a Section 22 Planning Grant Public Law 93-251 titled Wetlands Restoration Investigation – Leetes Island Salt Marsh Guilford, CT {March 1994 US Army Corps of Engineers – New England Division} of what sulfate digestion could do to salt marshes, these bacteria could consume them in high heat and in doing so kill fish and have long term toxic impacts.

Case study 1 – Lost Lake Guilford, CT – Sulfate Reduction – Sulfides

The foreword (pg 1) prepared by the Connecticut Department of Environmental Protection – Office of Long Island Sound Programs (today known as CT DEEP) for the Leetes Island Salt Marsh Lost Lake Report – describes acid sulphate soils case study (1) in Guilford, CT. (Author unknown – not delineated).

A 1994 publication for a Section 22 planning grant assistance to states – Water Resources Development Act of 1974 PL93-251 authorized the Army Corps of Engineers to cooperate with the states in preparation of plans for the development, utilization and conservation of water and related land resources. Section 319 of the Water Resource Act of 1990 Public Law 101-640 authorized the Army Corps to collect from non federal entities (commonly referred today as non government organizations or NGO) fees for the purpose of recovering fifty percent of Section 22 program costs. The non federal match for these projects came by the CT DEP Long Island Sound Clean Up Fund. The purpose of Leetes Island salt marsh study was to investigate the restoration of tidal flow to this marsh now bisected by a railroad and road causeways. From the report is this section below,

“A case in point is the Lost Lake-Great Harbor marsh complex in Guilford. This marsh had been drained by tide gates until a hurricane in the early 1950s removed the tide gate. The surface elevations of this marsh had subsided so much that two thirds of the wetland would no longer support vegetation because of overly wet soils and prolonged flooding. Forty years later, Lost Lake (a misnomer since this was a marsh) still supports no salt marsh vegetation.

Draining causes chemical changes in the soil which cause the marsh to become a non-point source of water pollution. Specifically, pyrite is unstable when exposed to oxygen. Through a series of chemical reactions, pyrite is converted to sulfuric acid which in turns causes a drastic decrease in soil and creek water pH. Levels as low as 3 to 4 are not uncommon in drained salt marshes. These altered soils are called acid sulfate soils. Under such low pH values, the aluminum associated with natural clays in mobilized and this metal is toxic to aquatic organisms at very low concentrations. Where dissolved oxygen levels have been monitored in drained salt marshes, low dissolved oxygen levels, known as hypoxia, have been observed during the summer months especially following rain storms. It appears that the leachate removes oxygen from the water. Fish kills have been observed in some of these wetlands.”

A few salt marshes studies looked at the increase of sulfate reduction as a condition of restricted tidal flows (or long term drought) subjecting organic deposits (peat) from oxygen in the air – but the same chemical reaction occurs when subjected to seawater flooding and sulfate, as an oxygen source which in not “limiting” as a function of bacterial respiration – bacteria breathing sulfur instead of oxygen, we know that today as “marsh die back.” The condition of high heat and low oxygen with sufficient sulfate – sulfur reducing bacteria now consumes the marsh peat sending high amounts of sulfides (sulfuric acid, toxic aluminum and ammonia). That can cause the plants roots to rot or dissolve in the lower marsh, with organic matter blocked bacterial digestion can lower marsh elevations. These marshes over time “sink” before organic reaches them to replace bacterial respiration. Salt hay operations on such meadows would case marshes to sink faster and to maintain elevations and salt hay crops would require Sapropel “dressing” or organic matter spread over them. In the Northern Maritimes at one time over 1,000 mussel mud harvesting machines scooping out Sapropel for terrestrial soil nourishment. (See IMEP #26 Connecticut Rivers lead Sapropel production 1850-1885, The Blue Crab Forum™ Sept 2014).

Case Study (2) Herring River Wellfleet Massachusetts – Aluminum – Toxic Metals

Droughts can reduce the freshwater lens on the marsh surface and in effect allows more sea water containing huge amounts of sulfate to enter coastal marshes. The lowering of groundwater tables (in times of drought) is also a historic practice associated with salt hay operations) allows sulfate reduction to occur driving sulfide levels (a by product of sulfur reducing bacteria very high) but this can also happen if a tidal restriction reduces water tables so in effect it is subjected to heat and sulfate reduction which occurs deep in the organic deposits themselves, below the salt marsh surface. Salt hay operations usually occurred during cooler seasons and the restriction of water – temporary and often controlled by gates. Such sulfate reduction can occur without visible signs until marsh surfaces collapse (often leaving what is described as salt marsh pannes). Sulfate reduction is in fact being investigated in the collapse of the tidal wall (barrier) in the flooding of New Orleans after Hurricane Katrina. Warmer temperatures and sea level rise put salt marshes at risk and at times lethal to oxygen requiring organisms from shallow warm organic deposits.

Buildings built over old marshes or on fill over them have been known to develop foundation cracks or floor setting. Some builders buried logs in the building bloom (1970s) and had collapses two or three decades later. It is a slow digestion process but in high heat greater favors sulfur reducing bacteria as organic matter is digested and toxic sulfides, ammonia and aluminum are discharged as water soluble products into local waterways. The condition can result in toxic discharges killing fish and shellfish larval forms even at times adults. (This condition can at times create a “sulfide block” after a long winter with ice – the (ice seals off oxygen) sulfide levels tend to rise – the source of salt pond winter kills on Cape Cod ruining or reducing alewife runs). (See Winter Ice Kills – DEP Pond Management). In high heat aluminum and sulfide blocks increase – and can be recognized by shore residents as sulfur rotten egg smells coming from the mashes themselves. Sulfide smell is the smoke of chemical burning of the salt marshes. When that occurs toxic fluids are discharged from them.

On page 94 of the US Park Service US Department of the Interior Cape Cod National Seashore – Herring River Restoration Project – Draft Environmental Impact Statement Environmental Impact Report October 2012 on page 94 is found this statement.

“Low dissolved oxygen concentrations have stressed anadromous fish species and resident aquatic fauna, and have resulted in fish kills (Portnoy 1991). In the past, low oxygen conditions in the summer compelled the NPS to control the emigration of juvenile herring to prevent complete mortality and loss of diadromous fish migration (Pornoy, Phipps, and Samora 1987), although this activity is no longer practiced. Conditions have improved since this discontinuation of annual dredging of the river for mosquito control in 1984 (HRT 2007).”

And further -

“Salt marsh soils in the Herring River estuary are naturally rich in sulfur. This is because salt marsh microbes commonly use sulfate, abundant in seawater, as an oxidizing agent to decompose organic matter in anoxic marsh sediments. The process produces dissolved sulfide, a large fraction of which is sequestered as iron sulfides, particularly pyrite; this mineral is very stable under water-saturated and anaerobic conditions. However, diking and drainage of the salt marsh has allowed air to enter the normally anaerobic subsurface environment converting it to an aerobic environment in which organic matter and iron sulfide minerals are readily oxidized. As a result, the sulfide has reacted with oxygen to form sulfuric acid which has acidified the soil to pH levels less than three. The pH of surface waters can also be lowered to pH levels of three to five when sulfuric acid contained in the soil infiltrates surface water. Acidic water can result in a loss of aquatic vegetation, as well as the killing of fish and other organisms. For example, in 1980 acidic water release into the Herring River main channel following mosquito – control ditching, accompanying sediment disturbance and aeration, and heavy rainfalls resulted in a die-off of thousands of American eel (Anguilla rostrata) and other fish species. During this event, pH levels of less than four were recorded in the mainstream of the Herring River (Soukup and Portnoy 1986).”

The toxic impacts of sulfur reduction in acidic waters were first investigated by the EPA in 1973. In 1973 (EPA 670/2-73-080 Lawrence Ross, Project Officer - National Field Investigations Center – Denver, Colorado prepared a report for EPA titled Removal of Heavy Metals From Mine Drainage By Precipitation. On page 5 of the report is found these sections.

“The Rocky Mountains have been the scene of intense mining activity for more than a century. In several districts, the mineral formations are highly pyretic, and the drainage from inactive as well as active mines in intensely acidic and loaded with metals toxic to aquatic life.

The characteristics feature of the metal-bearing drainage, as illustrated in Table I, is high toxicity combined with relatively small volume.

Drainage waters from mines in the sulfide-mineral districts of the Rocky Mountains are often highly acidic. The present investigators, for example, have found pH 1.4 in the drainage pond of mine K (Fig. 2) and the typical value for raw drainage water is about 2.5 to 3.0 everywhere in such regions. The oxidations reduction potential of these mine drainage waters is generally about +450 mV.

Adsorption has been studied very recently, and work is continuing. Perhaps the principal natural mechanism of elimination of toxic metals (or “heavy” metals) from mine drainage waters is dilution by ambient run-off from springs, rainfalls, and snowmelt, which will raise the pH sufficiently to cause precipitation of the metal as hydroxide. Despite these natural mechanisms, hundreds of miles of streams in the Rocky Mountains are severely polluted and incapable of supporting aquatic life.

{But the elimination of iron aluminum did not involve the complexity nature of sulfide (chemical addition) but the use of lime (in marine areas estuarine shell – as found in section four – chemical treatments.}

“The conclusion to be drawn from sections IV and V is that sulfide addition to mine drainage waters will eliminate the dissolved metals. However, elimination of ferric iron and aluminum would represent a waste of sulfide, because straightforward neutralization by dilution or addition of relatively inexpensive lime is sufficient to remove these two metals.

Finally, it is recommended that less expensive sources of sulfide than those commercially available (e.g., BaS, Na2S, NaHS) be investigated. This points directly to biological production of H2S (hydrogen sulfide) in situ from the plentiful SO42- (sulfate) available in drainage waters. The possibility of biological generation of S2- (sulfur) has been demonstrated by several investigators (including the present investigators), and merits further study.”

But the conclusion did refer to the cost of chemical (additions) of sulfate as a perhaps unnecessary expense that sulfate reduction itself was capable of doing this task naturally – when sulfate is not limiting – as it is not limiting in seawater.

This aspect is missing in many salt marshes studies currently – Bacterial Sulfide Weakening followed by diseases – fungus and molds.

Case study (3) Tom’s Creek, Madison, CT – Bacterial Sulfide Weakening

The third case history of sulfate reduction marsh die back (or collapse that can be described as gradual sinking) occurring in high heat with ample sulfate available to sulfur reducing bacteria leading to opportunistic infections all appear to be linked to high sulfide levels toxic impacts upon the vegetation crust – killing salt marsh plants or weakening them (as in the case of eelgrass die offs) leaving them susceptible to fungal infections. We have an example of that type of die off in Tom’s Creek, Madison, CT. Here the “browning” and the die off of the smooth cord grass (Spartina alterniflora) has been carefully monitored. (Elmer and Marra 2011 – Mycologia 103 (4) pages 806 to 819.” New Species Of Fusarium Associated With dieback of Atlantic Salt Marshes). Many marsh diebacks have been reported in areas or regions having drought but others such as Tom’s Creek (Madison, CT) occurred during periods of excessive heat. Here marshes that once appeared as healthy suddenly browned and patches of vegetation died – leaving voids in the vegetative canopy.

Karetsky et al 2003 Biogechemistry vol 64 pg 179 – 203 found that sulfate reducing bacteria (SRB) activity was lowest in winter and higher in summer. (Essential oscillation of microbial iron and sulfate reduction in salt marsh sediments – Sapelo Island, GA USA). Increased SRB activity resulted in increased sulfides - and that not directly caused the death of plants (although this could in fact happen) but weaken it sufficiently to allow opportunistic fungal infections as those described by Elmer and Marra mentioned above.

Salt marsh die off in high heat if accompanied by higher and at times toxic sulfides signify a much larger and significant negative habitat impact – aluminum toxicity to fish and sulfide purging* and also infections that can spread admidst a now weakened parent plant monoculture. The causative factor may be sulfides as suspected in earlier eelgrass die offs in 1931 and 1981.

Sulfate Digestion of Salt Marshes by Bacteria – A Sea Level Rise Concern

Many communities are unaware of the changes in salt marsh and herring run habitat quality – sulfate reduction that causes marshes to sink when bathed in saline waters rich in sulfate, or that salt marshes themselves can purge toxic levels of ammonia and saline hydrogen sulfide. These are the “low tide smells” often reported by coastal residents and under the correct conditions shed aluminum in amounts that can kill larval forms. One Capstone research area (Tom’s Creek case history) is to determine if local committees or commissions (especially those concerning sea level rise) took this into any fishway planning or monitoring consideration? (See should we reestablish alewife committees).

Fish Run Restoration – A related Living Marine Resource Concern

Did Connecticut alewife streams develop in high heat sulfide blocks – historically cold water and frequent storms were good periods for shad and alewife. Sulfate reduction will impact nearly all coastal communities surrounded by salt marshes similar to sulfate reduction during The Great Heat (the 1880-1920 period in which coastal CT experienced tremendous heat waves). The 1890s was wrapped around a gradual warming 1880 to 1890 and gradual cooling 1910 to 1920) salt marshes would sink. By the middle 1920s the relatively “warm” winters were gone. The 1890s would be known for killer heat waves malaria outbreaks and the infamous smell of “rotten eggs” hydrogen sulfide on hot August nights. In the 1950s a colder period with oxygen levels higher (Douglas Moss Account of the CT River 1965) these sulfide smells subsided.

With warming waters (until very recently the past cold winters has seen dramatic species reversals) and sea level rise salt marshes may (or will) transition into some very negative habitat types. The recent two warm to cold periods 1889 to 1915 and 1978 to 2011 have shown some of the same sulfate reduction discharges – from acidic sulfate soils both tidal (salt marsh) and subtidal Sapropel. These discharges can at times be highly toxic and dredging of Sapropel may be one of the few things we can do to slow subtidal sulfur discharges. Mapping Sapropel is also a factor in estuarine shellfish populations.

Herring – Alewife Runs – even smelt seem to be highly impacted by the presence of sulfide or aluminum.

Low alewife/herring returns into streams may not be a resource issue but a habitat quality issue. Low pH acidic waters mostly from Tannic acids (oak leaves desiccation) and sulfuric acid (oak leaf digestion) could turn tidal seeps into toxic discharges resembling acid mine waste waters – usually associated with abandoned western US mining operations. Contrary to much publishing information about ocean acidification (carbonic acid) coastal waters are more susceptible to tannic acids and sulfuric acids from terrestrial organic matter and bacterial reduction. This acidification has a direct climate and energy link – not pollution.

ISSP Potential Questions to Local Level Rise
Committees (Junior Students)
Do Sea Level Rise Plans Contain Habitat Elements?

1) Sulfate will continue to saturate a shallow fresh water lens – ground water will turn saline making fresh water recharge basins more important along the shore – plans for recharge basins. Small retention ponds?

2) Some dredging will need to occur to release trapped organics (Tannic acid) primarily oak leaves – in salt marshes dominated by the Mongolian Strains of Phragmites (boat access and fish/larval retention increases) could be dredged.

3) Sapropel will either be dredged for fertilizer or marsh nourishment – down to glacial till to benefit from groundwater release (cool and oxygen sufficient). This appears to be most important to maintaining habitat quality for winter flounder.

4) Nitrogen Attenuation – terrestrial plants will include non traditional bio extraction techniques and also those in seawater – docking, piling bio films – vertical and artificial reefs – are they included in nitrogen studies?

5) Oyster beds will be cleaned cleared of Sapropel reshelled for oyster beds – natures filter feeders and natural water clarifiers (venturi lift design). Is that mentioned as sulfuric acid impacts to shellfish populations from Sapropel bacterial digestion.

6) Dead zones will need greater energy – primarily be dredging to allow full tidal exchange and decrease “flushing time.” This has an impact upon bacteria in swimming beaches.

7) Living Shoreline Reefs – oyster shell and concrete rubble – tabby – energy modifications offshore than hard protection measures at the shore (students wishing to concentrate on this aspect should review Connecticut’s offshore breakwater construction program after the 1870s.)

Cool

Dredging organic deposits removed before they become sapropelic – reduce bacterial loading by increasing flushing – tidal change – salt pond inlets – sand waves and hydraulic stress. These could be “new” salt ponds dredged from phragmites populated meadows.

9) Testing in fishways for aluminum sulfide blocks or) leaves material cleared 30 inch trench to allow returning fish to enter areas prone to tremendous leaf falls were aluminum or sulfide levels checks. Some alewife runs have been completely filled with leaves.

Students wishing to submit SAE – FFA research proposals please contact Tim Visel in the Aquaculture Office. Juniors considering a independent credit for the ISSP program should pick up a ISSP proposal contact and ISSP guidelines fact sheet from Student Services.

Introduction – Salt Marshes A Bacterial Battlefield

Fishers have provided us a rare insight of what global warming can do. They are the first to ring the alarm as cold water species die off as they have in New England’s fisheries habitat history. The problem is -- no one appears to listen to them (my view). They with their habitat observations match the farm community only over a much greater time period. Each of us has seen pictures of farmers looking over parched fields – drying soil as wind creates dust storms. That weather can ruin a crop in a few weeks but always a chance of rainfall in time for next year’s plants. Because of the moderating influence of the sea such habitat changes in the marine environments can take decades. If you look at the hot periods – you can already see what the future will look like; sulfur likes heat, oxygen rules in cold. That is why currently so much concerns about releasing sulfur compounds from smoke – and the efforts to sequester (lock up) carbon to diminish C02 in the atmosphere. But those cycles have already happened in our estuaries and to assess potential future impacts we should review those cycles recorded in New England’s fisheries past. Much of that fisheries history can be found in state and federal records landings and fish surveys from the last century.

Public policies also changes for example when I was in high school (Nixon was President) many of science books were concerned about locking up carbon in wood frame houses. So much wood (carbon) was utilized in housing it would not recycle back for plant life and we would soon cause a carbon shortage, but 50 years later much emphasis today is spent on the need to lock up such carbon – there is too much. The late 1960s our textbooks extolled the success of the green revolution – the use of insecticides, pesticides, commercial fertilizers were the answer then to a growing need of food to feed the world. Only later did we learn what chemical excess could do – a modified green revolution exists today – use of fewer chemicals, genetics, low energy soil cultivation and biotic pest coupling (IPM). Things that appear important even critical over time change. With predictions of warm water we may find that change again for fish and shellfish habitats along our coast.

In time we may also need to reconsider many of the scientific values we hold today about the coast – a warming climate will return sulfur and vanquish oxygen as it had in the past. Historical fisheries’ records it seems provide many features of habitat failures and changes in coastal fisheries. Habitat observations of the shallow environments are so important just as agriculture field reports. The glaciers have left Connecticut about 10,000 years ago, so technically our climate has “warmed” since then but we do have cold periods and those cycles are frequently mentioned in the historical fisheries literature. So many of the collapses of fisheries appear to be natural cycles – and our ability to alter them part of any climate discussion, (my view) and fisheries could be an important piece in the climate change puzzle. I feel until very recently this opportunity has been largely missed – it should not any longer.

Salt Marsh Public Policies Change

Most likely when one pictures the New England shore it is often a shore front barrier beach or rocky shore and behind it a coastal salt marsh. I grew up living along one of them in Madison, CT along the western edge of Hammonaset State Park. I watched and wandered on the marshes and marveled at what lived in them – blue crabbing in the summer and oystering in the fall. In spring birds would come in the early spring to feed upon the first signs of life – killifish (mummies) that liked those shallow warm March and April pools. In the fall birds and Monarch butterflies would return on their migrating routes before winter, for shore life the salt marshes was a busy place but I also walked them in the snow and ice and sub zero temperatures. It left me with a bitter cold feeling of what it was like to live in the Arctic Circle – at least for a short while. Salt marshes were also the land of biting insects, unusual smells and at times dead zones. At time they were places of incredible life while at others barren and desolate with some of the hardest climate extremes in the temperate zone.

I also was incensed by the filling of salt marshes – in the late 1960s after all they contained the pools, creeks even the mosquito control ditches had “valuable habitats” in them. Creeks, I know they contained much life – oysters clams, blue crabs, you could see it, and the perception of marshes as disease vectors took a long time to extinguish and that happened in the 1970s. But that also is part of salt marsh life. That perception that marshes spread disease and vectored illness did have a foundation in truth, especially during the period I call the Great Heat, 1880-1920 summers here became very hot and a Malaria outbreak in Greenwich which spread to many coastal towns soon lead to efforts to fill them in, they had “bad” smells, biting insects – some that could infect you with parasites they were not the preferred coastal “habitat” type. Salt marshes were accompanied by dread (insects) and fear of disease – and at times noxious fumes. Local Health Depts. (sometimes under State Connecticut public health directives) ordered them often filled a century ago.

Salt marshes have much different ecological services in different climate patterns – in cold amazing places of life in high heat, zones of death. The salt marshes have a habitat history as well, born in periods of high heat and low energy and on occasion you could glimpse this habitat history. I used to walk along the Hammonasset Beach after a February storm – long ago edges of peat/roots marsh banks were exposed filled with thousands of clam like borrowing shells – I had not seen before evidence of long ago marshes that over time been were claimed by the sea. In the 1960s the State of Connecticut wanted to replenish (I guess today it is called beach nourishment) lost sand and along Hammonasset Beach by dredging up material about 1,500 feet offshore and in the process pumped up the remains of a prehistoric native American settlement placing many artifacts on the beach front. I had watched this process not realizing what was happening in the late 1960s . Hammonasset beach had lost about a foot a year for 1,500 years ago evidently the beach had extended much further out and sea level rise was an old feature of our shore. In the 2000’s fill from this 1960s dredge project was again excavated (and created a great intertidal habitat) and placed in front of the remaining two west beach bath houses and artifacts again re exposed could easily be found again. One day George Baldwin a Sound School teacher and I found several hammer, stones, cracking stones, George found a petrified tooth. It was such a sight I had Sue Weber come out and see it also (she types many of these reports) and we had a great walk looking at these “old” shoreline relics.

Much of these dredge deposits are still located on the park and reminders that this shoreline had been on the move retreating for hundreds of years.

Salt marshes formed after the last ice age 10,000 years ago, in periods of heat and low energy – they need these periods to form and why in cold high energy periods they are apt to “disappear” along with the shoreline. It’s not always constant heat and cold periods have happened before – heat and low energy they build in cold and energy periods they do not. Much of what can live in salt marshes at certain periods are in fact determined by bacteria. It is a conflict between bacterial strains as old as history itself. Aquaculture has in a way utilized bacterial forces to grow fish and shellfish in closed habitats. In most aquaculture classes students learn about nitrosonomas bacteria that convert ammonia to nitrate or nitrobacteria that then take nitrite and convert that to nitrate. But in this “closed system” oxygen is available when it is not you have system failure as ammonia builds to toxic levels. Oxygen is what keeps organisms and these bacterial filter systems alive. When oxygen is gone sulfur reducing bacteria increase. Nitrogen reduction does not impact the habitat quality in estuaries that obtain organic matter from land. Bacteria in these salt marshes don’t need the oxygen from the short cycle they have already be sealed from it as Sapropel ages it collects and concentrates wax, as it becomes sulfide rich and purges H2S. When it enters the sediment interface and disturbed forms a deadly sulfuric acid wash H2S04. After storms this acid wash can be not only devastating to marine life but often dissolves metal lobster and crab traps – not unlike of the agricultural examples from the last century reported by the New Haven Agriculture Experiment Station. When farmers re exposed it (Sapropel) to oxygen during land applications. Rebuilding the short oxygen/nitrogen cycle does little to improve sulfate reduction below Sapropel layers – dredging is the only to break this sulfide/ammonia cycle (or strong storms). Therefore much of the habitat nitrogen problem can be linked to climate – not human factors and this includes a tremendous increase in organic matter from a rebuilt forest canopy.

The Salt Marshes of Yesterday, Today and Tomorrow

In the 1870s here in Connecticut a cold and stormy period salt marshes were firm and hard – I recall some high school stories about that salt haying process from Charles Beebe (late of Madison) that the mashes were hard, then you could bounce a ball on them, but later to him the salt marshes became softer – horses had to wear special shoes (like snow shoes) to harvest this valuable salt hay crop. At the lower edge of the East River he would point to a log (cord a row) road built to harvest the school meadow salt hay (Guilford’s early public schools were supported by selling public land salt hay crops) it was still visible in the 1990s about three feet below the present day salt marsh – he knew that salt marshes were building up because he could see the old road to support the wagons – it was no longer at the top, it was buried exposed by a dredge cut made by the Army Corps in the 1960s. To him that was all the evidence he needed about sea level rise and erosion of the shore. What had made the marshes in these low energy areas that would be leaves from terrestrial environments slowing over time collecting and composting in low energy regions behind barrier beach sand spits or bars built up at the mouths of rivers. Heat is key because that typically meant that organic debris from land would slowly be reduced by bacteria slowing overtime in a long process I term the long sulfur nitrogen cycle – while cold and high energy periods favor the short oxygen nitrogen cycle – quickly rematerialized or moved by waves and currents. The marsh surface would be firmer during these times. Salt marsh habitats have two nitrogen reduction sides – the long cycle in heat/low energy and short cycle when it is cold and stormy. In very cold times the short cycle can invade these deposits with bacteria consuming them in the presence of oxygen – they would appear to melt away or in heat/few storms to accumulate organic matter and grow up in response to constant sea level rise (estimated to be seven inches here in the last two centuries).

Just as sand dunes are deposits of sand that for a time can “protect a shore” salt marshes fulfill a different “bank” function only with organic matter. In cold and stormy periods it is natural to have organic matter loss as oxygen levels favor faster “composting” processes and build up as leaves and organic matter slowly rot in heat in a very long process that overwhelmed bacteria as it collects in low energy areas. These cycles are very long and we can’t see the entire process but reminders exist like the buried log corduroy road in Guilford’s salt marshes.

That is the problem with the global warming sea level rise – what we today value in salt marshes will turn against us – as what we perceive marshes to be and the role in marine ecology they enjoy will see a quantum shift. In a global warming scenario with sea level rise salt marshes turn into natures killing fields vanquishing those organisms that need oxygen while furnishing those that prefer sulfur the food and nourishment they need long locked in these organic deposits with a “salt marsh crust” the vegetation that binds them. The instruments that will wage war upon oxygen dependent life (and us) is bacteria and opens the door to bias in the literature about salt marshes and how we perceived them today. This bias is connected to public policies of these hot and cold periods as well. In high heat and during the Malaria outbreaks of the 1900s (see Climate Change in Public Opinion written in 2008 – IMEP #16). Salt marshes were seen then as deadly dangerous places and the public policy response was simply to fill them in – in the 1910s it was an honor to serve on such public good committees to fill them in – such as here in New Haven sometimes under State Health Dept directives). In the colder periods salt mashes were valued as hunting grounds (ducks) or salt hay crops.

The last Malaria outbreak in Connecticut occurred in 1938 as it turned colder here Malaria had ceased but the public perception of marshes as ill smelling disease ridden lands continued far beyond the Malaria outbreaks attributed to them. With a colder negative North Atlantic Oscillation colder water meant more oxygen – with sea life abounding during a short cycle nitrogen reduction period. Colder water naturally contains more oxygen – organic matter was quickly consumed reduced by oxygen reducing bacteria – but smells during the Great Heat (the infamous hydrogen sulfide smells frequently attributed to hydrogen sulfide heat or rotten eggs that quickly spoiled in the 1890s) had now disappeared, fish kills (now linked to sulfate reduction) became rare as the coastal energy now increased. The 1950s and 1960s had cold winters and several powerful hurricanes the organic matter was quickly recycled or moved, Sapropel or “black mayonnaise” deposits subsided, inlets opened from strong storms and colder oxygen containing sea water entered again – killing off the sulfur bacteria and replacing bottoms with those bacteria that need oxygen. Greater storms and now alkaline sea water assisted the removal of organic acids (mostly sulfuric acid) in marine soils and sets of quahog clams then soared as oyster recruitment declined. Out of sight and leaving few clues of previous battles (other than in core samples) bacteria waged war and in this cold and energy period sulfur bacteria had now clearly “lost.” Oxygen requiring bacteria had won and the organisms that needed them now thrived. The 1950s and 1960s are now recognized a being a negative NAO – a period of cold and many storms – it was the time of the “great quahog sets,” improved lobster recruitment and the return of the bay scallop in southern New England.

Clint Hammond on Cape Cod often described the “Atlantic Oscillation” – during the fifties the term polar Vortex came into being. (I was not familiar with this climate pattern at this time (1980s). After many decades the Chatham shore front was on the move again retreating from the relentless series of Northeasters each storm would change Monomoy a barrier spit in the southern section of Chatham, MA where he once shellfished it had a notebook filled with notebook habitat observations and sketches with descriptions of Powder Hole aquaculture experiments on Monomoy that no longer existed – they had been washed away. Looking back I wish I had spent more time on these notebooks but at the time the study of shoreline change seemed so remote from the seafood population changes in “sour bottoms,” he described to me but it was all connected and on the Cape these concerns thrust themselves into the print media.

- Salt water intrusion into the ground water and the thin lens of fresh water in times of droughts.
- Bacteria levels were high immediately after heavy rains
- Warmer waters had more algal blooms and the “bad” summer smells from the marshes had returned.

Mr. Hammond felt the climate was turning against the inshore shellfishers and had linked in increase in foul smelling bottoms as evidence of this transition and wanted researchers to look at the bottom – he termed it compost (he also called marine humus). He had a practical example of this marine compost – mixed with oyster shell, huge tomatoes grew along his front walk.

He was concerned that with all the current debate about nitrogen no one was looking at what he termed “hard nitrogen” (hard because it was in a solid form mostly leaves) everyone was looking at nitrogen inputs from people or farmers. What he called humus I called Black Mayonnaise and most likely he was emphatic regarding this research need to him was going nowhere – it had been missed but not by him or area shellfishers – it was for them hard to miss. It had built upon shellfish bottoms and often contained a crust of eelgrass. They had watched it grow for years. What he was concerned about climate change would be missed but not only from ignorance but public policy decisions made decades before. In the 1960s after all it was policy to fill in salt marshes that would change in the 1970s.

Salt Marshes and Public Opinion

“Save the Salt Marshes” was the cause to finally galvanize public opinion in Connecticut much of that from Ann Conover in Guilford, CT (see climate change and public opinion IMEP #16. Blue Crab Forum™ (fishing, eels oystering thread). The salt marshes should have been saved, building close to the shore was something many coastal residents had already learned had risks following the Great Heat (see Clinton Harbor and The Great Heat on the State of Connecticut Shoreline Task Force website) especially those in the middle to east sections of CT – subject to higher energy levels. Their homes and land had been washed away.

Nixon and Oviatt 1973, Cordell 1975

Oviatt, A. S. Nixon 1975 – Sediment resuspension and deposition or organic matter in Narragansett Bay Estuaries Coast and Shelf Science 201-217.

Experimental Studies of the effect of organic deposition of the metabolism of a Coastal Marine Bottom community John R. Kelly – Scott W. Nixon Marine Progress Series Vol 47 157-169-1984.

Small Ponds in Connecticut
A Guide for Fish Management
by Brian Murphy and Donald Mysling

PUBLISHED BY THE CONNECTICUT DEPARTMENT OF ENVIRONMENTAL PROTECTION
FISHERIES DIVISON

DEP BULLETIN 1993

Winterkills

Winterkills occur under the cover of ice, but are usually not discovered until a pond’s ice cover melts. They occur most frequently in shallow, nutrient-rich ponds that are subject to abundant growth of weeds or algae during the summer. Conditions conducive to a winterkill arise when heavy snow cover on the ice inhibits sunlight penetration and plant photosynthesis. Oxygen levels may be reduced to critical levels by fish, living plants, bacteria, and other aquatic organisms if the snow persists for a prolonged period of time.

Manual snow removal, although a considerable effort in large ponds, can result in a significant improvement in dissolved oxygen levels. Snow should be removed from at least 50% of the pond surface. This method will promote photosynthesis by increasing sunlight penetration through the ice. Cutting holes in the ice is not an effective method since little water gets exposed to the air.

Increasing the water depth of a pond is also helpful. Also, always try to prevent additional nutrients and runoff throughout the year (see chapter 4). Added nutrients will increase pond productivity, creating a greater oxygen demand by bacteria and subsequently reducing the amount of oxygen available to fish.
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