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The Sound School Inter-District Marine Education Program Newsletter

- IMEP -

Habitat Information for Fishers and Fishery Area Managers

Understanding Science through History

The Sound School – December 2013

Are Changes in Shellfish Abundance Natural?
Did Native Americans leave us a Habitat History Lesson for Climate Change?

Tim Visel – The Sound School

Vol. 1 #3

One of the fisheries research areas that has been mentioned after Hurricanes Sandy and Irene is what are the long term patterns for climate change, and are we indeed seeing a large impact upon fisheries – over fishing, habitat loss or habitat change? Is it natural to have a lobster die-off followed by an increase in blue crabs? Has Connecticut experienced this before and if so how many times?

While terrestrial researchers often examine tree ring diameters for evidence of past habitat conditions during droughts and some of the first climate history information came from California and the examinations of old growth forests. Between 1948 and 1978, California experienced a benign and quiescent climatic period characterized by few storms capable of generating large storm swell or heavy surface runoff. During this time extensive urbanization occurred along the coast. Studies of tree rings in Southern California show that this was the longest drought period since the 1520’s. Then the 1970s and 1980s came and storm energy increased and so did coastal changes erosion. California residents were shocked to see coastal processes suddenly turn against them.1

As today’s coastal geologists examine coastal cove core studies to determine if layers (clasts) represent storms (they do), Connecticut’s past inhabitants in addition may have left us a separate “habitat history” in the remains of seafood consumption – Native American shell heaps called middens. Shell middens also can be called kitchen waste – the remains of cooking and consuming seafood use here centuries ago. We have learned much about the Native American diet and seafood use from them already, just by the shells and bones in them. Oyster, bay scallop, quahog and conch shells all are found in Connecticut shell middens. Until recently archeologists just noted the presence but not shell shape or size or relative abundance over the depth of the midden. For example oysters, conch, and razor clams species show the highest abundance during periods of heat and weaker storms while quahog, bay scallops and blue mussels like it colder and some of heaviest catches are following strong storms. Lobsters and blue crabs were also harvested, but may be hard to find as their shells may have dissolved in acidic soils and not be as evident as bivalve shells.

It might be better to look at the ease of catch, and abundant resource is often harvested more than one that is in decline. Why look for lobsters when blue crabs are so abundant? We do this today – we follow the fisheries today for the same reason. Coastal peoples living along Connecticut’s shores would have noticed this also and left “bands” of abundance of climate dependent species. Similar to marine cores they may have left us seafood use “horizons” to help us determine habitat conditions.

What we do know is that seafood was consumed in great quantities along the coast and roasted by fires. One of the roasting methods was baking seafood in dirt stone ovens, (ground had to be ice free) and the season’s aspect of use and comparative ease of catch. In the spring was alewife and shad by open fires; in the fall shellfish “bakes,” the water was warmer and more pleasant to catch seafood, etc – “The Indian Summer.” I think this is an area that deserves more attention: how many calories were spent in search of food? I believe that there was a severe accounting for the law of diminished returns – starvation. If it was easy to catch (not too much caloric work expanded) and especially “calorie rich” when the seafood came to them then it was utilized. Some of the tribes up here fought over smelt and alewife runs – rich in fish oil and calories. Those were valuable as a spring fishery and abundant and that would be evident in the middens.

As for blue crabs - I am certain that Native Americans consumed them in great numbers, but just as we do, the most favored was perhaps soft shells – they were accessible, high calories to work gain easy to cook but sadly left little to no remains. So the blue crab issue is more complex than the shellfish. I can see why conch and quahogs (hard clams) were favorites, cooking was easy: heated stones not that much prep and a good salt source also, etc. I have examined some midden remains from Westbrook, CT recently and it was loaded with conch shells, (a sign of warm quiet periods) and deeper into the midden bay scallop shells were dominant – significantly perhaps a colder stormier period here? People are very surprised to learn that the mid 1950s here with snowy winters, Long Island Sound freeze ups, numerous gales, floods and hurricanes that our bay scallop production actually soared. They just can’t believe it, but it there in the fishery statistics, and it’s just not Connecticut but other New England states as well. The bay scallop habitat quality is enhanced by such conditions. However, oyster habitat quality then quickly declined.

Blue crabs however offer an unusual indicator, it responds so quick to temperature changes as the “1950s” winter in 2010-2011 showed it really knocked down our population in the east and central locations but it also has a short life span as contrary to the quahog clam which lives to be a hundred and intense widespread sets occur in cold periods only after a large hurricane. The hard clam sets in 1939-42 were tremendous and big sets only occur here two or three times a century after strong storms explaining perhaps the need for a very long life span. Blue crabs can quickly benefit from warmer waters – they have a much shorter reproductive cycle with a huge egg potential. As such it is a species that can quickly fill habitat voids.

I feel shell middens may provide additional clues just by the shells themselves, small round oysters signify good growth and recent productivity – long thin clustered oyster shells significantly a dying population – burial in high heat, quahog shells with thick lips are called “blunts” in the industry, these are old or populations that stopped growing decades ago compared to new quick growth or younger “sharps.” Bay scallops also have a key habitat indicator, a raised seasonal growth ring – in colder periods scallops live longer and may show two such rings. I have seen that myself in some very old Niantic Bay shell remains, so much can be determined not only by the presence of shells but the condition of shells. Some of the early work of oyster shell shape was done by Paul Galtsoff in the 1960s (1964 Fish and Wildlife Service Bulletin the American or Eastern Oysters).

Shallow water quahog (hard clam) sets occur in the coldest of periods in coves and bays so a large number of little neck size quahogs in middens would signifying a recent set in estuarine soils now reversed to more alkaline pH conditions (low pH kills clams). As these coves and bays warmed, hard shell clam sets would naturally decline as marine soils became more acidic from the buildup of organic matter in the estuarine soil itself. Here after weaker storms sets of Mya, the soft shell clams would increase and like warmer waters. Fisheries would change from these climate conditions – the most famous the Great Bay, New York hard clam fishery. Here after some heavy quahog sets during the 1950s NAO (North Atlantic Oscillation) were tremendous.

Quahog production declined in the 1980s as waters warmed and marine soil pH dropped to lethal limits for clam larvae. A reduction in coastal “energy” tidal exchange can accelerate this process. Soft shell clams with long sleek tapered shells signify quick growth in loose sandy soils. Soft shells with bent lumpy thick shells provide some factors to soil type, pH and storm damage. At the end of The Great Heat, 1880-1920, razor clams (Ensis species) became prevalent only to collapse as the climate turned colder after 1920. Some species might find dominance between the shifts such as eelgrass and blue crabs. I believe this to be so; eelgrass is often first in to bind loosened marine soils after storms preferring the end of colder periods (1970-1990) blue crabs become prevalent at the end of warmer periods 1998 – present (fishery transitions follow habitat reversals which can take decades) and is the population to watch now. A sudden and prolonged drop in the blue crab population could signify the beginning of the end of an extended warm period. To help answer this question, we might be able to determine similar climate changes beyond those identified between 1880-1920 from fishing records and by looking at those who preceded us – Native Americans.

A Historic Trilogy by Harold Castner – 1950

In 1950 Harold Castner wrote several environmental fisheries histories for the Damariscotta River and a settlement he called Pemaquid. He didn’t realize at that time he would be one of the first historians to portray coastal history as a continuum of events far before European settlement. He looked to those who lived along the coast before his time to write about his favorite topic, history.

In his papers he examined evidence of past coastal life including the use of seafood. Decades before the concept of taking cores to examine climate conditions his description today of oyster populations remains just as valid as more recent papers regarding oyster reefs and dredging. He is perhaps best known for his descriptions of oyster middens. On page 14 of a reprinted edition by the Damariscotta Historical Society is an excerpt that mentions buried oyster reefs containing oysters of immense size – and indication of a long cold period with few storms. As centuries went by, organic matter must have covered them as a dredging project commenced uncovering this long ago habitat history – It is the shell shape and size that is key to his observation – deposition rates were slow allowing slow burial to assume the characteristic long and narrow shell shape so carefully described by Paul Galtsoff in 1964. In times of great heat, burial is often rapid. A slow, stable climate period is evidenced by huge oysters. In the 1890s; as New England sustained historic heat waves, oyster setting returned to Maine’s cooler waters. This account is significant as it is in the warm period, then 1880-1920.

An excerpt of an account of Ancient Oysters in the Damariscotta River in
Maine by Harold Casner

“As late as 1895, live, healthy edible oysters were taken from Oyster Creek. Mr. Gilbert E. Gay procured a supply from there for a novelty supper the men of the Damariscotta Baptist Church held at that time. They were not as large as the ancient variety, but of excellent flavor.

An experience of the author will serve to amuse the reader and shed considerable historical light on the extent to which these oysters propagated in the river. Shortly after the year 1900 A. D., the United States Government appropriated funds to dredge the Damariscotta River at the immediate approach to Cottrell’s Wharf. Tug boats, barges and a dredge came up the river and began operations. This location was immediately below the present bridge on the Damariscotta side of the river

It was soon learned that the barges were to be dumped in Fitch’s Cove, about five miles down the river. The more daring and resourceful boys, of which the author was one, were quick to attempt ways and means of riding up and down the river. To our surprise, there was no objection and we were among the first to get on the barges and were there when the first shovelful came up from the river bottom.

An unexpected thrill came to us when we observed great oyster shells in remarkable preservation, where imbedded in the mud of the river bottom and there they had remained below tide water for many years. Like all boys, our immediate impulse was to jump into the scow, grasp a souvenir and get out before the dredge brought up another load. Again, to our surprise, there was no objection and we soon collected remarkable specimens. There were many other interesting experiences connected with this work but we are at present concerned with the oysters of the Damariscotta River.

In due time a report reached Washington that unusual specimens of oyster shells were being taken from the Damariscotta River. Word was sent to Captain Frank Smithwick, who was Custom’s Officer at the time, to obtain a supply of these shells. A notice was sent out to the boys to bring in their souvenirs and that real money would be paid for those selected. There was a general parade to Captain Smithwick’s office. We came with carts and boxes, bags and bundles, and Captain Smithwick soon found he had a wide variety to choose from.

After considerable examination he selected quite an assortment and began passing out money. One of the shells which the author had been fortunate enough to find was an excellent specimen and consisted of both sides intact and remarkably preserved. The sides fitted perfectly and the whole was slightly curved ad though it had grown adjacent to a rock. This shell measured exactly eighteen inches from tip to tip.

Turning his attention to me, Captain Smithwick put his hand on my shoulder and said he would like to buy this shell, and in his kindly way, asked me the price. After over fifty years, I feel compelled to admit that I looked him over, wondering how much I could charge. One, I had the momentary and desperate impulse to say fifty cents, but my courage failed me and I dared not mention such a huge sum of money. He smiled, hesitated, and presented me with a piece of paper money. It was nothing I had seen before and I looked at it and then at Captain Smithwick, still wondering if it was real money. Another hasty glance revealed the figure five on it. I concluded it must be money but still had no idea how much.

Shell middens may have clues that the archaeology community doesn’t realize perhaps yet it’s just not the shells but what shells and what sizes and at what depth in the midden? This is something I have been thinking about putting together for some time a guide for the archaeological community so they can interpret the shell midden remains, etc. One day we may even be able to compare midden horizons to coastal core layers as a climate change comparison for habitat quality.

Perhaps some potential Capstone Research Projects that reexamine existing shell midden reports – I hope so.

The HIFFM IMEP Newsletter is possible by an Inter-District Cooperative Grant (Public Act 94 -1) and regional marine education bulletins can be obtained or accessed on the Adult Education and Outreach directory by accessing the Sound School website: www.soundschool.com/publications%201.html. For information about The Sound School website, publications, and / or alumni contacts, please contact Taylor Samuels at taylor.samuels@new-haven.k12.ct.us .

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Program reports are available upon request. For more information about New Haven Environmental Monitoring Initiative for IMEP reports, please contact Susan Weber, The Sound School Adult Education and Outreach Program Coordinator, at susan.weber@new-haven.k12.ct.us.