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The Sound School Inter-District Marine Education Program Newsletter

- IMEP -

Habitat Information for Fishers and Fishery Area Managers

The Sound School – November 2013

Soft Shell Clams in Connecticut – A New Opportunity? Volume 1, No. 1

A Habitat History from the Turn of the Century 1898 – 1905

Tim Visel- The Sound School

After Hurricanes Irene and Sandy, I am often asked about the impact to Connecticut’s shellfisheries. These incredibly powerful and destructive storms give the sense of devastating impacts to shore life. In some cases, it is, as evidenced by storm driven shellfish upon the beaches storm events are often quite destructive. In many circumstances however, it is not and I often turn to one of my best historical references: The 1905 Annual Report of the Commissions of Inland Fisheries for the State of Rhode Island (Thirty-Sixth Annual Report of the Commissioners of Inland Fisheries, E.L. Freeman and Sons, State Printers, 1906). The title is a bit misleading as most of the volume is devoted to marine fisheries clam sets, the upweller lobster hatchery and alewife restoration, not those typically associated with freshwater species.
1906 is a key year as it recorded habitat changes following the Portland Gale of 1898, most likely a November hurricane by today’s standards as it caused much damage and loss of life from the sinking of the steamship “Portland.” But following the Portland Gale and the summer gales of 1903 and 1905 the soft shell clam sets were tremendous. Warmer water temperatures now favored the soft shell clam and fishery managers were amazed at the “natural abundance” of soft shells after the numbers of clams on the shores of the Bay (Narragansett) surged tremendously and previously “has not been so great for many years.” Huge changes were now being observed, everywhere was huge sets of soft shell clams to the surprise of state biologists a century ago. On page 105 is found this quote:

“Whereas in past year the distribution of the clams has been uneven, some localities being thickly set while others close by were practically barren, this year 1905 the entire shores of the Bay are covered with clams. Places which were good clam territory in the memory of the oldest inhabitant, but which for many years have been barren; have taken part in this general revival. Owing to the great abundance of clams everywhere the size attained was not very great. The clams were so crowded together that they could not attain full size. This fact necessitated, in spite of the great abundance of clams on our own shores, the shipment of clams from other States to supply the great demands of our shore resorts.

These abundant native clams are mostly from the set of 1904, which, as described in the report for that year, were so abundance that in one locality 4,264 were found in an area of one square foot.”
And it was along the entire Narragansett Bay shore incredible densities were being observed in several areas.

“Another case in point was observed at Greene’s Island. On the east shore of this island is a long flat which in 1901 was set so thickly with clams that 7,910 were counted in a single shovelful. In 1902 and 1903 the clams from this set were abundant and the shore was dug over continually by clammers.” And while the report continued to talk about the surprising “return” of the soft shell clam in this period of great heat, it also reported the absence of bay scallops so prevalent during the colder and much stormier 1870s.

The writers of the 1906 report didn’t know that they were in the middle of the largest habitat reversal in a half century. The very hot temperatures of The Great Heat 1880-1920 had vanquished two of the most important commercial fisheries- lobsters and bay scallops- while ushering in a new age, the rise of blue crabs and soft shell clams. Lobsters and bay scallops would stage a return during the cooler and stormier conditions of the 1950s and 1960s and soft shell clams then retreated into cooler more protected areas. Fishers as well as fishery managers noticed this also and by the 1950s soft shells became scarce in the same areas they once prospered.

In the late 1950 and 1960s as the climate turned cooler and much stormier in New England, soft shell clams “retreated” into deeper water habitats, salt ponds, coves and bays. A popular seafood item, “Steamers”, since the Great Heat (1880-1920) clammers and coastal residents continued to seek this popular seafood. This effort soon had researchers such as Glude, Landers, Medcof and MacPhail looking for ways to harvest this popular and tasty seafood in deeper sub tidal areas. During The Great Heat, soft shell clams were everywhere in Cape Cod and areas north. Connecticut also experienced tremendous soft shell clam sets after 1898- dense beds were found in bays and coves, especially Clinton Harbor, Clinton, CT where summer visitors often dug their own “shore dinner.”

A half century later, soft shell sets in the open tidal habitat areas declined and mature beds were often destroyed by constant hurricanes during the 1950s. The protected sub-tidal areas however, continued to hold large quantities of soft shells in 4 to 8 feet water. Salt ponds were especially productive but tides never exposed these populations for coastal clammers. By 1955, soft shell clams in open areas were now rare; the constant recultivation of clam bars often destroyed sets before they could reach legal size, except in the deeper more “protected” areas- never exposed by tides.

Although sub-tidal digging had been done before in Connecticut, using a garden screen called a riddle and special offset shovel, in the 1920s off Great Island, Old Lyme, and in Guilford, shell-fishers had developed a clam gun – a metal cylinder that pushed down over clam holes at the turn of the century and pulled clams out in a plug – the introduction of sub tidal wet dredges was soon to show researchers the ability to cultivate marine soil habitats. They had incredible power to reverse marine soil acidification and obtain large sets by increasing habitat quality for clams. It also had the ability to over cultivate in an open, non-regulated fishery, requiring controls (either private or public) to prevent over “cultivation” and over washing of marine soils when seed clam sets were not readily seen(one advantage that terrestrial farmers have over those involved in Aquaculture). This is the same feature that hurricanes had to many storms in a short succession. Some cultivation was good followed by a period of “rest” the soil structure stabilizes, sets were allowed to mature. The period called The Great Heat 1880-1920 had only a few summer storms and they occurred several years apart, soils were cultivated, rinsed of acids and soon held great sets of steamers which then grew quickly in these loosened marine soils.

Shell-fishers had for centuries commented about the benefit of working the bottom, freeing it of high heat / organic acids and the reuse of “shell hash” (broken shells) to buffer marine soils – very similar to the Agricultural terrestrial use of lime. Early shell-fishers also noticed something else, that energy (tidal waves surges currents) were destructive to some species but seemed to prepare soils for heavy bivalve sets later. Some of the densest bivalve sets (both soft shell clams and hard shell clams) are recorded in dredged “spoils” (called dredged material today) - Belding for soft shells during the Great Heat (1880-1920) and Galtsoff for quahogs during the New England (Atlantic) Oscillation (1945-1970). It was the only large scale marine soil cultivation extensive aquaculture experiments of their times. Both researchers commented on the agitation and flushing of organic material from the soil itself. In the 1940s dredge operators often noticed clams by poles jetted into the bottom. The pumping of sand had released clams during the jetty process and in clean waters were frequently observed (Frank Dolan, personal communication – 1979 Tim Visel).

As additional experiments were undertaken in the 1950s , the use of hydraulics was to forever change harvest dredge methods. Suction dredges in New Haven Harbor vacuumed up starfish and oyster drills, venturi rigs developed by Fletcher Hanks harvested soft shell clams and a manifold of smaller jets developed by MacPhail was placed on the New Bedford rocking chair “dry” dredge and the modern “wet” hard clam dredge came into existence. This greatly reduced harvest mortality in the industry as the use of dry dredges quickly declined. Water pressure not horsepower became the chief harvest technology and in doing so resembled natural soil cultivation events.

In April 1965, on Martha’s Vineyard, a Hanks rig was placed upon a 28 foot long steel vessel (looked like a Novi style lobster boat) powered by a 40 horse power outboard. For the first time shell-fishers had not only a harvest device, but also a cultivation tool. In Maryland vessels also equipped with “Hanks rig” conveyer soon started to earlier harvest sub-tidal soft shell clam beds. G.C. Matthlessen and R.C. Toner (Marine Research Foundation) and later assembled a vessel with a gasoline pump, a 6 inch suction, 4 inch discharge 1,200 gpm to 40 pounds pressure to a manifold of jets before a continuous conveyor belt (pg. 99). The conveyor belt was powered by a Briggs and Stratton ™ 1.5 hp engine. The water washed clams free of the soil and collected them on the one-inch mesh steel belt to the surface to be handpicked or dropped in buckets on deck. This soft shell operation needed two operators one for the vessel, one for the clam lift (Possible Methods of Improving the Shellfish Industry of Martha’s Vineyard Duke’s County, Massachusetts 1966). For the months of April, May, June, July, and September (1965) every morning the vessel operated in Oyster Pond in Edgartown, Massachusetts for transplanting purposes. Although in use for 100 half days or 50 8 hour days the rig harvested about 30 bushels/day (total harvest was 1,600 bushels). The bushels were quite different as they were mostly seed – over 1,500 clams to the bushel. If aquacultural raised with sufficient space for growth a harvest potential of 3,000 bushels appears to have been realistic based on these bushel counts. Two concerns occurred – salinity shock transplant into higher salinity areas and recreational shell-fishers did not own the needed sub-tidal equipment to re-harvest them – and for those doing the math a bushel of steamers was worth 10 dollars then versus today’s retail about $200.

By the time I started working on the Cape (1981), following the Blizzard of 1978, heavy soft shell sets were in many sub-tidal areas and the use of an old rubber plumbers’ helper had already become widespread - A traditional clam rake equipped with plumbers helper at one end was used to plunge depressions from which soft shells were then raked. A hydraulic “rake” developed on Martha’s Vineyard rivaled any terrestrial plow and the knowledge to use it for natural sets by preparing marine soils, soil porosity and pH. Within a decade the secret of hydraulics was out- just as a hurricanes deeply cultivated marine soils (some of the heaviest Narragansett Bay quahog sets occurred in the 1950s after hurricanes) these “dredges” both harvested and prepared marine soils for sets. Fishers soon noticed the difference and Cape Cod experiments; on soil cultivation was conducted in Bourne Massachusetts by 1982 and documented by the Cape Cod Extension Service in 1987, H.K. Rask). Mr. Rask writes in 1988, “There is a link here (Cape Cod) to the excellent sets of shellfish found in new sand deposited by storms or currents. Clams (Mya), for example, are a colonizer species and can quickly populate an empty area. New sand is not only free of decaying organic detritus but is also free from predators. Hydraulic action can easily be seen to imitate some of these natural phenomena.”

Aquacultural Uses:

The soft shell clam beds were located and between 4 to 12 feet of water were much larger than first thought. It is these marine soils close to shore and subject to organic leaf material settling upon them (sometimes called marine snow) exhibited low pH acidic conditions. After the stormy 1950s and 1960s, things quieted down and heavy sub-tidal sets occurred especially in “black sands” those previously buried now cleared of acidic muck. Soft shells do need periodic energy for natural cultivation to free soils of acids. George C. Matthiessen and R.C. Toner (Marine Research Foundation 1966) were one of the first researchers to use a Fletcher Hanks “rig” from a growing Maryland soft clam fishery in New England.

At the turn of the century, 1896-1905, the intensity of soft shell clams were often immense (one hydraulic rake experiment in Niantic Bay in the mid 1980s uncovered 30 bushels of soft shell clams in 60 minutes) but often recorded after storm events for over a century. Within a few years of these great sets interest quickly grew surrounding the concept of cultivating them – especially off Cedar Island in Clinton, CT. The heavy soft shell clam sets in Clinton Harbor soon had public meetings asking the question if leases could now be obtained. This interest diminished as temperatures fell and storm activity increased after 1938.

The enthusiasm of culturing soft-shell’s in an organized way with the development of specialized plows and cultivators declined after 1924. In the late 1880s, Bridgeport Connecticut conducted field trials of soft shell clam plows and cultivators. The New England winters started to turn sharply colder, and by December 1931, the entire Northeast seaboard was locked in thick ice. The high hopes of high yields described in the Friday, January 23, 1903 (Clinton Recorder article) was just a distant memory by the 1950s, the age of the huge offshore beds of soft-shell’s had ended to be replaced with a new heavy inshore set of quahogs.

With warmer temperatures, the next great sets of soft shell clams may already be here after Irene and Sandy. Current research regarding cultivation and the use of shell to buffer marine soils are underway again in the State of Maine. Anyone interested in acidification of marine soils and bivalve sets should review the work of Mark Green at St. Josephs College in Maine.

REMEMBER TO FOLLOW ALL APPROPRIATE RULES AND REGULATIONS WHEN SHELLFISHING. MANY AREAS IN CONNECTICUT ARE CLOSED TO DIRECT SHELLFISH HARVESTING.

In a future newsletter a review of the bivalve habitat conditions that reversed and turned sharply against oysters, Narragansett Bay would soon contain the Great Sets of Quahogs.

The references below was first written in 2008 for the EPA-DEP Long Island Study Habitat Restoration Committee – The Great Steamer Clam Sets after the Turn of the Century Summer gales including the Portland Gale of 1905. Click here for April 21, 2008 -Soft Shell Habitat Creation and Associated Population Expansion Following Significant Marine Soil Cultivation Disturbances Report.
For a much larger report about the cultivation of marine soils, see: September 20, 1990 – Madison Shellfish Commission, Madison Town Hall – The Hydraulic Cultivation of Marine Soils to Enhance Clam Production, Timothy C. Visel, SGMAP. Please click here for this report. This report is the most often viewed of all of our Adult Education and Outreach bulletins.

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.

The Sound School is a Regional High School Agriculture Science and Technology Center enrolling students from 23 participating Connecticut communities.

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