SAUGUS DUMP SURVEY SAUGUS, MASSACHUSETTS APRIL 6, 1972 ------- iNTRODUCTION At the request of the United States Environmental Protection Agency’s (EPA) Region I Technical Operations Section, personnel from the Technical Studies Section conducted a study of the water surrounding the DeMatteo Construction Company’s Saugus Dump Operation (Saugus Dump). The Dump site encompasses approximately, 150 acres of salt marsh land located some 7 miles northeast of Boston. The south side of the site drains to the Pines River via an unnamed tributary. The north side of the site drains to the Saugus River via Bear Creek. The Pines River flows into the Saugus River about Ľ mile upstream from its confluence with Lynn Harbor (See Figure 1). Cochrane et al (1) in “ A Report on Water Resources Potential of an Urban Estuary” Northeastern University, Boston, Mass. June 1970, states “movement of pollutants from the Lynn outfall proceeds along the western channel of Lynn Harbor to the mouth of the Saugus and Pines Rivers. Since that study area was limited to Lynn Harbor itself, the dye was not followed into the Saugus and Pines Rivers but strong tidal action and currents would indicate that the pollutants would continue further upstream. ‘t OPERATI ON The Saugus Dump, a “dump and cover” operation apparently has two working faces On March 23, 1972 the working face was on the north or Bear Creek side, while on April 6, 1972 the working face was on the south or Pines River side. During both days, paper and other refuse lined ‘the banks of the tributaries to the Pines and Saugus Rivers and in some cases refuse was observed in the water. Light duty fencing surrounds the dump site area on the north arid south sides. This fencing was in a general state ------- of disrepair and was leaning or broken in numerous places. SAMPLINC INFORMATION The study included water quality and shellfish sampling during ebb and low tides at several stations around the dump area. Water quality sampling stations were located in the two major drainage paths to determine the effect of the dump on the surrounding water (See Table 1 and Figure 1). The unnamed tributary to the Pines River, which drains the south side of the dump, was sampled near the dump face (SDO].) and near its confluence I with the Pines River (SDO2). The Pines River was sampled upstream (SDO3) and downstream (SDO4) from its confluence with the unnamed tributary. Bear Creek was sampled near the north face of the dump(SDO5) and near its confluence with the Saugus River (SDO6). The Saugus River was sampled upstream from its confluence with Bear Creek (SD07) and downstream from its confluence with 1 the Pines River (SDO8). Shellfish samples were collected from the tidal flats of the Pines and Saugus Rivers (MIS 3,4,5, & 6). All water and shellfish samples were collected, identified, preserved, transported, and analyzed in accordance with standard EPA procedures where applicable. Metals analyses on the shellfish samples will be performed at the National Field Investigation Center in Cincinnati, Ohio. Coliforrn bacteria analyses on the shellfish were performed in accordance with the American Public Health Association’s (APHA) “Recommended Procedures for the Examination of Sea Water and Shellfish” Fourth Edition 1970. EPA’s chain of custody record system was used in handling the samples. Salinity, conductivity and temperature were determined in the field by use of an electrodeless induction salinometer. -2- ------- RESULTS Table 2 summarizes the water quality and shellfish results of the samples taken during the study with the exception of metals which will be reported at a later date. The oxygen demand created by the leachate and drainage as measured by the five day biochemical oxygen demand test (BOD 5 ), is an indication of the waste’s potential for reducing the dissolved oxygen (DO) in the receiving water. Adequate DO levels are necessary to support fish and other aquatic lifee If DO becomes totally depleted, hydrogen sulfide gas, (H 2 S), is produced creating obnoxious odors and unpleasant environment for persons living or working nearby. The H 2 S given off may turn nearby houses, bridge, or other lead based painted structures black. High BOD 5 was found in Bear Creek (11.0 and 2.6 mg/i) and extremely high BOD 5 values were found in the unnamed tributary to the Pines River (260 and 82 mg/i). See Table 2. The BOD 5 of “unpolluted”water is below 1.0 mg/i. The high BOD 5 causes the low DO values found in Bear Creek (5.1 and 5.5 mg/i) and the absence or near absence of DO in the unnamed tributary to the Pines River (0.0 and 0.6 mg/i). D.O. saturation values are shown on Table 3. The Massachusetts Water Quality criteria for DO in class SB waters is not less than 5 mg/i at any time. Suspended solids concentration found in the water samples are high. Suspended solids, if in sufficient quantity, can interfere with the normal estuarine ecology by reducing photosynthetic activity by sunlight reduction or by killing benthic organisms by forming sludge deposits. Total coiiform bacteria are used as indicators of pathogenic bacteria. Coliform concentrations in the unnamed tributary to the Pines River (SDO1 —3- ------- & SDO2) indicate that the Massachusetts Class SB bacteria criteria of not more than 700 total coliforms per 100 ml of sample nor more than 2300 total coliforms per 100 ml in more than 10% of the monthly samples may be exceeded. Shellfish taken from the tidal flats along the Saugus and Pines Rivers, with the exception of station MIS4 on the Pines River, have a fecal coliform con- centration which exceeds the National Shellfish Standard for marketable shell- fish of 230 fecal coliform per 100 ml sample. The Massachusetts Department of Public Health has closed portions of the Saugus and Pines Rivers for the taking of shellfish. This was done because of the poor bacterial quality of the water and a sanitary survey of the area which showed the shellfish beds to be exposed to various pollutant sources. Estuaries are literally the “nurseries” of the ocean since so many animals utilize them for breeding and early life development. Nutrients are necessary for a normal estuarine system. However, an excess or imbalance of nutrients such as nitrogen and phosphorus lcan upset the balance of the estuarine ecosystem. With the exception of the upstream station on the Saugus River, SDO7, the Massachusetts Class SB ammonia nitrogen criteria, 0.2 mg/l, is exceeded. The ammonia nitrogen values of the Pines and Saugus Rivers increase as drainage from the dump area enter them. Total phosphorus values exceeded the Mass- achusetts Class SB criteria, 0.07 mg/i, at all stations except SDO3 and SDO8. The waters samples exhibited an oil and grease range of 16.7 and 34.8 mg/i. This is in violation of the Mass. SB criteria for oil and grease which specifies “non allowable”. S Results of the metals analyses on the shellfish samples are not included in Table 2 but will be included as an addendum when the results are received from EPA’s National Field Investigations Center (NFIC) in Cincinnati, Ohio. -4- ------- The estuary is suffering from the effects of pollution, some of which is coming from the Saugus Dump. However, proving damages caused by the dump would require a great deal more sampling and even then proving gross damage is not certain. ------- SAUGUS • DUMP AREA SAUGUS DUMP STUDY SAUGUS, MASS. N LYNN HARBOR ------- TABLE 1 STATION SDO1 S DO 2 SDO3 SDO4 S D05 SDO6 SDO7 SDO8 MI S3 Ml S4 NI S 5 NI S 6 LATITUDE oI It 42 26 05 42 25 57 42 25 56 42 25 53 42 26 40 42 26 47 42 26 53 42 26 38 42 25 54 42 26 01 42 26 31 42 26 53 LONGITUDE o 70 59 03 70 59 01 70 59 07 70 59 00 70 58 50 70 58 25 70 58 28 70 58 70 59 08 70 58 38 70 58 16 70 58 31 DESCRI PTION An unnamed tributary to the Pines River near the dump ar The mouth of the unnamed tributary to the Pines River The Pines River upstream of the unnamed tributary The Pines River downstream of the unnamed tributary Bear Creek near the dump area The mouth of Bear Creek The Saugus River upstream of Bear Creek The Saugus River downstream of the Pines River The Pines River upstream of the unnamed tributary The Pines River downstream of the unnamed tributary Near mouth of the Pines River The Saugus River just above Bear Creek ------- SAMPLE ANALYSES ABBREVIATIONS AND UNITS OF MEASURE Analysis Reported Description Measured In Temperature Sample Temperature Degrees Centigrade (°c) Conductivity Conductivity Millimhos per square centimeter Salinity Salinity Parts per thousand Turbidity Turbidity Jackson candle turbidity units (JTu) Total non-filterable Total Suspended Solids Milligrams per liter (mg/U residue (NFR) Fixed non-filterable Inorganic Suspended Solids mg/l residue (NFR) DO Dissolved Oxygen mg/I BOD-5-Day 5-Day Biochemical Oxygen mg/I demand incubated at 20°C Oil and Grease mg/I as oil, and grease (Hexane extractable) TKN Total Kjeldahl Nitrogen mg/I as N NH 3 -N Ammonia Nitrogen as N mg/i Total P Total Phosphorus as P mg/i Total Coliforms Total Coliform bacteria Number per 100 milliliters Fecal Coliforms Fecal Coliform bacteria Number per 100 milliliters Letters preceding a reported value denote the following: N = Results qualified not quantified K = Less than recorded value ------- TABLE 2 SUMMARY OF DATA DEMATTEO CONSTRUCTION COMPANY SAUGUS DUMP AREA APRIL 6, 1972 TOTAL FIXED OIL & STATION TIME TEMPERATURE CONDUCTIVITY SALINITY TURBIDITY NFR NFR DO BOD 5 GREASE TKN NH 3 -N TOTAL P °C mii limhos/cm 2 0/00 JTU (mg/I) (mg/I) (mgJl)(mg/1) (mg/I) mg/i mg/i mg/I SDO1 1050 200 221.8 146.3 0.0 260.0 28.3 M 23.50 0.34 SDO2 1105 5.8 26.6 26.2 45 47.8 8.6 0.6 82.0 - - - 0.16 SDO3 1040 5.7 26.5 26.2 4.5 20.0 3.9 9.2 2.3 21.2 - - 0.06 SDO4 1050 5.8 26.7 26.1 4.0 26.2 5.0 9.6 1.6 16.7 M 1.23 0.08 SDO5 0945 10.0 47.4 17.8 5.1 11.0 26.8 3.60 2.76 0.14 SDO6 0935 - 7.0 20.0 5.6 5.5 2.6 - - - 0.10 ‘SDO7 0955 6.9 23.7 22.0 6.0 15.0 1.5 6.2 1.4 19.3 0.50 0.20 0.10 SDO8 1140 6.0 27.6 27.4 15.0 15.8 0.7 9.2 1.5 34.8 0.50 0.44 0.06 Note: All ‘eater samnies ‘ere collected at a c!enth of one foot. ------- TABLE 2 (Cont.) SUMMARY OF DATA DEMATTEO CONSTRUCTION COMPANY SAUGUS DUMP AREA APRIL 6, 1972 TOTAL FECAL STATION TIME COLIFORM COLIFORM per 100 ml per 100 ml SDO1 1050 3000 330 SDO2 1105 1000 220 SDO3 1040 30 2 SDO4 1050 J0 6 SDO5 0945 94 28 SDO6 0935 250 48 SDO7 0955 410 48 SDO8 1140 330 18 MIS3+ 1300* 17200 4600 M1S4+ 1050* ::2400 330 1130 230 K20 MIS S+ 1220* 13000 500 MIS6+ 0945* 70000 7000 * Denotes shellfish meat samples + Indicates analysis performed by APHA’S moi€probable number method. Note: All water samples were collected at a depth of one foot. All shellfish samples were collected from the tidal flat muds. ------- D. 0. SATURATION STATION SATURATIP ACTUAL °L SATURATION SDOI 0.0 0 SDO2 9.0 0.6 6.7 SDO3. 9.0 1 9.2 Super saturated SDO4 9.0] 9.6 Super saturated SDO5 5.1 - probably less SDO6 - 5.5 - than 750/ SDO7 ç9.4\ 6.2 66 SDO8 8.8 9.2 Super saturated TABLE 3 ------- BI BLI OGRAPHY 1) Cochrane et al ttReport on Water Resources Potential of an Urban Estuary’ t P.6 , Northeastern University, Boston, Massachusetts, June 1970. ------- ‘1 1w Loll tdz..: dntr. I r ,athmi I.tod an Urn ;‘ sieJrnOunp rurnrrnd I. • 1 b,. repor L natit. Lcd: Sauzus Dump Survey Saugus, Massachusetts April 6, 1972 All station numbers referred to In this addendum with the exce: Lon of station 3Db are described and located In the original r:port. Water samples were takon at. stations SDO1-3D38 to be analyzed for: mercury md arsenic. As can be seen from Table 1Ł, arsenic values at all stations were less than 6.0 u f).. A concentration f 3 ug/l in seawater is considered normal. The samples t ’ere not c’ole to ‘be analyzed f3r mercury at NflC because of interfera:ces encountered during testthg. Subsequently two more samples were taken on Kay 22, 1972 at itations Sf02 and Sf10 for mercury and arsenic analysIs. See Table IA. Station Sf10 is located at the zouth of Bear Creek slic.t;’:y south of Sf06. • ‘3eef i g n 1A. Shellfish samples frpr. stations NiS34 I56 were analy3cd fo: c:. f:d.in, copper, iron, chromium, zinc, lead and mercury. Se. ..s 1 A $& mcults : of the analyses; In an unpublished report, Hr. a’ t7or.g of Efl, c i S c - cusses the average trace metals expected to be found in sheflf’.h. Attichiiient #1. as values of the metals found in the shellf± A tar..’. taken durin t the survey are representative of t ia average met: .L, cct- baritrat1a s normally associated with ‘she1lf s .tung, the at: ‘ ------- / 7 / i 1/ / 1 ,1 / I — - • -;i - - - I _ / • • / / F —-__ — ‘- I —I.. .•.•J_•I• : : \\ / _ / / •-- • -:—— -: 7 p r y — 2 -. • f - . - • • ••• . - - -. :.. - • • /1 — S p, 1 — , — , L — — - - - — 1 •.: • \] r \ [ r y,,_/ // - : - /‘ --- r2/ / • • ,y’ / _-,-:- - \// / - N /I S - — - / // \ 7- - - - p. ‘7 • • “.; E’ zy ’ -A ’ - • f) .f - f ,Ct ,Rg /5 -c-r::-.’-’c p__? --. _.. ._ -. _J.__I -4 ------- A ‘LU ‘C CE ” ;;i’ u ,s tii ; 1).\ ‘ [ ‘ a SAiJC J3 DRflP ARi’A : lurj J. 6, 1972 . . N L 2?, 1972 , —— —---- —- ------ “- - -- - -MRL2LJ2J _ —--— --- - STXTICL’J “ Cu C c l Cr Zn Pb l i p x LhfiL .S2LLt.. J3ilJ1tL S Ec i - - - -• - - 81 )02 - - - - - - - * ‘ C 6.) 31 )03 - . - - - - - - < 6.0 - - . - - - - - * <6.a 3 1 )05 -. - . - - - - - K ó.o 6 1 )06 - - - - - - < -6.0 81107 - - - - - - - <6.o 01 )38 - - - . - -. - - <6.o 31110 - . - - - - . - - - - 1: 1 83 ÷ <0.1 3.9 20.0 3.5 1 5. 5 5.0 — — <0.1 L.fl 3.5 3.5 0.5 ib.5 5. 3 — — f 1c35-i - 43.1 J.’ 0i 19.0 2.0 1 9.5 9.0 — — <0 .1 1.9 0 .5 ih.o i. 5 io.5 9.o -. - f In (/ r1’ercrirr’c, i’ovcjt-i j ;‘ j I Ic ; *9: Shc ) if i ,h c.cu I c: is ph - l U.’ ,ltii:; j 4 :-r “ i I ogi’am lit - , I . tissue ucigh Ls i /i i’iicrrjj - j’cnis ‘Ci’ .11 Lur ‘a’ oar C p. ) !’ b ii tIA ‘j “j’ l ‘?72 _ _ _ .cz0j &cz9.0 ‘ <.. O. I .1 -4 ------- ENVIRONMENTAL PROTECTION AGENCY - - .YTO Edward F. . ong, Natural Resources Officer ATTN ‘ DATE: June 6, 1972 5UBJ GT. Shelifisheries — Pines River, Saugus, Massachusetts TO; • Thomas Devine, Chief, Technical Support Section Summary The Sau us Dumb is located on Route 107 with its easterly and southerly exposures bordering on the Pines River. The northeasterly portion of the dump borders on Bear Creek which empties into the Saugus River just north of the junction of the Pines and Saugus Rivers. The active dump- ing area has not approached the river bed, but the issue is raised that leachate from the dump site is entering into the waters of the Pines River and possibly Bear and Diamond Creeks. The effects of the discharges from the dump on the shelifisheries, based on bacterial and metal analyses of samples collected in the waters adjacent to the dump, show that at the time of sampling, the data partially but inconclusively incriminated the dump to the pollution of the shellfish. However, the shellfish beds were ordered closed to shelifishing by the State Department of Public Health due to excessive bacterial densities exceeding ciepuration criteria. Using metals as an index to pollution, the data did not show conclusively that leachate from the dump had caused inordinately high levels of metal in the shellfish. Shellfish Classification The Pines River in Saugus and Revere is classified by the State De artr er .t of ?ublic Health as shellfish area N26.l and made available to licensed commercial diggers under the supervision of the Division of Marine Fisheries. This classification is a restricted area (d.epuration) arid all shellfish harvested from the beds must be taken to the shellfish treatment plant before used for food purposes. Reference to shellfish in this report applies to the available commercial specie of soft clams, Mya Arenaria. The area is defined as follows: N26.1 The waters and flats of the Pines River, southwest of a line drawn between the remains of a breakwater the south of which is in Saugus. This is east of the Boston and Maine Railroad bed and west of Route lŔ. On June 8, 1971, the Depart:nent of Public Health, as a result of surveys, determined that shellfish harvc ted f:c:i tha; cc ’tion of shellfish a:ea N26l, as defined e1ow, are unfit i o food : poses and. iay be dangerous to the puolic health even after tr nt at the Itewburyport Shellfish /7 , 777C T ‘/ DA .. I I thL lII.7I ------- —2— eat ient Plant. Therefore, the Department, until further notice, closed t e area to the taking of shellfish for food. purposes. The prohibited. area of N26.l now include all the waters and flats of the Pines River from the bridge crossing the Pines River, Route 107 northeasterly to its point of confluence with the Saugus River. :- 3Wever, not all of the Pines River was closed to shellfish harvesting. On the sa:. date, a portion of the river remained restricted to depuration. N26.1 Restricted Area (Depuration) All the vaters and. flats of the Pine River, including Diamond Creek from the bridge crossing the Pines River at Route 107 northwesterlY to Route Ci, Saugus. Field Data A. Bacterial results - The State Department of Public Health closed shellfish area N26.l be- cause surveys indicated that the overlying shellfish waters did not meet the depuration standard of 700 N per 100/mi of sample. At no time did the State incriminate the dump as the polluting source and the reason for closure of a portion of N26.1. The National Shellfish Sanitation Standard considered satisfactory for market shellfish is a fecal coliform density of not more than 230 N per 100 grams (shellfish meats) and 35°C plate count of not more than 500,000 per gram (shellfish meats) will be acceptable without question. Shellfish samples collected on April 6, 1972 showed that results of bacterial fecal coliform data at all stations failed to meet the market standard of -the National Program. The ranges vent from the lowest figure of 330 TN at Station fISh to a high of 700 MPN at Station MIS6, a location on the Saugus River between the railroad tracks and. Route 107. Other shellfish samples collected during the _:‘st survey, July 20, 1971 indicated contrasting bacterial densities at all stations as compared to subsequent surveys of the following day and. the survey of April 6, 1972. Of the nine fecal results, only two met the standard for market shellfish. The differences between the three surveys showed that hydrographic influences caused by the Saugus River, Revere Sound, and. Lynn Harbor do relate to the flushing of the Pines River causing inconsistent bacterial results. ------- —3— Bacterial Results of Shellfish Meats, Pines River Statl3fls Dates Fecal Coliforms 100/grams MIS 3 July 20, 1971 3300 July 21, 1971 200 April 6, 1972 6o MIS i July 20, 1971 3300 July 21, 1971 200 April 6, 1972 330 !IS 5 July 20, 1971 1700 July 21, 1971 1 OO April 6, 1972 500 MIS 6 April 6, 1972 7000 B. Shellfish Metal Analyses In 1967, Doctors Benjamin H. Pringie and Carl N. Shuster, Jr., forirerly of the Northeast Marine Health Sciences Laboratory, Narragansett, Rhode Island, in an unpublished report, produced a guide to trace metal levels in shellfish. Pringle and Shuster analyzed eight species of shellfish from about one hundred stations along the Atlantic coast, Maine through North Carolina and from two stations on the Pacific coast of Washington. The test performed by Pringle on the different species of shellfish gave wide ranges for each metal. For example, zinc analyses on the soft clam gave a range of 9.0 — 28, iron was I 9.70 — 1710, lead 0.10 - 20 and chromium 0.10 — 5.0, all expressed in ppm. To arrive at some index for the ranges, Pringle settled on computing and designating an arithmetical metal average for each specie of shellfish. I an using this average as a baseline to compare with the results of the metal analyses, which were made by the Division of Field Investigations, Cincinnati for NEBO of shell- fish sam 1es collected during the July 21, 1971 survey by NEBO. Cincinnati took the three shellfish samples and with each lot divided it into 10-12 separate portions and proceeded with the analyses. I averaged the results of each station (the separate portions) and arrived at a single number for each metal of each sampling point. This gave me a figure to use as comparability with Pringle’s average figures covering the East Coast. Shellfish from all three stations contained higher levels of lead and chromium when matched against Pringle’s data. One other metal, zinc, in sl-.ellfish from Station MIS 3 exceeded Pringle’s average by a slight amount. The iron level from all three stations were less than the control average, especially Station MIS 3 with a reading of 85.8 as against &05.0. The mercury levels from all stations were within the FDA standard for market shellfish. ------- _14 — c pariso: of Trace Metal Levels in Soft Clams from the Pines River, MA j) . P:- r c :96T Atla ;i Coast. M — North Ca NEBO rolina MIS3 July 21, M1S 1 4 1971 MIS5 MLTAL mg/kg in t tissue wei ’hts Zinc 17.0 20.5* 16.7 16.3 Co uer 5.8 14.6 .5.5 14.3 Iron 2405.0 85.8 379.6 289.3 Lead. 0.7 6.66k 57ii 24.249* Chromium 0.52 1.02 w i.6 2. 1 43* !‘ ercu rv 0.2 0.1 4 0.1 0.1 Discussion Shellfish can selectively concentrate chemical materials up to many hundreds of times those levels found in the environment. Accumulation occurs through several pathways, chiefly by ingestion of particulate material and by ab- sorption. Oysters for example, have a propensity to accu.mmulate more cop- per, zinc, and. cadmium in preference to other heavy metals. The shellfish, because of physiological reaction to certain environmental conditions such as o rgen, temperature, salinity, algalblooms, can be stimulated to hypera- ctive response or relegated to a dorzna.nt state of hybernation. Oysters again of temperatures below l°P’ are known to hybernate for the winter and bacterial examination at that time would generally yield low results. There- fore, environmental levels of the metals cannot be accurately determined based simply on the levels found in shellfish. Seasonal or any other variations in the levels of contamination in the environment can be key factors in the concentration of trace metals accumulated by the shellfish. In general, leachate from a sanitary landfill is quite polluting. Some- times it may take as long as 20 years to appear but its appearance may show up much sooner. The short-term study of this particular landfill may not at the present, establish the magnitude of the problem. Common in the leachate are many metals in various physical and chemical states. It is generally accepted that the waste contains iron 200 — 1TOO, zinc 1 — 135, nickel 0.01 — 0.8, and copper 0.10 — 9.0, all expressed in mgll. Using iron as the index to show a cause and effect relationship between the shellfish and dump waste, we find that the levels of iron in the shell- fish were no greater than what normally was found in the estuaries (Pringle’s findings). We know that chloride and other ions such as iron are not re- leased in one slug; rather periodically or seasonally. It generally takes from 200 to 1400 days from the day of deposit for the iron to be released in a heavy concentrations, a range of less than 300 to 1700 mg/i. In other words, did we survey at the right ti.rne? In our shellfish sampling I would look for a high level o iron concentration in the shellfish which indeed did not appear. Based only on three stations and during one single run, I would not, under any circumstances, draw definitive conclusions. The dump, however, has been in exist ance for a long time and. I would, assume that the shellfish were exposed to these C Ci C trends. Shellfish Populations On April 6, 1972, while collecting samples of shellfish for analyses, I did ------- —5— not use a grid, pattern to determine shellfish population densities of the Pines River estuary, however, shellfish uncovered at the three stations and a few othei adjacent ones did reveal heavy sets of spat an juvenile soft clams. Juvenile class of clams are not marketable, being less than one and one/half inch. The legal i-arket size is two inches. I noted that most of the beds were about 25 feet from the high water irLark edging irregularly toward the river channel in the in ’ ertidal areas. The channel area is clear except for patches of mussels which extend into the sand bars. During the collection, I also noted that most of the i arket size clams were found on the sand bars further up the Pines River beyond the railroad bridge. In the absence of sheilstock measurements at the time of collection I would guess from general observations that the number of in mature clans were at least, 5—6 times that of market shell- fish. ------- |