A Shellfish Study for the Proposed Floating PersonalWater Craft Dock System and Fixed Access Dock at Penny Lane Marina, Margate, NJ. Survey Conducted For: Penny Lane Marina Roy Goldberg, Owner 9420 Amherst Avenue Margate, New Jersey 08402 Survey Conducted By: Richard Stockton College of New Jersey’s Coastal Research Center 30 Wilson Avenue Port Republic, NJ. 08241 (609) 652-4245 November 18th & 19th, 2010
Penny Lane 1 A Shellfish Study for the Proposed Floating Personal Water Craft Dock System & Fixed Access Dock at Penny Lane Marina 9420 Amherst Avenue, Margate, Cape May County, New Jersey November 18th & 19th, 2010IntroductionThe shellfish study was designed and implemented using the Shellfish Survey Guidelinespublished by the New Jersey Department of Environmental Protection (NJDEP) as authorized byJeffrey C. Lockwood, 1991 National Marine Fisheries Service, Habitat and Protected ResourcesDivision. The proposed development of Penny Lane Marina includes two main floating docksand 51 Jet Ski ports. The dock would extend 250 feet from the existing bulkhead along AmherstAvenue (in the northwest to southeast direction), and is approximately 75 feet wide. Theproposed marina is bordered on both sides by existing dock structures. The bay floor slopesfrom a depth at the bulkhead of -5.0 out to a depth of -30.0 feet NAVD 88. The target species isthe Hard Clam (Mercenaria mercenaria) a shellfish of commercial and biological significance.Methods and MaterialsThe study area was selected by analyzing the area of the proposed marina and evenly distributingthe entire study area into uniform sub-sections (chart 1). The range of water depths was from -5.0 to -30.0 feet below the North American Vertical Datum of 1988 shown in McLarnon’sUSACOE Permit Plan.Using ESRI ArcGIS 9.3.1 a virtual grid was set up in the same approximate position of theproposed dock system with corresponding known locations at each of the intersections of thegrid totaling 24 points (charts 1 and 2). These points within the grid served as the locations forboth the juvenile and adult clam survey. Twelve locations were used for the juvenile clamsurvey and twelve for the adult clam survey. The distance between points in both the adult andjuvenile clam survey is 25 feet. Using the Leica RTK GPS system 1200, the positions of all thedata points for both the juvenile clam study and the adult clam raking study were obtained.To conduct the juvenile clam study the 12 data point locations stored on the GPS system wereused as waypoints to locate each sample site (chart 1, table 5). At each location, a single anchorwas set to help stabilize the boat. A Wildco Ponar grab sample; with an area of 0.75 sq. ft., wasused to acquire the samples. Replicate grabs were often necessary to obtain a full sample size.Once a full sample was obtained, the material was sifted through a 5mm sieve and inspected forjuvenile clams. This process was repeated at each individual location. Additional variables suchas sediment type, additional bivalve mollusks, as well as aquatic vegetation were also noted ateach site. At each location the abundance per square foot (ft2) and size distribution (mean andrange) were also reported (tables 1 and 3).To conduct the adult clam rake study, site locations stored on the GPS were again used tonavigate to the pre-established locations (chart 1, table 6). At each location two anchors wereset, one at the bow and one at the stern. The anchor lines were let out equally and incrementallyin 10’ sections. Each 10’ section was raked using a 16” x 3” toothed bull rake at each locationuntil a 30’ transect distance was achieved. Additional variables such as sediment type, otherbivalve mollusks, as well as aquatic vegetation were also noted at each site. At each location, theabundance per ft2 and size distribution (mean and range) was also reported (Tables 2 and 4).
Penny Lane 2Results – juvenile shellfish surveyAs reported above the study area was sampled for juvenile shellfish by utilizing a Wildco PonarGrab Sample with an area of 0.75 sq. ft. Twelve sites were established and sampled representingthe area of the proposed marina. Zero juvenile Hard Clam (Mercenaria mercenaria) were foundin the study area. A total of 9 sq. ft. was sampled with an overall density of 0 clams/sq. ft. Thesedimentology of the area consisted of very fine black sand with silt, black silt with sand, or fineblack sand with silt. There were only 2 major species of aquatic vegetation at all of the locationssurveyed, Sea Lettuce (Ulva lactuca) and Agardh’s Red Weed (Agardhiella tenera). A total of,17 Long-Clawed Hermit Crabs (Pagurus longicarpus), 8 Mud Dog Whelks (Nassariusobsoletus), 2 Juvenile Blue Crab (Callinectes sapidus), 2 Blue Mussels (Mytilus edulis), and 1Blood Ark (Anadara ovalis), were found in the process of locating juvenile Hard Clams (tables 1and 3).Results – adult shellfish surveyAs reported above the study area was sampled using a 16” x 3” toothed bull rake. A total of 3Hard Clams (Mercenaria mercenaria) were found in the entire area which consisted of 12individual sites approximately 25 feet from each other respectively. Each site was raked adistance of 30’. Clams were found in 2 of the 12 sites. A total of 479.88 square feet was rakedwith an overall density of 0.0062 clams/sq. ft. The mean size of the clams collected was 7.73cmwith an overall range from 5.6 to 10.0 cm. The sediments in the area consisted of very fine blacksand with silt, or black silt with sand. There was only 1 major species of aquatic vegetation at allof the locations surveyed, Sea Lettuce (Ulva lactuca). One Common Spider Crab (Libiniaemarginata) was found in the process of locating adult Hard Clams (tables 2 and 4).ConclusionThe study area at 9420 Amherst Avenue, Margate, Atlantic County, NJ is the location of theproposed development of Penny Lane Marina. The area was surveyed by utilizing ArcGISsoftware, GPS equipment, grab sampling techniques, and a clam rake to help isolate the HardClam (Mercenaria mercenria). According to The NJAC’s Coastal Zone Management Rules “ashellfish habitat area is defined as an area which… has a current shellfish density equal to orgreater than 0.20 shellfish per square foot”. Both the juvenile and the adult clam study haddensities below the cited threshold. The juvenile clams (those surveyed with the 5mm sievescreen) produced a value averaged across the total surface area sampled by the ponar grabsamples (9.0 ft2) at 0 clams per square foot. The adults recovered in the clam rake that covered479.88 square feet yielded 0.0062 clams per square foot. These numbers indicate that the clamdensity within the area delineated for the installation of a personal water craft dock system andfixed access dock at Penny Lane Marina does not substantiate a viable Hard Clam habitat.
Penny Lane 3 Water Quality Characteristics for Penny Lane, Margate, NJ. Site of the Proposed Marina Development Temperature, Salinity, Dissolved Oxygen, Depth, pH, Specific Conductivity, and Turbidity Data for (Mercenaria mercenaria), Hard Clam PopulationsIntroduction:The Richard Stockton Coastal Research Center (CRC) completed a juvenile and adult hard clamstudy for the proposed development of Penny Lane Marina, Margate, NJ in November 2010.Twenty four sites were raked and grab samples were taken for juvenile and adult hard clams. Inthis study, no juvenile clams were observed and just 3 adult clams were obtained within 480square feet of space raked in the project area. A water quality assessment was also included inthe proposal based on the follow variables: temperature, salinity, dissolved oxygen, depth, pH,specific conductivity, and turbidity for the water just above the sediment surface.Water Quality at the Site:The CRC complied the data on November 18th & 19th 2010 with a study of the water qualityparameters for the 24 sites subjected to clam raking or grab sampling using a YSI water qualityprobe to obtain the results listed in table 7, below. The table lists the site location using the samedesignations used in the clam study. The dissolved oxygen values are shown as both a percentageof the maximum level in seawater and as milligrams per liter of water. The depth ofmeasurement at the mid-tidal elevation stage the work was done is also listed. The specificconductivity is given as well although the salinity is the most common expression of the saltcontent of the water.Conclusions:The temperature is normal for the time of year within the bay environment of Atlantic County.The salinity is also within normal ranges for mid-tide conditions behind the barrier island,however, the average value failed to fall within the optimal range for the Hard Clam of 26.5 to27.5 ppt. The dissolved oxygen levels are excellent with average values of 8.74 mg/L, and95.6% respectively. The pH value of 7.94 is within the normal range for all stages of Hard Clamdevelopment. None of the remaining water quality parameters including depth, specificconductivity, and turbidity, would dictate that Mercenaria mercenaria could not live in thewaters of the proposed development of Penny Lane Marina (see appendix at end).
Penny Lane 7 Table 2: Rake Samples of 12, 30-foot Traverses within development SiteTransect Adult Clams (live) (cm) Clams Per Site Other Shellfish Observations Transect Length Hard Clam Density Mean (cm) Range (cm) A1 0 2 Adult Hard Clam shells 30 0 - - A2 0 30 0 - - A3 0 1 Adult Hard Clam Shell 30 0 - - A4 0 30 0 - - A5 0 30 0 - - A6 7.6, 10.0 2 2 Adult Hard Clam shells 30 0.05 8.8 2.4 A7 5.6 1 30 0.025 - - A8 0 30 0 - - A9 0 30 0 - - 1 Adult Common Spider Crab A10 0 Mussel Shells 30 0 - - (Libinia emarginata ) A11 0 30 0 - - A12 0 36 Mussel Shells 30 0 - - 479.88 sq. ft. sampled, 3 adult Hard Clams = 0.0062 clams/sq. ft.
Penny Lane 8 Table 3: Aquatic Vegetation & Sediment Type / Grab SampleSite # Species & viability of aquatic vegetation Sediment J1 no vegitation found Very Fine Sand with Silt, Black J2 Minimal amounts of Sea Lettuce (Ulva lactua ) Very Fine Sand with Silt, Black J3 no vegitation found Very Fine Sand with Silt, Black J4 no vegitation found Very Fine Sand with Silt, Black J5 Minimal amounts of Sea Lettuce (Ulva lactua ) Silt with Sand, Black J6 no vegitation found Very Fine Sand with Silt, Black J7 no vegitation found Very Fine Sand with Silt, Black J8 no vegitation found Fine Sand with Silt, Black J9 no vegitation found Very Fine Sand with Silt, Black J10 Minimal amounts of Sea Lettuce (Ulva lactua ) Very Fine Sand with Silt, Black J11 no vegitation found Very Fine Sand with Silt, Black J12 no vegitation found Silt with Sand, Black
Penny Lane 9 Table 4: Aquatic Vegetation & Sediment Type / Rake SampleSite # Species & viability of aquatic vegetation Sediment A1 Minimal amounts of Sea Lettuce (Ulva lactua ) Very Fine Sand with Silt, Black A2 Minimal amounts of Sea Lettuce (Ulva lactua) Very Fine Sand with Silt, Black A3 no vegitation found Very Fine Sand with Silt, Black A4 Minimal amounts of Sea Lettuce (Ulva lactua ) Very Fine Sand with Silt, Black Minimal amounts of Sea Lettuce (Ulva lactua ), and Agardhs Red A5 Very Fine Sand with Silt, Black Weed (Agardhiella tenera ) A6 no vegitation found Silt with Sand, Black Minimal amounts of Sea Lettuce (Ulva lactua ), and Agardhs Red A7 Very Fine Sand with Silt, Black Weed (Agardhiella tenera ) A8 no vegitation found Silt with Sand, Black A9 Minimal amounts of Sea Lettuce (Ulva lactua ) Silt with Sand, BlackA10 Minimal amounts of Sea Lettuce (Ulva lactua ) Very Fine Sand with Silt, BlackA11 Minimal amounts of Arardhs Red Weed (Agardhiella tenera ) Very Fine Sand with Silt, BlackA12 Minimal amounts of Sea Lettuce (Ulva lactua ) Very Fine Sand with Silt, Black
Penny Lane 12 References1. J. C. Lockwood, “Shellfish Survey Guidelines”, National Marine Fisheries Service, Habitat and Protected Resources Division, Highlands, N.J., 1991.2. N.J.A.C., “Coastal Zone Management Rules”, 7:7E-3.2, 19-22, (2009).3. R. D. McLarnon, PE., “Penny Lane Associates USACOE Permit Application Plan”, (2010).
Penny Lane 13 APPENDIX OF LITERATURE FOUND DISCUSSING HARD CLAM HABITAT PARAMETERSThe References Below Cover Specific Parameters for Mercenaria mercenaria clams1. ER-L and ER-M sediment quality guideline values are from Long et al. (1995) and Longand Morgan (1990). TEL and PEL sediment quality guidelines are from MacDonald (1994) andMacDonald et al. (1996). Unacceptable DO: any observation with DO < 0.3 mg/l, or 20% ormore time-series observations < 2 mg/l, or all time-series observations < 5 mg/l.2. Northern quahog Mercenaria mercenaria abundance and habitat use inChesapeake BayJournal of Shellfisheries Research, August, 2005 by RogerMann, Juliana M. Harding, Melissa J. Southworth, James A.WessonClam densities decreased significantly across the four types of substrate with the highestdensities observed in shell substrate followed by sand, mud and anoxic muds in order ofdecreasing occupation (Kruskal Wallis, H = 1,414.27, DF = 3, P < 0.01; Fig. 3). Less than 1% ofall clams collected were from anoxic mud substrates whereas shell, sand, and mud substratescontained 11%, 68% and 21% of clams, respectively. Although shell and sand substratescontained the highest observed densities of hard clams, these substrate types were only present in38% of patent tong samples collected from potential clam habitats.3.Abundance:In the IRL as in other areas within its range, Mercenaria mercenaria is most abundant in shell-containing soft bottoms. They are also found (in decreasing order of abundance) on sand flats,sand/mud flats and on muddy bottoms (Wells 1957; Pratt 1953). A study by Peterson et al.,(1984) also showed that densities of 0 - 2 year old hard clams in eelgrass (Zostera marina) bedsof North Carolina was more than 5 times the average density of clams in nearby sand flats (9 persquare meter in eelgrass, vs. 1.6 per square meter in nearby sand flats. Further, hard clams fromZostera beds appeared to be somewhat larger, on average, than those from sand flats.Hydrodynamic baffling by seagrasses may be at least partially responsible for the observed result(Peterson et al., 1984). Reduction in currents near the benthos enhances the deposition of finesediments and suspended materials between blades of seagrass, especially near patch edges.Hydrodynamic baffling therefore provides a rich food source for juvenile clams.
Penny Lane 144. FWS/OBS-82/10,77 AUGUST 1984HABITAT SUITABILITY INDEX MODELS: HARD CLAMRosemarie MulhollandFlorida Cooperative Fish and Wildlife Research UnitU.S. Fish and Wildlife ServiceSchool of Forest Resources and Conservation117 Newins-ZieglerUniversity of Florida, Gainesville, FL 32611 SPECIFIC HABITAT REQUIREMENTS: Embryo, Larva, JuvenilepH. Calabrese (1972) observed that the successful recruitment of mercenaria requires thatthe pH of estuarine waters not fall below 7.0; he found no significant decrease in the number ofclam embryos developing normally within the pH range of 7.0-8.75, but that number was greatlyreduced at pH 9.0. Survival of clam larvae was normal at pH 6.25-8.75, but the range for normalgrowth was 6.75-8.50. Although clam larvae can survive at pH 6.25, a pH of 7.0 is required fornormal development of the embryo. Levels of pH below 7.0 limit recruitment of the species(Calabrese 1972).Dissolved oxygen. Morrison (1971) found that growth of shelled veligers of M. mercenaria wasnormal when dissolved oxygen concentration was 4.2 mg/l or greater. Growth essentially ceasedat concentrations of 2.4 mg/l and less. Larvae survived extended exposures (14 days) to 1 mg/ldissolved oxygen but grew little. Prolonged exposure to levels of less than 4.0 mg/l lengthenedthe clams planktonic stage and decreased its probability of survival. Embryos developednormally at oxygen levels as low as 0.5 mg/l; however, 100% mortality occurred at 0.2 mg/l.Fluctuations in dissolved oxygen do not affect adult hard clams as much as do fluctuations intemperature and salinity (Stanley and DeWitt 1983). The burrowing ability of M. mercenaria wasneither severely nor permanently impaired by exposure to reduced oxygen levels (less than1mgl1 seawater) for up to 3 weeks (Savage 1976). Pratt and Campbell (1956) found nocorrelation between growth rates and various concentrations of dissolved oxygen. All life stagestolerate nearly anoxic conditions for long periods, though they may cease growing (Stanley andDeWitt 1983).Salinity. Salinity appears to be most critical for M. mercenaria during the egg and larval stages(Stanley and DeWitt 1983). At Long Island Sound, New York, eggs developed into straight-hinged veligers only within the relatively narrow salinity range of 20.0 to 32.5 parts per thousand(ppt ), The optimum for development of clam eggs was about 26.5 to 27.5 ppt (Davis 1958).Growth of larvae, once they attained the straight-hinged stage, was comparatively good atsalinities as low as 20 ppt (Davis 1958), but Chanley (1958) found that growth of juvenile M.mercenaria was retarded at salinities of 22.5 ppt or lower. Castagna and Chanley (1973) foundthat metamorphosis of M. mercenaria from veliger to seed clam (byssal plantigrade stage) wasinhibited below 17.5 to 20 ppt.Temperature. Davis and Ca1abrese (1964) noted that 1aboratory-rea red straight-hinged
Penny Lane 15veligers of M. mercenaria were capable of ingestion, but not digestion, at 10°C (50°F),- andconsequently did not grow. Growth was positively related to temperature at 18.0° to 30.0°C (64°to 86°F). Growth of straighthinged veligers of M. mercenaria was little affected by temperaturedifferences within the range of 20° to 30°C (68° to 86°F). Although the optimum temperature forgrowth of M. mercenaria larvae was not well defined, growth was optimum at the followingtemperature/salinity combinations: 30°C (86°F)/22.5 ppt and higher, 27.5°C (81.5°F)/17.5 and20.0 ppt, and 25°C (77°F)/15.0 ppt.Substrate. The nature of the bottom substrate seems to be the main factor responsible forsettling of larvae and for the qualitative composition of bottom communities (Thorson 1955).Keck et ale (1974) reported from laboratory studies that significantly higher (P ~ 0.05) numbersof M. mercenaria larvae set in sand than in mud; they suggested that the addition of organicmaterial to the sediment may be responsible for reduced setting because of increased bacterialevels, reduced dissolved oxygen, and increased production of hydrogen sulfide. Carriker (1959)recommended that the substrate be firm and free of excessive organic mud for larval clamculture; muddy bottoms can be surfaced with shells, sand, or gravel. Adult Clams were mostabundant in predominantly fine sediments, but in these sediments their abundance was generallya function of the coarseness of the minor constituents. Clams do not grow well in silty substrates.Pratt and Campbell (1956) found an inverse relationship between growth of M. mercenaria andthe fineness of the sediment (expressed as percentage of silt and clay). The inferior growth wasattributed to frequent gi1l clearing, which expended energy and interfered with feeding. Johnson(1977) also reported slower growth of M. mercenaria in finer sediment due to increasedexpulsion of pseudofeces.Suspended solids. Davis (1960) noted that both the larvae and egg stage are affected bysuspended solids. “Eggs did not develop correctly at silt concentrations of 3.0 or 4.0 g/L, andstraight-hinged veligers was normal at silt concentrations of 0.75g/L, retarded at 1.0 to 2.0g/L,and negligible at 3.0 and 4.0g/L.”