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Northeast Fisheries Science Center Reference Document 05-07

Benthic Macrofauna and Associated Hydrographic Observations Collected in Newark Bay, New Jersey between June 1993 and March 1994

Linda L. Stehlik, Stuart J. Wilk, Robert A. Pikanowski, Donald G. McMillan, and Eileen M. MacHaffie
National Marine Fisheries Serv., James J. Howard Lab., 74 Magruder Rd.., Highlands, NJ 07732

Web version posted July 25, 2005

Citation: Stehlik LL, Wilk SJ, Pikanowski RA, McMillan DG, MacHaffie EM. 2005. Benthic macrofauna and associated hydrographic observations collected in Newark Bay, New Jersey, between June 1993 and March 1994. US Dep Commer, Northeast Fish Sci Cent Ref Doc. 05-07; 37 p.

Information Quality Act Compliance: In accordance with section 515 of Public Law 106-554, the Northeast Fisheries Science Center completed both technical and policy reviews for this report. These predissemination reviews are on file at the NEFSC Editorial Office.

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ABSTRACT: Summary tabulations are presented for quarterly benthic macrofaunal collections at 25 station locations within Newark Bay and the lower Passaic and Hackensack rivers, NJ, for the period June 1993 through March 1994. Approximately 75 benthic invertebrate taxa were found in the collections.  They included marine to oligohaline species and were dominated by polychaetes.


Geographic Setting

Newark Bay, part of the Hudson-Raritan Estuary system, New Jersey, lies at the mouths of the Hackensack and Passaic rivers.  The estuary is one of the world’s busiest ports as it is part of Greater New York City (Figure 1).  The west shore of this water body is heavily industrialized, containing oil refineries, chemical and other manufacturing facilities, and serves as a major east coast container shipping port.  The east shore is bulkheaded and contains industry, residential areas, and parkland.  Little undisturbed shoreline habitat exists on either side of the bay.  This bay, which leads to Newark, New Jersey’s largest city, has been a major navigation route since colonial times and was a fishery and oyster seed producing area until the twentieth century. Dredging channels to improve navigation began before the Civil War.

The freshwater input to Newark Bay includes the Hackensack-Passaic watershed and the Hackensack Meadowlands.  As the watershed and its floodplains became physically altered by filling and construction of abutments, flooding became a problem for certain communities.  To relieve this problem, several proposals were investigated, one of which would have diverted flood waters from above the affected communities through a large tunnel directly into the northern portion of Newark Bay (see Wilk et al., 1997).  The National Marine Fisheries Service was asked to survey the fishery and related biological resources that might be affected by water effluents from this proposed tunnel.  Most of the results of this request were reported in Wilk et al. (1997) but the benthic macrofaunal data were not and are herein provided.


The objective of this part of the overall survey effort was to characterize the benthic macrofauna communities in areas that might be affected by the construction or subsequent use of the proposed tunnel.  Although that proposed tunnel project has not been implemented, there are or could be other habitat-related issues in this bay where the results of this brief survey may provide some relevant and useful background information.  The results are presented here without any attempt at further ecological analysis to expedite making the data available. METHODS AND MATERIALS

Twenty-five strata in northern and central Newark Bay were chosen for benthic sampling (Figure 1).  Eighteen strata in channels (coded B) were sampled from the RV Gloria Michelle, while seven strata on the east side of the bay in < 3 m depths (coded V) were sampled from a small boat.  Seven strata  (B1, B2, B3, B4,  B11, B12, and B13) were located north of the Route 78 bridge and the Lehigh Valley railroad bridge.  Benthos was sampled quarterly:  June 1993, August 1993, December 1993, and March 1994.  One grab per stratum was taken, as close to the center of the stratum as possible.  The total number of grabs was 100.

LORAN C coordinates or GPS positions, latitude, longitude, depth, and time were recorded when each grab was taken.  Concurrently, water temperature, salinity, and dissolved oxygen were measured at 1 m intervals from the water surface to the bottom with a Hydrolab® Surveyor III.

An 0.04 m2 (8” x 8”) Young-modified Van Veen grab was used to collect the samples.  A grab was considered successful if the surface was level and the jaws were at least 75% full or filled to a depth of 7 cm.  If a cast was  unsuccessful, it was repeated.  Appearance of the sediment, visible macrofauna, and debris were noted.  The samples were washed in an 0.5 mm mesh sieve to remove sediment and meiofauna (those organisms that pass through an 0.5 mm sieve).  They were preserved in stained, buffered 10 % Formalin and transferred to 70% ethanol three days to two weeks later.

Sorting and identification of the macrofauna were contracted to Cove Corporation, Lusby, MD.  Each sample was completely sorted, using dissecting microscopes.  Meiofauna such as nematodes, copepods, and ostracods that had been retained in the samples were discarded.  Under the corporation’s quality control routine, a randomly selected 10% of the samples were resorted, and were acceptable only when 95% or more of the animals were found.

Specimens were identified to the lowest possible taxonomic level (usually species).  Rhynchocoels and oligochaetes were not further identified.  Number of individuals of each taxon was counted.  A randomly selected 10% of the samples were checked by senior taxonomists for accuracy of identification.

Wet weight (blot-dried on absorbent toweling for three minutes) biomass was determined (±1mg) three times and the mean weight was reported for each taxon.  Colonial species (e.g. barnacles, tunicates) were removed from substrates for weighing.  Unidentified fragments of major taxa (e.g. polychaetes, amphipods) were pooled.  A randomly selected 10% of the samples were reweighed, and were accepted if the percent weighing error was no more than 20%. RESULTS

Benthic grab samples and hydrographic data were obtained at all strata and dates (Table 1).  The sediment at strata B1, B2, B3, and B4 north of the bridges was generally soft with varying amounts of gravel, shell, sand, silt, and clay.  At strata B11, B12, and B13 at the mouth of the Passaic River, grabs contained soft black silty clay.  Grabs at channel strata B8, B9, and B10 usually contained lumps of thick, hard, red clay.  At all other stations south of the bridges, in channels and in the shallow strata V1-V7, grabs generally contained light, soft silt and clay with some shell.  Detritus, consisting of bits of plant matter, wood, and plastic trash, was found in most locations.  A few samples contained fuel oil, but not consistently at the same stations.

The samples contained living softclams (Mya arenaria), dwarf surfclams (Mulinia lateralis), other mollusks, errant and tubicolous polychaetes, crustaceans, and lesser numbers of other taxa (Table 2).  Total number of individuals collected was as follows:  June, 5758; August, 6102; December, 6776; March, 5698.  Overall abundance and biomass of the macrofauna are presented per sampling period in Table 3 and the numerically top ten dominant taxa for the entire survey period are listed in Table 4.  Large softclams in some samples added greatly to the biomass. 

The full collection results for this survey are found in Appendix ATharyx sp. A and Monoculodes sp. 1 refer to species that were identifiable but did not have proper taxonomic names at the time of the report.


The late Anthony Pacheco was an integral part of the overall survey effort.  Frank Steimle and Joseph Vitaliano contributed to the final preparation of the report. REFERENCES

Cerrato, R.M.  1986. The benthic fauna of Newark Bay.  Spec. Report 68,  Marine Research Center, State Univ. of N.Y.

Coch, N. K.  1986.  Sediment characteristics and facies distributions in the Hudson system. pp. 109-129 in: N. K. Coch and H. J. Bokuniewicz, eds.  Sedimentation in the Hudson system: the Hudson River and contiguous waterways.  Special Issue, Northeastern Geology 8: 94-170.

Steimle, F. W., and J. Caracciolo-Ward.  1989.  A reassessment of the status of the benthic macrofauna of the Raritan Estuary.  Estuaries 12:145-156.

Wilk, S. J., D. G. McMillan, R. A. Pikanowski, E. M. MacHaffie, A. L. Pacheco, and L. L. Stehlik.  1997.  Fish, megainvertebrates, and associated hydrographic observations collected in Newark Bay, New Jersey, during May 1993 - April 1994.  Northeast Fish. Sci. Cent. Ref. Doc. 97-10, June 1997, 91 p., NMFS, Woods Hole, MA.
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