LINJ 1997 Environment and Ecology

Science Center Objects

The LINJ study area is in one of the more densely populated areas of the country. There is more than a century of a strong and prosperous industrial economy behind an industrial growth that was centered around the ports and metropolitan areas of New York City and Philadelphia, now considered the older urban portions of the study area. There also is a very productive agricultural heritage around the fringes of these metropolitan areas and in more rural areas of southern and northwestern NJ and eastern LI (figure 2) . These areas, however, are rapidly becoming urban and suburban communities. Below is a basic description of the study setting and resources that contribute to the diversity and complexity upon which the LINJ stratification and water-quality issues are based.

Population and Land Use

The Long Island-New Jersey Coastal Drainages (LINJ) study unit covers more than 6,000 mi2 in New York and New Jersey. The study unit contains the metropolitan areas of New York City, Philadelphia, and the highly urbanized corridor in between. In 1990, the population of study unit was more than 10 million, concentrated mostly on Long Island and in northeastern New Jersey. In 1973, the study area was 35% urban (28 percent urban residential and 7 percent urban nonresidential). We know that a significant increase (+9%) in urban land use and subsequent decrease in forest and agriculture land uses (-6%) has occurred between 1973 and 1990 in the study area. The large extent of urban area and continued growth in NJ and LI is the primary focus of this NAWQA study.

Stratification of the Study Area

Fortunately, there have been several significant efforts in NJ to develop an objective procedure for classifying or differentiating factors controlling both ground- and surface-water systems. Physiography plays a major role. An interagency ecomapping committee headed by the USFS is the most recent effort. Based on the ecoregion concept, they have defined subsections of NJ based on ecosystem differences within physiographic provinces (NJDEP 1994). This ecomapping fits well conceptually and practically with the stratification needs of the NAWQA study. It also works out well with Long Island; we simply treat LI as another subsection of the Coastal Plain. The result is a stratification of the LINJ into 6 ecoregion strata. We believe there is not enough differentiation between the inner and outer Coastal Plain subregions and so we lumped them as Coastal Plain-NJ. Furthermore, because land use plays such a dominate role in this study area, we believe that both SW and GW stratification can be simplified even further by combining similar ecoregion strata back to 3 primary SW strata and 4 primary GW strata. Land use then becomes the primary differentiating substrata within each of these primary strata.

Description of the Study Area

About two-thirds of the 6,000 square mile study area is Coastal Plain and characterized by flat to gently rolling topography of unconsolidated sedimentary (NJ and LI) and glacial (LI only) deposits. The other one-third is within the Piedmont and New England provinces (north of the Fall Line) and is characterized by rolling to hilly topography of weathered bedrock and glacial deposits in the northern half of each.

Hydrogeologic characteristics of provinces north of the Fall Line differ greatly from those of the Coastal Plain. The New England province is underlain by igneous and metamorphic rocks, where as, the Piedmont province consists of layered shale, siltstone, and sandstone bedrock. Bedrock aquifers of these provinces are associated with water-bearing weathered joint and fracture systems typically within 300 feet of land surface. The top 100-150 feet is largely unconfined. Valleys in the glaciated northern half of each, however, are underlain by stratified drift and glacial till. These stratified drift aquifers are generally 30 to 40 feet thick, but may be 300 feet thick in some valleys.

In contrast, the Coastal Plain is underlain by a thick wedge of unconsolidated sediments that form permeable units of sand and gravel interbedded with poorly permeable units of silt and clay. These sediments differ in areal extent and thickness, but generally dip and thicken southeastward to about 6,500 feet thick at the southern tip of NJ. The Kirkwood-Cohansey aquifer system and the outcrop of the Potomac-Raritan-Magothy aquifer system are the principal surficial aquifers in the NJ Coastal Plain. Groundwater pumpage from confined systems exceeds pumpage from surficial systems, but since NJ water supply permits for pumpage from confined systems are fully allocated, most of the future population growth in the Coastal Plain will depend directly on surficial sources for supply. Glacial deposits of sand and gravel overlie most of LI and form the surficial aquifer. To large extent these systems are underlain and hydraulically connected to the deeper Magothy aquifer, the principal source of water for LI.

LI and the Coastal Plain of NJ have relatively flat slopes of sandy soils that allow rapid infiltration of rainfall. In fact, 75 to 90 percent of streamflow is derived from groundwater discharge over much of the Coastal Plain (Kirkwood-Cohansey aquifer system). The New England and Piedmont provinces have steeper slopes of thin, clayey soils, which produce runoff more rapidly than Coastal Plain soils. Much of western LI, northeastern NJ, and the corridor between New York City and Philadelphia consists of heavily urbanized areas that yield runoff more rapidly. Groundwater pumpage considerably reduces baseflow in streams on the western portion of LI.

The principal river systems within the study unit are the Hackensack (202 mi2), Passaic (950 mi2), Raritan (1,105 mi2), Toms (192 mi2), Mullica (569 mi2), and Great Egg Harbor (347 mi2) Rivers in NJ. Many other smaller rivers and streams drain the Coastal Plain, including the Peconic River (75 mi2) on LI. Middle and downstream reaches of the Hackensack, Passaic, and Raritan Rivers receive urban runoff and treated effluent from point sources. Upstream reaches of these and most other rivers in the study are mixed agricultural, forested, and/or urban land use.

Average annual precipitation ranges from 42 to 52 inches south-to-north, and annual snowfall ranges from 13 in the south to more than 50 inches in the north. Precipitation is evenly distributed throughout the year. Average annual temperature ranges from 56 to 50 oF south to north. Average annual runoff is 21-23 inches in NJ and on LI, but is significantly lower (from <3 to 10 inches) for many LI streams due to the heavy groundwater pumpage on the western part of LI. Annual groundwater recharge varies from 20 to 22 inches for the more permeable aquifers, but is estimated to be less than half that for the bedrock systems of the study area.

The study area contains 13 major water-supply reservoirs, most north of the Fall Line, and receives about 100 Mgal/d of flow diverted from the Delaware River to the Raritan River basin for water supply. In fact, water-supply facilities in most river systems are highly connected and transfer of water is common. Major water uses in the study unit include domestic, commercial, industrial, mining, power production, and crop irrigation.

Total freshwater withdrawals for the LINJ is 1,617 Mgal/d, serving over 10 million people and related infrastructure. Surface-water withdrawals account for 37% (613 Mgal/d), most of which is in the northern NJ portion. These figures do not include the New York City surface water imports from outside sources to western LI (Queens and Kings Counties). Groundwater withdrawals account for 63% (1,004 Mgal/d) of the LINJ water use; 44% of which is on LI, 37% in southern NJ, and 19% in northern NJ. Only 20 to 40% of the total water use is groundwater from confined aquifers, indicating that much of the used resources in the LINJ are either SW or surficial GW and are, therefore, highly vulnerable to contamination.


Ecological Activities

There are a myriad of factors affecting the health of biological communities located within the LINJ study unit. Major water-quality issues identified by the LINJ liaison committee include (1) the identification of factors that contribute to biologically impaired communities (nutrients, pesticides and VOC's), (2) the relations of land use (non-point) and degraded in-stream habitat to biotic condition, and (3) the impacts of biocides and herbicides for given land uses on aquatic organisms. The synthesis of these issues have been recognized as being of local, regional, and national significance, especially within highly urbanized systems. The LINJ surface water program will concentrate efforts in NE NJ on the largest and most urbanized of these systems, the Passaic and Raritan Rivers, and in the NJ CP near Glassboro in association with GW land use/flow path studies, and in the highly urbanized areas in Nassau and Suffolk County on LI. The LINJ study unit has worked hard to choose candidate sites where surface-water activities can be directly linked with biological community assessment.

HIP Plans as Modified by FY96 Conference Call

As a result of the conference call and other communications between the NLT and LINJ, our final SW network included:

(2) indicator IFS (Bound Brook at Middlesex; Great Egg Harbor River at Sicklerville),

(3) indicator BFS (Neshanic R at Reaville; Saddle R at Ridgewood; Stony Brook at Princeton), and

(2) integrator BFS (Passaic River at Two Bridges; Raritan at Queens Bridge).

Further conversations with NCEG regarding ecological sampling suggested the addition of at least one other reference site to complement the new SW network. Mulhuckaway at VanSyckle, NJ, was chosen, as a synoptic site, to represent a relatively unimpacted reference area located within the Northeastern Highlands Ecoregion. We applied the full suite of eco-sampling at Mulhuckaway at VanSyckle and at Passaic at Millington, NJ, an additional synoptic site in a high priority urban indicator basin within the unglaciated portion of the Norther Piedmont Ecoregion (Figure SW1). Although these 2 sites were not sampled as part of the LINJ SW BFS program in FY96, they are NJ COOP network sites and are included as part of the SW synoptics scheduled in the spring of FY97 (see section D-Water Quality Synoptics). These 2 sites are currently sampled five times per year as part of the existing 79 site NJ QW network.

Accomplishments in FY 1996

All ecological activities proposed in the FY96 workplan were accomplished as planned. The following is a summary of those activities.

Ecological sampling at BFS, IFS, and Synoptic sites began May 25, 1996 (FY96) and ended October 20, 1996 (FY97). We implemented the full suite of NAWQA protocols at Bound Brook at Middlesex, Saddle River at Ridgewood, Stony Brook at Princeton, Neshanic River at Reaville, Passaic at Millington and Mulhuckaway at VanSyckle. This included reach assessment, algae and invertebrate RTH, DTH, QMH, Level I habitat characterization and fish sampling (Table SW9). Raritan River at Queens Bridge was sampled for invertebrate and algae RTH, DTH, QMH. The Great Egg Harbor River at Sicklerville was only sampled for fish, and no ecological samples were collected at Passaic River at Two Bridges (Table SW9). No Level II habitat characterization was accomplished in FY96 with the exception of Wolman pebble counts (Wolman 1954) which were done at all 34 sites sampled as part of the special ecological synoptic (Table SW10). Level II habitat characterization at BFS and IFS sites is currently scheduled for FY98. No multi-reach surveys were done in FY96, however, one multi-reach site is scheduled to be implemented in FY97 and one in FY98 (Saddle River at Ridgewood and Bound Brook at Middlesex, respectively).

Fish community composition was assessed at 7 sites during FY96 (Table SW11). We electrofished 9488 fish representing 42 species using the standard two pass method outlined by Meador and others (1993). This was accomplished at all fixed sites except Great Egg Harbor River at Sicklerville where a single pass approach was implemented due to low conductivity and extremely low fish density. Because NAWQA does not attempt to establish density estimates of fish species in streams, a single pass under these conditions is adequate to provide a "representative" sample. More than 3000 fish were captured at Neshanic River (Figure SW9). Fish abundances in Stony Brook and Bound Brook were 2537 and 1432, respectively. Species richness ranged from 10 in Great Egg Harbor River to 25 in Stony Brook (Table SW11). The Shannon-Weiner index was used to assess diversity at all fish sampling sites. This index assumes that all individuals are randomly sampled from an infinitely large population (Pielou 1975, Magurran 1988). The most diverse site was mixed agricultural/developing urban Stony Brook at Princeton. Our agricultural site at Neshanic River at Reaville was the least diverse (Figure SW10). Tesselated darters (Ehteostoma olmsteadi), white suckers (Catostomus commersoni), and spottail shiners (Notropis hudsonius) were the 3 most abundant fish species in NJ streams (Figure SW11). Tesselated darters were the only species captured at all fixed sites sampled. Unfortunately, white suckers (LINJ's target taxa) were not captured at Great Egg Harbor River, our Coastal Plain developing urban IFS. During BS&T sampling in FY97/98, a suitable replacement target taxa will have to be chosen. The most appropriate candidate species would likely be the creek chubsucker (Erimyzon oblongus).

Special Ecological Synoptics

In FY96/97 LINJ completed a 34 site algae and invertebrate synoptic that augments our current fixed site network and integrates it with sites sampled by the NJDEP and USEPA for invertebrates and fish, respectively. The primary objective of this survey was to provide LINJ with a more comprehensive understanding of factors affecting aquatic communities in indicator-size basins distributed among our major strata. Additionally, little information exists regarding lotic algal communities in these watersheds. We hope to expand on the current knowledge of algal communities along environmental (land-use, water quality and habitat) gradients in NJ streams. This is especially important when considering the power of algal communities as indicators of water-chemistry conditions over short time periods. Algal communities are often the first to respond to a water-quality stress and the first to recover following mitigation.

Analysis of existing retro data determined that 62 sites directly overlap between NJDEP's invertebrate data and USEPA's fish data. Of these 62 sites, approximately 32 of them are sampled for water quality in the COOP network. Additionally, the NJDEP has sampled 750+ sites as part of their Ambient Biological Sampling Network (AMNET) for aquatic invertebrates and of those, 43 sites represent what they consider to be regional reference sites based on 152 benchmark (pollution sensitive) organisms showing minimal impairment. Invertebrate RTH samples collected during LINJ's ecological synoptic will be directly compared with samples collected by NJDEP at overlapping sites to assess sampling consistency and invertebrate richness and equitability.

State and Federal agencies in NJ are continually looking for ways to assess multiple lines of evidence. Synoptic studies like this not only helps their efforts in aquatic community assessment, but at the same time maintains good cooperative working relations and enhances our efforts in assessment of urban impacts within this SU. From a national perspective, cooperative efforts like these promote NAWQA's visibility and help bridge the gap between fixed and synoptic site analysis. The NJDEP and USEPA have played a major role in the development of this synoptic investigation by providing coveted data sets of benthic invertebrate and fish communities, respectively, that are currently part of ongoing retrospective analyses. Additionally, they have been integral in providing ancillary data on habitat and substrate to complement these data. The NJDEP benefits from this investigation by the enhancement of their AMNET program with an algal component that will undoubtedly provide additional support of trends in water quality in NJ and add one more piece to the `multiple lines of evidence' puzzle. The USEPA is currently involved in fine tuning their IBI (Index of Biotic Integrity) approach to fish species composition at 164+ sites in NJ. It is their hope that this synoptic will further expand our knowledge of the health and stability of aquatic communities in NJ and provide complementary algal information in support of known trends. Synoptic sites were also sampled on Long Island as part of our 34 site network. Information about LI aquatic communities is needed to assess and related levels of urban land-use on Long Island to those in the Coastal Plain of NJ.

We reconned 95 potential surface water sites in NJ and LI during August 16-28, 1996. Of these, 28 NJ and 6 LI locations were chosen for further study (Table SW10) based on physiography (NJ physiographic subsections), landuse, substrate comparability, existing invert & fish data and availability of water quality information. Discussions with NAWQA's CR phycologist suggested that the greatest information about algal communities in NJ gained for the least monetary expenditure could be the accomplished with epilithic RTH samples. RTH samples provide estimates of composition, abundance and standing crop from a targeted microhabitat that ideally would be relatively consistent among sites. We realized that the monetary trade-off of not doing QMH samples would subsequently limit extraction of important autecological information, especially for macro-algae and moss species often present at these synoptic sites. However, because macro-and micro-algae are closely associated on stream substrates, many of the RTH samples taken will contain both groups. It was suggested that these samples be taken during the early fall (stable low-flow periods) to correspond with the same sampling period of many other NAWQA Study Units. In addition, it was suggested that we resample a subset of the synoptic sites in the late spring FY97 to assess additional autecological information during the time of year when taxa richness is at a maximum (Stephen Porter, pers. com.) and to take advantage of timely surface water QW synoptics scheduled this spring. This information would supply a greater `n' for correspondence analysis. Ideally, we would like to have 30 samples in each of our major land-use strata providing us with more sites than species, a caveat associated with most types of correspondence analysis (see Gauch 1982). We realize due to monetary and time constrains that this may not be possible.

In Sep.-Oct. 1996, 34 special ecological synoptic sites were sampled for RTH algae and invertebrates (Table SW10). A modified habitat assessment was implemented at these synoptic sites that included all aspects of the NAWQA Level I habitat protocols except point-quarter methodology. However, Wolman pebble counts (Wolman 1954) were completed at all 34 sites to complement the RTH samples taken in riffle habitats. Substrate size in NJ streams varies from site to site, thus, a quantitative assessment of stream bed material is essential in understanding how algal and invertebrate communities vary relative to substrate size and composition. Minimally, percent substrate composition can be used as a covariable to eliminate potential "noise" in correspondence analysis. Staffing for this synoptic included a minimum of 2 and often 3 SU personnel to accomplish our goal of sampling two sites per day. On most days we achieved this goal, however, inclement weather and extensive travel time did, on occasion, precluded the sampling of two sites in a day.

Proposed Work in FY 1997

Late winter VOC and early summer pesticide SW synoptics are proposed for FY97 to complement the algae and invertebrate sampling network already established (see SW section D -Water Quality Synoptics). We designed these surface water synoptics to build `multiple lines of evidence' into our currently established Synoptic Network and incorporate known biological information on invertebrate and fish populations.

We will continue to expand ecological sampling in FY97 to enhance our ability to assess water-quality in NJ and LI streams. Most applicable community ordination techniques have an underlying assumption of more sites than variables (Gauch 1982), therefore, it is in our best interests to increase the number of representative indicator sites within major land-use strata. Four additional single-reach, single-year intensive ecological sites will be sampled in FY97 (Beden Brook near Rockey Hill, NJ, Rockaway near Berkshire Valley, NJ, Rahway R. at Washington Park, NJ and Swan River at E. Patchogue, NY). Beden Brook is a 28 m2 stream located in the Stony Brook-Millstone watershed within the Raritan River basin. Beden Brook is complementary in land-use to Stony Brook at Princeton, composed primarily of formerly agricultural lands that are rapidly converting to residential developments (e.g., town houses and condominium complexes). Rockaway River near Berkshire Valley is a 25 m2 stream in a moderately forested basin that is currently showing rapid suburbanization in the upper part of its drainage. This area is located minutes from US Highway 80, a major commuting corridor to New York City. Rahway River at Washington Park is a 20 m2 urban indicator site located in Hillside, NJ. This area is a densely urban (>80%) with more than 2000 individual per square mile. Swan River at E. Patchogue, NY, is an urban indicator site located on LI that was selected to complement a VOC reach synoptic study scheduled for February of FY97 (see SW section D -Water Quality Synoptics). All four of these sites were sampled for invertebrates and algae as part of our ecological synoptic completed in 1996 (Table SW10). Therefore, only intensive ecological fish samples and habitat Level I assessment will be done at these sites during FY97. These sites will also be sampled for VOCs and pesticides as part of our surface water synoptics proposed for FY97.

Intensive ecological assessments will begin in May and continue through low flow periods in August/September of FY97. Reach and Level I habitat assessments will be made during May & June prior to intensive ecological sampling. All candidate IFS and BFS sites are currently targeted for all ecological components. It is this SU's intent to establish temporal trends at candidate fixed sites. Therefore, we will continue single-reach, multiple-year intensive ecological assessments at Bound Brook at Middlesex, Stony Brook at Princeton, and Neshanic River at Reaville. Saddle River at Ridgewood will be converted to a multi-reach site in FY97. Additional multiple-reach sampling and level II habitat characterization is planned for FY98. Currently, Saddle R. at Ridgewood, Stony Brook at Princeton, and Neshanic R. at Reaville represent good candidates for continued sampling though the LIP. All 3 are rapidly developing watersheds.