NOAA Technical Memorandum NMFS-NE-167
Assessment and Characterization of Salt Marshes in the Arthur Kill (New York and New Jersey) Replanted after a Severe Oil SpillDavid B. Packer, Editor
National Marine Fisheries Serv., 74 Magruder Rd., Highlands, NJ 07732
Web version posted June 24, 2004Citation: Packer DB, editor. 2001. Assessment and characterization of salt marshes in the Arthur Kill (New York and New Jersey) replanted after a severe oil spill. NOAA Tech Memo NMFS NE 167; 218 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.
For further information on the oil spill in the Arthur Kill, as well as pictures of the marsh sites and plantings, see the National Oceanic and Atmospheric Administration (NOAA), Damage Assessment and Restoration Program (DARP), Exxon Bayway Wetland Acquisition and Restoration webpage (http://www.darp.noaa.gov/northeast/exxon/index.html). DARP is a collaborative effort among NOAA’s National Ocean Service, National Marine Fisheries Service, and the Office of General Counsel. DARP’s mission is to restore coastal and marine resources that have been injured by releases of oil or hazardous substances and to obtain compensation for the public’s lost use and enjoyment of these resources.
On January 1 and 2, 1990, a 576,000-gal oil spill seriously damaged the salt marshes of the Arthur Kill, the strait separating Staten Island, New York, from New Jersey. The New York City Salt Marsh Restoration Team (SMRT) implemented a multiyear restoration and monitoring project to restore those parts of the marshes directly impacted by the oil spill. Restoration activities included successfully reintroducing Arthur-Kill-propagated saltmarsh cordgrass, Spartina alterniflora, and monitoring several parameters both in oiled marshes that were replanted and in oiled marshes that were left for natural recovery. Those parameters included: peak standing biomass, stem and flower density, and height of S. alterniflora; sediment total petroleum hydrocarbons (TPH); density of ribbed-mussels (Geukensia demissa); fish abundance and diversity; and wading bird (i.e., egret) foraging success.
Results of the monitoring suggest that the replanting of S. alterniflora was very important for recovery and restoration of the saltmarsh ecosystem. This replanting of S. alterniflora provides much of the structural component of the marsh; restoring this component to levels found elsewhere in the Arthur Kill is important to the other members of the food web, such as the mussels, mummichogs, and birds. It is particularly significant in an urbanized landscape, where habitats are few and isolated.
However, questions remain as to the ecological viability and functional equivalency of these marshes. The problem is compounded because not only was almost every low marsh within the Arthur Kill affected to some extent by the 1990 spill, but this estuary is heavily urbanized and degraded; its marshes are continuously impacted by contaminants and other anthropogenic influences. In 1996 and 1997, the National Marine Fisheries Service (NMFS) sought to supplement the SMRT monitoring efforts via a preliminary characterization and assessment of marshes that were oiled and replanted, marshes that were oiled but not planted, and nearby pre-existing S. alterniflora reference marshes, with a view toward noting any differences among the marshes, especially those that might be attributable to the replanting efforts. The measured parameters include trace metal and hydrocarbon contaminants in ribbed-mussels and sediments, sediment biogeochemistry, age and growth of ribbed-mussels, macrobenthic distribution and abundance, and diets of the mummichog (Fundulus heteroclitus). Sampling occurred in fall 1996 and spring-summer 1997.
Results of the NMFS study are less clear than those of the previous SMRT monitoring effort with regard to the benefits of replanting, or even to the differences among sites. Trace metal concentrations in the sediments at each marsh were site specific and more dependent upon the general characteristics of the sediment, such as the percentage of fine-grained sediments and iron content, than upon whether or not the marsh was replanted. Compared to concentrations from a reference marsh outside the Arthur Kill, metal concentrations in sediments from the entire Arthur Kill were elevated. There were no consistent differences in metal concentrations in mussels collected from replanted and unplanted marshes, while concentrations of many metals in mussels from two of three reference marshes were significantly lower. However, as with the metal concentrations in the sediments, replanting may not have had a great effect on the levels of trace metals in the mussels.
The TPH concentrations in surface sediments from the southernmost reference marsh were numerically the lowest, those from the northernmost oiled and replanted marsh were intermediate, and those from one oiled but unplanted barren marsh were the highest; residual oil is still evident in sediments at this latter marsh. The lower levels of oil at the reference and replanted marshes may be due to oxidation and weathering of the oil, perhaps caused by the physical disturbance of planting and by the mineralization of oil by microbes around the roots of S. alterniflora. The TPH concentrations in mussels from all marshes were low, were not significantly different, and showed no temporal trend; thus, replanting efforts do not appear to have affected the levels of TPH in the mussels.
For biogeochemistry, the spatio-temporal patterns of porewater redox potential, soluble sulfide, and total organic carbon in the marsh sediments showed statistically significant differences with depth and season. However, these differences were not meaningful for assessment of replanting success because they appeared to owe more to the peculiarities of individual sampling stations within each of the marshes than to replanting status. Quantitative differences among station data within each marsh were so large, and distributions of values at those stations were so skewed, as to render differences uninterpretable in terms of replanting. No patterns characteristic of replanted, unplanted, or reference marshes were identified, nor were characteristic differences among sites fitting these treatment categories evident. The biogeochemistry appears to be mediated by factors not clearly related to replanting. The marshes were heterogeneous with respect to these factors, confounding efforts to identify replanting-specific effects. Among those confounding factors were differences in grain size distribution, surface and subsurface hydrology, macrobiotic activity, and anthropogenic influences.
Ribbed-mussels from the replanted sites were younger, smaller, weighed less, and grew slower than mussels from the southernmost Arthur Kill reference site. The older, larger mussels collected at the reference marsh represent cumulative growth processes over many generations at a mature and relatively undisturbed marsh that was minimally affected by the oil spill. The younger, smaller mussels collected at the replanted sites most likely reflect growth processes since replanting. Although the chronic effect of oil from the spill and the disturbance caused by the replanting process may have affected growth rates at the replanted sites, other natural and anthropogenic site-specific factors may also have been responsible.
The invertebrate taxa found within the sediments of the Arthur Kill marshes appear to be similar to invertebrate taxa found in S. alterniflora marshes elsewhere. Abundances of most taxa were highest in the spring. Although there may be similarities in invertebrate abundances between the replanted and reference marshes, quantitative evaluation was confounded due to the low number of replanted and reference sites sampled and to the high variability in the data, which is typical of benthic surveys.
The high percentages of detritus and algae, as opposed to live prey, in the mummichog stomachs may indicate a poor diet in a polluted environment, as suggested by previous studies. The mummichog diets may or may not have been site specific. A more thorough investigation would be necessary to discern such patterns in the data, as has been demonstrated for several of our other investigations.
In conclusion, although replanting of the oil-damaged Arthur Kill marshes by SMRT may have successfully "restored" them, at least structurally, to the level of the existing marshes found within the Arthur Kill, because this is an urban estuary, the extent to which the ecological functions of these marshes have been restored is more difficult to ascertain due to confounding factors such as pollution and other anthropogenic impacts. Also, the time span of the NMFS studies may have been too short and the number of treatment sites chosen may have been too small to accurately assess the performance of the replanted marshes, especially given the many scales of natural spatial and temporal variability and anthropogenic perturbations inherent in this ecosystem. Nevertheless, SMRT continues to replant and monitor these marshes where necessary, insuring that this vital habitat is protected from further loss and degradation.
NMFS funding was provided by the NMFS Office of Habitat Conservation/Restoration Center. The authors would particularly like to express their appreciation to New York City's Salt Marsh Restoration Team: Carl Alderson, Andrew Bergen, Robbin Bergfors, and others from that office who helped us with the study and allowed us access to their restoration sites.
We thank Beth Leimburg and others for help in the field with sampling of ribbed-mussels during the age, growth, and allometric relationships phase of this study. We greatly appreciate the work of Vickie Bejda and her students in the Advanced Biology Class at Ocean Township High School, Ocean Township, New Jersey, for doing the weight and length measurements and compiling those data. We also thank Bob Reid and Anthony Paulson for helpful comments on earlier drafts of the chapter on age, growth, and allometric relationships of ribbed-mussels.
AAS = atomic absorption spectrophotometry
ANOVA = analysis of variance
BOD = biological oxygen demand
CPI = carbon preference index
DARP = (NOAA) Damage Assessment and Restoration Program
DDI = double de-ionized
DIW = de-ionized water
FID = flame ionization detection (detector)
GC = gas chromatography (chromatogram)
GC-FID = gas chromatography - flame ionization detection
GC/MS = gas chromatography/mass spectrometry
HDPE = high-density polyethylene
HP = Hewlett-Packard
LC = labile carbon
MDL = method detection limit
MS = mass spectrometry
nd = not detected
NIST = (U.S. Department of Commerce) National Institute of Standards and Technology
NJDEP = New Jersey Department of Environmental Protection
NMFS = (U.S. Department of Commerce, NOAA) National Marine Fisheries Service
NRC = National Research Council
NYCDEP = New York City Department of Environmental Protection
OC = organic carbon
PAH = polycyclic aromatic hydrocarbon
PCA = principal component analysis
PD = percent difference
QA = quality assurance
RPD = relative percentage difference
RSD = relative standard deviation
SMRT = (New York City Department of Parks and Recreation) Salt Marsh Restoration Team
SRM = standard reference material
TIPH = total of individual petroleum hydrocarbons
TOC = total organic carbon
TPH = total petroleum hydrocarbons
WI = weathering index