The New Bedford Harbor Superfund site long-term monitoring program (1993–2009)

New Bedford Harbor (NBH), located in southeastern Massachusetts, was designated as a marine Superfund site in 1983 due to sediment contamination by polychlorinated biphenyls (PCBs). Based on risks to human health and the environment, the first two phases of the site cleanup involved dredging PCB-contaminated sediments from the harbor. Therefore, a long-term monitoring program (LTM) was developed to measure spatial and temporal chemical and biological changes in sediment, water, and biota to assess the effects and effectiveness of the remedial activities. A systematic, probabilistic sampling design was used to select sediment sampling stations. This unbiased design allowed the three segments of the harbor to be compared spatially and temporally to quantify changes resulting from dredging the contaminated sediments. Sediment was collected at each station, and chemical (e.g., PCBs and metals), physical (e.g., grain size), and biological (e.g., benthic community) measurements were conducted on all samples. This paper describes the overall NBH-LTM approach and the results from the five rounds of sample collections. There is a decreasing spatial gradient in sediment PCB concentrations from the northern boundary (upper harbor) to the southern boundary (outer harbor) of the site. Along this same transect, there is an increase in biological condition (e.g., benthic community diversity). Temporally, the contaminant and biological gradients have been maintained since the 1993 baseline collection; however, since the onset of full-scale remediation, PCB concentrations have decreased throughout the site, and one of the benthic community indices has shown significant improvement in the lower and outer harbor areas.     

A minimum data set of water quality parameters to assess and compare treatment efficiency of stormwater facilities

Urban stormwater runoff is often of poor quality, impacting aquatic ecosystems and limiting the use of stormwater runoff for recreational purposes. Several stormwater treatment facilities (STFs) are in operation or at the pilot testing stage, but their efficiencies are neither well documented nor easily compared due to the complex contaminant profile of stormwater and the highly variable runoff hydrograph. On the basis of a review of available data sets on urban stormwater quality and environmental contaminant behavior, we suggest a few carefully selected contaminant parameters (the minimum data set) to be obligatory when assessing and comparing the efficiency of STFs. Consistent use of the minimum data set in all future monitoring schemes for STFs will ensure broad-spectrum testing at low costs and strengthen comparability among facilities. The proposed minimum data set includes: (i) fine fraction of suspended solids (<63 μm), (ii) total concentrations of zinc and copper, (iii) total concentrations of phenanthrene, fluoranthene, and benzo(b,k)fluoranthene, and (iv) total concentrations of phosphorus and nitrogen. Indicator pathogens and other specific contaminants (i.e., chromium, pesticides, phenols) may be added if recreational or certain catchment-scale objectives are to be met. Issues that need further investigation have been identified during the iterative process of developing the minimum data set.     

Natural pollution caused by the extremely acidic crater lake Kawah Ijen, East Java, Indonesia

Background. Aims and Scope Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH 〈 0.3. It is the source of the extremely acid and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed. Methods Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards. Results and Discussion The river carries a very high load of SO4, NH4, PO4, Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980 – 2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1600 mg/l) and aluminium (up to 3000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acid water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acid irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents” diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis. Conclusions, Recommendations and Outlook In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production.     

The effect of summer drought on the predictability of local extinctions in a butterfly metapopulation

The ecological impacts of extreme climatic events on population dynamics and community composition are profound and predominantly negative. Using extensive data of an ecological model system, we tested whether predictions from ecological models remain robust when environmental conditions are outside the bounds of observation. We observed a 10-fold demographic decline of the Glanville fritillary butterfly (Melitaea cinxia) metapopulation on the Åland islands, Finland in the summer of 2018 and used climatic and satellite data to demonstrate that this year was an anomaly with low climatic water balance values and low vegetation productivity indices across Åland. Population growth rates were strongly associated with spatiotemporal variation in climatic water balance. Covariates shown previously to affect the extinction probability of local populations in this metapopulation were less informative when populations were exposed to severe drought during the summer months. Our results highlight the unpredictable responses of natural populations to extreme climatic events.     

Multispecies and Multiscale Conservation Planning: Setting Quantitative Targets for Red‐Listed Lichens on Ancient Oaks

Abstract: Species occurrence in a habitat patch depends on local habitat and the amount of that habitat in the wider landscape. We used predictions from empirical landscape studies to set quantitative conservation criteria and targets in a multispecies and multiscale conservation planning effort. We used regression analyses to compare species richness and occurrence of five red‐listed lichens on 50 ancient oaks (Quercus robur; 120–140 cm in diameter) with the density of ancient oaks in circles of varying radius from each individual oak. Species richness and the occurrence of three of the five species were best explained by increasing density of oaks within 0.5 km; one species was best explained by the density of oaks within 2 km, and another was best predicted by the density of oaks within 5 km. The minimum numbers of ancient oaks required for “successful conservation” was defined as the number of oaks required to obtain a predicted local occurrence of 50% for all species included or a predicted local occurrence of 80% for all species included. These numbers of oaks were calculated for two relevant landscape scales (1 km² and 13 km²) that corresponded to various species responses, in such a way that calculations also accounted for local number of oaks. Ten and seven of the 50 ancient oaks surveyed were situated in landscapes that already fulfilled criteria for successful conservation when the 50% and 80% criteria, respectively, were used to define the level of successful conservation. For cost‐efficient conservation, oak stands in the landscapes most suitable for successful conservation should be prioritized for conservation and management (e.g., grazing and planting of new oaks) at the expense of oak stands situated elsewhere.     

Relationship between depth, sediment, latitude, and the structure of benthic infaunal assemblages on the mainland shelf of southern California

A regional benthic survey was conducted in 1994, and the data were used to assess the relationship among three habitat factors (depth, sediment grain size, and latitude) and the distribution of benthic infaunal assemblages on the southern California coastal shelf. Benthic samples were collected with a 0.1 m² Van Veen grab from 251 sites on the continental shelf (10–200 m deep) from Point Conception, California, to the United States–Mexico international border. The relationship between habitat and assemblages was investigated by conducting a Q-mode cluster analysis to define groups of stations with similar species composition and then examining whether differences were present in physical habitat attributes among those groups of stations. Analysis of data from 175 uncontaminated sites yielded four habitat-related benthic infaunal assemblages along the southern California coastal shelf: a shallow-water assemblage from 10–32 m, a mid-depth assemblage between 32 and 115 m, and two deep-water (115–200 m) assemblages, one in fine and one in coarse sediments. These empirically defined points in the depth and sediment grain size gradients can be used to define reference habitats for the development of biocriteria. Benthic abundance and diversity were greatest in the mid-depth assemblage, conforming to predictions for benthic assemblages in regions of upwelling. Within the 500 km of coastline examined, latitude was not an important factor in defining assemblages. Received: 3 December 1999 / Accepted: 9 October 2000     

Environmental Monitoring Of Remedial Dredging At The New Bedford Harbor, Ma, Superfund Site

New Bedford Harbor (NBH), MA, is a Superfund site because of high polychlorinated biphenyl (PCB) concentrations in the sediment. From April 1994 to September 1995, a remedial dredging operation (termed the “Hot Spot”) removed the most contaminated sediments (PCB concentrations greater than 4000μg/g) from the upper harbor. During remediation, a monitoring program assessed the potential environmental impacts to NBH and adjacent Buzzards Bay. The monitoring program was developed with input from federal, state, and local authorities. Site-specific decision criteria were established to assess net PCB transport, water column toxicity, and PCB bioaccumulation in blue and ribbed mussels (Mytilus edulis and Geukensia demissa, respectively). The remediation was completed without exceeding PCB net transport or acute toxicity effects specified in the decision criteria. In addition, PCB bioaccumulation in mussels during this time period was not significantly greater than pre- or post-operational measurements. The results indicated that approximately 14000 cubic yards of highly PCB contaminated sediment were permanently removed with minimal environmental effects. The lessons learned during this operation, as well as previous pilot studies at the site, will be used to make full-scale remedial efforts in NBH more efficient and environmentally protective.     

Variability in the identification and enumeration of marine benthic invertebrate samples and its effect on benthic assessment measures

Studies designed to measure anthropogenic impacts on marine benthic communities depend on the ability of taxonomists to consistently discriminate, identify, and count benthic organisms. To quantify errors and discrepancies in identification and enumeration, 20 samples were completely reprocessed by another one of four participating laboratories. Errors were detected in 13.0% of the data records, affecting total abundance by 2.1%, numbers of taxa by 3.4%, and identification accuracy by 4.7%. Paired t-tests were used to test for differences in the Benthic Response Index (BRI), total abundance, numbers of taxa, and the Shannon-Wiener index between the original and the reanalysis data. Differences in the BRI were statistically insignificant. Although statistically significant differences were observed for numbers of taxa, total abundance, and the Shannon-Wiener index, the differences were small in comparison to the magnitude of differences typically observed between anthropogenically affected and reference sites.     

Retrospective monitoring of persistent organic pollutants,including PCBs,PBDEs, and polycyclic musks in blue mussels (Mytilus edulis) and sediments from New Bedford Harbor,Massachusetts, USA: 1991–2005

Blue mussels (Mytilus edulis) and sediments collected from 1991 to 2005 from New Bedford Harbor (NBH), MA, were analyzed for two polycyclic musks (HHCB or Galaxolide® and AHTN or Tonalide®), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs). HHCB and AHTN were found in mussel tissues at mean concentrations of 836 and 376 ng/g lipid weight (lw), respectively, which were two- to seven-fold higher than those found at a reference site. Mean concentrations of HHCB and AHTN in NBH sediments were 12 and 6.3 ng/g dry weight (dw), respectively. Four- and five-ringed PAHs, such as phenanthrene, anthracene, fluoranthene, and pyrene, collectively accounted for 61 % of the ∑PAHs concentrations in mussels from NBH. Mean ΣPCB concentrations in mussels from upper and lower NBH were 942 and 182 μg/g lw, respectively, and were dominated by tetra- and penta-chlorobiphenyl congeners, collectively accounting for 61 % of the ΣPCB concentrations. The mean concentration of ∑PBDEs in mussels from NBH was 277 ng/g lw, and no significant difference existed in the concentrations between upper and lower NBH. DDTs were the major OCP found in mussels, found at a mean concentration of 778 ng/g lw. The concentrations of HHCB, AHTN, ΣPBDEs, ΣPAHs, and DDTs in mussels decreased significantly (r ²?≥?0.56, p?≤?0.052) from 1991 to 2005. The concentrations of PCBs and chlordanes did not exhibit a decreasing trend in mussel tissues (r ²?<?0.50; p?>?0.076) from 1991 to 2005. Based on the temporal trends in the concentrations of HHCB, AHTN, ∑PAHs, and ∑PBDEs found in mussels from NBH, it was estimated that between 5.5 and 12 years were required for the concentrations of these compounds to decrease by half (i.e., environmental halving time) of the levels found in 1991.