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Preview: Recent EPA Catalog Records.

Recent Science Inventory records from the EPA



Up to 100 Science Inventory records released or updated since midnight 12/11/2017



Published: Mon, 11 Dec 2017 15:58:51 GMT

Copyright: Public Domain
 



Changes in nitrogen isotope ratios in estuarine biota following nutrient reductions to Narragansett Bay

Mon, 11 Dec 2017 15:37:01 GMT

Increased nutrient inputs globally have resulted in widespread eutrophication to many coastal water bodies including Narragansett Bay. Efforts to reduce point source nitrogen load¬ings from waste water treatment facilities (WWTFs) and combined sewer overflows (CSOs) started in 2006, with tertiary upgrades to 11 of the major WWTFs discharging to Narragansett Bay and its tributaries. One approach to monitoring nutrient inputs to coastal water bodies and biota include the use of stable isotopes. In this study, we monitored the changes in stable nitrogen isotopes( δ15N) in several estuarine marsh species (smooth cord grass, Spartina alterniflora; sea lettuce, Ulva lactuca; ribbed mussels Geukensia demissa; mud snails, Nassarus obsoletus; grass shrimp, Paleomonetes pugio and the common mummichog, Fundulus heteroclitus) before and after tertiary treatment upgrades to Rhode Island’s WWTFs. Results from our study showed a pronounced gradient down the bay for most species, except cord grass, with higher δ15N values measured in biota from the upper bay site (Passeonkquis cove) and lower δ15N values in biota from mid-bay (Prudence Island) and the lower-bay site (Fox Hill Marsh). Nitrogen isotope ratios in biota from the upper bay station (Passeonkquis cove) were on average 2‰ greater after WWTF upgrades than before, reflecting reduced preferential fractionation by biota and or an increase in the δ15N of NO3- and NH4+ released to the estuary by WWTFs. Based on our study, stable isotopes of nitrogen may be a good tool for identify nutrient sources and tracking anthropogenic changes to coastal water bodies.



The Lives and Times of the Narragansett Bay Benthos: Biodiversity Trends over 182 Years

Mon, 11 Dec 2017 15:17:34 GMT

Narragansett Bay has high benthic invertebrate biodiversity that supports many ecosystem functions and services. A master list was compiled of all benthic species collected from the Bay beginning in 1862, including a U.S. Bureau of Commercial Fisheries survey in 1871 and studies at Alexander Agassiz’s Marine Zoological Laboratory in Newport, 1877–1910. The list, spanning 154 years, was compiled from 77 studies and includes invertebrate macrofauna (>0.5 mm) and more limited studies of meiofauna. It currently holds 1,150+ unique taxa from 22 phyla, 62% of all animal phyla on Earth. A species accumulation curve suggests more species are yet to be discovered. Often, the only data collected by early studies were lists of species. Also, when abundance data were available, widely-varying sampling gear and sieve mesh sizes in the early studies precluded a quantitative comparison of abundances. Instead, non-metric multidimensional scaling and Average Taxonomic Distinctness were used with presence-absence data (species lists) to examine trends over time. Trends using quantitative abundance data from later studies were examined at a reference site (North Jamestown in mid-Bay) and at a more impacted site at Spar Island in Mount Hope Bay. The North Jamestown site is characterized by the typical Narragansett Bay Nephtys-Nucula community and has been sampled by 17 different studies, 1957–2010. Community composition and biodiversity were relatively constant, making it a good control site. At Spar Island in Mount Hope Bay (five studies, 1975–2015), changes in natural and anthropogenic factors—including an end to the discharge of heated water into the Bay by a power plant at Brayton Point—forced changes in the benthic community, as shown by significant decade-to-decade differences (<0.01) in an Analysis of Similarity on a Bray-Curtis similarity matrix and an ANOVA on Average Taxonomic Distinctness. Biodiversity is a useful ecological indicator of historic trends.



IRIS Toxicological Review of Hexabromocyclododecane (HBCD) (Preliminary Assessment Materials)

Mon, 11 Dec 2017 13:46:48 GMT

In March 2014, EPA released the draft literature searches and associated search strategies, evidence tables, and exposure response arrays for HBCD to obtain input from stakeholders and the public prior to developing the draft IRIS assessment. Specifically, EPA was interested in comments on the following:
  • Draft literature search strategies
    • The approach for identifying studies
    • The screening process for selecting pertinent studies
    • The resulting list of pertinent studies
  • Preliminary evidence tables
    • The process for selecting studies to include in evidence tables
    • The quality of the studies in the evidence tables
The literature search strategy, which describes the processes for identifying scientific literature, contains the studies that EPA considered and selected to include in the evidence tables. The preliminary evidence tables and exposure-response arrays present the key study data in a standardized format. The evidence tables summarize the available critical scientific literature. The exposure-response figures provide a graphical representation of the responses at different levels of exposure for each study in the evidence table.