EcoAnalysts, Inc.

Aquatic ecosystems in the American Southwest have experienced biotic and abiotic degradation, which have deleteriously impacted the native fish communities that have evolved in these systems. The native fish community in the Moapa (Muddy) River in Nevada faces many of these challenges, including changes in flow regimes, changes in temperature regimes, habitat fragmentation, and nonnative species introductions. By 2007, the only native fishes to occupy the Muddy River downstream of the warm, spring-fed headwaters were Virgin River Chub Gila seminuda and Moapa Speckled Dace Rhinichthys osculus moapae. From 2007 to 2015, biannual standardized hoop-net sampling of portions of a 38-km reach of the Muddy River was utilized to characterize and monitor the fish community. The results of this study have shown a decline in the abundance of these native species through time, as well as changes in flow and temperature regimes throughout the study area. This is especially concerning because the Moapa Speckled Dace is a species endemic to the Muddy River and is state listed as Sensitive and of Conservation Priority. Although the protected status of the Muddy River population of Virgin River Chub is complicated due to the taxonomic uncertainty at the time of consideration for listing under the Endangered Species Act, the species is state listed as Sensitive and of Conservation Priority. In the nearby Virgin River, the species is federally listed as Endangered. Intervention through increased management, population monitoring, and additional research will be critical for these species to persist in the Muddy River.

The crangonid shrimps Argis hozawai, A. lar and A. toyamaensis, co-distributed in the Sea of Japan, exhibit intriguing differences in geographical and bathymetric distributions and in reproductive biology. Argis hozawai (150–250 m depth) and A. lar (200–300 m) are broadly distributed in the north-western Pacific Ocean and spawn relatively large numbers of small eggs, whereas A. toyamaensis (250–2000 m) is distributed in the Sea of Japan and spawns a small number of large eggs. We examined the relationship between egg size and dispersal patterns in the deep sea by comparing genetic population structures using mitochondrial DNA sequence variation. We found little or no genetic divergence within the Sea of Japan for A. hozawai and A. lar, whereas there was a slight but significantly higher genetic differentiation in A. toyamaensis. This suggests that A. toyamaensis has lower dispersal ability than A. hozawai and A. lar, and therefore might maximize larval survival through larger size at hatching, with either direct or abbreviated larval development, to adapt to the deep-sea environment in the Sea of Japan. We also detected the effects of drastic environmental changes during the Pleistocene glacial periods on their demographic processes in the Sea of Japan.

Upper Mississippi River (UMR) resource managers need a quantitative means of evaluating the health of mussel assemblages to measure effects of management and regulatory actions, assess restoration techniques, and inform regulatory tasks. Our objective was to create a mussel community assessment tool (MCAT), consisting of a suite of metrics and scoring criteria, to consistently compare the relative health of UMR mussel assemblages. We developed an initial MCAT using quantitative data from 25 sites and 10 metrics. Metrics fell in five broad groups: conservation status and environmental sensitivity, taxonomic composition, population processes, abundance, and diversity. Metric scoring categories were based on quartile analysis: 25% scoring as good, 50% scoring as fair, and 25% scoring as poor. Scores were meant to facilitate establishing management priorities and mitigation options for the conservation of mussels. Scoring categories assumed that a healthy mussel assemblage consists of species with a variety of reproductive and life-history strategies, a low percentage of tolerant species, and a high percentage of sensitive species; shows evidence of adequate recruitment, a variety of age classes, and low mortality; and has high abundance, species richness, and species and tribe evenness. Metrics were validated using a modified Delphi technique. MCAT metrics generally reflected the professional opinions of UMR resource managers and provided a consistent evaluation technique with uniform definitions that managers could use to evaluate mussel assemblages. Additional data sets scored a priori by UMR resource managers were used to further validate metrics, resulting in data from 33 sites spanning over 980 km of the UMR. Initial and revised MCAT scores were similar, indicating that data represent the range of mussel assemblages in the UMR. Mussel assemblages could be evaluated using individual metrics or a composite score to suit management purposes. With additional data, metrics could be calibrated on a local scale or applied to other river systems.

This review covers selected 2019 articles on the biological effects of pollutants, including human physical disturbances, on marine and estuarine plants, animals, ecosystems and habitats. The review, based largely on journal articles, covers field and laboratory measurement activities (bioaccumulation of contaminants, field assessment surveys, toxicity testing and biomarkers) as well as pollution issues of current interest including endocrine disrupters, emerging contaminants, wastewater discharges, marine debris, dredging and disposal etc. Special emphasis is placed on effects of oil spills and marine debris due largely to the 2010 Deepwater Horizon oil blowout in the Gulf of Mexico and proliferation of data on the assimilation and effects of marine debris microparticulates. Several topical areas reviewed in the past (e.g. mass mortalities ocean acidification) were dropped this year. The focus of this review is on effects, not on pollutant sources, chemistry, fate or transport. There is considerable overlap across subject areas (e.g. some bioaccumulation data may be appear in other topical categories such as effects of wastewater discharges, or biomarker studies appearing in oil toxicity literature). Therefore, we strongly urge readers to use keyword searching of the text and references to locate related but distributed information. Although nearly 400 papers are cited, these now represent a fraction of the literature on these subjects. Use this review mainly as a starting point. And please consult the original papers before citing them.

A study was performed to evaluate the potential biological impacts from 8 different miscellaneous discharges from an oil and gas mobile offshore drilling unit (MODU) including: deck drainage, desalination unit waste, boiler blowdown, fire control system test water, non‐contact cooling water, and bilge water. Samples were evaluated for toxicity using a rapid (<1 h) initial screening test (echinoderm [Dendraster excentricus] fertilization test), and if toxicity was found, further testing was conducted using 3 chronic whole effluent toxicity (WET) tests. This additional testing included the embryo larval development 72‐h echinoderm (D. excentricus); 7‐d mysid (Americamysis bahia) survival, growth, and fecundity invertebrate test; and 7‐d topsmelt (Atherinops affinis) survival and growth fish test. Toxicity identification evaluations were performed on 3 discharges that consistently elicited a toxic response during WET testing. To place the results of the toxicity testing into the context of environmental risk, the spatial extent of potential biological effects was investigated using the CORMIX mixing zone model. The output of the modeling indicated that discharge of selected effluents did not result in concentrations, or duration of exposure, that would elicit toxic effects to organisms living in the surrounding environment. This study provides a comprehensive data set that was used to characterize potential toxicity and environmental risk of MODU “miscellaneous discharges” which could help inform future risk assessments of these discharges. This article is protected by copyright. All rights reserved.

Based on tanaidacean material collected primarily during the IceAGE cruises in the North Atlantic, three new species from the family Akanthophoreidae are described; one is classified in the genus Parakanthophoreus, and the other two represent a new genus—Brixia n. gen. The main characters that distinguish Brixia n. gen. from other akanthophoreids is the lack of fully developed pleopods in adult females and a seven-articled antenna. The diagnosis of the family Akanthophoreidae is amended. Cheliped ornamentation of Parakanthophoreus catharina n. sp. is illustrated using SEM pictures.

Water temperatures are warming throughout the world including the Pacific Northwest, USA. Benthic macroinvertebrates are one of the most important and widely used indicators of freshwater impairment; however, their response to increased water temperatures and their use for monitoring water temperature impairment has been hindered by lack of knowledge of temperature occurrences, threshold change points, or indicator taxa. We present new analysis of a large macroinvertebrate database provided by Idaho Department of Environmental Quality from wadeable streams in Idaho that is to be used in conjunction with our previous analyses. This new analysis provides threshold change points for over 400 taxa along an increasing temperature gradient and provides a list of statistically important indicator taxa. The macroinvertebrate assemblage temperature change point for the taxa that decreased with increased temperatures was determined to be about 20.5 °C and for the taxa assemblage that increased with increased temperatures was about 11.5 °C. Results of this new analysis combined with our previous analysis will also be useful for others in neighboring regions where these taxa occur.

The deep-sea crangonid shrimp, Argis lar, is a highly abundant species from the northern Pacific Ocean. We investigated the phylogeographic and demographic structure across the species’ extensive range using mitochondrial DNA sequence variation in order to evaluate the impact of deep-sea paleoenvironmental dynamics in the Sea of Japan on the population histories. The haplotype network detected three distinct lineages with allopatric isolation, which roughly corresponded to the Sea of Japan (Lineage A), the northwestern Pacific off the Japanese Archipelago (Lineage B), and the Bering Sea / the Gulf of Alaska (Lineage C). Lineage A showed relatively low haplotype / nucleotide diversities, significantly negative value of Tajima’s D and star-shaped network, suggesting that anoxic bottom-water in the Sea of Japan over the last glacial period may have brought about its Sea of Japan population reduction. Furthermore, unexpectedly, the distributions of Lineage A and B were closely related to the pathways of the two ocean currents, especially in the Sanriku Coast. This result indicated that A. lar could disperse across shallow straits through the ocean current, despite their deep-sea adult habitat. Bayesian inference of divergence time revealed that A. lar was separated into three lineages approximately 1 million years before present (BP) in the Pleistocene, and then had been influenced by deep-sea paleoenvironmental change in the Sea of Japan during the last glacial period, followed by a more recent larval dispersal with the ocean current since ca. 6 kilo years BP.

Background The blunt bladed shrimp Spirontocaris truncata inhabits sponges and is typically found on subtidal rocky reefs, and is distributed from the Strait of Georgia, British Columbia to Baja California, Mexico at depths of 37 to 92 m. ResultsThis paper presents a new record of this species obtained from stomach contents of the Pacific cod, Gadus macrocephalus, from the northern Gulf of Alaska, which extends its distribution range over 1800 km. This is the first record of the species in Alaska. ConclusionsA large northward range extension was documented for the shrimp Spirontocaris truncata. A clear understanding of the distribution of marine species is a necessary prerequisite for effective monitoring and predictions about future changes to marine ecosystems.

A new species, Monokalliapseudes guianae, is described from French Guianese estuaries. It is distinguishable from its only congener most notably by lacking an exopodite on pereopod 1 and by the nature of the basal article of the uropod. The inner distal corner of the basal article is only slightly produced and lacks a rounded lobe. The bases of pereopods 2 and 3 lack numerous long setae. Sexual dimorphism is observed in the antennule, cheliped, and pereopod 1. Depending on size, males can exhibit two forms of chelae. A new diagnosis is presented for the genus Monokalliapseudes.

A new species, Elanella haifensis, is described from off the coast of Israel, collected in depths ranging from 9.8–22.4 m. It is easily distinguishable from congeners by the spinulate bulbous setae III and IV of the female caudal ramus, and the shape of the male antennule. A new diagnosis is presented for the genus Elanella. This is the first record of the genus in Mediterranean waters.

Large impoundments remove substantial amounts of sediment and nutrients from rivers and often limit production by downstream primary producers and secondary consumers. Nutrient levels and macroinvertebrate and fish abundance in the lower Kootenai River (7th order, mean annual discharge = 454 m3/s) in Idaho and Montana declined dramatically after Libby Dam was built in 1972. A subsequent study implicated ultraoligotrophic conditions (total dissolved P [TDP] ≤ 2 µg/L TDP) as a principal causative agent and prompted an on-going experimental nutrient-addition program for the Kootenai River downstream from Libby Dam, with dosing at the Idaho—Montana border. Pre-treatment monitoring began in 2003 and liquid ammonium polyphosphate fertilizer (10-34-0) was added each year during the growing season from 2006 through 2010 with a target TDP concentration of 3 µg/L and TN:TP near 20:1. We studied benthic macroinvertebrate responses to the experimental addition and hypothesized moderate increases in invertebrate richness, abundance, and biomass with little change in assemblage structure. We used a before—after control—impact BACI design with macroinvertebrate samples collected pre- and post-treatment from July to early November 2003–2010 from fertilized and unfertilized reaches. After treatment, mean modified (Oligochaeta and Chironomidae subtaxa excluded) total abundance increased 72%, mean total abundance increased 69%, and mean biomass increased 48%. Abundance of Ephemeroptera, the principal insect order in the study area increased 66%. Filter-feeder abundance also increased, indicating increased suspended organic matter in addition to the attached forms consumed by other benthic macroinvertebrates. The first 5 y of experimental treatment resulted in increased food resources for resident native fishes with no major alteration of macroinvertebrate community structure or trophic pathways.

We collected surface water, pore water, and sediment samples at five impounded wetlands adjacent to Great Salt Lake, Utah, during 2010 and 2011 in order to characterize pond chemistry and to compare chemistry with plant community health metrics. We also collected pore water and sediment samples along multiple transects at two sheet flow wetlands during 2011 to investigate a potential link between wetland chemistry and encroachment of invasive emergent plant species. Samples were analyzed for a suite of trace and major elements, nutrients, and relevant field parameters. The extensive sampling campaign provides a broad assessment of Great Salt Lake wetlands, including a range of conditions from reference to highly degraded. We used nonmetric multidimensional scaling (NMS) to characterize the wetland sites based on the multiple parameters measured in surface water, pore water, and sediment. NMS results showed that the impounded wetlands fall along a gradient of high salinity/low trace element concentrations to low salinity/high trace element concentrations, whereas the sheet flow wetlands have both elevated salinity and high trace element concentrations, reflecting either different sources of element loading or different biogeochemical/hydrological processes operating within the wetlands. Other geochemical distinctions were found among the wetlands, including Fe-reducing conditions at two sites and sulfate-reducing conditions at the remaining sites. Plant community health metrics in the impounded wetlands showed negative correlations with specific metal concentrations in sediment (THg, Cu, Zn, Cd, Sb, Pb, Ag, Tl), and negative correlations with nutrient concentrations in surface water (nitrite, phosphate, nitrate). In the sheet flow wetlands, invasive plant species were inversely correlated with pore water salinity. These results indicate that sediment and pore water chemistry play an important role in wetland plant community health, and that monitoring and remediation efforts should consider pore water and sediment chemistry in addition to surface water chemistry.

We read with great interest the correspondence article entitled “Taxonomic certification versus the scientific method” (Rogers 2012), and, as members of the Taxonomic Certification Committee of the Society for Freshwater Science (formerly, the North American Benthological Society [NABS, 1975–2011]) (SFS-TCC 2012), we agreed to respond in a constructive fashion with factual information to correct and provide perspective for a few errors, unfounded and confused assumptions, and misperceptions it presents. The nature and structure of the article and its title requires that our response be segregated into two main parts. First, we briefly describe the philosophy, purpose, and objectives of the Taxonomic Certification Program (TCP [http://www.sfstcp.com/]) as developed and administered by the SFS, including correcting inaccurate statements or false assumptions. Second, we will address the issues Rogers has with terminology used in a paper he cites (Stribling et al. 2003 [not 2002 as cited by Rogers]). The former issue is, by far, most important—primarily because it has the potential of adversely affecting a program that has already had a large positive impact on the quality of biological monitoring in the USA and Canada by recognizing laboratory staff with demonstrated ability to perform taxonomic identifications of benthic macroinvertebrate samples. The terminology issue is trivial, but because the comments are made in print, we correct them in print by rebutting Rogers’ perception that we were in error.

Multiple specimens of the rusty crayfish (Orconectes rusticus) collected from the Susquehanna River in Pennsylvania exhibited Rheotanytarsus sp. (Diptera: Chironomidae) living on their carapaces and chelipeds. Although chironomid larvae have been reported as living on many aquatic organisms, this is the first record of chironomids living phoretically on crayfish.

The Calapooia River watershed in the Willamette Valley of Oregon drains a forested area managed for timber for more than a hundred years. The watershed supports two anadromous salmonids, Winter Steelhead (Oncorhynchus mykiss) and Spring Chinook (Oncorhynchus tshawytscha); both are listed as threatened under ESA. The early loggers harvested the riparian forest and transported the logs using the river, causing a lack of large wood, elevated water temperatures, and impaired hyporheic exchange. We examined species viability in the watershed from an energetic perspective by measuring food production, stream temperature, and rearing habitat availability in tributary and mainstem locations during baseflow. Summer baseflow has been shown to be an energetic bottleneck for salmon and steelhead young. Drift was measured in fifteen tributaries ranging in size from 1 to 3rd order (2004) and eight randomly chosen sites in the mainstem (2010) weekly in August. Flow adjusted drift rates were similar at mainstem and tributaries sites ranging from <1 to 13 invertebrates/m3. At all sites drift rate declined with declining discharge. Rearing habitat is rare and stream temperature maxima approach species thermal limits at lower mainstem locations with maxima > 50 C cooler in the upper mainstem. Initial results show food is not limiting, although thermal maxima necessitate a large ration to support growth. These factors limit abundance and constrict the distribution of suitable habitat for both Spring Chinook and Winter Steelhead. Broadly applied measures to increase roughness for habitat expansion and development of hyporheic exchange in conjunction with growth of riparian forests appear needed for the system to sustain anadromous salmonids.

Anadromous populations of Alewife (Alosa pseudoharengus) and blueback herring (A. aestivalis) in the Northeast are commonly referred to and managed collectively as “river herring” since their distribution is overlapping and their morphology, ecological role, and environmental requirements are similar. Nevertheless, significant differences in certain physical, physiological and biological characteristics exist between the two species. There is compelling recent evidence that river herring populations in the Northeast are declining. For example, annual passage within the Connecticut River at various fish passage facilities has recently declined in orders of magnitude over the last 20 years. In response to these declines, emergency closures and moratoriums have been instituted by management agencies in several New England States. Facilities located within estuaries with large intake water demands are commonly required to assess species-specific impacts. Species-specific impacts are typically assessed using Equivalent Adult Models (EAM), in which stage-specific mortality rates are a model input. Sampling programs designed to generate these data often require large sample sizes and result in the collection of relatively high densities of herring eggs and larvae; making ichthyoplankton sorting and identification very labor intensive. Due to the perceived difficulty of taxonomically distinguishing among species at the egg and larval life stages, laboratories do not typically identify to the species level, consequently mortality estimates are only derived to the genus level (Alosa). Since the northern populations of river herring are in decline, it is important to understand the individual population dynamics of these species separately. Several taxonomic methodologies for distinguishing larval life stages reference techniques including the analysis of preanal myomeres and preanal length for discrimination. Myomere analysis is extremely labor intensive and often thought to give inconsistent taxonomic information. This paper compares and contrasts the utility of various taxonomic methods used to discriminate between larval alewife and blueback herring with the goal of developing a procedure that will yield a high degree of efficiency and accuracy. Ichthyoplankton samples will be collected in the spring of 2011 within the Taunton River, Massachusetts and river herring will be identified to species utilizing at least two of the most promising methodologies. Taxonomic identification will be verified by developing a genetic marker for herring in the Taunton River.

This chapter focuses on the class Branchiopoda, which includes the common Daphnia, and other members of the suborder Cladocera (order Diplostraca). Branchiopods are a heterogeneous group linked by similar mouthparts and leaf-like thoracic legs (phyllopods). Virtually all species within the eight extant orders of Branchiopoda are limited to inland waters (mostly freshwater lentic systems). Branchiopods occupy key positions in aquatic communities. As consumers, they are algivorous herbivores, detritivores (often assimilating bacteria on benthic or suspended organic matter), and occasionally predators of small invertebrates. They are important prey items in the diets of many fish, waterfowl, and certain other vertebrate and invertebrate predators. Many species are planktonic while others live in shallow water benthic habitats. Some, like the fairy shrimp Artemia, are adapted to temporary ponds and to hypersaline ponds and lakes. Scientists estimate that the United States and Canada contain ?645 species of cladocera and nearly 100 species of the generally larger, noncladoceran branchiopods. This chapter introduces the general biology, morphology, phylogeny, evolution, ecology, physiology, and classification of Branchiopods, with focus on those found in freshwaters of North America.