Entanglement and ingestion of microfibers by the oyster pea crab Zaops ostreum, an endosymbiont of the eastern oyster Crassostrea virginica.

The kleptoparasitic pea crab Zaops ostreum lives within the gills of bivalves, including the economically important eastern oyster Crassostrea virginica. Previous research along the east coast of central Florida has found an average of 2.3 pieces of plastic per oyster. The goals of our research were to determine if filter-feeding oysters transfer microfibers to Z. ostreum via the crab: 1) actively consuming plastic particles, or 2) passively becoming entangled in microfibers. Our results show that both occur. While only 11.6 % of Z. ostreum (total n = 122) consumed microfibers, those that did had up to 14 pieces in their soft tissues. Similarly, only 7.4 % of Z. ostreum had microfibers entangled around their appendages. Mean lengths of consumed and entangled fibers were similar, 1.9 and 2.7 mm, respectively. Additional research is needed to understand the positive and negative impacts of microfibers associated with pea crabs on both species.

Oyster reef restoration facilitates the recovery of macroinvertebrate abundance, diversity, and composition in estuarine communities.

Historic declines in oyster populations have resulted in diminished production of ecosystem services and habitat function in many estuaries. Due to the important role of oysters in ecosystem function, scientists and resource managers have employed oyster reef restoration to mitigate declines, recover essential ecosystem services, and better habitat function. Yet, there are knowledge gaps regarding the impact of restoration efforts on ecologically valuable mid-trophic level organisms inhabiting these systems. To address this knowledge gap, here we quantify macroinvertebrate species abundance, community diversity, and composition on experimental restored oyster reefs before and after restoration, and from live (positive control) and dead (negative control) reefs in the Indian River Lagoon, Florida. Species diversity and composition on restored reefs shifted towards states similar to live (positive control) reefs within 12 months of restoration. Recovery of species abundance occurred within 18 months of restoration. The results presented herein quantify the effect of restoration on resident macroinvertebrates and provide timelines of recovery for each attribute of these communities. Further, this study presents an actionable and transferable framework for identifying effective single-species metrics of restoration success across ecosystems. The application of this framework will provide managers and researchers with tools to improve the efficiency and efficacy of post-restoration monitoring. By doing so, this study contributes significantly to the improvement of broader restoration practices in an era of unprecedented habitat loss.

In-situ microplastic egestion efficiency of the eastern oyster Crassostrea virginica.

Microplastics (MP) are a pervasive environmental pollutant that enter coastal water bodies, posing an ingestion risk to marine biota. This study quantified the ability of the Eastern oyster (Crassostrea virginica) to egest MP in-situ in their biodeposits - feces and pseudofeces. Oysters of all sizes were able to egest environmental MP at a mean rate of 1 MP per 1 h through feces, and 1 MP per 2 h through pseudofeces. Smaller C. virginica were more efficient at egesting MP, and efficiency decreased by 0.8% per 1-g increase in tissue weight, with C. virginica of harvestable size being much less efficient. These findings are of relevance to resource managers for C. virginica populations as it further contributes to our understanding of MP accumulation in wild populations and has implications for not just C. virginica but also for their consumers.

Hydrodynamic and biogeochemical evolution of a restored intertidal oyster (Crassostrea virginica) reef.

Oyster reef restoration is increasingly used as a tool for restoring lost ecosystem services in degraded aquatic systems, but questions remain about the efficacy of the practice and when/if restored reefs may behave similarly to intact natural reefs. In this case study, field observations highlighted short- (<1 month post-restoration) and longer-term (30 months; 3 recruitment cycles) transformations in canopy, hydrodynamic, and biogeochemical characteristics of a restored intertidal oyster reef relative to nearby intact and degraded reefs. Within 12 months of restoration, live oyster density (326 oysters/m2), mean shell length (47 mm), and mean canopy height (76 mm) did not differ significantly from those observed on a reference reef. Lowering of the reef crest during restoration reestablished over-reef flow and periodic tidal inundation, improving hydraulic connectivity between the channel and the reef surface. This immediately restored much of the reef's hydrodynamic function and eliminated the irregular flow patterns observed on the previously degraded reef. Results showed that mean flow (channel-to-reef flow attenuation: 98% / 62%; within/above canopy) and velocity normalized turbulence (w'2¯/U2: 10-1/10-2; ϵ/U3: 100/10-2 m-1) characteristics were similar across the restored and reference reefs within 1 year of restoration, with temporal changes in mixing within the canopy attributed to increases in live oyster density. Nutrient pools (mean total carbon, total nitrogen) on reference and restored reefs had similar magnitudes within 1 year (C: 39 & 33 g/kg, N: 1.5 & 1.8 g/kg), while increases in DOC and NH4+ were correlated with the presence of live oysters. Most changes that occurred on the restored reef were linked to oyster recruitment and canopy growth, which modulated hydrodynamics through direct flow interactions and controlled sediment nutrient and organic matter content through waste deposition and burial.

Large-scale variation in wave attenuation of oyster reef living shorelines and the influence of inundation duration.

One of the paramount goals of oyster reef living shorelines is to achieve sustained and adaptive coastal protection, which requires meeting ecological (i.e., develop a self-sustaining oyster population) and engineering (i.e., provide coastal defense) targets. In a large-scale comparison along the Atlantic and Gulf coasts of the United States, the efficacy of various designs of oyster reef living shorelines at providing wave attenuation was evaluated accounting for the ecological limitations of oysters with regard to inundation duration. A critical threshold for intertidal oyster reef establishment is 50% inundation duration. Living shorelines that spent less than one-half of the time (<50%) inundated were not considered suitable habitat for oysters, however, were effective at wave attenuation (68% reduction in wave height). Reefs that experienced >50% inundation were considered suitable habitat for oysters, but wave attenuation was similar to controls (no reef; ~5% reduction in wave height). Many of the oyster reef living shoreline approaches therefore failed to optimize the ecological and engineering goals. In both inundation regimes, wave transmission decreased with an increasing freeboard (difference between reef crest elevation and water level), supporting its importance in the wave attenuation capacity of oyster reef living shorelines. However, given that the reef crest elevation (and thus freeboard) should be determined by the inundation duration requirements of oysters, research needs to be refocused on understanding the implications of other reef parameters (e.g., width) for optimizing wave attenuation. A broader understanding of the reef characteristics and seascape contexts that result in effective coastal defense by oyster reefs is needed to inform appropriate design and implementation of oyster-based living shorelines globally.

Replacement of oyster reefs by mangroves: Unexpected climate-driven ecosystem shifts.

Increases in minimum air temperatures have facilitated transitions of salt marshes to mangroves along coastlines in the southeastern United States. Numerous studies have documented mangrove expansion into salt marshes; however, a present-day conversion of oyster reefs to mangrove islands has not been documented. Using aerial photographs and high-resolution satellite imagery, we determined percent cover and number of mangrove patches on oyster reefs in Mosquito Lagoon, FL, USA over 74 years (1943-2017) by digitizing oyster reef and "mangrove on oyster reef" areas. Live oyster reefs present in 1943 were tracked through time and the mangrove area on every reef calculated for seven time periods. There was a 103% increase in mangrove cover on live oyster reefs from 1943 (6.6%) to 2017 (13.4%). Between 1943 and 1984, the cover remained consistent (~7%), while between 1984 and 2017, mangrove cover increased rapidly with a 6% year-1 increase in mangrove area on oyster reefs (198% increase). In 1943, 8.7% of individual reefs had at least one mangrove patch on them; by 2017, 21.8% of reefs did. Site visits found at least one mature Avicennia germinans on each tracked mangrove reef, with large numbers of smaller Rhizophora mangle, suggesting the post-1984 mangrove increases were the result of increased R. mangle recruitment and survival. Escalation in the coverage and number of mangrove stands on oyster reefs coincided with a period that lacked extreme freeze events. The time since a temperature of ≤-6.6°C (A. germinans mortality threshold) and ≤-4°C (R. mangle mortality threshold) were significantly correlated with the increased ratio of mangrove area:oyster area, total mangrove area, and number of mangrove patches, with greater variation explained by time since ≤ -4°C. The lack of freezes could lead globally to an ecosystem shift of intertidal oyster reefs to mangrove islands near poleward mangrove range limits.

Microplastic accumulation in the gastrointestinal tracts in birds of prey in central Florida, USA.

A study was conducted to quantify the abundance of plastic pollution in the gastrointestinal tracts in birds of prey. Data was collected from all birds retrieved from the Audubon Center for Birds of Prey in central Florida, USA from January to May 2018. Individuals were either dead prior to reaching the Center or died within 24 h of arrival with no food consumed during captivity. Sixty-three individuals representing eight species were dissected to extract the gastrointestinal (GI) tract from the esophagus to the large intestine. Microplastics were found in the GI tracts in all examined species and in all individual birds. The overall mean number (±S.E.) of microplastics for species of bird of prey in central Florida was 11.9 (±2.8), and the overall mean number of microplastics per gram of GI tract tissue was 0.3 (±0.1). A total of 1197 pieces of plastic were recorded. Microfibers accounted for 86% of total plastics followed by microfragments (13%), macroplastics (0.7%) and microbeads (0.3%). Most fibers were either clear or royal blue in color. Micro-Fourier-transform infrared spectroscopy (µ-FTIR) found that processed cellulose was the most common polymer identified in birds (37%), followed by polyethylene terephthalate (16%) and a polymer blend (4:1) of polyamide-6 and poly(ethylene-co-polypropylene) (11%). Two bird species, Buteo lineatus (red-shouldered hawk, n = 28) and Pandion haliaetus (osprey, n = 16), were sufficiently abundant to enable statistical analyses. Microplastics were significantly more abundant per gram in the gastrointestinal tract tissue of B. lineatus, that consumes small mammals, snakes, and amphibians, than in fish-feeding P. haliaetus (ANOVA: p = 0.013). If raptors in terrestrial food webs have higher densities of microplastics than aquatic top predators, then it potentially could be due to a combination of direct intake of plastics and indirect consumption via trophic transfer.

Quantity and types of microplastics in the organic tissues of the eastern oyster Crassostrea virginica and Atlantic mud crab Panopeus herbstii from a Florida estuary.

This study determined the quantity and diversity of microplastics in water and soft tissues of eastern oysters (Crassostrea virginica) and Atlantic mud crabs (Panopeus herbstii) in Mosquito Lagoon, a shallow, microtidal estuary along the east coast of central Florida. One-liter water samples had an average of 23.1 microplastic pieces (n = 15). Crabs (n = 90) had an average of 4.2 pieces in tissues/individual plus an average of 20.3 pieces/individual temporarily entangled in exposed surfaces and released within 5 days in tanks. Adult oysters (n = 90) had an average of 16.5 microplastic pieces/individual. Fibers, mostly royal/dark blue in color, dominated our collections. When compared per gram of tissue, crabs had two orders of magnitude more microplastic pieces than oysters. Our numbers were higher than previous studies on invertebrate microplastics; this is potentially the result of extensive urbanization, limited flushing, and intensive recreational usage of Mosquito Lagoon.

Correction: Genetic structure provides insights into the geographic origins and temporal change in the invasive charru mussel (Sururu) in the southeastern United States.

[This corrects the article DOI: 10.1371/journal.pone.0180619.].

Genetic structure provides insights into the geographic origins and temporal change in the invasive charru mussel (Sururu) in the southeastern United States.

In 2004, Mytella charruana (d'Orbigny, 1842) (Mollusca: Bivalvia: Mytilidae) became established along the coast of the southeastern United States (SE-US). Using mitochondrial DNA sequencing (cytochrome c oxidase subunit I), we compared genetic variation throughout its native range in South America to its invasive range in the SE-US. Samples from the SE-US were collected in 2006 and 2010 enabling a temporal comparison to evaluate possible genetic changes of the invasive population. We addressed two questions. First, what are the potential source populations (or geographic regions) for the SE-US invasion? Second, how has genetic diversity changed between the two sampling periods within the SE-US? We identified a total of 72 haplotypes, 64 of which were isolated to geographic sites and only 8 were shared among sites. The highly structured native range provides insight into the origin of invasive populations where our results suggest that the introduced SE-US population originated from multiple source populations with the Panama region as the primary source. Additionally, our results indicate that genetic composition of the non-native populations was unchanged between the two sampling periods. Mytella charruana exhibit a significant pattern of genetic structure among natural populations, owing to biogeographic barriers that limit natural dispersal, and an ability to persist in novel habitats, owing to a suite of life-history characters that favor survival under variable conditions. Overall, this study explains why M. charruana may become an increasing threat to locations founded by anthropogenic transportation.

An alternate dissection approach to the female urogenital triangle.

Traditional dissections of the female urogenital (UG) triangle can lead to early destruction of the erectile tissues, associated musculature, and neurovascular structures. Here, we present an alternate dissection of the female UG triangle. Rather than begin the female UG triangle dissection with the fatty tissue of the labia majora, we utilize an early identification of the suspensory ligament of the clitoris to organize the dissection. The suspensory ligament leads to the body of the clitoris, which can be palpated from distal to proximal to find the crura of the clitoris with overlying ischiocavernosus muscles. Once the crura have been defined, the bulbs of the vestibule with overlying bulbospongiosus muscles can be palpated medially and posteriorly. This dissection approach results in a clean dissection that well demonstrates homologies between male and female external genitalia. Through the use of this method, most student dissection attempts are able to demonstrate the erectile tissues and associated musculature that comprise the female UG triangle. This technique can also be used for male UG triangle dissections, encouraging identification of male and female homologies.

A qualitative study of continuing education needs of rural nursing unit staff: the nurse administrator's perspective.

BACKGROUND: This study reports perceptions of the continuing education (CE) needs of nursing unit staff in 40 rural healthcare facilities (10 hospitals and 30 long-term care facilities) in a rural Midwestern U.S. region from the perspective of nurse administrators in an effort to promote a community-based academic-practice CE partnership. METHODS: Qualitative data collection involving naturalistic inquiry methodology was based on key informant interviews with nurse administrators (n=40) working and leading in the participating health care facilities. RESULTS: Major themes based on nurse administrators' perceptions of CE needs of nursing unit staff were in four broad conceptual areas: "Cultural issues", "clinical nursing skills", "patient care", and "patient safety". Major sub-themes for each conceptual area are highlighted and discussed with narrative content as expressed by the participants. Related cultural sub-themes expressed by the nurse administrators included "horizontal violence" (workplace-hospital and LTC nursing unit staff) and "domestic violence" (home-LTC nursing unit staff). CONCLUSIONS: The uniqueness of nurses' developmental learning needs from a situational point of view can be equally as important as knowledge-based and/or skill-based learning needs. Psychological self-reflection is discussed and recommended as a guiding concept to promote the development and delivery of relevant, empowering and evidence-based CE offerings for rural nursing unit staff.

Robotic-assisted surgery and the need for standardized pathways and clinical guidelines.

Robotic surgical techniques are revolutionizing the way surgery is performed in an effort to improve patient outcomes. Although current literature is limited, studies have shown that patients who undergo robotic-assisted procedures experience reduced surgical time, scarring, blood loss, pain, infection rates, and lengths of stay compared with patients who undergo open or laparoscopic procedures. Currently, start-up costs for robotic systems are high and include the major equipment purchase as well as supplemental equipment purchases and staff member training. There is a need to develop standardized perioperative procedures or clinical guidelines that define optimal application of robotic-assisted surgery to ensure a standard of care that is consistent across procedures and operators. Implementing a clinical pathway or guideline that is guided by evidence-based practice will involve change. Lewin's 1947 basic change theory and the Marker umbrella model may be of use to help facilitate change.

Superficial peroneal nerve (superficial fibularis nerve): the clinical implications of anatomic variability.

The purpose of this study is to refine further the knowledge about the anatomic variability of the superficial peroneal nerve in the middle third of the leg. Approaching the superficial peroneal nerve in this location is required: 1) when either the deep or the superficial peroneal nerve must be resected for the treatment of dorsal foot pain; 2) when a neurolysis of the superficial peroneal nerve is required; 3) when a fasciotomy must be performed either for trauma or for exertional compartment syndrome surgery; and 4) during elevation of a fasciocutaneous or fibular flaps. Because of the variability encountered during these procedures, a prospective study was carried out via lower extremity cadaver dissection with fresh, frozen specimens. A total of 35 nonpaired lower extremities and 40 paired lower extremities were dissected with 3.5 loupe magnification. The superficial peroneal nerve was identified in the lateral compartment immediately adjacent to the fascial septum in 72% of the specimens (54 of 75), with a branch in both the anterior and the lateral compartment in 5% of the specimens (4 of 75), and located in the anterior compartment in only 23% of the specimens (17 of 75). The clinical implications of these anatomic findings are that the surgeon operating in the anterior and lateral compartments of the leg should be aware that the superficial peroneal nerve may be located in the lateral compartment and may also exhibit branches in both the anterior and lateral compartments.