Assessing natural recovery from contaminants in a river using sediment chemistry and toxicity from different depth ranges

Sequential risk mitigation approaches the remediation of contaminated sediments in three phases designed to: (1) immediately reduce the ecological and human health risks associated with high levels of contamination, using methods such as the confinement or capping of high-risk materials; (2) reduce the risks associated with moderate levels of pollution to a minimum, on a less urgent schedule and at a lower cost; and (3) address areas of limited contamination through a combination of natural recovery and enhanced natural recovery (to aid or speed those natural processes). Natural recovery, the reduction of contaminant concentrations through natural processes, is based on the practical observation that overall ecosystem recovery appears to be largely a function of time. Sediment decomposition and the mixing of new and old sediments by bottom-dwelling organisms can both contribute to reduced contaminant concentrations. Knowledge of these processes--sediment decomposition, sediment mixing by bottom-dwelling organisms, and chemical residence time is critical in the development of appropriate ecosystem recovery and waste management strategies. Evaluations to support natural recovery predictions are designed to collect and evaluate information necessary to determine whether surface sediment chemical concentrations, with adequate source control, will reach the cleanup standards within a ten-year period.

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Highly restricted dispersal in habitat-forming seaweed may impede natural recovery of disturbed populations

Scientific Reports ◽

10.1038/s41598-021-96027-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Florentine Riquet ◽

Christiane-Arnilda De Kuyper ◽

Cécile Fauvelot ◽

Laura Airoldi ◽

Serge Planes ◽

...

Keyword(s):

Genetic Structure ◽

Spatial Scales ◽

Mediterranean Ecosystems ◽

Dispersal Distance ◽

Genetic Connectivity ◽

Restricted Gene Flow ◽

Isolated Populations ◽

Natural Recovery ◽

Limited Dispersal ◽

Ecological Importance

AbstractCystoseira sensu lato (Class Phaeophyceae, Order Fucales, Family Sargassaceae) forests play a central role in marine Mediterranean ecosystems. Over the last decades, Cystoseira s.l. suffered from a severe loss as a result of multiple anthropogenic stressors. In particular, Gongolaria barbata has faced multiple human-induced threats, and, despite its ecological importance in structuring rocky communities and hosting a large number of species, the natural recovery of G. barbata depleted populations is uncertain. Here, we used nine microsatellite loci specifically developed for G. barbata to assess the genetic diversity of this species and its genetic connectivity among fifteen sites located in the Ionian, the Adriatic and the Black Seas. In line with strong and significant heterozygosity deficiencies across loci, likely explained by Wahlund effect, high genetic structure was observed among the three seas (ENA corrected FST = 0.355, IC = [0.283, 0.440]), with an estimated dispersal distance per generation smaller than 600 m, both in the Adriatic and Black Sea. This strong genetic structure likely results from restricted gene flow driven by geographic distances and limited dispersal abilities, along with genetic drift within isolated populations. The presence of genetically disconnected populations at small spatial scales (< 10 km) has important implications for the identification of relevant conservation and management measures for G. barbata: each population should be considered as separated evolutionary units with dedicated conservation efforts.

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Preliminary observations on abundance and distribution of fish fauna in a canyon of the Bay of Biscay (ICES Division 8c)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315420001265 ◽

2021 ◽

pp. 1-10

Author(s):

G. Diez ◽

L. Arregi ◽

M. Basterretxea ◽

E. Cuende ◽

I. Oyarzabal

Keyword(s):

Deep Sea ◽

Basque Country ◽

Fish Fauna ◽

Fishing Effort ◽

Fishing Gear ◽

Clear Trend ◽

Depth Ranges ◽

Abundance And Distribution ◽

Sea Fish ◽

Distribution Of Fish

Abstract The changes in abundance and biodiversity of deep-sea fish fauna are described based on an annual deep-water longline survey with data collected during the period 2015–2019 in the Basque Country continental Slope (ICES Division 8c). The sampling scheme included hauls in four 400 m strata, from 650–2250 m deep. The DST sensors installed in the main line have allowed us to set an accurate soak time for each haul, and they were used to calculate fishing effort and CPUE by haul. The catchability of the fishing gear indicated that 15% of the total hooks deployed in the five-year period were able to fish, and that the bottom longline was very effective in fishing a wide number of different species in all depth ranges. The fishing gear caught 14 different species of sharks (13 deepwater and one pelagic), two chimaeras and nine teleosts. The abundance and biomass registered on the hooks attached to the bottom were between three and four times higher than in the floating sections, and the highest CPUE and biomass were recorded between 1051–1450 m, from 2015 to 2017, and in the 1451–1850 m strata, but they do not show any clear trend throughout the five years of the series.

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Potential Use of the Benthic Foraminifers Bulimina denudata and Eggerelloides advenus in Marine Sediment Toxicity Testing

Water ◽

10.3390/w13060775 ◽

2021 ◽

Vol 13 (6) ◽

pp. 775

Author(s):

Mary McGann

Keyword(s):

Sea Urchin ◽

Marine Sediment ◽

Sediment Toxicity ◽

Toxicity Testing ◽

Fertilization Success ◽

Toxicity Tests ◽

Sediment Chemistry ◽

Benthic Foraminifers ◽

Sediment Toxicity Tests ◽

Unionized Ammonia

The benthic foraminifers Bulimina denudata and Eggerelloides advenus are commonly abundant in offshore regions in the Pacific Ocean, especially in waste-discharge sites. The relationship between their abundance and standard macrofaunal sediment toxicity tests (amphipod survival and sea urchin fertilization) as well as sediment chemistry analyte measurements were determined for sediments collected in 1997 in Santa Monica Bay, California, USA, an area impacted by historical sewage input from the Hyperion Outfall primarily since the late 1950s. Very few surface samples proved to be contaminated based on either toxicity or chemistry tests and the abundance of B. denudata did not correlate with any of these. The abundance of E. advenus also did not correlate with toxicity, but positively correlated with total solids and negatively correlated with arsenic, beryllium, chromium, lead, mercury, nickel, zinc, iron, and TOC. In contrast, several downcore samples proved to be contaminated as indicated by both toxicity and chemistry data. The abundance of B.denudata positively correlated with amphipod survival and negatively correlated with arsenic, cadmium, unionized ammonia, and TOC; E. advenus negatively correlated with sea urchin fertilization success as well as beryllium, cadmium, and total PCBs. As B. denudata and E. advenus are tolerant of polluted sediments and their relative abundances appear to track those of macrofaunal toxicity tests, their use as cost- and time-effective marine sediment toxicity tests may have validity and should be further investigated.

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Assessing the Natural Recovery of Mangroves after Human Disturbance Using Neural Network Classification and Sentinel-2 Imagery in Wunbaik Mangrove Forest, Myanmar

Remote Sensing ◽

10.3390/rs13010052 ◽

2020 ◽

Vol 13 (1) ◽

pp. 52

Author(s):

Win Sithu Maung ◽

Jun Sasaki

Keyword(s):

Neural Network ◽

Change Detection ◽

Transfer Learning ◽

Mangrove Forest ◽

Kappa Coefficient ◽

Mangrove Forests ◽

Ann Model ◽

Shrimp Ponds ◽

Natural Recovery ◽

Sentinel 2

In this study, we examined the natural recovery of mangroves in abandoned shrimp ponds located in the Wunbaik Mangrove Forest (WMF) in Myanmar using artificial neural network (ANN) classification and a change detection approach with Sentinel-2 satellite images. In 2020, we conducted various experiments related to mangrove classification by tuning input features and hyper-parameters. The selected ANN model was used with a transfer learning approach to predict the mangrove distribution in 2015. Changes were detected using classification results from 2015 and 2020. Naturally recovering mangroves were identified by extracting the change detection results of three abandoned shrimp ponds selected during field investigation. The proposed method yielded an overall accuracy of 95.98%, a kappa coefficient of 0.92, mangrove and non-mangrove precisions of 0.95 and 0.98, respectively, recalls of 0.96, and F1 scores of 0.96 for the 2020 classification. For the 2015 prediction, transfer learning improved model performance, resulting in an overall accuracy of 97.20%, a kappa coefficient of 0.94, mangrove and non-mangrove precisions of 0.98 and 0.96, respectively, recalls of 0.98 and 0.97, and F1 scores of 0.96. The change detection results showed that mangrove forests in the WMF slightly decreased between 2015 and 2020. Naturally recovering mangroves were detected at approximately 50% of each abandoned site within a short abandonment period. This study demonstrates that the ANN method using Sentinel-2 imagery and topographic and canopy height data can produce reliable results for mangrove classification. The natural recovery of mangroves presents a valuable opportunity for mangrove rehabilitation at human-disturbed sites in the WMF.

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Physiological and biochemical responses of two precious Carpinus species to high-concentration NO2 stress and their natural recovery

Scientific Reports ◽

10.1038/s41598-021-84702-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Qianqian Sheng ◽

Min Song ◽

Zunling Zhu ◽

Fuliang Cao

Keyword(s):

Ecosystem Function ◽

Room Temperature ◽

Normal Growth ◽

Urban Greening ◽

High Concentration ◽

Scientific Application ◽

Natural Recovery ◽

Biochemical Responses ◽

Damage Response ◽

Physiological And Biochemical

AbstractCarpinus betulus and Carpinus putoensis are precious species in the world. Studies on the ecosystem function of the two species are rare. This study investigated the physiological and biochemical responses of C. betulus and C. putoensis to NO2 stress and their natural recovery. C. betulus and C. putoensis seedlings underwent fumigation with 12.0 mg/m3 NO2 for 0, 1, 6, 12, 24, 48, and 72 h, respectively. Then, the plants were allowed to recover at room temperature for 30 d. Physiological and biochemical changes in the leaves were compared between the two species. In terms of peroxidase (POD) activity, the damage response of C. betulus under NO2 stress appeared later than that of C. putoensis. The soluble protein content of C. betulus was noticeably higher than that of C. putoensis, and C. betulus exhibited more stable membrane lipoperoxidation. The tendency of the changes in nitrate reductase of C. betulus was less noticeable than that of C. putoensis. The variation amplitudes of N, K, Mg, Zn and Mn in the leaves of C. putoensis were greater than those of C. betulus. C. putoensis showed more sensitive metabolisms in response to NO2 stress compared with C. betulus. High-concentration NO2 caused damage to C. betulus and C. putoensis was reversible, and both species returned to normal growth via their own metabolism after 30-d recovery. The results of this study may provide useful reference data for quantitative assessment of the ecosystem function of C. betulus and C. putoensis and for their scientific application in urban greening.

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Let’s Focus on Solutions to Entrepreneurial Ill-Being! Recovery Interventions to Enhance Entrepreneurial Well-Being

Entrepreneurship Theory and Practice ◽

10.1177/10422587211006431 ◽

2021 ◽

pp. 104225872110064

Author(s):

Amanda Jasmine Williamson ◽

J. Jeffrey Gish ◽

Ute Stephan

Keyword(s):

Resource Constraints ◽

Negative Impact ◽

Well Being ◽

Natural Recovery ◽

Health And Well Being ◽

Scholarly Inquiry

Entrepreneurship is uniquely stressful. Entrepreneurs often cannot avoid entrepreneurial stressors (e.g., uncertainty, workload, resource constraints) and these stressors can deter natural recovery activities (e.g., detachment and sleep). Yet, entrepreneurs may be able to lessen the negative impact of stress on their well-being, health, and productivity by engaging in recovery. In this editorial, we outline how scholars can employ recovery interventions to ameliorate some of entrepreneurship’s ill effects and support entrepreneurs’ health, well-being, and productivity. We aim to move the focus of scholarly inquiry from documenting the health and well-being challenges of entrepreneurs, toward identifying and implementing solutions to support entrepreneurs.

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