A review of exotic earthworm observations in the Canadian boreal forest and taiga zones

In the last decades, concerns have emerged that boreal forests could convert from a carbon sink to a carbon source, thus accentuating climate change. Although forest fire is generally mentioned as the main factor that could cause the boreal forest to transition to a carbon source, other factors, such as exotic earthworm activity, could also play an important role. Invasive exotic earthworms can also affect nutrient cycling, biodiversity and forest dynamics. In this context, a better knowledge of the distribution of exotic earthworms can help understand the likely changes in the ecosystems that they have colonized. Here we report the results of an exhaustive literature review of the presence of exotic earthworms in the Canadian boreal forest and taiga zones. We identified 230 sectors containing 14 earthworm species (11 exotic, 2 native and 1 putative native) in 6 provinces and 3 territories across Canada’s boreal forest and taiga zone. We also report 23 as-yet unpublished observations from the province of Quebec. We note the presence of earthworms in environments (acid soils, harsh climate) that were historically considered inadequate for their survival. This suggests that the portion of Canada’s boreal forests suitable for their presence or colonization is larger than what was previously believed. This study represents the first compilation of exotic earthworm presence in this large northern area. Factors that could affect their distribution and potential effects on boreal ecosystems are also discussed. Globally, several earthworm species seem to be overcoming the previously assumed limitation by temperature and pH.

The Green Wave: Reviewing the Environmental Impacts of the Invasive European Green Crab (Carcinus maenas) and Potential Management Approaches

The European green crab (Carcinus maenas), native to northwestern Europe and Africa, is among the top 100 most damaging invasive species globally. In some regions, including the Atlantic coast of North America, C. maenas has caused long-term degradation of eelgrass habitats and bivalve, crab, and finfish populations, while areas are near the beginning of the invasion cycle. Due to high persistence and reproductive potential of C. maenas populations, most local and regional mitigation efforts no longer strive for extirpation and instead focus on population control. Long-term monitoring and rapid response protocols can facilitate early detection of introductions that is critical to inform management decisions related to green crab control or extirpation. Once C. maenas are detected, local area managers will need to decide on management actions, including whether and what green crab control measures will be implemented, if local invasion might be prevented or extirpated, and if population reduction to achieve functional eradication is achievable. Due to the immense operational demands likely required to extirpate C. maenas populations, combined with limited resources for monitoring and removal, it is unlikely that any single government, conservation and/or academic organization would be positioned to adequately control or extirpate populations in local areas, highlighting the importance of collaborative efforts. Community-based monitoring, and emerging methods such as environmental DNA (eDNA), may help expand the spatial and temporal extent of monitoring, facilitating early detection and removal of C. maenas. While several C. maenas removal programs have succeeded in reducing their populations, to our knowledge, no program has yet successfully extirpated the invader; and the cost of any such program would likely be immense and unsustainable over the long-term. An alternative approach is functional eradication, whereby C. maenas populations are reduced below threshold levels such that ecosystem impacts are minimized. Less funding and effort would likely be required to achieve and maintain functional eradication compared to extirpation. In either case, continual control efforts will be required as C. maenas populations can quickly increase from low densities and larval re-introductions.

Reviewing taxonomic bias in a megadiverse country: primary biodiversity data, cultural salience, and scientific interest of South African animals

Taxonomic bias, resulting in some taxa receiving more attention than others, has been shown to persist throughout history. Such bias in primary biodiversity data needs to be addressed because the data are vital to environmental management. This study reviews taxonomic bias in South African primary biodiversity data obtained from the Global Biodiversity Information Facility (GBIF). The focus was specifically on animal classes, and regression analysis was used to assess the influence of scientific interest and cultural salience on taxonomic bias. A higher resolution analysis of the two explanatory variables’ influence on taxonomic bias is conducted using a generalised linear model on a subset of herpetofaunal families from the focal classes. Furthermore, the potential effects of cultural salience and scientific interest on a taxon’s extinction risk are investigated. The findings show that taxonomic bias in South Africa’s primary biodiversity data has similarities with global scale taxonomic bias. Among animal classes, there is strong bias towards birds while classes such as Polychaeta and Maxillopoda are under-represented. Cultural salience has a stronger influence on taxonomic bias than scientific interest. It is, however, unclear how these explanatory variables may influence the extinction risk of taxa. We recommend that taxonomic bias can be reduced if primary biodiversity data collection has a range of targets that guide (but do not limit) accumulation of species occurrence records per habitat. Within this range, a lower target of species occurrence records accommodates species that are difficult to detect. The upper target means occurrence records for any species are less urgent but nonetheless useful and thus data collection efforts can focus on species with fewer occurrence records.

Linking functional diversity to ecological indicators: A tool to predict the anthropogenic effects on ecosystem functioning

Functional diversity is related to the maintenance of processes and functions in ecosystems. However, there is a lack of a conceptual framework that highlights the application of functional diversity as an ecological indicator. Therefore, we present a new initiative for motivating the development of ecological indicators based on functional diversity. We are interested in showing the challenges and solutions associated with these indicators. We integrated species assemblage theories and literature reviews. We considered plant traits related to ecosystem processes and functions (specific leaf area, leaf dry matter content, wood density, phenology, and seed mass) to show the application of a selection of functional diversity metrics that can be used as ecological indicators (i.e., Community Weighted-Mean, Functional Divergence, Functional Richness and Functional Evenness). We caution that functional diversity as an ecological indicator can be misinterpreted if species composition is unknown. Functional diversity values can be overrepresented by weed species (species established in disturbed sites) and do not maintain original processes and functions in ecosystems. Therefore, we searched for evidence to demonstrate that weed species are ecological indicators of functional diversity changes. We found support for two hypotheses that explain the effect of weed species on ecosystem function: functional homogenization and functional transformation. Likewise, we showed the application of some tools that can help study the anthropogenic effect on functional indicators. This review shows that the paradigm of addressing the effects of disturbances on ecosystem processes by using functional diversity as an ecological indicator can improve environmental evaluation, particularly in areas affected by human activities.

Progress of Optical Biosensors for Analysis of Pathogens and Organic Pollutants in Water since 2015

Water contamination by pathogens and organic pollutants is one of the major environmental problems that risk human health. Climate change with extreme weather can promote their prevalence in waters. Environmental monitoring of these pollutants in a fast, continuous, and accurate manner is of increasing demand, especially under the climate change context, but is challenged by their ubiquity and trace concentrations. Optical biosensing is one of the desired solutions owing to its rapid and accurate detection with high sensitivity. Principally, an optical biosensor recognizes these bioactive toxins and contaminants by tailored bioreceptors (e.g., aptamer, enzyme, and cells) and transduces the biological response to optical signals. Research efforts have been made on tailoring bioreceptors and enhancing signal transducing by nanoparticles. This study comprehensively reviewed the mechanisms of optical biosensing and the recent development of bioreceptors and nanomaterials on the enhancement for the rapid, easy, and accurate analysis of emerging contaminants in water. The advantages and challenges on sensitivity, selectivity, and durability of biosensors were discussed along with the opportunities and development strategies.

New Open-loop Recycling Approaches for Disposable Diaper Waste

Today's disposable diapers have become an indispensable choice among hygiene products, reflected in their massive global consumption and waste generation. Most of the diaper waste is neither segregated nor treated and ends up in landfills or incinerators. The reported life cycle assessment highlights that the diaper waste is not solely generated after single-use but begins as early as the raw materials acquisition stage. Although what is done cannot be undone, diaper waste can be recycled. Diaper waste valorization has been explored on laboratory- and commercial-scales for years, with varying degrees of success. Leading diaper manufacturers such as Procter & Gamble, Kimberley-Clark and Unicharm are making progress in establishing closed-loop recycling of used diapers and converting diaper waste into new diapers. However, the wide window of possible new products made from diaper waste has yet to be fully exploited. This review focuses on the enormous promise of diaper waste from the perspective of emerging open-loop recycling pathways. We demonstrate that diaper waste was harnessed and converted into non-diaper products, including energy pellets, anode material for lithium-ion batteries, concrete admixture, catalysts, soil amendment, and mushroom cultivation substrates. We also explore several active, commercial-scale diaper recycling approaches and provide a comprehensive blueprint to encourage open-loop recycling. Open-loop recycling is a practical strategy for managing diaper waste, rectifying environmental damage, and contributing to circular supply chains.

Why do we monitor? Using seabird eggs to track trends in Arctic environmental contamination

Contaminant levels and trends have been monitored in eggs of seabirds from the Canadian Arctic since 1975. Nearly 50 years of monitoring have provided key information regarding the temporal and spatial variation of various contaminant classes in different seabird species. However, previous work has primarily assessed individual or related contaminant classes in isolation. There is therefore a need to collectively consider all of the contaminants monitored in seabird eggs to determine where monitoring has been successful, to find areas for improvement, and to identify opportunities for future research. In this review, we evaluated monitoring data for the major legacy and emerging contaminants of concern in five seabird species from three High Arctic and three Low Arctic colonies in Canada. We review the history of Canada’s Arctic seabird egg monitoring program and discuss how monitoring efforts have changed over time; we summarize temporal, spatial, and interspecies variations in Arctic seabird egg contamination and identify important knowledge gaps; and we discuss future directions for ecotoxicology research using seabird eggs in Arctic Canada. Ultimately, this paper provides a high-level overview of the egg contaminant monitoring program and underscores the importance of long-term and continued seabird contaminant monitoring in Arctic Canada.

Microplastics in lakes and rivers: an issue of emerging significance to limnology

Microplastics—plastic particles in the size range of planktonic organisms—have been found in the water columns and sediments of lakes and rivers globally. The number and mass of plastic particles drifting through a river can exceed those of living organisms such as zooplankton and fish larvae. In freshwater sediments, concentrations of microplastics reach the same magnitude as in the world’s most contaminated marine sediments. Such particles are derived from a unique biogeochemical cycle that ultimately influences productivity, biodiversity, and ecosystem functioning. Furthermore, microplastics act as vectors of toxic substances to invertebrates, fishes, herpetofauna, and waterfowl. We contend that the concentration of this distinct particle component is an ecologically significant parameter of inland waterbodies because of its ubiquity, environmental persistence, and interactions with key ecological processes. No environmental field survey that has searched for microplastics has yet failed to detect their presence. Standardized limnological protocols are needed to compare spatio-temporal variation in the concentration of microplastics within and across watersheds. Data obtained from such protocols would facilitate environmental monitoring and inform policy for managing plastic waste; furthermore, they would enable more accurate modeling of contaminant cycling and the development of a global plastic budget that identifies sources, distribution and circulation pathways, reservoir size and retention times.

Cadmium pollution of water, soil, and food: a review of the current conditions and future research considerations in Latin America.

The presence of cadmium (Cd) in Latin American produced food has been in the spotlight in recent years. Regarding food safety, this element can be toxic to humans at low exposure levels, and its monitoring is a question of public health. Cadmium concentrations from different sources, such as water, soil, sediments, food and beverages were examined and discussed to address the non-occupational exposure of the Latin American population. A literature review was conducted, which considered publications from 2015 to 2020 and available in the ScienceDirect and PubMed databases. Twenty-eight papers were considered for Cd in water, forty-nine for Cd in soil and sediments, and eighty-six for Cd in food. We identify and discuss factors affecting Cd environmental behavior and bioaccumulation, the main species used in monitoring studies, and the necessity for future research. Brazil and Mexico are the countries with the most available information, whereas for some countries in Central America, no information was found. The Cd levels in food examined in these studies (mostly fish and cacao) were generally below the established maximum levels, indicating a low risk. When considering the presence of Cd in food, water, and soil, Cd fractionation and chemical speciation studies are fundamental to understand which Cd species are the most toxic. In turn, studies on bioaccessibility and bioavailability of Cd in food are also needed for more adequate risk assessment but they are currently scarce in all of Latin America.