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The accuracy of posttranslocation population monitoring methods is critical to assessing long-term success in translocation programs. Translocation can produce unique challenges to monitoring efforts; therefore, it is important to understand the flexibility and robustness of commonly used monitoring methods. In Florida, USA, thousands of gopher tortoises Gopherus polyphemus have been, and continue to be, translocated from development sites to permitted recipient sites. These recipient sites create a broad range of potential monitoring scenarios due to variability in soft-release strategies, habitat conditions, and population demographics. Line transect distance sampling is an effective method for monitoring natural tortoise populations, but it is currently untested for translocated populations. We therefore produced 3,024 individual-based, spatially explicit scenarios of translocated tortoise populations that differed in recipient site and tortoise population properties, based on real-world examples, literature review, and expert opinion. We virtually sampled simulated tortoise populations by using line transect distance sampling methods and built a Bayesian hierarchical model to estimate the population density for each simulation, which incorporated individual-level covariates (i.e., burrow width and burrow occupancy). Line transect distance sampling was largely appropriate for the conditions that typify gopher tortoise recipient sites, particularly when detection probability on the transect lines was greater than or equal to 0.85. Designing the layout of transects relative to the orientation of soft-release pens, to avoid possible sampling biases that lead to extreme outliers in estimates of tortoise densities, resulted in more accurate population estimates. We also suggest that use of individual-level covariates, applied using a Bayesian framework as demonstrated in our study, may improve the applicability of line transect distance sampling surveys in a variety of contexts and that simulation can be a powerful tool for assessing survey design in complex sampling situations. [ABSTRACT FROM AUTHOR]

Emerging fungal pathogens pose a greater threat to biodiversity than any other parasitic group (1), causing declines of many taxa, including bats, corals, bees, snakes and amphibians (1-4). Currently, there [...]

Agricultural expansion is predicted to increase agrochemical use two to fivefold by 2050 to meet food demand. Experimental evidence suggests that agrochemical pollution could increase snails that transmit schistosomiasis, a disease impacting 250 million people, yet most agrochemicals remain unexamined.Here we experimentally created >100 natural wetland communities to quantify the relative effects of fertilizer, six insecticides (chlorpyrifos, terbufos, malathion, λ‐cyhalothrin, permethrin and esfenvalerate), and six herbicides (acetochlor, alachlor, metolachlor, atrazine, propazine and simazine) on two snail genera responsible for 90% of global schistosomiasis cases.We identified four of six insecticides (terbufos, permethrin, chlorpyrifos and esfenvalerate) as high risk for increasing snail biomass by reducing snail predators. Hence, malathion and λ‐cyhalothrin might be useful for improving food production without increasing schistosomiasis. This top‐down effect of insecticides on predators was so strong that the effects of herbicides on schistosomiasis risk were masked in the presence of predators because there were so few snails. In the absence of snail predators, herbicide effects on snails were generally negative by reducing submerged vegetation Hydrilla verticillata. The exception was that atrazine and acetochlor significantly increased the biomass of infected snails and total snails respectively.Like insecticides, fertilizer had strong positive effects on snail populations. Fertilizer increased both snail habitat (submerged vegetation) and snail food (periphyton), but of these two pathways, the increases in snail habitat resulted in greater snail population growth. Total snail biomass was positively associated with both infected snail biomass and parasite production and thus human infection risk.Synthesis and applications. Our findings suggest that fertilizers and insecticides generally have consistently higher chances of increasing human schistosomiasis than herbicides in natural communities. Furthermore, our results highlight the need to identify other low risk insecticides, which might help reduce crop pests without increasing snails and thus risk of schistosomiasis. [ABSTRACT FROM AUTHOR]

Pesticide pollution can alter parasite transmission, but scientists are unaware if effects of pesticides on parasite exposure and host susceptibility (i.e. infection risk given exposure) can be generalised within a community context. Using replicated temperate pond communities, we evaluate effects of 12 pesticides, nested in four pesticide classes (chloroacetanilides, triazines, carbamates organophosphates) and two pesticide types (herbicides, insecticides) applied at standardised environmental concentrations on larval amphibian exposure and susceptibility to trematode parasites. Most of the variation in exposure and susceptibility occurred at the level of pesticide class and type, not individual compounds. The organophosphate class of insecticides increased snail abundance (first intermediate host) and thus trematode exposure by increasing mortality of snail predators (top–down mechanism). While a similar pattern in snail abundance and trematode exposure was observed with triazine herbicides, this effect was driven by increases in snail resources (periphytic algae, bottom–up mechanism). Additionally, herbicides indirectly increased host susceptibility and trematode infections by (1) increasing time spent in susceptible early developmental stages and (2) suppressing tadpole immunity. Understanding generalisable effects associated with contaminant class and type on transmission is critical in reducing complexities in predicting disease dynamics in at‐risk host populations. [ABSTRACT FROM AUTHOR]

Ecosystems are often exposed to mixtures of chemical contaminants, but the scientific community lacks a theoretical framework to predict the effects of mixtures on biodiversity and ecosystem properties. We conducted a freshwater mesocosm experiment to examine the effects of pairwise agrochemical mixtures [fertiliser, herbicide (atrazine), insecticide (malathion) and fungicide (chlorothalonil)] on 24 species- and seven ecosystem-level responses. As postulated, the responses of biodiversity and ecosystem properties to agrochemicals alone and in mixtures was predictable by integrating information on each functional group's (1) sensitivity to the chemicals (direct effects), (2) reproductive rates (recovery rates), (3) interaction strength with other functional groups (indirect effects) and (4) links to ecosystem properties. These results show that community ecology theory holds promise for predicting the effects of contaminant mixtures on biodiversity and ecosystem services and yields recommendations on which types of agrochemicals to apply together and separately to reduce their impacts on aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Although studies on biodiversity and ecosystem function are often framed within the context of anthropogenic change, a central question that remains is how important are direct vs. indirect (via changes in biodiversity) effects of anthropogenic stressors on ecosystem functions in multitrophic-level communities. Here, we quantify the effects of the fungicide chlorothalonil on 34 species-, 2 community- and 11 ecosystem-level responses in a multitrophic-level system. At ecologically relevant concentrations, chlorothalonil increased mortality of amphibians, gastropods, zooplankton, algae and a macrophyte (reducing taxonomic richness), reduced decomposition and water clarity and elevated dissolved oxygen and net primary productivity. These ecosystem effects were indirect and predictable based on changes in taxonomic richness. A path analysis suggests that chlorothalonil-induced reductions in biodiversity and top-down and bottom-up effects facilitated algal blooms that shifted ecosystem functions. This work emphasises the need to re-evaluate the safety of chlorothalonil and to further link anthropogenic-induced changes in biodiversity to altered ecosystem functions. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Atrazine does not affect algal biomas or snail populations in microcosm communities at environmentally relevant concentrations," by Leilan R. Baxter and colleagues in the 2011 issue.

A correction to the article "Early-life exposure to a herbicide has enduring effects on pathogeninduced mortality" that was published in a 2014 issue is presented.