Global concerns related to water biology and security:The need for language and policies that safeguard living resources versus those that dilute scientific knowledge

Increasingly,scientists and non-scientists,especially employees of government agencies,tend to use weak or equivocal language when making statements related to science policy and governmental regulation.We use recent publications to provide examples of vague language versus examples of strong language when authors write about regulating anthropogenic pressures on natural resources.Lifeless language is common in agency reports,policy documents,and even scientific papers published by academics.Such language limits success in regulating anthropogenic pressures on natural resources.This challenge must be recognized and countered as a driver of the condition of water and associated resources.We also list sources of vague wording,provide global examples of how ambiguous language and political influences have contributed to water resource degradation,discuss the recent history of science censorship,and offer possible solutions for more direct scientific discourse.We found that:(1)equivocal language was especially common in concluding statements and not only by government employees;(2)authors discussed confusing language concerns in an agency publication;and(3)agency employees sometimes used active,strong language.Key drivers of weak language include:(1)holding on to old paradigms and resisting new knowledge;(2)scientific uncertainty;(3)institutional manuscript review policies;(4)employment and funding insecurity;and(5)avoiding the appearance of advocacy.Examples associated with euphemistic language included climate change,flow and physical habitat alteration,dams,agriculture,mining,forestry,and fisheries,as well as resistance towards monitoring,assessing,and reporting ecological conditions.Suggestions for mitigating equivocal language involve employment protections and greater focus on scientific ethics.We conclude that natural resource scientists should resist calls to employ imprecise language.Instead,they should be strong advocates for prescriptive and protective natural resource actions—based on their science—to halt and reverse the systemic degradation of those resources.

Physical habitat condition as a key tool to maintain freshwater biodiversity in neotropical artificial ponds

In areas highly affected by anthropogenic disturbances,artificial(human-made)freshwater ecosystems can provide habitat for maintaining and conserving regional freshwater biodiversity.We assessed how the physical habitat of artificial ponds affected the structure of benthic macroinvertebrate assemblages.To do so,we tested two hypotheses.(1)Physical habitat disturbances are not detrimental to the diversity of nearby artificial ponds,and(2)Physical habitat disturbances do not cause significant shifts in taxonomic composition.Our results rejected both null hypotheses,i.e.,macroinvertebrate diversity metrics correlated significantly and positively with Physical Habitat Integrity index scores,and only sites with high habitat condition scores were significantly associated with sensitive indicator taxa.Our results highlight the importance of maintaining physical habitat conditions for sustaining the ecological health of artificial ponds.

Tropical and subtropical streams:A synthesis

Tropical and sub-tropical streams harbor great biodiversity and are responsible for crucial ecosystem services.Intending to contribute to the understanding of how anthropogenic stressors and pressures alter functional or taxonomic diversity in biotic assemblages or processes in these systems,Water Biology and Security published eight papers.The research originated from Cameroon(Central Africa),southeastern Brazil,eastern Amazonia,and eastern China,representing eight river basins:Huai,Sui and Yishusi from east Asia;São Francisco,Doce,Jequitinhonha,and Amazon from South America;and Congo from Africa.The last two are the most biodiverse on the planet.The studied biomes included tropical rainforest and savanna,neotropical savanna and rainforest,neotropical savanna mountains,and subtropical monsoon forest.The response variables included fish assemblages(3 papers),entire macroinvertebrate assemblages or sub-groups(4 papers),and stream physical habitat structure(1 paper).

Which metrics drive macroinvertebrate drift in neotropical sky island streams?

Despite long-standing interest,the mechanisms driving aquatic macroinvertebrate drift in tropical streams remain poorly understood.Therefore,the objective of this study was to evaluate which environmental metrics drive macroinvertebrate drift in neotropical sky island streams.We evaluated whether altitude,the abundance of food resources,and variations in water quality influenced macroinvertebrate drift density,diversity,richness,and functional feeding groups.An hypothesis was developed to test whether increased altitude,lower food availability(particulate organic matter),and discharge would increase the density,taxonomic richness,and diversity of drifting invertebrates.Nine headwater stream sites were sampled in the rainy and dry seasons in the Espinhaço Meridional Mountain Range(EMMR)of southeast Brazil.Samples were collected using drift nets deployed from 5:00 p.m.to 8:00 p.m.The abundance of food resources was assessed through estimates of coarse(CPOM)and fine(FPOM)particulate organic matter,and primary producers.CPOM availability was an important explanatory variable for Gathering-Collectors and Scrapers,Altitude was important for Shredders and Predators,and Filtering-Collectors were linked to water discharge,suggesting that functional group drift masses were linked to different ecosystem components.Water temperature,conductivity,dissolved oxygen,current velocity,FPOM biomass and microbasin elevation range exerted little influence on macroinvertebrate drift.Regarding taxa composition,this study also found that Baetidae and Leptohyphidae(Ephemeroptera)and Chironomidae and Simuliidae(Diptera)were the most abundant groups drifting.

Assemblage-based biomonitoring of freshwater ecosystem health via multimetric indices:A critical review and suggestions for improving their applicability

Freshwater biota are more comprehensive and direct indicators of biological impacts,and more meaningful to the public than water quality or physical habitat surrogates.Freshwater biotic data and the multiple biological indicators developed from them offer a much richer array of data for assessing the impacts of pollution controls than a limited set of physical or chemical measures.In recent decades,assemblage-based assessments by ecologists,environmental scientists,and water quality agencies have been employed globally for determining the condition of,and threats to,freshwater ecosystems.A key step in this advance has been the development of multimetric indices(MMIs)or indices of biotic integrity(IBIs)based on quantitative assessments of algae,macrophyte,macroinvertebrate,fish or riparian bird assemblages.In Europe,where biological assemblages are mandated for assessing freshwater ecosystem health,many indices are multimetric.However,the proliferation of MMIs globally has not always occurred through the application of rigorous study designs and monitoring protocols,nor have they always effectively incorporated functional metrics,stressor assessments,and statistical analyses.Therefore,in this review,we discuss eleven major concerns with the development and application(including logistical limitations)of multimetric indicators based on freshwater biota to encourage more rigorous and widely applicable(transferable)MMI use and implementation.Specifically,our concerns focus on reference conditions;sampling effort,methods,and season;trophic guild definition;metric comprehensiveness,options,screening and scoring;and MMI validation.MMIs could also benefit from increased attention to ecological mechanisms and metric development,to further improve our understanding of anthropogenic impacts as well as rehabilitation effects on freshwater ecosystems globally.Paying closer attention to study designs,ecological mechanisms and metric development should further improve our understanding of anthropogenic impacts and better facilitate rehabilitation of degraded freshwater ecosystems,as well as aiding in the conservation of healthy freshwater ecosystems globally.

What physical habitat factors determine the distribution of gastropods in neotropical headwater streams?

Freshwater gastropods play a pivotal role in the structure and functioning of freshwater ecosystems,but despite their importance,there are still gaps in their ecology.Our goal was to understand what physical habitat factors are the most important for the distribution of freshwater gastropods in headwater stream ecosystems in the Neotropical Savanna and provide a baseline for conservation and management efforts for freshwater gastropods in this biome.We identified five taxa,each with different environmental prefferences.Littoridina presence related negatively with stream slope,Biomphalaria presence related positively with total dissolved solids and the proportions of cobble,fine sediment and organic matter.Gundlachia presence correlated positively with elevation and the proportion of pools in the site.Physa presence related negatively with total dissolved solids and positively with alkalinity.Melanoides tuberculata presence correlated positively with the proportion of coarse gravel.Our results highlight the challenge for protecting native freshwater gastropod assemblages(and managing non-native invasive species),because environmental preferences vary widely amongst taxa and most are vulnerable to common anthropogenic disturbances.