A Proposal to Classify and Assess Ecological Status in Mediterranean Temporary Rivers: Research Insights to Solve Management Needs

Abstract

The biomonitoring methods implemented by water authorities are mostly developed for perennial rivers, and do not apply to temporary rivers (TRs). We propose a new classification for TRs to better assess their ecological status. It arises from the LIFE+ TRivers project, which was conducted in the Catalan and the Júcar Mediterranean river basin districts (RBD). The European Water Framework Directive (WFD) provided two systems to set river types (systems A or B from Annex II), which have been officially used by water authorities across Europe to set “national river types” (NRTs). However, essential hydrological variables for TRs are largely omitted. NRTs established according to the WFD were compared with TR categories obtained by using a rainfall-runoff model, “natural flows prescribed regimes” (NFPRs), and with “aquatic phases regimes” (APRs) calculated by using TREHS software. The biological quality indices currently used in Spain, based on macroinvertebrates and diatoms (IBMWP, IMMI-T, and IPS), were compared with a “general degradation” gradient in order to analyze the two TR river classification procedures (NFPR and APR). The results showed that NRTs did not properly classify TRs, and that the APR classification identified ecologically meaningful categories, especially those related to stagnant phases. Four “management temporary river categories” based on APRs are proposed to be used for water managers to properly assess the ecological status of TRs.

Gut Microbiota and Accumulation of Heavy Metals: A New Study of Water Scorpions (Hemiptera: Nepidae)

“…Therefore, the results of metagenomics analysis of gut microbiota of the hexapod are listed on the last page of this article. In addition, the influence of microbial community composition on microbial functional genes remains unclear in the aquatic ecosystem [14] and in relation to insecticide use. The list of bacteria is available at the end of the article.…”

“…In this context, identifying the microbiome of aquatic Hemiptera was our primary purpose. Biological indices are based on the richness of the aquatic community [14]. Aquatic insects help to indicate the relative degree of purity or pollution of water; some aquatic hemipteran are active predators acting as biological control for mosquito larvae [6].…”

Taxon-specific sensitivities to flow intermittence reveal macroinvertebrates as potential bioindicators of intermittent rivers and streams

“…Although they account for a substantial proportion of the world's waterways (Raymond et al, 2013), IRES have historically been neglected in monitoring, management and water resource assessment plans (AQEM Consortium, 2002;Hering et al, 2006;Stubbington et al, 2018). However, recent recognition of their prevalence and ecological importance is now motivating international efforts to develop effective, IRESspecific ecological status assessment methods (e.g., Gallart et al, 2017;Steward et al, 2018;Stubbington et al, 2018Stubbington et al, , 2019Munné et al, 2021). Effective IRES management strategies are urgently needed as climate change causes these ecosystems to increase in spatiotemporal extent in many global regions (Döll and Schmied, 2012;Tramblay et al, 2021;Zipper et al, 2021).…”

“…IRES bioassessment is most developed in global regions in which climatic drivers make intermittence particularly widespread, namely dryland regions within the Mediterranean Basin, North America, South Africa and Australia (Dallas, 2013;Mazor et al, 2014;Prat et al, 2014;Munné et al, 2021). Within the Mediterranean Basin, region-specific multimetric indices have been developed for macroinvertebrates which inhabit streams including IRES (Munné and Prat, 2009;Prat et al, 2014).…”

Ecological relevance of non‐perennial rivers for the conservation of terrestrial and aquatic communities

“…However, current paradigms in river science and conservation have emerged from and been developed for perennial rivers (Allen et al., 2020 ). For example, in Europe the Water Framework Directive excludes NPRS almost entirely from its ecological status assessment and recovery goals (Munné et al., 2021 ) because they do not meet the criteria established for the definition of water bodies (WFD 2000/60/EC) (Skoulikidis et al., 2017 ). Also, NPRS are underrepresented in the most important conservation frameworks (Fritz et al., 2017 ), such as the RAMSAR Convention (1971) and the Habitats Directive (92/43/CEE).…”