Biological indicators

Abstract

Changes in living conditions caused by natural variability or anthropogenic activitieselicit distinct responses of species, populations and communities. Bioindication is the recording of such responses and the entity measured is called a "bioindicator". 2. A bioindicator can be any relevant component or measure that can be used to estimate the environmental status based on the performance of all types of organisms (prokaryotes, protists, macroalgae, vascular plants, invertebrates, fish, mammals), including bulk measurements such as the chlorophyll a concentration in the seawater or the lower depth limit of macrophytes. 3. To be able to conclude if environmental change has taken place based on bioindication, it is essential to have knowledge of the specific ecological requirements of the organisms with respect to their habitats. 4. Bioindication using individuals or species includes e.g. behavioural adaptations, modifications of organ and cell structures and changes in population dynamics. 5. Bioindication by recording dramatic increases or decreases in the proportion and/or density of species in a community provides a conspicuous sign of environmental change, especially when this includes the extinction of species. 6. Strong decreases and extinctions of species in a community coupled to immigration of non-indigenous species may signify a shift in community composition that has a bearing on the functioning of the entire ecosystem. 7. Bioindication is a major tool used in the implementations of the EU environmental legislation: the Habitats Directive (HD), the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD).

Metabarcoding vs Microscopy: Comparison of Methods To Monitor Phytoplankton Communities

“…In the Baltic Sea, the ciliate M. rubrum is a major contributor to primary production and is considered a mixotroph in the national monitoring programs . In this study, M.…”

“…In the Baltic Sea, the ciliate M. rubrum is a major contributor to primary production and is considered a mixotroph in the national monitoring programs. 26 In this study, M. rubrum was identified by both microscopy and metabarcoding with the 18S primer pair used.…”

Trophic lengthening triggered by filamentous, N2‐fixing cyanobacteria disrupts pelagic but not benthic food webs in a large estuarine ecosystem

“…The cyanobacteria are the trigger of this effect, but not the general effector. The general effector is the microbial system including microzooplankton, which can modulate (cause or F I G U R E 7 Isotopic signature of total nitrogen (δ 15 N in ‰) in seston from a sediment trap at 35 m depth in the central Arkona Basin in 2016-2019 (Wasmund et al, , 2019Zettler et al, 2020). Shaded in gray is the δ 15 N wms value range between 2-8 ‰ found in flounder (see Figure 5).…”

Biodiversity and ecosystem services in Nordic coastal ecosystems

“…Bladder wrack forms one of the most diverse Baltic Sea habitats down to 10-11 m depth. The lowest depth limit of bladder wrack (and other macroalgae) is widely used as one of the ecological quality indicators in the Water Framework Directive assessments in the Baltic Sea (Zettler et al, 2017).…”