Use of mesohabitat‐specific relationships between flow velocity and river discharge to assess invertebrate minimum flow requirements

Abstract

The benthic macroinvertebrate community in the sixth order lowland River Spree (Germany) was investigated in order to assess ecological effects of a flow reduction. The benthic habitat was composed of visually distinguishable mesohabitats. Eight mesohabitats were delineated, Dreissena-bank, unionid mussel bed, rip-rap, coarse woody debris (CWD), alder roots, stable sand, shifting sand and mud. The mesohabitats differed in their physical structure and hydraulic nature. These functional habitats were partly inhabited by distinct invertebrate assemblages. The use of mesohabitat-specific relationships between flow velocity and discharge seemed the most appropriate approach in order to assess the impact of flow reduction on lotic fauna. In combination with the species-specific optima and tolerances for flow velocity, this approach can be used to develop a minimum flow level that mitigates the effects of flow reduction and enables the persistence of rheophilic invertebrates in their specific mesohabitat.

Potential habitatsversusfunctional habitats in a lowland braided river (Córdoba, Argentina)

“…The identified functional habitats presented distinct physical features and characteristic invertebrate assemblages. In agreement with other research carried out at the mesohabitat scale (Brunke et al, 2001) we recommend the functional habitat approach, because may provide useful tools in management (Harper and Everard, 1998) and river rehabilitation (Kemp et al, 1999). The identification of functional habitats in lotic systems with periodic flow variations such as the Chocancharava River has practical consequences for management and biomonitoring.…”

“…In the field, stream ecologists deal with the difficulty of discerning which the different habitat units are and which their limits are, when carrying out the sampling. A simple and widespread way of handling the problem is to select recognizable habitat units by visual survey, with apparent differences in flow, depth, vegetation and substrate type (Vadas and Orth, 1998;Brunke et al, 2001).…”

“…A great deal of research has been done to identify and to characterize the available habitats to instream fauna in USA as well as in many European countries (Hawkins et al, 1993;Buffagni et al, 2000;Brunke et al, 2001;Halwas and Church, 2005) and more recently in streams of the neotropical region (Ramı´rez et al, 1998;Baptista et al, 2001;Vela´squez and Miserendino, 2003;Principe et al, 2007). Most of this research was made in large lowland rivers with low gradients (Thomaz et al, 2007) or mountain streams with high to moderate gradients, where pools and riffles are the characteristic habitat units (Vadas and Orth, 1998;Brooks et al, 2005).…”

Occurrence Pattern Analysis of Dragonflies (Odonata) on the River Tisza Between Vilok and Huszt Based on Exuviae

“…It has already been proved that the composition of aquatic macroinvertebrate communities is largely influenced by the abiotic and biotic factors of the habitat. (Corbet, 1983;Gibbons and Pain, 1992;Brookes, 1994;Beisel et al, 1998;Brunke et al, 2001;Angelier, 2003;Ward and Mill, 2005). This has been confirmed by several detailed odonatological surveys in respect of dragonflies as well (Müller, 1995;Lohr, 2010), however the variegation of the habitat factors and the adaptability of dragonflies, make it more difficult to learn the habitat factors on the level of species.…”

“…Examining the river bank and channel characteristics of the sampling sites the following factors were taken into consideration: channel width (1), water depth in the stream-channel (2), deepening tendency of the channel (3), mosaiclike nature of the channel (4), condition of the channel near the river banks (5), type of plant coverage on the river bank (6), rate of plant coverage of the riverbank (7), rate of foliage closure (8), intensity of water flow near the river banks (9), water colour (10), water temperature (11), type of the river bank (12), in case of river bank protection, characteristics of the work (13), characteristics of the river bank (14), and forms of the river banks (15).…”