Invertebrate fauna

In addition to reproductive effects, fish exposed to endocrine disrupters may have a decreased response to stress or decreased growth and metabolism which can affect their ability to survive, or to defend themselves against predators. All of these factors can affect the ability of the species to survive and to reproduce itself in sufficient numbers to maintain the stocks on which our commercial and sport fisheries are based. Not all fish species will be equally susceptible to the effects of endocrine disrupters. Selective sensitivity to such effects, especially those affecting reproduction, may well lead to major changes in the flora and fauna of some of our major aquatic ecosystems as the balance between fish, mammals, invertebrates and plants, and between predators and prey, is destabilised... 

Wishart Ml (2000) The terrestrial invertebrate fauna of a temporary stream in southern Africa. Afr Zool 35 193-200... 

Gregory, R.W. and J. Trial. 1975. Effect of zinc-coated culverts on vertebrate and invertebrate fauna in selected Maine streams. Land Water Resour. Inst., Univ. Maine at Qrono, Completion Rep. A-033-ME. 18 pp. 

Bioaccumulation factors for fenvalerate by representative freshwater and estuarine organisms during exposure for 28 to 30 days to various sublethal doses ranged from 40 to 570 for fish, 356 to 4700 for invertebrates, and 477 to 933 for algae (Smith and Stratton 1986). Because of its unusually high lipophilicity, fenvalerate is accumulated at only 30% efficiency by aquatic fauna, and uptake is not dose dependent (Coats et al. 1989). Contamination of algal food of daphnids with fenvalerate does not seem to contribute to an increase in whole-body burdens, although reduced filtration rates... 

Changes in fauna of a reservoir following use of paraquat for weed control are likely to be indirect effects caused by decomposition of angiosperms (Brooker and Edwards 1974). Planktonic invertebrates closely associated with aquatic macrophytes were either eliminated by paraquat or survived at lower densities for at least a year posttreatment analysis of fish stomachs showed dietary changes following weed control and reflected availability of many invertebrate species associated with aquatic plants (Brooker and Edwards 1974). 

Soil fauna, including invertebrates, like nematodes and earthworms. Effects are connected with biodiversity, productivity and biomass changes ... 

In alpine regions, especially in maritime climates, snow depths may be considerable. This insulates the stream environment from subzero temperatures. River ice is an important environmental component of alpine rivers and has resulted in adaptive mechanisms among the fauna [50, 51]. Despite these adaptations, winter conditions inevitably cause high mortality to stream invertebrates and fish, especially in reaches with unstable snow and ice cover and thereby susceptible to formation of frazil and anchor ice. The lack of winter ice cover in lake outflows and groundwater-fed reaches provides a favourable environment for primary producers and those benthic invertebrates utilising primary production [52]. 

Jarvis, A. P. Younger, P. L. 1997. Dominating chemical factors in mine water induced impoverishment of the invertebrate fauna of two streams in the Durham Coalfield, UK. Chemistry and Ecology, 13, 249-270. 

Aquatic Invertebrates. The initial impact of insecticides on most benthic invertebrates in streams is the inability to maintain their position on the streambed resulting in increased numbers being carried downstream in what is termed drift. Invertebrate drift in treated streams is easily sampled by holding a net in the current. Post-spray catches can be compared to both pre-spray diurnal patterns and catches at an untreated upstream station or in an untreated control stream. This method also can be used to document knockdown of streamside foliage-dwelling or arboreal insects if the net is set so as to sample the stream s surface. Impacts on stream invertebrates can also be determined by caging studies and by pre- and post-spray bottom fauna population assessments which either sample the numbers within a given area of natural streambed (e.g., Surber sampler) or on artificial substrates intentionally set in the stream before treatment to be colonized by resident populations. 

Conventional applications of fenitrothion at 210-280 g/ha have been found to sometimes induce short-lived increases in invertebrate drift and opportunistic feeding by native fish on aquatic and terrestrial invertebrates drifting in streams following spraying, but do not appear to cause significant depletion of stream bottom fauna (10, 11). Applications of dosages up to 420 g/ha fenitrothion have been found to have limited impacts on lake fauna aside from occasional short term suppression of zooplankton populations (10, 12, 13). 

Kreutzweiser, D.P. "The effects of permethrin on the invertebrate fauna of a Quebec forest" Report FPM-X-50, Forest Pest Management Institute Sault Ste. Marie, Ont., 1982. 

Carrion itself forms a lucrative substrate for invertebrate colonization however, in outdoor situations the interface between this substrate and the underlying soil, and the soil itself, also form attractive environments for certain organisms. The seepage of nutrient-rich fluids into the soil beneath the corpse significantly alters the microenvironment, affecting the inhabitant fauna. The arthropod assemblage may thus be considered to be affected by and reflective of the decomposition of the corpse and may therefore have some potential in contribution to forensic investigation (Bornemissza 1957). 

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