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The effects of stream substratum composition on the emergence of salmonid fry
Author(s) -
Sternecker K.,
Geist J.
Publication year - 2010
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/j.1600-0633.2010.00432.x
Subject(s) - salmo , brown trout , biology , river ecosystem , ecology , freshwater ecosystem , habitat , fishery , trout , ecosystem , biodiversity , salmonidae , fish <actinopterygii>
Sternecker K, Geist J. The effects of stream substratum composition on the emergence of salmonid fry.
Ecology of Freshwater Fish 2010: 19: 537–544. © 2010 John Wiley & Sons A/S Abstract – Salmonid fishes are target species for the conservation of freshwater habitats, but their natural reproduction is often insufficient. The emergence of fry is a crucial phase in the life cycle of salmonids and the stream substratum is the key habitat which regulates the emergence success. In this study, brown trout ( Salmo trutta ) and Danube salmon ( Hucho hucho ) eggs were exposed to different sediment textures and the emergence and the postemergence survival and growth were observed under constant water chemical conditions in the laboratory. In both species, textural effects on emergence rate, chronology of emergence, survival rate after emergence and growth after emergence were detected. Fine‐textured substratum (5–8 mm) formed a physical barrier to the posthatch migration of salmonids from the interstitial zone to the open water. The time period between the first and the last emerged fish was shorter in treatments with fine texture compared with coarse substratum. The survival rate was higher in treatments of coarser sediment. The effects of different textures on the growth of fry after emergence differed between brown trout and Danube salmon, which can be explained by different life history strategies. These results suggest that physical characteristics of substratum texture can have strong effects on salmonid emergence, and ultimately on the persistence of salmonid populations. They also suggest that biodiversity conservation in stream ecosystems can greatly benefit from an inclusion of the physical characteristics of the stream bed into catchment‐based management plans.