The Mid-Atlantic region is a hot
spot for stream habitat restoration in degraded watersheds yet few studies have
determined whether the fish assemblage would respond to restoration
practices. I tested effects of instream
habitat enhancement through fish selection response using three treatments
(woody debris - LWD, shade - SH, and both - SHWD) in first order urban (>
60% urban land use, ULU), suburban (27-46% ULU), and rural (< 15% ULU)
eastern Piedmont streams in Maryland
(n = 36). Twenty meter block-netted
experimental segments were split into combinations of one enhancement section
(10 m) paired with a control section (10 m).
Fish were removed by double-pass electrofishing, treatments were
constructed and only Rhinichthys
atratulus and Semotilus atromaculatus
were replaced into the center of the segment.
For 6 h the fish were allowed to range freely between sections, then
treatment and control sections were separated by a blocknet
and fish were retrieved and tallied.
Habitat selection was significantly different between rural SHWD vs.
LWD, and between SHWD and SH in suburban fish (P < 0.05). Fish total
length differed significantly between urban, suburban, and rural fish, where
urban fish were the smallest (P <
0.05). CKB who selected the treatment were
significantly larger than in the control section (P < 0.05). Size-dependent
habitat segregation may occur as a result of intraspecific
competition. Rural and suburban fish
recognized and selected the most complex stream habitat enhancements, yet urban
fish most commonly selected SH. Thus,
increasing the amount of overhead cover in urban stream channels would be
beneficial for fish populations when implementing stream restoration practices.