Bl. Chisnall, HABITAT ASSOCIATIONS OF JUVENILE SHORTFINNED EELS (ANGUILLA-AUSTRALIS) IN SHALLOW LAKE-WAAHI, NEW-ZEALAND, New Zealand Journal of Marine and Freshwater Research, 30(2), 1996, pp. 233-237
Small meshed G-minnow traps were used to assess the habitat associatio
ns of juvenile shortfinned eels in Lake Waahi, a shallow mesotrophic l
ake in the lower Waikato River basin, New Zealand. Five distinctive ma
rginal habitats (raupo, aquatic macrophyte, reed, willow, exposed clay
, and mud), and five offshore positions at various depths through the
water column and distances from the margin (1-3 m and 50-500 m, respec
tively) were compared. Eels smaller than 400 mm were closely associate
d with marginal habitat. The highest catch per unit effort (CPUE) of j
uveniles occurred in raupo, the most complex cover. CPUE in marginal h
abitats declined in autumn particularly in the willows which correspon
ded to defoliation. Offshore sampling revealed that eels smaller than
350 mm were almost exclusively in the margins, and that larger eels we
re mostly offshore. Beyond 50 m from the margin, the size of eel did n
ot change with increasing distance offshore. Eels were not caught in s
uspended traps (other fish were), suggesting that eels in this lake we
re benthic foragers. Reasons for juvenile habitat selectivity are disc
ussed and management implications highlighted.