Spawning related seasonal variation in fyke net catches of golden galaxias ( Galaxias auratus ): implications for monitoring lacustrine galaxiid populations

Fishes belonging to the family Galaxiidae are\udrelatively small (usually <300 mm long), freshwaterdwelling\udteleosts that are found on several land\udmasses in the southern hemisphere (McDowall &\udFulton 1996). Many galaxiid species have nondiadromous\udlife histories and the distribution of some\udof these consists of discrete lacustrine populations\ud(McDowall 2000; Allen, Midgley & Allen 2002). As a\udresult of restricted or fragmented distributions,\udalong with other impacts (e.g. introduced fish species),\udmany lacustrine galaxiid species are considered to\udbe threatened; hence monitoring populations for\udconservation purposes is a common management\udpractice.\ud\udFyke nets are known to be effective for capturing\udsmall-sized benthic or littoral fish in lakes (Fago 1998;\udKrueger & Hubert 1998), including galaxiids (Rowe &\udChisnall 1997; Rowe, Konui & Christie 2002). Fyke\udnet catches of Atlantic salmon, Salmo salar L., in lakes\udvary seasonally, suggesting relative abundance indices\udbased on catch data often require correction for\uddifferences in catchability (Ryan 1984). Seasonal\udfluctuations in fyke net catches of European perch,\udPerca fluviatilis L., due to spawning-related habitat\udshifts were also reported by Kubeka (1992). Other\udstudies showed that cover-orientated fish species tend\udto have increased catchability by fyke nets because fyke nets provide cover (Krueger & Hubert 1998;\udRogers, Hansen & Beard 2003)