Survival, reproduction, and recruitment of gizzard shad (Dorosoma cepedianum) at the northwestern edge of its native range

Abstract

South Dakota (SD) represents the northwestern edge of gizzard shad's (Dorosoma cepedianum) native range. However, with recent climate warming the gizzard shad is experiencing a natural range expansion northward. Little knowledge exists regarding temperatures that are required for overwinter survival, and less is known regarding population dynamics of gizzard shad in these populations. The objectives of this research were to determine the extent of reproduction, recruitment, and overwinter survival after annual introductions of adult gizzard shad in two northeastern SD glacial lakes relative to other SD systems. Prior to spawning, the gizzard shad was introduced into East Krause Lake and Middle Lynn Lake and successfully spawned during 2008 and 2009. Mean (±SE) peak larval abundances (number/100 m3) were 3.87 (±1.87) and 1.72 (±0.89) in East Krause Lake and 0.79 (±0.22) and 0.17 (±0.11) in Middle Lynn Lake in 2008 and 2009, respectively. Larval abundances were lower than those observed in most other SD populations. Survival to fall age-0 was documented in both years in Middle Lynn Lake, but only during 2008 in East Krause Lake. No overwinter survival was documented. Low water temperatures and rapidly cooling water likely caused overwinter mortality of gizzard shad in these systems. Temperature at the sediment–water interface during the winter of 2009–2010 was below 2.2°C for 114 and 62 consecutive days in East Krause Lake and Middle Lynn Lake, respectively.