Among year variation in seasonal patterns of larval production by bluegill sunfish in two Ohio ponds

Since bluegill sunfish (Lepomis macrochirus) commonly occur or are stocked into small ponds in the midwestern United States, they may play an important role in structuring these pond communities, as they do in many lakes.  However, few studies explore bluegill population dynamics in small ponds.  I monitored larval abundance across the breeding season in two small ponds for eight summers to assess whether the seasonal pattern of larval production was similar between ponds and if it varied among years.  Between 2002 and 2009 I collected estimates of larval abundance using biweekly ichthyoplankton tows.  Larval production was significantly different between the two ponds, a difference that was consistent across years.  The timing of when larvae first appeared in the open water also differed between ponds and among years.  Within each pond I found that the seasonal pattern of abundance differed among years.  For example, in some years larval production was low across the entire breeding season, while in other years the pond produced multiple peaks of larval abundance ranging between 20 and 150 larvae/m³.  These annual differences may be driven in part by temperature and water levels, as well as by resources.