Storm-related variation in the growth rate of otoliths of larval Atlantic menhaden Brevoortia tyrannus: a time series analysis of biological and physical variables and implications for larva growth and mortality

Abstract

Vertical mixing induced by storms is hypothesized to modify the spatial and temporal availability of food to fish larvae and thus influence their feeding and growth. We investigated the effects of storms on sagitta growth rates of 2 age classes (3 to 15 d and 16 to 50 d, post-hatching) of larval Atlantic menhaden Brevoortia tyrannus during winter 1986 in Onslow Bay, North Carolina, USA.We tested the null hypothesis that sagitta growth rate of 3 to 15 d and 16 to 50 d old larvae is independent of the timing and intensity of storms by using transfer functions to investigate relationships among daily time series of sagitta growth rate and meteorological and oceanographic variables. Variation in sagitta increment width was greatest during the first 1 to 2 wk after hatching. Reduction in sagitta growth rate coincided with storms and corroborated laboratory results that growth increments are formed daily and stressful events are manifest in sagitta microstructure. Age-related trends in sagitta growth rate were observed for both age classes and were removed from the analysis by a standardization procedure. Fluctuation in sagitta growth rate for 3 to 15 d old larvae was inversely crosscorrelated with time series of wind speed. Fluctuation in sagitta growth rate for 16 to 50 d old larvae was inversely cross-correlated with tune series of wind speed and heat flux The pattern of crosscorrelations for 3 to 15 d old larvae indicated an immediate response of sagitta growth rate to periods of strong winds while sagitta growth rate in 16 to 50 d old larvae lagged strong winds and heat fluxes by 2 to 5 d. Transfer function models incorporating wind speed and heat flux accounted for 40 to 54 % of sagitta growth rate variation. Reduction in larval Atlantic menhaden growth rate during early life is consistent with the critical period concept and may be related to dispersion and aggregation mechanisms coupled to wind-induced vertical mixing and its effect on food concentration and availability.

Postflexion larvae and juvenile daily growth patterns of the Albor&aacute;n Sea sardine (<em>Sardina pilchardus</em> Walb.): influence of wind

“…Thus, these periods of northern and western winds would be those in which "Lasker events" (Lasker, 1978;Peterman and Bradford, 1987;Mendelssohn and Mendo, 1987;Cury and Roy, 1989) occur, favouring larval survival. On the other hand, stormy conditions in coastal areas induced by Levantine winds modify spatial and temporal availability of food to fish larvae and thus negatively influence their feeding and growth (Maillet and Checkley, 1991), and hence their survival. A parallel study on larval condition based on the same postflexion larvae analysed in this study (García et al, 2006) suggests that the growth strategy of sardine larvae in the Alborán Sea is adapted to pulses of low food availability, which would agree with the fluctuating daily growth rates observed.…”

Meso-scale distribution patterns of larval and pelagic juvenile fishes in the central Great Barrier Reef lagoon

“…While such studies are a necessary prerequisite to any understanding of larval biology, little remains known of the processes influencing larvae over 'meso' spatlal and temporal scales (days-weeks and 1-10's of km). Paradoxically, it is variability over these scales that may be critical to larval survival and recruitment (Peterman & Bradford 1987, Davis et al 1991, Maillet & Checkley 1991.…”

Contrasting years of prey levels, feeding conditions and mortality of larval walleye pollock Theragra chalcogramma in the western Gulf of Alaska

“…Various environmental conditions or features have been linked to prey concentrations and the feeding success of marine fish larvae. Some of these conditions and features include light intensity (Heath 1989), frontal zones (Ki~rboe et al 1988, Munk 1993, storms or turbulence (Lasker 1975, Tilseth & Ellertsen 1984, Heath 1989, Sundby & Fossum 1990, Maillet & Checkley 1991 and density stratification (Govoni et al 1985, Buckley & Lough 1987, Coombs et al 1992.…”