Spatial variation in growth rate of early juvenile European plaice Pleuronectes platessa

Abstract

Patterns and causes of spatial variation in RNA-predicted growth rates in mid-August were examined in young-of-the-year European plaice Pleuronectes platessa ('YOY plaice') at 22 beaches along a 300 km stretch of coastline in west Scotland in 3 consecutive years. According to restricted maximum likelihood models, growth rates varied among beaches (25 km scale), but these spatial patterns were not consistent across years. We found no evidence for spatial variation in growth at the scale of subregions (50 km) or regions (100 km). Growth rate was positively correlated with total length, both within and among beaches and years. In general, YOY plaice in mid-August grew more slowly than estimated ad libitum laboratory rates. Average growth rates by beach and year were inversely related to intraspecific competitor densities, but not interspecific competitor densities (brown shrimp Crangon crangon) or 2 environmental productivity metrics (nearshore chlorophyll a concentration and lugworm Arenicola marina cast density). Physical beach characteristics also explained a significant source of spatial growth variation, with fish growing faster at beaches with larger tidal range and wave fetch. Therefore, the hypothesis of sub-maximum growth due to intraspecific competition (density-dependent growth) was supported, but additional, previously unexplored processes related to physical beach characteristics appear to have important influences on the spatial growth dynamics of YOY plaice.

Effect of nursery ground variability on condition of age 0+ year Merluccius hubbsi

“…However, it should also be considered that patterns of juvenile fish habitat quality can show considerable temporal variation both within and between years (Ciotti et al, 2013). This is probable in the San Jorge Gulf, a highly dynamic habitat controlled by physical features such as different water masses, topography and the presence of frontal systems.…”

Food limitation of juvenile marine fish in a coastal and estuarine nursery

“…A decline in growth rate of juvenile plaice P. platessa during late summer was also broadly reported (Freitas et al 2012;Ciotti et al 2013b), and could be related to intra-or interspecific competition for food (Ciotti et al 2013a;van der Veer et al 2016). However, the underlying causes of that pattern remain unclear (Ciotti et al 2014).…”

Windowpane flounder (Scophthalmus aquosus) and winter flounder (Pseudopleuronectes americanus) responses to cold temperature extremes in a Northwest Atlantic estuary

“…Mechanisms underlying the smaller size at lower temperatures are unknown and may include a combination of lower prey availability, slower metabolic processes, and reduced foraging activity. It is unlikely that intraspecific (density-dependent) competition for food contributed to the body size disparity, as indicated with juvenile European plaice (Ciotti et al, 2013) because of the similar densities of the two cohorts for the years compared. Disadvantages to smaller body size include an increased predation risk, reduced feeding success if a correspondingly smaller gape width reduces prey availability, and a potential delay in the onset of sexual maturity.…”