Temporal dynamics of condition for estuarine fishes in their nursery habitats

Rw Schloesser,Mc Fabrizio

doi:10.3354/meps11858

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 557:207-219 (2016) - DOI: https://doi.org/10.3354/meps11858 Temporal dynamics of condition for estuarine fishes in their nursery habitats R. W. Schloesser1,2,*, M. C. Fabrizio1 1Virginia Institute of Marine Science, College of William & Mary, PO Box 1346, Gloucester Point, Virginia 23062, USA 2Present address: Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, Florida 34236, USA *Corresponding author: rschloesser@mote.org ABSTRACT: The condition of individuals in a year class may contribute to recruitment variability due to differential survival of poor- and well-conditioned fish, but the temporal dynamics of juvenile fish condition are poorly understood. We examined inter- and intra-annual dynamics of condition for juveniles of 3 species collected from estuarine nursery areas of Chesapeake Bay from November 2010 to June 2014. We describe temporal patterns in length-based indices, the hepatosomatic index (HSI), and relative subdermal lipid estimates for juvenile summer flounder Paralichthys dentatus (n = 1771), Atlantic croaker Micropogonias undulatus (n = 3911), and striped bass Morone saxatilis (n = 874). Multiple indices provided a more complete understanding of energy-storage strategies for juveniles because temporal patterns among condition indices were not congruent for a given species. Most juvenile summer flounder and Atlantic croaker migrate from Chesapeake Bay in the fall, and both species exhibited increases in subdermal lipids in the time period prior to migration. For all species, individuals that remained in the estuary during winter exhibited high HSI values, indicating a common energy-storage strategy during winter. Mean condition of juveniles varied among year classes, but differences were inconsistent among indices, suggesting that energy was differentially stored among tissues for these year classes. Density-dependent effects contributed to variation in mean condition for summer flounder and striped bass. Our understanding of recruitment variability may be improved by assessing annual differences in mean condition as revealed by multiple indices. KEY WORDS: Fulton’s K · Hepatosomatic index · Subdermal lipid · Fish fatmeter · Juveniles · Bioenergetics · Recruitment Full text in pdf format PreviousNextCite this article as: Schloesser RW, Fabrizio MC (2016) Temporal dynamics of condition for estuarine fishes in their nursery habitats. Mar Ecol Prog Ser 557:207-219. https://doi.org/10.3354/meps11858 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 557. Online publication date: September 28, 2016 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2016 Inter-Research.

Highlights

In fishes, the number of individuals that recruit to the adult population is highly variable among years, and the strength of a year class is influenced by the survival of post-larval stages (Sissenwine 1984, Fogarty et al 1991, Houde 2009)
We examined 3 hypotheses concerning the condition of juvenile fishes: (1) multiple indices are required to capture condition dynamics for a species because indices do not exhibit similar intra-annual patterns; (2) species with similar life-history strategies exhibit similar condition dynamics; and (3) mean fish condition differs among years
Individuals that remained in Chesapeake Bay after the peak migration period had significantly lower mean subdermal lipids and significantly higher mean K and hepatosomatic index (HSI) than what we observed prior to peak migration (Table 1)

Summary

Introduction

The number of individuals that recruit to the adult population is highly variable among years, and the strength of a year class is influenced by the survival of post-larval (juvenile) stages (Sissenwine 1984, Fogarty et al 1991, Houde 2009). Survival of young fishes is affected by many factors, one of which is nutritional condition. Fish in poor condition may have lower survival rates than conspecifics in good condition. Condition of individual fish may play a critical role in recruitment variability. For. Mar Ecol Prog Ser 557: 207–219, 2016 year-class strength has not been fully explored due in part to limited knowledge of the dynamics of juvenile fish condition. The purpose of our study was to examine condition dynamics for 3 species that inhabit estuarine nursery areas and relate the observed dynamics to their life-history strategies

Objectives

Methods

Results

Conclusion