Review of salinity effects on abundance, growth, and survival of nearshore life stages of pink shrimp (Farfantepenaeus duorarum)

Abstract

The pink shrimp (Farfantepenaeus duorarum) has been selected as an ecological indicator to assess ecological effects on estuaries of implementation of the Comprehensive Everglades Restoration Plan that seeks to restore historical freshwater flows and nearshore salinity regimes in southern Florida. Concern over altered freshwater delivery impacts on pink shrimp productivity was expressed as early as the 1960s. The present review assessed pink shrimp scientific literature of the past 75+years (>500 publications) to glean information relevant to understanding potential influence of freshwater management on pink shrimp productivity. The review was organized around “Essential Fish Habitat” metrics concerning abundance, growth, survival, distribution, productivity, and behavior. It summarizes previous pink shrimp field, laboratory, and modeling studies. Where possible, statistical analyses and meta-analyses of previously published data were performed to investigate consistency among independent findings. Pink shrimp occur in a wide range of salinities (0.5–67ppt). A majority of studies (53.3%) reported maximal abundance between ∼20 to 35ppt salinities. One laboratory study reported maximal growth at 30ppt. Meta-analysis of reported growth rates did not yield results due to non-convergence of regression models. Reported survival was maximal at ∼30ppt and remained high (>80% survival) across salinities of ∼15 to 40ppt. A regression model that combined survival data across studies confirmed a previously reported parabolic relationship between salinity and survival; in this regression, 35ppt maximized survival. Productivity, conditional upon survival and growth, was maximized at polyhaline (18–30ppt) conditions. Inshore hypersalinity (>40ppt) may elicit young pink shrimp behavioral cues counterproductive to settlement in nearshore areas. Virtually no information exists regarding postlarval pink shrimp movement or preference relative to salinity gradients. Realization and preservation of nearshore polyhaline conditions and elimination of hypersalinity should maximize growth, survival, and density, thus improving pink shrimp productivity. New and updated statistical models predicting pink shrimp distribution, abundance, growth, survival, and productivity relative to salinity conditions are needed to better guide freshwater management decisions.