Effects of local and large-scale climate patterns on estuarine resident fishes: The example of Pomatoschistus microps and Pomatoschistus minutus

Abstract

a b s t r a c tLarge-scale and local climate patterns are known to influence several aspects of the life cycle of marine fish. In this paper, we used a 9-year database (2003e2011) to analyse the populations of two estuarine resident fishes, Pomatoschistus microps and Pomatoschistus minutus, in order to determine their relationships with varying environmental stressors operating over local and large scales. This study was performed in the Mondego estuary, Portugal. Firstly, the variations in abundance, growth, population structure and secondary production were evaluated. These species appeared in high densities in the beginning of the study period, with subsequent occasional high annual density peaks, while their secondary production was lower in dry years. The relationships between yearly fish abundance and the environmental variables were evaluated separately for both species using Spearman correlation analysis, considering the yearly abundance peaks for the whole population, juveniles and adults. Among the local climate patterns, precipitation, river runoff, salinity and temperature were used in the analyses, and North Atlantic Oscillation (NAO) index and sea surface temperature (SST) were tested as large-scale factors. For P. microps, precipitation and NAO were the significant factors explaining abundance of the whole population, the adults and the juveniles as well. Regarding P. minutus, for the whole population, juveniles and adults river runoff was the significant predictor. The results for both species suggest a differential influence of climate patterns on the various life cycle stages, confirming also the importance of estuarine resident fishes as indicators of changes in local and large-scale climate patterns, related to global climate change.

The impact of estuarine salinity changes on the bivalves Scrobicularia plana and Cerastoderma edule, illustrated by behavioral and mortality responses on a laboratory assay

“…However, the frequency of flooding episodes has increased (e.g. 1995/96, 2000/01, 2002/03 and 2006/07) (Santos et al, 2002;Miranda et al, 2006;Zêzere et al, 2014), resulting in increased freshwater flows and salinity declines (Cardoso et al, 2008;Grilo et al, 2011;Nyitrai et al, 2013;Verdelhos et al, 2014). These events have been linked to decrements in abundance, biomass and production of S. plana and C. edule (Cardoso et al, 2008;Dolbeth et al, 2011;Grilo et al, 2011;Verdelhos et al, 2014).…”

Changes in the Functional Role of the Tejo Estuary (Portugal, Europe) According to Fish Ecological Guilds

“…The presence of estuarine species in the Tejo estuary seems to be related to lower values of river flow, and while these species complete their life cycle within these systems, it has been previously observed that strong variations in river flow may adversely impact estuarine larval fish assemblages [70]. In fact, the opposite results were found in the Mondego estuary (Portugal), which presented abundance peaks of resident species in years with higher precipitation and river runoff levels [71], and consequently, lower salinity values, which has been shown to be an advantage for these species' egg development, as their survival is lower at higher salinities [72]. Differences found for this guild, between the Mondego and the Tejo estuaries, may be attributed to their different specific geomorphological and hydrological characteristics.…”

Genetic analysis reveals the diversity of larval Gobiidae in a temperate estuary

“…In addition, gobies are highly affected by climatic variability and different species have different response patterns to the environmental variables. For example, changes in the river run‐off and precipitation could potentially shift the proportions of P. minutus and P. microps (Nyitrai et al ., ). Therefore, current observations from just 1 year can certainly not be extrapolated to time periods characterized by different hydroclimatic conditions.…”

“…Genetic methods have proved very useful for uncovering the diversity of species that otherwise exhibit low morphological differentiation. Owing to different habitat requirements and environmental preferences, species identification is required to resolve population response to the changed environment, including climate change effects (Dolbeth et al ., ; Nyitrai et al ., ), or shifts in the functional diversity and ecosystem functioning. Linking the genetically resolved species dynamics to climate variability assumes performing genetic analysis at selected multi‐annual intervals ( e.g .…”