Assessing the effects of temperature and salinity oscillations on a key mesopredator fish from European coastal systems

Abstract

A population dynamics model was developed to assess the short and long-term effects of temperature and salinity variations in the common goby Pomatoschistus microps in a Portuguese estuary (Minho estuary, NW Portugal). The population was divided into juveniles, females and males, which constituted the model's state variables. Linear regressions between the observed and the predicted density of juveniles, females and the total population were significant. Parameter's sensitivity and uncertainty analysis were estimated. The model was able to satisfactory describe the P. microps population dynamics, and thus was used to simulate the effects of climatic changes on the fish population. Simulations indicated that the common goby population is sensitive to both temperature and salinity changes. Overall, scenarios of more than 3 °C increase caused significant population decreases. Similarly, increased salinities led to a population shrinkage, whereas scenarios of salinity decrease generated an opposite variation on the population. According to the IPCC predictions for climatic tendencies, the population of the common goby will tend to decrease in the near future, experiencing marked oscillations (decrease or increase) during climatic extremes, namely droughts and floods, respectively. These results may be a useful for future planning and management of estuarine systems given that the common goby is an important species of estuarine food webs in many temperate ecosystems.

Morphology and growth pattern of Nike fish (amphidromous goby larvae) in Gorontalo Waters, Indonesia

“…Several studies reported the influences of water salinity and temperature on fish larval development and growth. Simulations through the model to assess the effects of climatic changes in the fish population by Souza et al (2018) indicated that the common goby population is sensitive to both temperature and salinity changes. Overall, scenarios of more than 3 °C increase caused significant population decreases.…”

Subpolar gyre and temperature drive boreal fish abundance in Greenland waters

“…Abundance of fish in Greenland waters can be influenced by local and external physical and biological processes. Local processes may consist of changes affecting fish growth, reproduction and survival, while changes in conditions in adjacent areas could as well affect migration or drift patterns of early life stages and thereby affect local abundance (Biro et al, 2010; Dahlke et al., 2018; Kuczynski et al, 2017; Souza et al, 2018). As local temperature is not the only mechanistic driver of these processes, we discuss the role of temperature and other pathways linked to the distribution of mode waters in the North Atlantic as guidance for future research.…”

Evaluation of fish assemblages’ composition in the Euphrates River, southern Thi-Qar province, Iraq

“…Increased temperature and salinity may alter fish assemblage structure; this may lead to an impact on all feeding levels of fish that feeding on phytoplankton and small fishes (Beaugrand, 2009). The variations in these parameters (temperature and salinity) will have strongly impact on small-sized fish communities which reinforce connective position in food webs (Souza et al, 2018). The results revealed a noticeable rise in the concentrations of salinity from May to October due to low water levels, as well as higher temperatures which lead to increase evaporation rates (Abdullah et al, 2017).…”