Effects of environmental variability on abundance of commercial marine species in the northern Gulf of California

Abstract

Studies have shown that environmental variables significantly affect variation in stock abundance of marine populations. The northern Gulf of California (NGC) is a highly productive region of interest due to its fish resources and diversity. Conservation of the marine species inhabiting the region is of public interest. Our study analysed the influence of physical environmental factors on several commercial marine species, using catch per unit effort (CPUE) as a proxy for abundance. Generalized additive models were used to test the significance of selected environmental variables on stock abundance. Deseasonalized cross-correlation analysis was used to examine time-lagged correlations between CPUE and abiotic variables to identify response timings. The results suggest that for most commercial species the sea surface temperature and the long-term climate Pacific Decadal Oscillation index are the predominant predictors for species abundance, followed by the Colorado River discharge. The Multivariate ENSO Index and the Pacific-North American pattern indices also showed specific effects on certain species. The NGC is a highly dynamic region, where species respond to environmental changes according to the characteristics of their life histories.

Growth and Sex Ratio of Octopus Paroctopus Digueti (Perrier & Rochebrune, 1894) in a Wild Population

“…In this current study, the condition index (K) was higher during winter than in the rest of the climatic seasons, where a recovery in the condition of octopus P. digueti was seen during autumn, decreasing in spring and increasing during the summer. In general, these variations could be caused by many factors such as reproductive activity, dietary changes and environmental factors (Ramirez and De la Cruz, 2015;Ruiz-Barreiro et al, 2019). The trend observed in the present study for the K index may be caused by the incidence of ovigerous females found in shelters.…”

Current status of Iraqi artisanal marine fisheries in northwest of the Arabian Gulf of Iraq

“…Now, the discharge of the river was almost completely dependent on the freshwater influx from the Tigris River as a result of diverting the flow of Karun River inside the Iranian boundaries and cut off the Euphrates River before influx to the Basrah province (Mohamed and Abood, 2017). The impacts of freshwater inflow to estuarine systems as well as the influence of natural and anthropogenic factors have been discussed by several scientists (Gillson, 2011;Taylor et al, 2014;Ruiz-Barreiro et al, 2019;Osadchiev et al, 2020). Jesintha and Madhavi (2020) stated that the construction of dams diverts nutrient-rich water from entering into the sea, and obstruct the migratory path of some fish.…”

Size at sexual maturity, seasonal variation by maturity stages, and fecundity of the spotted round ray (Urobatis maculatus) and the thorny stingray (Urotrygon rogersi) from the northern tropical eastern Pacific

“…The abundance and distribution patterns of elasmobranchs can be affected by interannual changes in water temperature associated with climatic anomalies such as El Niño Southern Oscillation (ENSO) and its variations between warm (El Niño) and cold (La Niña) conditions (Arnés‐Urgellés et al, 2021; Osgood et al, 2021; Ruiz‐Barreiro et al, 2019). Further studies are necessary to analyse the impact of these climatic anomalies on the distribution of analysed round rays by maturity stages in the Gulf of California.…”

“…An annual reproductive cycle has been reported for Urobatis halleri in California (Babel, 1967;Mull et al, 2010), whereas a biannual reproductive cycle, with ovulation coinciding with parturition, has been described for the yellow stingray Urobatis jamaicensis (Cuvier, 1816) in south-east Florida (Schieber et al, 2023). and its variations between warm (El Niño) and cold (La Niña) conditions (Arnés-Urgellés et al, 2021;Osgood et al, 2021;Ruiz-Barreiro et al, 2019). Further studies are necessary to analyse the impact of these climatic anomalies on the distribution of analysed round rays by maturity stages in the Gulf of California.…”