Conservation of freshwater fishes in Saudi Arabia

Alharthi, Ibrahim Gabel Z.

Abstract

This study aims to gain fundamental knowledge to underpin the formulation of practical solutions to ensure the protection and conservation of Saudi Arabian fishes threatened by anthropogenic activities, whilst taking into account all users and stakeholders.
Multivariate analysis, based on species presence/absence data in different water bodies in different regions collected from the literature and this study, was used to determine the biogeographical distribution of fish species in Saudi Arabia. Freshwater fish are mainly located within drainages in the south-west of the Kingdom, both in lowlands (western drainage systems) and highlands (eastern drainage systems) of the Sarawat Mountain Range. Importantly, this study recorded the presence of non-native fish species in the dams located in Al Baha Region, Abha and Rabigh, which means both western and eastern drainage systems are being invaded by non-native species such as Oreochromis spp. and Carassius spp.
The ecology of three native (Carasobarbus apoensis, Cyprinion mhalensis, Garra buettikeri) and four non-native (Oreochromis niloticus, Poecilia latipinna, Carassius carassius and Gambusia affinis) species were studied in eight water bodies (five dams, two wadis and one lake) considered representative of the habitats occupied by freshwater fish in Saudi Arabia. Fish were caught by a variety of sampling methods (gill nets, traps and angling) in three seasons (spring [post floods], summer [extreme temperatures and drought conditions] and winter) and examined for age and growth, feeding ecology and reproductive characteristics. The growth of each species was found to vary between sites and was related mostly to habitat type and the quality of the environment.
The dietary studies provided valuable information about the feeding habits of native and non-native fish species in Saudi Arabia and the how foods consumed varied between species, habitat types, size/age of fish species and with season. All species were found to be omnivorous, with varying degrees of specialism towards planktivorous, herbivorous or detritivorous diets, with the exception of Garra buettikeri, which is a planktivorous/benthivorous species. Differences in diets were found between locations and seasons for the three native species, and these were concluded to be related to variability in environmental conditions and approximation to the preferred habitat type of the species. Ontogenetic shifts in diet were found among the three native species examined, but the small individual sizes of two of the non-native species, Poecilia latipinna and Gambusia affinis, and small sample sizes of other non-natives precluded such an analysis. Little overlap was found between the food items consumed by native and non-native species, and where it was observed it was largely food items in abundant supply, such as detritus and benthic algae.
Carasobarbus apoensis and Cyprinion mahalensis spawned exclusively in spring during the rainy seasons. Garra buettikeri is as batch spawner, and was reproductively active throughout the year. Oreochromis niloticus is reproductively throughout the year, and Poecilia latipinna and Gambusia affinis are viviparous species with two main periods of spawning in spring and autumn. Spawning appears to be driven by rainfall and increased productivity associated with high water events.
The findings of this study were used to formulate a Saudi freshwater fish management plan targeting mainly conservation issues. The plan provides an overview of the status of the fisheries, threats, exploitation pressures and governance structures. Options for management of the fisheries are provided and the integration of freshwater fisheries in water resource management plans is stressed as an affirmative action.

Citation

Alharthi, I. G. Z. Conservation of freshwater fishes in Saudi Arabia. (Thesis). University of Hull. https://hull-repository.worktribe.com/output/4223191

• Thesis Type: Thesis
• Deposit Date: Jun 14, 2021
• Publicly Available Date: Feb 23, 2023
• Keywords: Biological sciences
• Public URL: https://hull-repository.worktribe.com/output/4223191
• Additional Information: Department of Biological Sciences, The University of Hull
• Award Date: Oct 1, 2019