Ecological dynamics and conservation implications of Indo-Pacific Tarpon (Megalops cyprinoides) in Lake Siombak, North Sumatra, Indonesia

Abstract

This study presents a comprehensive examination of the Indo-Pacific Tarpon (IPT) population in Lake Siombak, North Sumatra Province, Indonesia. Through a year-long investigation, we analyzed various facets of IPT ecology, encompassing population structure, growth dynamics, reproductive behavior, feeding habits, and mortality parameters. Male dominance in collected specimens, coupled with consistently immature gonads in females, suggests a unique reproductive pattern influenced by the brackish nature of Lake Siombak. Utilizing the von Bertalanffy method, we determined a moderate growth rate in IPT, with a predominance of medium-sized, sexually immature individuals. The dietary analysis revealed an omnivorous nature, with a notable reliance on zooplankton, particularly Cladocera and Copepods. However, the most significant concern arises from the estimation of the exploitation rate (E), surpassing the annual optimum exploitation threshold, indicating a state of overexploitation. This underscores the urgent need for regulatory measures to ensure the sustainability of IPT resources in Lake Siombak. Our findings contribute to a nuanced understanding of IPT ecology in this specific ecosystem, emphasizing the importance of balanced conservation and management practices. The documented reproductive, growth, and feeding patterns provide crucial insights for informing targeted conservation strategies and safeguarding the enduring viability of the IPT population in Lake Siombak. This research serves as a foundational contribution to the broader field of fisheries science, advocating for evidence-based management to preserve the ecological balance of aquatic ecosystems.