Minimum viable population size and population growth rate of freshwater fishes and their relationships with life history traits

Teng Wang,Huanzhang Liu,Xin Gao,Masami Fujiwara

doi:10.1038/s41598-019-40340-z

Teng Wang, Huanzhang Liu + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-40340-z

Copy DOI

Abstract

The minimum viable population (MVP) size has been compared for a wide range of organisms in conservation biology, but a limited number of studies investigated it for freshwater fishes, which exhibit diverse life history strategies. In this study, the MVP size and population growth rate of 36 fish species in the Yangtze River were estimated and compared with their life-history traits. The results indicated that the MVP size ranged from 42 to 320 individuals, and instantaneous per-capita population growth rate ranged from 0.009 to 0.188 per year. MVP size and population growth rate were significantly associated with three life history traits: the age at maturity, generation time, and fecundity. Long-lived species with delayed maturation, long generation time, and high fecundity had a greater MVP size and a lower population growth rate than short-lived species. Therefore, our results emphasize a need for prioritizing our conservation effort more on long-lived species.

Highlights

Freshwater fishes are confronting some of the most serious threats in the world, including habitat loss and fragmentation, pollution, species invasion, and overfishing[1], which caused freshwater fishes to experience a high risk of extinction[2]
Our results indicated that the minimum viable population sizes of 36 fish species ranged from 42 to 320 individuals with the average value of 117 (SD: 66) individuals (Table 1)
The minimum viable population (MVP) values for Mylopharyngodon piceus, Ctenopharyngodon idellus, Schizopygopsis malacanthus chengi, Xenocypris microlepis were more than 200 individuals

Summary

Introduction

Freshwater fishes are confronting some of the most serious threats in the world, including habitat loss and fragmentation, pollution, species invasion, and overfishing[1], which caused freshwater fishes to experience a high risk of extinction[2]. To make the situation worse, the number of endangered freshwater species on the International Union for the Conservation of Nature (IUCN) Red List has more than tripled since 20033 This is partly because we have more data than 2003, permitting us to categorize them as threatened, these facts are prompting need for a comprehensive effort to assess the viability of freshwater fishes. The objectives of this study were to (1) calculate the MVP and population growth rate of fishes in the Yangtze River, (2) estimate the relationships between the two population viability measures and life-history traits, and (3) suggest conservation strategies for fishes in the Yangtze River

Objectives

Methods

Results

Conclusion