The Population Dynamics of Endangered Blue Whales: Past, Present, and Future

Abstract

Blue whales (Balaenoptera musculus) are the largest animals that have ever lived on earth, but their populations were nearly driven to extinction due to industrial hunting at the beginning of the 20th century. Their numbers were estimated to be between 250,000 and 300,000 before the hunting, but this drastically declined over the years.

Continuous models of population dynamics are used to estimate the intrinsic growth rate and other demographic characteristics of their populations. The Euler-Lotka equation is used to determine the mean annual growth rate, and with the help of the piecewise exponential distribution as a life table model, simple formulas can be derived for the calculation of important demographic parameters such as the age structure, life expectancy, and maximum age.

The pre-exploitation abundance of Antarctic blue whales is found using the logistic function, assuming a minimum abundance of 1,000 in 1970, an intrinsic growth rate of 4.1%, and documented annual catches between 1904 and 1972. The estimated pre-exploitation abundance is forecast as 280,471 in 1904. Using the logistic model to forecast the population, it is calculated that it will take nearly 140 years for the population to recover to even half of its pre-exploitation abundance at current assumed rates.

To preserve the endangered blue whales, it is essential to monitor their populations continuously, develop effective conservation strategies, and reduce the anthropogenic pressures on the species. Through collaborative efforts and conservation measures, it may be possible to help these magnificent creatures recover and thrive once again.