Introduction
The problem under researchers’ investigation is the changes in fish population quality and size due to overfishing. Increased volumes of caught fish have a negative influence on the biological determinants of the species (Hauser, Adcock, Smith, Ramirez, & Carvalho, 2002).
Although fishery is inexhaustible, there exists a threat to diversity of species. As the researchers state, the extensive exploitation of fishery “not only affects the abundance of target species but also changes the physical and trophic structure of marine ecosystems” (Hauser et al., 2002, p. 11742).
The research question aims at identifying the change in genetic diversity of wild fishery populations.
The study investigates how fishing affects the genetics of diverse species.
Methods used for the study
The research was conducted with the help of such methods as laboratory DNA tests and statistical analysis of the retrieved results.
Firstly, for data collection, DNA tests were conducted for two sets of DNA materials. The first one included dried scales from 1950 to 1986, and the second one included fresh samples of the species DNA extracted in 1998. The materials were screened at seven microsatellite loci (Hauser et al., 2002).
Secondly, the method of statistical analysis was used to compare the DNA test results conducted for the two sets of materials and identify the changes in the genetic characteristics of the populations of the species across half a century.
Findings and Results
Temporal changes in both populations were interpreted based on the DNA analysis and indicated consistency in the number of individuals within the species, which suffices the requirements of the effective population size.
As the results demonstrate, over the investigated period (from 1950 to 1998), the estimated effective population size was approximately 180 individuals (Hauser et al., 2002). Despite the stability in the number of population individuals, significant shifts in genetic characteristics have been identified. The genetic diversity of the fish in Tasman Bay has significantly declined over the years. The results imply that fishing activity might be harmful to the marine ecosystem in terms of its diversity even though the population size remains sufficient.
Conclusions and Implications
Despite possible bias due to the migration of fish and the overlapping of several generations, the overall findings of the research are relevant and contribute to the current academic literature. The study’s findings allow concluding that the effective size of the fish population is stable. However, there is a significant decrease in the diversity of species in Tasman Bay and Hauraki Gulf.
Commercial overfishing negatively affects fish genetic diversity, which has significantly decreased since the beginning of fishery exploitation at an industrial level.
The marine ecosystem suffers from the loss of variability of species, and the further decline in the number of species is anticipated. It is implied that the identification of the individuals capable of reproducing new populations is necessary to protect such individuals for the purposes of preserving genetic variability.
References
Hauser, L., Adcock, G. J., Smith, P. J., Ramirez, J. H. R., & Carvalho, J. R. (2002). Loss of microsatellite diversity and low effective population size in an overexploited population of New Zealand snapper (Pagrus auratus). Proceedings of the National Academy of Sciences, 99(18), 11742-11747.