Tuesday, November 28, 2017

Indo-Pacific Tiger shark Genetic Analysis

                                        Population structure and connectivity of tiger sharks (Galeocer docuvier) across the Indo-Pacific Ocean basin, this article is about how a genetic structure of the indo-pacific tiger shark population was created using polymorphic nuclear microsatellite loci. 7 locations across the indo-pacific were assessed and the loci of the shark were all analyzed and it was all in an effort to determine if there was linkage between the sharks (being that they are one stock) or are part of a more complex migratory route and actually several stocks all intermixed.
                                          In fisheries it is very difficult to assess populations of specific species, for one you cannot accurately see all of the population to count, and two the information on the migration of the indo-pacific tiger sharks is very limited. In order to create a plan to manage the stock the scientists need a baseline and it is very important to manage them by stock by region as to preserve and be the most efficient.
                                          It was found in this study that because of the analysis of the loci in different sharks found over the home range it was actually multiple separate stocks that came from all over that congregated to mate in the indo-pacific. This was a monumental discovery in that it shows governments and scientists that the tiger sharks need to be managed even more carefully because the range of the sharks is even larger than initially proposed.
                                          Genetically, the result of the power analysis let scientists know that they have to manage multiple interwoven stocks. This was done by taking blood from multiple sharks in specific strata over the indo pacific and determining their genotypes, Hardy Weinberg equilibrium, was then tested, and lastly tested each shark for gene linkage to the next. Because of the strata and the time of year and also the data taken, there was a clear correlation in which sharks were found where. It was concluded that there was two separate genetically different stocks functioning a one in some circumstances in the indo pacific. Without a genetic analysis this discovery would not have been possible and the health of the indo-pacific tiger shark stocks would not be at the health that they are today.

1 comment:

  1. This is very intriguing to me as I am trying to go into the fisheries field myself. Fisheries is a very hard field to study and manage because so many factors affect it. The news about how the tiger sharks are from separate stocks is fantastic as it means they are genetically diverse and that they should be managed more carefully. This makes it possible to have a few of the same governing conservation laws on them throughout multiple countries instead of different laws in different countries.