Seal Placentas Aid in Conservation Efforts

A recent article in Scientific American discusses the new importance found in seal placentas. Recent research has displayed that seal placentas are very effective in genetic research, showing the amount of inbreeding and even the gender of the offspring. This method of collection allows conservationists to collect DNA samples easier, with no risk to themselves or the seals being studied.

Seals are being monitored for inbreeding due to the occurrence of a small gene pool. When an animal becomes endangered, a limited amount of breeding choices result in a much greater risk of inbreeding within the population. Scientists wish to observe inbreeding to gain a better understanding of the risks involved with extremely endangered species.


A group of Finnish researchers collected several placentas from the extremely rare Saimaa ringed seals. Material extracted from the side of the placenta attached to the uterine lining contained DNA from the mother, while the side connected to the fetus gave DNA from the offspring. The sample of collected placentas exhibited the expected low amount of genetic diversity.With only an estimated number of three hundred seals remaining in the wild, inbreeding becomes a very critical issue. Unfortunately, this collection technique can not be applied to most mammals because the vast majority exhibit placentophagia, or eating the placenta after the birthing process.

A New Tool for Conservation Genetics: Seal Placentas

Not only are seal populations on the decline due to loss of habitat, competition for resources, and hunting, but now a lack of genetic diversity is also causing problems with the Pinnipeds. The issue is inbreeding, which can lead to birth defects and other problems that threaten the lives of these animals.

Conservation biologists test the DNA of endangered species when they are able to obtain a sample. However, it is often difficult to get a sample from a wild animal because they either cannot be found in their natural habitat, there is too little DNA in hair or feces that are found, or it is hazardous to the researcher or the animal to get close to each other. The new way of genetic testing is performed by obtaining the placentas of newborn seals. By using the placenta scientists can learn additional information as well, such as the gender of the pup or if inbreeding occurred.  

This study was performed in Finland on Saimaa ringed seals, one of the most rare species of seal on earth. From 2009-2011, scientists collected 59 placentas from these seals. Even though they were not completely fresh and new, the placentas still contained a vast amount of testable DNA. Unfortunately, what the researchers discovered was that many of the pups born were stillborn. The genetics of the pups revealed there was not much diversity in the genes and led to fatal birth defects.

This is only the beginning of this new method of genetic testing. The information placentas can give about a newborn seal (or any animal) could be extremely beneficial to conservation efforts. The reason this study works well with seals is because the mothers do not eat the placentas after giving birth, as many species of animals do. 

I was very happy to see this article and read about the ways we are using genetics to help with conservation efforts. As someone interested in working in wildlife conservation, it gives hope to the future of these animals. It seems as though the key to solving many of the problems occurring in animals, including humans, lies within the field of genetics. 

Original Article

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