{"id":2998,"date":"2019-09-24T00:10:18","date_gmt":"2019-09-24T00:10:18","guid":{"rendered":"http:\/\/blogs.oregonstate.edu\/gemmlab\/?p=2998"},"modified":"2019-09-24T00:10:24","modified_gmt":"2019-09-24T00:10:24","slug":"the-significance-of-blubber-hormone-sampling-in-conservation-and-monitoring-of-marine-mammals","status":"publish","type":"post","link":"https:\/\/blogs.oregonstate.edu\/gemmlab\/2019\/09\/24\/the-significance-of-blubber-hormone-sampling-in-conservation-and-monitoring-of-marine-mammals\/","title":{"rendered":"The significance of blubber hormone sampling in conservation and monitoring of marine mammals"},"content":{"rendered":"\n

By: <\/strong>Alexa Kownacki<\/strong><\/a>, Ph.D. Student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab<\/strong><\/p>\n\n\n\n

Marine mammals are challenging to study for many reasons, and\nspecifically because they inhabit the areas of the Earth that are uninhabited\nby people: the oceans. Monitoring marine mammal populations to gather baselines\non their health condition and reproductive status is not as simple as trap and\nrelease, which is a method often conducted for terrestrial animals. Marine\nmammals are constantly moving in vast areas below the surface. Moreover,\ncetaceans, which do not spend time on land, are arguably the most challenging\nto sample. <\/p>\n\n\n\n

One component of my project<\/a>, based in California, USA, is a health assessment analyzing hormones of the bottlenose dolphins that frequent both the coastal and the offshore waters. Therefore, I am all too familiar with the hurdles of collecting health data from living marine mammals, especially cetaceans. However, the past few decades have seen major advancements in technology both in the laboratory and with equipment, including one tool that continues to be critical in understanding cetacean health: blubber biopsies. <\/p>\n\n\n\n

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Biopsy dart hitting a bottlenose dolphin below the dorsal fin. Image Source: NMFS<\/figcaption><\/figure><\/div>\n\n\n\n

Blubber biopsies are typically obtained via low-powered crossbow with a bumper affixed to the arrow to de-power it once it hits the skin. The arrow tip has a small, pronged metal attachment to collect an eraser-tipped size amount of tissue with surface blubber and skin. I compare this to a skin punch biopsies<\/a> in humans; it\u2019s small, minimally-invasive, and requires no follow-up care. With a small team of scientists, we use small, rigid-inflatable vessels to survey the known locations of where the bottlenose dolphins tend to gather. Then, we assess the conditions of the seas and of the animals, first making sure we are collecting from animals without potentially lowered immune systems (no large, visible wounds) or calves (less than one years old). Once we have photographed the individual\u2019s dorsal fin to identify the individual, one person assembles the biopsy dart and crossbow apparatus following sterile procedures when attaching the biopsy tips to avoid infection. Another person prepares to photograph the animal to match the biopsy information to the individual dolphin. One scientist aims the crossbow for the body of the dolphin, directly below the dorsal fin, while the another photographs the biopsy dart hitting the animal and watches where it bounces off. Then, the boat maneuvers to the floating biopsy dart to recover the dart and the sample. Finally, the tip with blubber and skin tissue is collected, again using sterile procedures, and the sample is archived for further processing. A similar process, using an air gun instead of a crossbow can be viewed below:<\/p>\n\n\n\n

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