Image of Steller sea lion by Daniel Hershman from Federal Way, US (A crashing wave) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
Animals exposed to military sonar are thought to develop symptoms similar to decompression sickness. Since microparticles in the blood are known to increase with decompression sickness in diving land animals, researchers explored whether levels were also increased in Steller sea lions (Eumetopias jubatus), that similarly hold their breath while diving. Microparticles are fragments of cell membranes. The research team compared values before and after fixed depth dives of 5 or 50 meters in trained animals. Metabolic rate and blood microparticle levels were increased in the animals following diving. What was interesting though is that microparticle levels were not any higher when animals dove to the deeper depth or with the time spent underwater. Thus the increase in microparticle number was not thought to be related to decompression sickness per se.
Source:
Fahlman A, Moore M, Trites AW, Rosen DA, Haulena M, Waller N, Neale T, Yang M, Thom SR. Dive, food, and exercise effects on blood microparticles in Steller sea lions (Eumetopias jubatus): exploring a biomarker for decompression sickness. American Journal of Physiology Regulatory Integrative and Comparative Physiology. [In Press]. doi:10.1152/ajpregu.00512.2015.