Great Whites get down to business, the Ocean Cleanup flounders, and a livestock carrier goes down – What’s up with the Ocean this week?

Frisky business for Great White Sharks. For only the second time since western scientists began studying the ocean, Great White Shark mating has been documented in the wild. Shark sex is infrequently observed in the wild, and this fisherman’s observations can provide invaluable insight in the lives and loves of this iconic species.

The Ocean Cleanup. Dr. Rebecca Helm of UNC Asheville spent the last week doing an extensive dive into the problems surrounding the Ocean Cleanup Project. The who thread, including all the updates, is worth a read for anyone interested in tackling the global problem of ocean plastics with practical solutions that don’t increase harm to marine ecosystems.

Search called for Gulf Livestock 1. The livestock carrier Gulf Livestock 1 capsized last week amidst heavy storms. Though three crew members have been found, the remaining crew, as well as the ship and its 6000 cattle, are still missing. The search was suspended earlier this week, due to weather.

Upwell

Burning Man, the legendary gathering in the Nevada desert, had its own shark jumping moment. After cancelling the main event due to the pandemic raging across America (and pretty much under control almost everywhere else), organizers decided to hold a mini-Burning Man on the actual playa–San Francisco’s Ocean Beach. It was a reckless and selfish gathering of 1000 people that put people’s lives at risk and forced the mayor to shut down beach access, depriving many city-dwellers of their nearest connection to nature in an age of lockdowns and limited travel.

Ocean of Pseudoscience Shorty – Can methane bubbles sink ships?

One of the often cited causes for ships that mysteriously and quickly disappear are methane bubbles, released from sub-seafloor gas pockets. The story goes that as methane rises to the surface, the bubbles cause the density of seawater to drop, and any ships in the area suddenly lose buoyancy and spontaneously sink. This effect has been describe as so powerful that it can even knock aircraft out of the sky. Is it true? Can methane bubbles really sink ships?

The short answer is yes, under very specific conditions, but not in the way proposed. At least two studies have been conducted to determine if methane can really sink ships. In a static system with no current, a bubble that rises close to a ship, but not immediately underneath it, can force the ship into a trough created by the bubble, swamp it, and cause it to sink. If multiple bubbles are present in an unconfined system, as is likely in the ocean, ships do not sink.

So while it is conceivable that some sinkings could be caused by methane gas release, the conditions are so specific that it is unlikely that this phenomenon can account for all but a handful of disappearances.

~Southern Fried Scientist


ResearchBlogging.org

May, D., & Monaghan, J. (2003). Can a single bubble sink a ship? American Journal of Physics, 71 (9) DOI: 10.1119/1.1582187

Hueschen, M. (2010). Can bubbles sink ships? American Journal of Physics, 78 (2) DOI: 10.1119/1.3263819