Submerged Science— February 14, 2023
Finding whales in a haystack, resilient corals, and grouper love
Happy Valentine’s Day to those who celebrate!
I know many people hate this holiday, and I probably wouldn’t mention it if it weren’t the day this edition were being released. As it is, I think fish love is very cute. There are two Valentine’s themed sections in today’s edition.
Let’s get on to the science!
Turning the Tide
Well-written popular articles in marine science
With satellite technology advancing rapidly, you would think that finding some of the biggest creatures on the planet would be easy. Light-colored whales like Belugas are easy to see in satellite images of the ocean, but countershaded ones like humpbacks are not. I love the metaphor in this piece: “it’s like taking a picture of a toothpick on the sidewalk from an upstairs balcony.” And science is usually not the highest bidder on satellite time.
My first ever field research project I assisted with as an undergraduate was trapping invasive European green crabs on the Oregon coast. They tear up seagrass beds, eat shellfish and outcompete native crabs for habitat. They’ve made their way up to British Columbia, where they have been dealt with so far by freezing and dumping them in a landfill. One First Nation is arguing that the crabs are edible and it makes no sense to throw them out, especially when grocery prices are sky high from inflation. And with traps are catching incredible amounts of crab, there must be some way to curb their numbers.
Ainslie Cruickshank, The Narwhal
The discovery of millions of dead red crabs in a protected area of Pacific Ocean seafloor in 2015 is still baffling scientists. The crabs were found far from where they normally hang out, much deeper than normal, and more intact than expected for a prime deep sea scavengeable meal. The current hypothesis is that some environmental event killed the crabs, currents took them offshore before they sank, and there were so many that scavengers just haven’t been able to eat them all yet.
Some Science
Fresh discoveries and peer-reviewed papers
These days, much of the news surrounding the status of coral reefs is negative, but there are occasionally bright spots. One of those positive stories was published today: some reefs in the Eastern Tropical Pacific Ocean may survive warming waters longer than expected by altering their communities of algal symbionts. They appear to be more resilient than anyone thought, able to maintain high cover despite heatwaves. Full disclosure: my husband is an author on this paper; his image of the lead author Dr. Ana Palacio is featured in the press release!
One of the ways that humans determine whether other animals are self-aware or not is to put them in front of a mirror and see if they recognize that the reflection is themself. A recent study did this with a small fish called a bluestreak cleaner wrasse, who passed this self-awareness test. This test is controversial, however, so either these fish are smarter than we thought, or the mirror test is actually a useless way to think about intelligence.
It just so happens that Valentine’s day this year is one of the days that Nassau grouper are…. well, basically having an orgy. They reproduce by gathering in large numbers to release their eggs and sperm into the water, which they do for about 10 days after the full moon from approximately January through March. Nassau grouper are critically endangered due their vulnerability to fishing when reproducing. The story of an aggregation of Nassau grouper in the Cayman Islands represents one of the only successful efforts to bring back a population that had crashed.
Reef Environmental Education Foundation, YouTube
Fun and Fascinating
Thanks for reading! Remember to drink water, eat plants, and don’t be too salty.
Til next time,
Sarah
If you liked this post, consider sharing it with a friend.
If a friend sent you this email, they are now your new bestie. And you can subscribe yourself by clicking the button below.
See previous newsletters here.
Have a suggestion, or just want to say hi? You can email submergedscience@substack.com or hit reply.