Submerged Science— December 6, 2022
Trampling fur seals, cannibalistic mouthbrooders, and a moody sea lion
Hi friends,
It’s officially December! If you love all the music and decorations and family time then enjoy! If not, I’m sorry, it will be over soon. I myself am somewhere in the middle: I like the spirit of the season but I think many people get way too into it. I don’t want to hear Christmas songs on repeat 24/7. Everything in moderation, people.
Since there are usually such strong opinions in both directions, let’s practice some escapism and learn about the ocean for a while. On to the science!
Turning the Tide
Well-written popular articles in marine science
Conservation is rarely black and white. Ecosystems by nature are interconnected and its components ebb and flow. In Antarctica, the protection and subsequent recovery of fur seals means they are trampling vegetation and wrecking nutrient cycles of inland lakes. Are these effects natural? Should we respond or let things play out?
The Great Barrier Reef is not dead. Heat and storms are threatening its future, but there is still hope. Scientists are doing what they can to help the GBR survive, using techniques like restoration and breeding more resilient genetic lines. Indigenous groups are also playing a growing role in managing the reef.
The snow crab population in Alaska declined about 80% from 2021 to 2022, causing the government to completely shut down the fishery. But was fishing really to blame for the decline in snow crabs, or was it climate change? Fishing has been restricted in previous years after smaller declines, but it is unclear how big of an effect fishing is having on the populations.
Elizabeth Claire Alberts, Mongabay
Some Science
Fresh discoveries and peer-reviewed papers
Illegal, unreported, and unregulated fishing is costly to economies as well as ecosystems, but is difficult to police. Automatic identification systems (AIS) are required so fishing activity can be monitored, but the devices can be easily disabled. A new study looked at where tracking devices were disabled to identify areas where illegal fishing may be happening.
Many fish protect their eggs in their mouths in a strategy called mouthbrooding. The parent can’t properly breathe or eat during this time, which they apparently mitigate by eating some of their young. This cannibalism seems counterintuitive, but a new study has found that it gives the mom an antioxidant boost that allows them to spawn again a few months later.
Tom Metcalfe, National Geographic
Usually it is more difficult for species with longer lifespans to adapt to changing conditions like warming waters. But there seems to be hope for narwhals, who live for 50-100 years. Narwhals have been delaying their seasonal migration, staying longer in warmer waters and taking an average of four days longer to make the trip to winter grounds. Their behavioral flexibility is promising, but also comes with additional risks of being trapped in ice and being more vulnerable to predators.
Fun and Fascinating
Wrapping up work at the end of the year and impending extensive holiday family time has me wanting to stick my head in the sand…
Thanks for reading! Remember to drink water, eat plants, and don’t be too salty.
Til next time,
Sarah
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