To find out more about the podcast go to The contagious buzz of bumble bee positivity, and when snow crabs vanish.
Below is a short summary and detailed review of this podcast written by FutureFactual:
Snow Crab Die-Off in the Bering Sea: Recovery, Climate Drivers, and Bumblebee Affect Contagion
In this episode, Science Magazine examines the dramatic 2020 die-off of Bering Sea snow crabs and the ongoing rebound by 2025, detailing how warmer waters, reduced ice, and a diminished cold pool disrupted crab metabolism and predators. Regulators and scientists are refining early-warning tools, including a quick measure of fat content in the crab's hepatopancreas to forecast population health and harvest levels. The show also reports on a groundbreaking study by Fei Pang and colleagues showing that bumblebees can transfer an optimistic affect to peers after brief social interactions, revealing a potential contagion of mood in insects.
Snow Crab Die-Off and Recovery in the Bering Sea
The episode revisits the extraordinary snow crab crash in 2020, when the wind-driven ice and cold pool conditions in the Bering Sea collapsed after two warmer years in 2018 and 2019. The lack of a robust cold pool, combined with rising temperatures, pushed snow crabs beyond their comfort zone and likely increased metabolic costs, leading to mass mortality. NOAA surveys in 2021 found extremely low crab abundance, with estimates of losses approaching tens of billions. By 2025, crab numbers have rebounded toward more normal levels, but the population structure is skewed toward younger crabs that are not yet marketable under current regulations. This demographic shift poses questions for fisheries management and economic viability of the Bering Sea snow crab fishery, valued at roughly $150–$200 million per year.
“crabs during those heat wave years burned as much as 4 times the energy that they had burned the year prior to the heat wave starting.” - Warren Cornwall
Forecasting Crab Abundance: A New Quick Measure
Researchers have been developing tools to avoid another sudden blindsiding event like the 2021 die-off. A key advance is using the hepatopancreas, a fat-rich organ in crabs, as an index of energetic health. While detailed lipid analyses are time-consuming, scientists have devised a rapid proxy: weighing a chunk of hepatopancreas, drying it, and interpreting the water loss as a proxy for stored energy and fat content. If crabs are energy-depleted, the weight change provides a warning that the stock may be more vulnerable to warming or food scarcity, enabling regulators to adjust harvest limits before crises unfold.
“weigh a chunk of hepatopancreas ... the difference in that weight will tell you how much basically was water content.” - Warren Cornwall
Bumblebee Affect Contagion: Social Transmission of Mood
The episode also highlights a study by Fei Pang and colleagues on affect in bumblebees. Bees can be made optimistic through unexpected rewards and can transfer this optimistic state to naive observers after brief interactions. By pairing foraging tests with ambiguous color cues, researchers show that an observer bee can adopt an optimistic bias simply after a 30-second interaction with a demonstrator. Visual contact appears essential for transmission, as isolating conditions that block sight but allow smell or touch reduce contagion, suggesting rapid, visually mediated social cues drive mood-like states in insects.
"spending 30 seconds together was enough to transmit an optimistic state from one bee to a second observer bee" - Fey Pang