The global salmon industry is experiencing a "catastrophe" | Expo Daily

Sudden mass die-off of salmon around the world

Since 2012, mass die-offs of farmed salmon around the world have become more frequent and the numbers of deaths have increased, sometimes with millions of fish dying at the same time.

Research published recently in Scientific Reports shows that these mass salmon die-offs are often caused by factors such as fluctuating ocean temperatures and poor living conditions, highlighting the need to improve animal welfare measures on salmon farms.

The team found that high salmon mortality events increased over time between 2012 and 2022, particularly in Norway, Canada and the United Kingdom, with a total of 865 million salmon deaths during that period.

If this trend continues, the researchers predict that up to 5.14 million fish could die in Norway, 5.05 million fish in Canada, and more than 1 million fish in the UK in the future.

Environmental stressors, including marine heatwaves and lack of oxygen in the water, as well as infestations of sea lice are possible triggers of these mass mortality events.

Algal bloom kills salmon at a Norwegian fishery.

Image credit: Berit Roald/EPA-EFE

Cicada : Don’t think I’m noisy . Do you know what I have been through in the past 100 million years?

Although cicadas are currently the "loudest" insects (they can make sounds of nearly 120 decibels), according to fossil research, their ancestors spent hundreds of millions of years in silence, so that the dinosaurs that lived with them may never have heard their voices.

The male cicadas in the existing cicada family mainly produce high-pitched sounds. The male cicada uses the well-developed tympanic membrane muscles in the abdomen to pull the tympanic membrane through the inner protrusion of the epidermis, causing the ribs on the membrane to bend back and forth to produce sound.

Their abdomens have resonance cavities, which act like natural speakers, further amplifying these sounds and transmitting them through the air to achieve communication. Of course, cicadas have also developed an auditory system, including structures such as the auditory membrane, auditory ridges, and auditory capsules, to assist in receiving sounds.

The loud chirping of cicadas depends not only on the eardrum, but also on the coordination of the entire set of sound-producing devices in the abdomen. Further physical examination of the fossil cicadas in amber revealed that most fossil cicadas did not have other structures related to sound production and hearing, or structural features that were clearly developed and similar to those of modern cicadas.

Paleontologists have concluded that these members of the superfamily Cicadoidea, which lived in the middle Cretaceous period about 100 million years ago, may not have complex vocalization and hearing devices, and could not produce and receive high-decibel songs similar to modern cicadas. Their communication method may be more similar to that of today's katydids, where the body generates vibration signals, which are transmitted through branches and leaves, and quietly exchange thoughts.

“Parallel imported goods” are not fake and are very safe!

Although electric vehicles and other transportation equipment are convenient, traditional lithium-ion batteries may pose safety risks in some cases, such as poor battery quality or improper use. At the end of February, a major fire in Nanjing made many people refocus their attention on the safety hazards of electric vehicles.

Recently, a study published in Advanced Materials demonstrated a "water battery". Researchers used a mixture of water and inorganic salts as electrolyte, replacing the traditional organic electrolyte. This new battery design aims to reduce the risk of battery explosion and improve the safety of transportation such as electric bicycles.

The core advantage of "water batteries" lies in the safety of their electrolytes. The organic electrolytes used in conventional lithium-ion batteries are prone to decomposition at high temperatures or under overcharge and discharge conditions, generating heat and gas that can lead to thermal runaway and fire. In contrast, the electrolytes in water batteries are more stable at high temperatures and less likely to burn, thus reducing safety risks.

In addition, the team also coated the two electrodes of the battery with a layer of bismuth oxide. This not only makes the battery life longer, but also makes its performance more stable. Such a battery is like a "super shield" for electric vehicles, making riding more secure. Looking forward to its production and use!

Members of the research team and the "water battery" they made.

Image credit: Carelle Mulawa-Richards, RMIT University

What is it like to sleep in amber for 100 million years?

Tapeworms belong to the phylum Platyhelminthes. There are about 5,000 known species, all of which are parasitic and can infect almost all vertebrates, including humans.

Recently, Luo Cihang, a doctoral student at the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, under the guidance of researcher Wang Bo, collaborated with Chinese and foreign scientists to discover the fossil of marine parasitic tapeworms in Burmese amber for the first time.

The external morphology and internal structure of the tapeworm fossils discovered this time are completely consistent with those of the living Conodontidae tapeworms, providing direct evidence for understanding the early evolution of tapeworms. This research result not only reports the first body fossil record of tapeworms, but also proves that amber can preserve the internal structure of soft-bodied organisms, providing new clues for amber taphonomy and paleoenvironmental restoration.

In addition, the study also provides a rare case of marine parasites encased in amber, further proving that the formation environment of Kachin amber in Myanmar was close to the sea. The hypothetical scenario restoration diagram of the study shows that the tapeworm may have parasitized in the intestines of the stingray, and was preyed upon by dinosaurs after being stranded. When the dinosaurs ate the stingray's internal organs, the tapeworm was pulled out and fell into the nearby amber.

The tapeworm may have been parasitic in the intestines of the ray, and after being stranded, it was preyed on by a dinosaur. When the dinosaur ate the ray's internal organs, the tapeworm was pulled out and fell into the nearby amber.

Why is black soil called black soil?

Recently, researchers from the Institute of Geology and Geophysics of the Chinese Academy of Sciences conducted a large-scale field survey and sample collection in the black soil area of ​​Northeast China. Through the analysis of the collected black soil samples, they found that the black soil materials were originally transported by wind. So, how were the black soil materials transported by wind? How did the aeolian materials form the black soil?

The content is compiled from China Science Expo Weibo, China Science Daily, Global Science, Institute of Southern Paleontology, Chinese Academy of Sciences, and Science Popularization Weibo

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