The one thing stopping jellyfish from taking over - Mariela Pajuelo & Javier Antonio Quinones

Summary

Jellyfish are overwhelming oceans worldwide, causing environmental and industrial issues. Leatherback sea turtles, which eat large quantities of jellyfish, are key to controlling these populations. Leatherbacks consume up to 400 kilograms of jellyfish daily, despite their low nutritional value. However, human activities, such as pollution and climate change, are increasing jellyfish numbers while threatening sea turtles. Sustainable fishing practices, like using LED-lit gillnets, can help protect sea turtles from accidental capture, supporting both marine ecosystems and fishing communities.

Takeaways

• 🌊 Jellyfish populations are rapidly increasing, overwhelming oceans globally.
• 🐠 In New Zealand, divers face swarms of jellyfish, no larger than a grain of pepper.
• ⚡ In Sweden, a jellyfish cluster shut down a nuclear reactor by clogging its pipes.
• 🎣 Nomura’s jellyfish in the Sea of Japan are breaking fishing nets and eating local fish.
• 🍳 Jellyfish consume fish eggs, larvae, and outcompete fish for resources, disrupting marine ecosystems.
• 🐢 Sea turtles, especially leatherbacks, are ancient predators of jellyfish.
• 🥇 Leatherback sea turtles can eat over 400 kilograms of jellyfish daily, despite the low calorie content.
• 🛡️ Sea turtles are immune to jellyfish stings due to their thick, keratin-covered skin.
• 💥 Jellyfish reproduce both sexually and asexually, leading to massive population blooms.
• 💡 Protecting sea turtles and implementing solutions like LED lights on fishing nets can help control jellyfish numbers and safeguard turtle populations.

Q & A

What problems are caused by jellyfish overpopulation in the oceans?

Jellyfish overpopulation disrupts marine ecosystems by consuming fish eggs and larvae, undermining marine farming efforts, clogging pipes at nuclear reactors, and outcompeting adult fish for resources. These factors threaten fish populations and affect human industries.

What event occurred in Sweden involving jellyfish and a nuclear reactor?

In Sweden, a massive cluster of moon jellyfish clogged the pipes of one of the world’s largest nuclear reactors, causing it to shut down temporarily.

How do leatherback sea turtles contribute to controlling jellyfish populations?

Leatherback sea turtles play a crucial role in controlling jellyfish populations by eating jellyfish almost exclusively, consuming up to 400 kilograms of jellyfish per day over their lifetimes, which helps balance marine ecosystems.

Why are jellyfish difficult for most predators to handle?

Jellyfish possess venomous cells called cnidocytes, which contain nematocysts that can sting and paralyze their prey or irritate predators. However, these stings are ineffective against sea turtles due to their keratin-covered scales, which act as armor.

What adaptations help leatherback sea turtles consume jellyfish effectively?

Leatherbacks have thick keratinized scales that protect them from jellyfish stings, and keratinized spikes lining their esophagus that allow them to impale and consume jellyfish whole, even as they attempt to escape.

How do jellyfish reproduce, and why does this make them hard to control?

Jellyfish can reproduce both sexually and asexually, allowing them to multiply rapidly with or without a partner. This ability, combined with environmental conditions like warmer waters, makes their populations grow uncontrollably, particularly during blooms.

How does climate change contribute to jellyfish overpopulation?

Climate change increases ocean temperatures, which speeds up jellyfish reproduction and extends their reproductive season. Additionally, pollution and human activity create more surfaces for jellyfish polyps to attach and grow.

What human activities are exacerbating jellyfish blooms?

Human activities such as fertilizer runoff from farms, pollution, and marine construction create favorable conditions for jellyfish blooms. These activities kill off other fish species while simultaneously boosting jellyfish reproduction.

How does fishing by small-scale fisheries threaten sea turtles?

Small-scale fisheries often use gillnets that unintentionally capture and kill sea turtles. This is especially dangerous in areas like the Eastern Pacific, where these practices could drive leatherback sea turtles to extinction in the next 60 years.

What solution has been proposed to reduce the accidental capture of sea turtles by fisheries?

Researchers have developed an inexpensive solution involving attaching green LED lights to gillnets, which helps sea turtles, dolphins, and seabirds avoid the nets, reducing accidental captures and deaths.