Neue Aufnahmen zeigen, dass Haie wild auf Seeigel aus sind

Summary of the article by ScienceAlert journalist Jessica Cockerill:

Australian scientists have found an unlikely accomplice in the fight against an exploding sea urchin problem that is stripping the continent’s temperate reefs bare.

The East Australian Current is [intensifying as a result of global warming](https://overland.org.au/2019/02/in-the-wake-of-a-leviathan-the-eastern-australian-current-and-the-of-our-oceans/), pushing tropical waters and many species that inhabit them further south, while enhancing conditions that encourage other marine life to grow in numbers.

This includes various groups of sea urchin, which by [steadily stripping the lush kelp beds](https://overland.org.au/2018/03/hauntology-on-country/) of southeast Australia’s temperate reefs have transformed [diverse and valuable](https://www.sciencealert.com/a-hidden-underwater-resource-is-worth-way-more-than-expected-study-reveals) ecosystems into eerie [urchin barrens](https://en.wikipedia.org/wiki/Urchin_barren).

One of the few species thought to prey on urchins is the eastern rock lobster, [*Sagmariasus verreauxi*](https://en.wikipedia.org/wiki/Sagmariasus)*.*

We know they eat native short-spined urchins, [*Heliocidaris erythrogramma*](https://bie.ala.org.au/species/https:/biodiversity.org.au/afd/taxa/a83c96b0-64d5-4b14-97ec-894a158ee417), but it’s unclear how involved they are in the fight against the long-spined [*Centrostephanus rodgersii*](https://en.wikipedia.org/wiki/Centrostephanus_rodgersii)*.* So a team led by University of Newcastle ecologist Jeremy Day wanted to find out just how useful of an ally these lobsters are.

Their experiment off the shores of Wollongong, a town on Australia’s southeast coast, monitored 100 sea urchins (half short-spined, half long-) that were tethered outside a known lobster den – a rocky overhang in the reef, 5 to 8 meters deep, in which the nocturnal lobsters lurk during the day – for 25 nights, recording the ensuing carnage with GoPro cameras.

“‘Tethering’ is where urchins are surgically restrained to remain available for predation overnight and to stay within view of our cameras. We used a red-filtered light to film the experiments because invertebrates don’t like the white light spectrum,” [says](https://www.scimex.org/newsfeed/sea-urchins-a-surprising-delicacy-for-sharks) Day.

The footage revealed the lobsters are actually uninterested in long-spined urchins. There is, however, another predator crunching down on them with far more relish.

Read the peer-reviewed paper here: [https://doi.org/10.3389/fmars.2024.1418506](https://doi.org/10.3389/fmars.2024.1418506)