E sulcatus my mysteriously endangered crayfish

[I wrote this in 2024, but this is where my whole Euastacus thing started lmao]

I was scrolling through the IUCN Red List of threatened species for decapods when I saw an awful lot of this Euastacus genus. Naturally, I decided to spend hours of my time researching random Australian crayfish instead of being productive.

What is a Euastacus? Euastacus is a genus of freshwater crayfish native to southeastern Australia. Species were discovered as early as 1837 (e. australasiensis) and as late as 2005 (e. girumulayn). These are actually the second-largest genus of crayfish in the world, growing up to 12 cm in length. E. Sulcatus, moreover, is known for its striking blue color and spikes, hence its common name, the Lamington Spiny crayfish. In spite of there only being 50 species, 34 of them are marked as endangered on the IUCN Red List. In fact, only 10 of the 50 species are… okay?? Idk man. Either way, this is not looking good Why are they endangered? Probably climate change. That's literally the answer to everything A crayfish's shell is made of calcium carbonate. To maintain its shell's strength, it must absorb more calcium carbonate from the water in which it lives. Where does climate change come in? When bodies of water absorb all our carbon emissions, it causes acidification in both salty and fresh water. When the CO2 enters the water, it reacts and forms carbonic acid. Carbonic acid is a bit unstable. To stabilize itself, it releases a hydrogen ion and becomes bicarbonate. This hydrogen ion is the one trying to mess with the crayfish's ability to live. Calcium carbonate is ... made of calcium and carbonate. When a hydrogen ion enters the equation, the carbonate is more motivated to bond with the hydrogen instead of the calcium. Now the crayfish can't have its calcium carbonate, the molecule upon which its exoskeleton relies for stability. This leads to its shell slowly weakening over time, similar to the contributions of global warming towards coral bleaching. Since this is dependent on the calcium concentration in the water, large populations of crayfish can be affected in such a way. However, Euastacus seems more endangered than other species of crayfish. In fact, a study done by Hossain, Md Anwar, showed that despite the US having way more species of crayfish, Australian crayfish were much more likely to suffer from climate change related issues. Why is that? I don't know. I couldn't find anything. Genuinely scavenged for information tho. A study of a population of Euastacus armatus was done by Raymond Scott et al in Hydrobiologia, attributing some of the population loss to illegal poaching of large males. Since the larger male crayfish are the ones most capable of reproducing, this has a significant impact on their population. The only ways to prevent all this would be to cut carbon emissions and put more regulations on poaching, but that's not something we can do overnight. Thank you for listening to my ted talk

PS im not autistic or anything i just do this