Climate change is always in the spotlight of attention. Melting glaciers, spreading deserts and pollution is always considered to be a massive problem, while changes in the ocean are pushed to the shadow. However, now scientists from the University of Adelaide have found that even baby fish will suffer from ocean acidification in a quite unexpected way – they will lose their shelter from predators.
Interestingly, baby fish tend to hide between the poisonous tentacles of jellyfish to avoid predators. This symbiotic relationship is going to be harmed from rising acid levels in the ocean. This will lead to a higher mortality of baby fish, which will trigger many more problems, many of which will affect human fishing patterns. Among the species that will be affected is a famous clown-fish, popularised in the animated movie, Finding Nemo.
Symbiosis between species is common both on land and in water. It is very important in many areas and provides safety for certain species that are typical pray for predators. But scientists only now are trying to figure out how climate change will affect such relationship between species. Researchers managed to prove that acidification of the ocean will affect this cooperation and it will have a huge impact on baby fish of about 80 different species, many of which are important for fishing industries. But how exactly this symbiosis works?
Most baby fish are not immune to the jellyfish venom. However, they are small enough to avoid them while swimming very close to them. This means that bigger fish and other marine life have to stay away and baby fish remain protected. Scientists performed experiments which showed that an aquarium under high CO2 conditions baby fish spent three times less time with the jellyfish host in comparison with the control group. Furthermore, only 63% initiated any relationship at all, while in control group this figure reached 86%.
Professor Kylie Pitt at Griffith University, co-author of the study, said: “Shelter is not widely available in open water so juvenile fish rely on the jellyfish for protection against predators. As shelter providers, the jellyfish could play a role in enhancing the populations of these fish species. Changing ocean conditions are likely to have significant negative impacts on this relationship and therefore, fish populations”. Therefore, both quick decisions are necessary as well as further research to see what other effect acidifications of oceans might have.