Exposure To Oil Is Damaging To Coral Reef Fish

coral reef fish

Coral reef fish can have long term problems because of their early exposure to oil.

Coral reef fish have a hard time as they grow up because of their being exposed to oil in the early stages of their life, at least according to a new study. Even small amounts of this chemical substance in marine environments can lead to more problems than believed.

Research on the matter was conducted by US, Australian, and Norwegian scientists. They published their results in the journal Nature Ecology & Evolution. The paper also brings to attention the risks provoked by an increased industrial activity in regions such as the Great Barrier Reef.

Coral Reef Fish Impaired by Oil As They Look For Home

Study results are based on tests carried out in simulated marine environments which housed six reef fish species. These were all part of the Lethrinidae and Pomacentridae families. All of them can be found swimming in the Great Barrier Reef.

The team introduced minimal amounts of oil in their simulated environments, and then monitored the fish. According to a study co-author, Dr. Jodie Rummer from the James Cook University, the results were “quite alarming”.

The oil concentration in the simulated environments was reportedly the equivalent of ‘a few drops of oil’ in a swimming pool. Even so, they caused significant problems especially to the coral reef fish exposed to them in their early life stages.

These were noted to be worse at escaping from possible predators. Or at choosing a habitat for them to live in. The fish were also observed to be traveling in smaller groups and also towards more dangerous and open waters.

“In such early life stages, if these reef fishes are exposed to oil, they’re experiencing some really dangerous cognitive difficulties,” states Dr. Rummer.

As the coral reef fish seem unable to make proper decisions, this could also lead to “their ultimate demise” according to the study co-author. Oil could be affecting the fish’s neurotransmitters function in the brain.

The study specifically looked at emperor and damselfish that typically live in tropical coral reefs. These brightly colored fish play a significant role in the reef’s survival, as they help remove algae. They are also part of the local food chain as larger fish species prey on them.

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Tardigrades Are Likely To Be Alive Even 5 Billion Years From Now

tardigrades

Tardigrades are seemingly likely to survive another five billion years from now on.

Scientists have known for some time that tardigrades, also known as water bears, are capable of surviving almost anything they can throw at it. Extended periods of dehydration, exposure to vacuum conditions, and even heavy doses of radiation would fail to kill these micro-animals.

Even though they are less than a millimeter long, they may well be some of the toughest creatures in existence. They have also been around for quite some time. Now, researchers predict that they could survive, as a species, for another 5 billion years.

Tardigrades are Quite Indestructible Creatures

A team looked into the issue as a way of examining how life might survive extinction level events and possibly transmit from planet to planet, even between stars. It also helps them predict life on other planets might exist long enough for us to find it. Of all the members of the animal kingdom, the tardigrade appears to be the most likely to survive a major destructive event. Only some microbes might have a greater chance to continue afterward.David Sloan, a physics researcher at Oxford University, stated that this new study considered “the hardiest species”, namely, the tardigrade. It did so as quite a number of previous studies focused on ‘doomsday’ scenarios.

These revolve around Earth and the astrophysical events, such as supernovae, which could wipe out humanity. However, few considered what species could still survive them.

Sloan, a co-author of the study, continued, relating his comments to other recent discoveries. “As we are now entering a stage of astronomy where we have seen exoplanets and are hoping to soon perform spectroscopy, looking for signatures of life, we should try to see just how fragile this hardiest life is.”
The main reason they put the 5 billion years time limit on the tardigrades’ existence is tied to the Sun. This is predicted to expand to such a size that Earth’s oceans would completely boil away. Still, humans will be gone long before that.
Study results are available in the journal Nature.  
Image Source: Wikimedia