Updated: 7 days ago
With the increasing issue of climate change, the planet is getting warmer, which means our oceans are not only rising but they’re heating up.
Although this may sound like a heap of fun for swimming in summer it has drastic consequences for our marine environment.
Marine life is being damaged all over the world due to this issue, but there are a couple of species being affected in a more surprising way than you might think.
Sharks are already running the risk of going extinct, but with the oceans warming up, this is quickening, quite literally; Shark eggs are developing at an alarming speed due to the increase in water temperatures, which means baby sharks are being born almost prematurely.
As their environment heats up, the development of shark embryo’s speeds up, the faster birth of sharks may sound positive, but the reality is that baby sharks are coming out of their egg cases malnourished, lacking nutrients and significantly smaller than they should be.
“The hotter the conditions, the faster everything happened, which could be a problem for the sharks.
The embryo grew faster and used their yolk sac quicker, which is their only source of food as they develop in the egg case. This led to them hatching earlier than usual”
-Carolyn Wheeler, PhD student at James Cooke University and University of Massachusetts comments on a study of the effects of increased temperatures on the growth and performance of epaulette sharks.1
Once sharks have laid their eggs, they abandon them, leaving them to fend for themselves as soon as they are born. This is to be expected as sharks are independent creatures, but as they are being born early this leaves them with a lesser chance of survival as they are now being born weaker, unable to fend for themselves as easily. Lacking the energy to feed, sharks also run the risk of starvation, all of this on top of the many other risks they may face, including the biggest- humans.
Unlike most fish, sharks are slow growing, which already sets them back, leaving them more at risk as this overall threatens their population.
It is not only sharks at risk, many species of starfish are also affected by climate change, including our oceans warming up. The heated environments are increasing extinction rates in starfish species.
Warmer water temperatures are causing an increase in the growth of organic matter. Organic matter is not the direct cause of the issue for starfish but the bacteria that feeds on it is. As this bacterium (Copiotrophs) consumes the organic matter, it grows and reproduces and as there’s an increase in their food source, they are thriving and growing more rapidly.
This bacterium is causing a decrease in oxygen within the starfish’s environment, causing them to suffocate and eventually die.
“Changes in the environment rob the creatures of their ability to breathe” researchers from Cornell University have said2
Starfish diffuse oxygen from their surrounding environments, they do not breathe in the same way we do. So, if the water around them becomes contaminated so does their oxygen supply. The respiratory distress can cause starfish to often curl up, become discoloured or deflated and even die
It is said that by the end of the century the ocean could be 31°C, from what we are already seeing, this could mean that by then many, many more marine species could be extinct.
1) Cockburn, H. (2021). Warming oceans mean baby sharks born ‘exhausted and undernourished’, scientists warn. The Independent. Retrieved 24 November 2021, from https://www.independent.co.uk/climate-change/news/baby-sharks-climate-change-b1785901.html.
2) Cockburn, H. (2021). Warming oceans linked to mass starfish die-offs around the world. The Independent. Retrieved 24 November 2021, from https://www.independent.co.uk/climate-change/news/starfish-oceans-climate-change-b1783780.html.