By: Harper Dame
Due to the changes in environmental behaviors, there has been a great loss in biodiversity throughout the oceans. Through studies conducted by Professor Fred Wells, from Curtin’s School of Molecular and Life Sciences, Wells claimed that there was a “catastrophic decline” in marine biodiversity (Wells, Marine heatwaves decimate sea urchins, molluscs and more at Rottnest). From 2007 to 2021, there has been documented evidence of this decline in wildlife in Radar Reef and Cape Valmigh at Rottnest Island. Since both of these areas were exposed to the warm Leeuwin Current, the animals were placed in contact with increased temperatures. Other reefs, such as those located in the metropolitan area, were not exposed to warmer currents and still maintained sufficient wildlife.
Marine heat waves are commonly the cause for the decline in wildlife populations in the oceans. These heat waves exist in periods of abnormally high temperatures relative to the average temperature of the current season. These waves can be brought to a specific area or through larger currents that travel through the oceans. These are known to cause a change in biodiversity dynamics throughout the ocean. Though only small creatures were greatly impacted on the Rottnest Island, this not only impacts their population but the life cycle and food chain within the area.
Studies have shown that there has been a greater number of marine heatwaves between the years of 1981 and 2017. Furthermore, approximately 27 major heat waves were recorded and lasted approximately a month. Some of these heat waves even reached temperatures greater than 5.5 degrees above the average sea temperature. Though this may seem like a “tropical climate” or nice for a “beach day”, these heat waves can actually be detrimental to the wildlife in the ocean. Some may not even be able to adapt to these changes fast enough and become extinct.
Without a good course of action, our marine ecosystems may not be present for much longer. Since humans have a huge influence on the frequency of these heat waves, they may become more frequent if we do not understand their causes. Due to our carbon emissions and disregard for what goes into the ocean, these heat waves become more consistent. In fact, these are 20 times more consistent due to human interaction.
Sources:
Curtin University. "Marine heatwaves decimate sea urchins, molluscs and more at Rottnest." ScienceDaily. ScienceDaily, 24 February 2023. <www.sciencedaily.com/releases/2023/02/230224134808.htm>.
University of Bern. "Marine heatwaves are human-made." ScienceDaily. ScienceDaily, 25 September 2020. <www.sciencedaily.com/releases/2020/09/200925113351.htm>.