UNESCO Alerts: Rising Ocean Temperatures Threaten Marine Life

December 11, 2024

A recent UNESCO report marks the risks faced by fish species in tropical and subtropical regions. If greenhouse gas emissions continue at current levels, temperatures may rise by 4.4°C by the century’s end, termed SSP 8.5, which could push many fish species beyond their heat tolerance limits.

Current Ocean Temperature Trends

Ocean temperatures are increasing at an alarming rate. They are now rising twice as fast as they did two decades ago and the warming recorded in 2023 is among the fastest since the 1950s. This rapid increase poses challenges for marine life, even for species that can typically adapt.

The warming oceans threaten up to 50% of fish species in temperate zones. Tropical areas, such as the Tubbataha Reefs and the Belize Barrier Reef, are already experiencing extreme temperatures. Many marine species may struggle with heightened stress, impacting their survival and reproduction.

Monitoring Marine Biodiversity

UNESCO employed environmental DNA (eDNA) technology to assess marine biodiversity. This innovative method involves collecting water samples to identify genetic material from marine organisms. Over three years, researchers studied 21 World Heritage sites, identifying nearly 4,500 species, including various fish, sharks, mammals, and turtles.

Findings from eDNA Studies

The eDNA studies revealed biodiversity, with the Ningaloo Coast in Australia hosting 787 species. Rare and critically endangered species, like the white-spotted guitarfish, were also identified. Additionally, eDNA helped detect invasive species, such as lionfish, enabling timely conservation efforts.

Challenges of eDNA Technology

While eDNA technology is beneficial, it has limitations. It struggles to detect certain species, particularly in turbid waters. For example, requiem sharks were harder to identify in such environments. Clear waters yield better results for species detection.

Many marine species may not adapt swiftly enough to rising temperatures. This could lead to biodiversity losses. Species may shift their distributions in search of cooler or deeper waters. The future of marine ecosystems hangs in the balance as temperatures continue to rise.

GKToday Facts for Exams:
SSP 8.5 SSP 8.5 refers to a scenario predicting a 4.4°C rise in global temperatures by the century’s end. It represents a “business as usual” approach to greenhouse gas emissions.
eDNA Technology Environmental DNA (eDNA) technology collects water samples to identify marine organisms’ genetic material. This method helps monitor biodiversity and detect invasive species in marine ecosystems.
Tubbataha Reefs Tubbataha Reefs is a UNESCO World Heritage site in the Philippines. It is known for its rich marine life and is currently threatened by rising ocean temperatures and climate change.

« Previous Post Next Post »