[Anchor]

Algal blooms are spreading rapidly across the Naktong River due to a combination of prolonged heatwaves and a severe drought, threatening even the drinking water sources of local citizens.

For today's Morning Zoom-In, Reporter Kim su-yun brings us the report from the field.

[Reporter]

Samnak Ecological Park Water Sports Town in Busan, located in the lower reaches of the Naktong River.

Parts of the vessel mooring area are covered with thick, green particles.

I scooped up some river water myself like this.

It looks just like a matcha latte sold at a cafe.

At the Samnak Ecological Park sampling point, the concentration of toxic cyanobacterial cells exceeded 20,000 cells per milliliter twice in a row, prompting the issuance of an algae warning "Attention" stage.

Banners urging people to refrain from water leisure activities and harvesting fish and shellfish have been hung up across the park.

Around this time of year, this space should be bustling with water leisure sports like kayaking, but operations have virtually been halted due to the algal blooms.

[Official at Samnak Water Sports Town : We have currently suspended experiences because of the algal blooms. We hope the algae will disappear quickly so that citizens can make use of the facility.]

Heading further upstream along the Naktong River to the Mulgeum-Maeri area between Yangsan and Gimhae in Gyeongsangnam-do, the situation is severe.

As of August 3, the number of toxic cyanobacterial cells surged elevenfold in just a week, leading to the issuance of an "Attention" stage warning.

[Sagong Hye-sun / Steering Committee Member, Gimhae-Yangsan Korea Federation for Environmental Movements : With the lack of rain continuing, the current situation with the algae seems much worse than last year.]

Experts analyze that high water temperatures in the Naktong River caused by the heatwave, combined with slowed water velocities due to the drought, have created an optimal environment for algae to proliferate.

[Lee Seung-jun / Professor, Department of Applied Biosciences, Kyungpook National University : At temperatures above 28°C (82°F), cyanobacteria have no choice but to multiply very rapidly. As the heatwaves continue, the intensity, frequency, and severity of the algal blooms are expected to grow stronger.]

With an algae warning "Attention" stage issued for Hoeyah Lake, the drinking water source for Ulsan citizens, for the first time in 17 years since 2009, algal blooms are threatening even the water sources of the Busan-Ulsan-Gyeongnam region.

(Photo: Yonhap News / Video reporting: Jung Kyoung-mun, Design: Lee Ga-jin, Video courtesy of Ulsan City Hall)