World Oceans Day: Oceans Are Getting Murkier and Darker, IPB University Expert Explains
In commemorating World Oceans Day every June 8, Dr Steven Solikin, an expert from the Department of Marine Science and Technology (MST) of IPB University, expressed concern about the darkening ocean phenomenon.
He explained that the darkening ocean conditions are caused by a reduction in the depth of the photic zone, which is the layer of the ocean that receives sunlight and is the main support for more than 90 percent of marine life.
“One of the main causes of ocean darkening is changes in phytoplankton communities, which affect the optical properties of seawater. Changes in the composition and distribution of phytoplankton as primary producers in the marine food chain also affect water clarity,” he explained.
Furthermore, he continued, rising sea surface temperatures also exacerbate this condition. Warming causes thermal stratification that inhibits nutrient mixing from the lower layers to the surface. Thereby reducing phytoplankton productivity.
“Changes in ocean circulation patterns also affect the distribution of nutrients and microscopic organisms. This has a direct impact on ocean clarity and color,” he explained.
According to Dr Steven, this phenomenon has broad impacts on marine ecosystems. The decrease in light intensity in the ocean causes a decline in primary productivity due to reduced photosynthesis by phytoplankton.
“This causes a chain effect starting from zooplankton to fish and marine mammals, even potentially causing disruptions in the food chain and habitat changes,” he said.
He stated that marine organisms that depend on light for navigation, reproduction, and foraging are forced to move to shallower layers. “This increases competition and the risk of unbalanced predator interactions,” he said.
Changes in ocean color, according to Dr Steven, reflect changes in the composition of organisms and organic particles. The consequence is a decline in the population of phytoplankton, fish, and other predators.
“Ecosystems such as coral reefs and seagrasses are also threatened because the lack of light inhibits the photosynthesis process of marine plants,” he said.
He emphasized that climate change plays a significant role in ocean darkening. Warming sea surfaces, changes in circulation patterns, and increasing occurrences of extreme weather events are worsening ocean conditions.
To address these impacts, Dr Steven suggested reducing greenhouse gas emissions, improving ocean monitoring with satellite technology, and protecting and restoring coastal ecosystems such as mangroves and coral reefs.
As a mitigation measure, he also encourages conservation of marine ecosystems, reduction of nutrient pollution from agricultural and industrial waste, improving public education, and strengthening research and international collaboration in addressing this global challenge. (dh) (IAAS/ANF)
