The Southern Ocean’s Crucial Role in Whale Survival and Human Health
Whales and humans both have a significant interest in the Southern Ocean’s dense krill populations. Sovca et al.’s 2024 study sheds light on the importance of these tiny crustaceans for both marine mammals and human health. Despite their small size, krill are essential in the global food web, supporting the diets of various whale species, seabirds, seals, and more. Additionally, humans have developed a taste for krill, often consuming them in the form of omega-3 supplements.
Krill, often mistaken for small shrimp-like creatures, are actually a diverse group of crustaceans found throughout the world’s oceans. Antarctic krill, specifically Euphausia superba, plays a crucial role in the Antarctic ecosystem. It serves as a primary food source for marine mammals and seabirds, while also playing a role in carbon storage. Antarctic krill can remove a significant amount of carbon dioxide from the atmosphere annually, highlighting their vital ecological function.
The demand for krill has led to a booming fishery in the Southern Ocean, with a notable increase in consumption for dietary supplements. From 2007 to 2022, the demand for krill as a dietary supplement skyrocketed from 104,728 metric tons to 415,508 metric tons. This surge in demand has raised concerns about the potential impact on whale populations, particularly as they continue to recover from centuries of industrial whaling.
Commercial fishing for krill in the Southern Ocean has become a significant industry, with trawlers from various countries such as Chile, China, Norway, South Korea, and Ukraine actively harvesting these tiny crustaceans. Aker BioMarine, a Norwegian company, is a major player in the krill fishery, responsible for approximately 70% of the krill catch. The company markets krill oil capsules containing omega-3 vitamins, touting various health benefits such as supporting brain, heart, and joint health.
As whale populations in Antarctica have started to recover from the devastating impacts of commercial whaling, a new challenge has emerged. Researchers, including Stanford University conservation biologist Matthew Savoca, have found that whales in Antarctica are consuming significantly more krill than previously estimated. This increased consumption coincides with the expanding krill fishery, raising concerns about potential conflicts between human fishing activities and whale foraging.
Savoca and his team conducted a study to assess the overlap between the krill needed by whales for survival and the amount harvested by human fishers. Their findings revealed that the current krill biomass in the Southern Ocean may not be sufficient to support both the expanding fishery and the recovery of whale populations to their pre-whaling size. This conflict highlights the need for stricter regulations to protect marine wildlife in the region.
The Association of Responsible Krill Harvesting Companies (ARK) has implemented measures such as catch limits, fishing in designated areas, and the use of marine mammal exclusion devices to minimize potential impacts on whale populations. However, incidents such as humpback whales becoming entangled in fishing nets raise concerns about the effectiveness of these measures. Despite a 2022 study indicating a low bycatch rate in Antarctic krill fishing, further efforts are needed to mitigate potential conflicts between human activities and marine wildlife.
In light of these challenges, the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) will convene in Hobart, Australia, in October to discuss potential solutions. Savoca and his team recommend including whale populations and prey requirements when calculating catch limits each year. They also advocate for increased monitoring of krill and larvae hotspots, as well as collaboration with the International Whaling Commission (IWC) to incorporate whale prey requirements into updated krill harvesting regulations.
The researchers emphasize the importance of raising awareness about the impact of krill fishing in the Antarctic and the need for stronger regulations to protect wildlife in the region. With common-sense regulations and collaborative efforts among stakeholders, it is possible to ensure the sustainability of krill populations while safeguarding the vital role they play in supporting marine ecosystems and human health.