Scientists warn of serious threat to fish species crucial for food supply: 'Indispensable to the livelihoods of hundreds of millions'

Small pelagic fish — including sardines, herrings, and anchovies — are under pressure from overfishing and rising global temperatures. A new study underscores the importance of sustainable fishery management and ecosystem protection for long-term resource availability.

How do overfishing and the warming climate affect small pelagic fish populations?

According to the Global Seafood Alliance, strong, climate-linked La Niña events can disrupt fish reproduction, while El Niño events limit nutrient availability and alter migratory patterns. Heavy precipitation and hurricanes can worsen these impacts and push fisheries to the brink of collapse.

Another study suggests the warming climate will cause 23% of transboundary fish stocks (fish stocks between neighboring countries' exclusive waters and the high seas) to move away from their established habitats and migration paths by 2030. By 2100, the figure could reach 45%.

Overfishing of small pelagic fish populations also causes significant declines. Nearly 60% of global fish stocks have been completely overexploited, while 34% are overexploited. Humans are fishing too much and too intensively, causing species to move to new areas, disrupting critical food webs, and hurting a crucial industry that provides nutrition and employment.

Why you should care about pressures on small pelagic fish

The warming climate and other human factors — including overfishing — caused biodiversity to decrease by 73% between 1970 and 2020, according to the World Wildlife Fund. When it comes to small pelagic fish, the decline is dire.

Seafood is a significant source of omega-3, iron, and calcium. If global average temperatures rise 4 degrees Celsius (7.2 degrees Fahrenheit), scientists project marine-derived nutrient availability will decrease by 30% by 2100, while a 1.5- to 2-degree rise could result in a 10% nutrient decline, according to a study published in Nature Climate Change. Likewise, removing too many fish from their natural habitats can mean there may not be enough to satisfy the nutritional needs of growing populations.

Watch now: Giant snails invading New York City?

According to the Global Seafood Alliance, marine fisheries are "indispensable to the livelihoods of hundreds of millions of fishers and the nutrition of billions of people." They are essential to animal food production, aquaculture, and similar industries. They're also important for employment and food security in developing nations.

How fishery management and resource conservation helps

Understanding the most critical climate issues can drive informed decision-making and meaningful communication about fishery management and resource conservation. The study — in particular — highlighted the interconnectedness between these ecological problems.

The researchers suggested adaptive management plans to monitor environmental conditions and fish populations and set reasonable catch limits. Comprehensive fishery management plans must also consider habitat protection, the socioeconomic conditions of regions, and integrating early warning systems for climatic changes.

Addressing other marine environmental concerns — such as pollution — is another way to ensure adequate ocean resources. Policies including the National Ocean Biodiversity Strategy — which helps conserve 30% of United States-managed seas — can further protect small pelagic fish populations and species that rely on them.