Wildlife Photographer of the Year The Rise and Fall of the Humble Herring

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Audun was accompanying rescuers in Norway on an expedition when they discovered a mass of dead and dying Norwegian herring floating in the spring. On the horizon floated a fishing boat with a broken net. It was clear that the fishermen had caught more herring than the net could hold.

“We were at sea to observe the interaction between killer whales and a fishery,” explains Audun. “Killer whales often congregate around fishing boats for leftover fish. That’s when we saw thousands of herring drifting by – it was obvious it was all from a specific boat.

Overfishing – catching fish faster than their populations can recover – is one of the biggest threats to ocean ecosystems and future food supplies. It is estimated that more than a third of the world’s fish stocks are exploited at unsustainable levels.

The ripple effect of herring overfishing

In the North Atlantic Ocean, herring is a keystone species, which means that many other organisms in the ecosystem depend on these fish and their eggs to survive.

Herring shapes both ends of the food chain. On the bottom, they feed on plankton and other small organisms like copepods, krill and fish larvae. At the top, they are a rich source of nutrients for many marine predators, including cod, saithe, marcel, tuna, Atlantic salmon and sea trout.

They are also on the menu of marine mammals, such as whales, dolphins, porpoises and seals, as well as a variety of seabirds. In fact, a herring can provide four times the energy of eating any other species of fish.

Each year, herring migrate from their coastal spawning grounds to their open-ocean feeding grounds, often farther north. This migration attracts a number of predators that work together to catch the herring, resulting in a spectacular feeding frenzy showing an entire food web at work in one place.

The late 20th century saw global herring populations plummet to near extinction, primarily due to the use of new and advanced fishing gear. The introduction of giant trawlers allowed fleets to fish longer and catch larger quantities of fish.

There were no frameworks in place limiting the amount of fish that could be caught. As a result, world herring stocks have shrunk to almost nothing. Spring-spawning Norwegian herring, in particular, has fallen from around 14 million tonnes to less than 1 million tonnes in just over a decade.

The decimation of herring populations has had a ripple effect on the ocean ecosystem, leading to a decline in many herring predators, including those at the top of the food web such as sharks and whales, as well as many seabirds. .

Countries that depended on fishing, such as Norway, the Faroe Islands, Iceland and Russia, have been hit hard. Herring was a staple food source for many communities in these countries and had historically sustained people during difficult times when food was scarce, such as during World War II. As herring populations plummeted, the price of fish rose, people lost their livelihoods, and businesses were forced to close.

A near total 20-year ban on herring fishing was introduced in the late 1970s in an attempt to allow the species to recover. Following the lifting of this ban, strict regulations were put in place that still exist today.

Currently there are fixed times in the year when herring cannot be fished at all and there is also a limit on the amount of herring a boat can fish in total in a season. These quotas are set after detailed surveys have been carried out to ensure that stock levels remain sustainable.

Illegal fishing slows recovery

Some populations, including the largest herring population in the world – the spring-spawning Norwegian herring – have rebounded and the benefits are evident.

“Much of my research is whale-based, and my colleagues and I have noticed an increase in killer whale, humpback and fin whale numbers over the past decade,” says Audun. “The recovery of the herring has led to an increase in the number of other animals linked to it.”

Other herring populations, however, remain threatened. This is due to a combination of illegal fishing and inaccurate stock estimates, both of which slow the rate of recovery.

Some companies fish without a license or with an incorrect license, while others continue to catch more fish than they are allowed to – hoping to get away with it.

Audun was quick to capture the herring spill on his camera and his photos were later used in court to help convict and fine the company responsible.

“We managed to bring the herring back from near extinction because we took drastic measures,” says Audun. “However, if we were managing the fishery sustainably, we could have avoided going down that route to begin with.”

“We kept fishing until the herring were almost gone, but what we should have done was figure out how many herring there were in the sea and then fish accordingly.”

Assessing the size of fish stocks in the sea is an important task carried out through various methods, such as the use of echo sound. The acoustic waves are transmitted through the water and bounce off the fish, giving scientists an idea of ​​how many fish there are in the area.

The information helps make informed decisions about sustainable practices, such as when to fish and what type of gear should be used.

“What happened to herring can happen to other fish stocks,” says Audun. “We need better science to inform sustainable management and change policies to avoid depleting fish stocks and repeating the disaster that has been the near extinction of a key ocean species.”

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