A tale of two hake - Oceana
Home / Blog / A tale of two hake

December 27, 2021

A tale of two hake

What can separate stocks of the same species teach us about bringing fish back in Europe? A lot, according to scientists. Credit: © Shutterstock/Anna L. e Marina Durante


If you’ve ever ordered seafood in Spain, there’s a good chance you’ve had European hake. Called merluza in Spanish, this relative of cod and haddock is a strong contender for the nation’s favorite fish. Its filets are mild-flavored and flaky, pairing perfectly with roasted vegetables or pan-fried clams. 

Whether or not it’s sustainable, though, depends entirely on where it’s coming from. Formerly overfished northern hake – a specific European hake stock found in the northern Bay of Biscay, Celtic Seas, and Greater North Sea – are once again thriving under a robust fisheries management plan. Hake in the Mediterranean Sea, on the other hand, are fighting for their lives.  

“Hake is the most overexploited species in the Mediterranean, which is the world’s most overfished sea,” said Javier López, Oceana’s director of sustainable fisheries campaigns in Europe. “In some cases, the fishing mortality is four times above sustainable levels, which is unacceptable.” 

Though the geographic distance between these stocks is relatively small, their management plans are worlds apart. To understand what went wrong with the management of hake in the Mediterranean, it helps to understand what went right in the northern Atlantic. 

A record-breaking biomass 

European hake (scientific name: Merluccius merluccius) is a species of groundfish that appears not only in Europe’s waters, but also those off Northwest Africa’s. It supports thousands of jobs across the Black Sea, Mediterranean, and open Atlantic, from as far south as Mauritania to as far north as Norway. 

This fishery’s economic and cultural significance is strongly felt in the European Union (EU), where it’s among the top 15 species caught and top 10 species consumed. This is especially true for France, Spain, and the United Kingdom (UK), whose fleets catch the most northern hake by volume.  

The story of hake hasn’t always been rosy, though. Like many other groundfish, northern hake were overfished to the brink of collapse in the ‘90s, with their biomass (or collective weight) hovering near or below the safe biological limit for about a decade. This reference point is a dangerous threshold to cross because it diminishes a fish’s ability to reproduce and carry on its species. 

The European Union stepped in at a crucial moment, adopting a recovery plan in 2004 that reversed the stock’s trajectory. Science-based limits on how much hake could be caught, and what types of fishing gear could be used, alleviated some of the pressure and gave hake a chance to recover. 

As a result, the stock’s biomass hit a record high in 2016, weighing in at more than 307,000 metric tons. This is more than three times higher than 1980 levels, which were the highest biomass on record prior to 2004. In this case, a higher biomass means there are more fish to catch.  

Then, in 2019, Oceana supported the EU’s adoption of a new mixed fisheries management plan that covers nearly 40 different stocks – including northern hake – and requires them to be maintained at maximum sustainable yield (MSY). MSY refers to the maximum amount of fish that can be removed from the ocean while still allowing the population to replenish and sustain itself in the long-term. In other words, scientists can calculate the amount of fishing that will ensure a healthy hake population while still allowing fishers to keep catching hake indefinitely.  

“The goal and the target of the new management plan is even more ambitious because it is in line with MSY,” López said. “Nowadays, the scientific knowledge is much better and the management standards are higher – and it seems like it is working for now.” 

Med still in the red 

This European hake was spotted in the São Vicente Canyon area of Portugal during an Oceana expedition in 2011. The species is mostly found at depths of up to 300 meters (more than 980 feet).
Photo credit: © Oceana

European hake are no longer considered a species of concern by the International Union for Conservation of Nature (IUCN), but at the regional level, Mediterranean hake stocks were listed as vulnerable to extinction due to overfishing.

In 2017, Paul Fernandes, marine biology professor at the University of Aberdeen in Scotland, led a study that assessed the status of 115 fish stocks across Europe, including 39 in the Mediterranean Sea. The takeaway? Not a single one of the Mediterranean stocks could be classified as “sustainable,” including all 12 Mediterranean hake stocks.

It’s not uncommon to see undersized juvenile hake on the menu in Spain and France, compounding the problem and making it even harder for Mediterranean hake to replenish their population.

“They have a tradition of eating small fish, small hake. How those populations are still alive with the fishing mortality that they have is just amazing,” said Fernandes. “[Mediterranean hake] are sort of hanging on, and they’ve been subject to high exploitation rates for decades.”

Part of the problem is poor enforcement, Fernandes said. Northern Europe’s fishing fleet is fairly small and concentrated, so it’s easier to check whether fishers are complying with regulations. Compare that with a country like Greece, which has thousands of small vessels scattered across hundreds of islands, and it becomes clear that enforcing fisheries policies in the Mediterranean is more difficult.

According to López, the other problem is that Mediterranean hake didn’t have a recovery plan until 2019, and even then, its scope was limited. While the management of northern hake is focused on the big picture – regulating the total allowable catch, or TAC, of all northern hake in accordance with scientific advice – management in the Mediterranean is focused on fishing effort restrictions at a smaller scale.

These restrictions apply to certain aspects of the fishery, such as the number of days per week that a fisher can catch hake. Notably, this does not preclude a fisher from catching the same amount of hake in four days that they previously caught in five, López said. Oceana is campaigning to fix this problem, but member states in the Mediterranean are reluctant to implement catch limits.

Fishing effort restrictions for certain species in the western Mediterranean equate to a fishing reduction of 30% over five years. Mediterranean hake have been showing small signs of recovery, but it’s far too early to celebrate. Some Mediterranean hake stocks are so precarious that that even a 30% reduction won’t be enough to ensure the species’ recovery, López said.

The Food and Agriculture Organization of the United Nations (FAO) takes a similar position, recommending improved management plans for hake and other depleted species in a recent report. Earlier this year, Oceana urged fisheries ministers to make good on their previous promises to fight illegal fishing and protect vulnerable ecosystems and essential fish habitats in the Mediterranean and Black seas.

The success of northern hake has proven it’s possible to restore fisheries to their former abundance – often in just 10 years or less – but the longer policymakers wait to take action, the harder it gets.

Nowhere to go but up

According to scientists, northern hake have become so plentiful and so dense that they’ve outgrown their usual territory, prompting them to swim further north in search of space. This has led them to areas they haven’t frequented since the 1950s, including the uppermost part of the North Sea.

“We don’t have estimates of the population’s status at that time [in the 1950s], so we don’t know whether the population was at a similarly high level or higher, but we do know that there were large catches taken from the northern North Sea, and there were a lot of hake in the North Sea at that time,” Fernandes said.

This means that northern hake are not expanding into new areas; they are merely returning to old ones as their population surges. While hake’s increased abundance is an encouraging sign, its renewed presence in the northern North Sea has highlighted the failings of fisheries management in that region.

According to Fernandes, quotas for Northern European countries were modeled after fishing patterns in the 1970s. This was the period when hake were absent from many of the areas they’ve since returned to, so the quotas for hake were – and still are – small.

When fishers in these areas catch haddock, cod, and whiting, for which they have a quota, they also catch hake, for which they have little or no quota. Considering that these are mixed fisheries with multiple species managed under one plan, the current framework limits opportunities for fishers to catch other species when hake turn up in their nets.

“The high increase in biomass in the north has produced a mismatch between the biomass and catch quotas available,” said senior researcher Dr. Dorleta Garcia of AZTI, a marine and food technology research institute in northern Spain. “This has led to an increase in discards in some countries.”

When the quota for hake is reached, the entire mixed fishery should theoretically be closed to prevent the quota from being exceeded and the fish from being discarded, but this has not occurred. Instead, illegal discards persist, potentially posing significant risks to the status of the stock.

“Decisive steps must be taken to introduce robust controls and remedy the current poor implementation of the discard ban,” López said.

Other possible solutions could include updating the hake quotas in those countries or devising better technology and fishing gear. Some researchers are using industry data to map out “hot spots” of various species, with the ultimate goal of enabling fishers to access this information in real-time.

Fernandes is working on a “Smartrawl” capable of capturing underwater images to determine the size and species of an animal. This information is then passed to a gate which allows the trawl to be opened or closed, bringing wanted species in or letting unwanted species out. Once developed, the Smartrawl has the potential to reduce bycatch of hake as well as other species, including endangered charismatic megafauna like sharks, sea turtles, and dolphins.

In the meantime, Oceana continues to monitor northern hake, advocating for catch limits in line with the best available science. Though northern hake are a success story – proving that effective management can bring fish back – the work is never finished. Fisheries management is a constant battle of ensuring that catch limits adapt to any population or environmental changes.

“We are always trying to push the EU and UK to implement the highest possible standards, and sometimes we succeed,” López said. “After all, when you have access to the best scientific advice in line with MSY, why not use it?”

This article appeared in the Winter 2021 issue of Oceana Magazine. Read it online here.