Protecting sharks to save the Mediterranean Sea

The main threat to shark populations in the Mediterranean is overfishing, even if not targeted. Unlike most species affected by overfishing – about 75% of Mediterranean stocks are overexploited – sharks and rays are generally not the actual target of fishers. Nevertheless, many are caught accidentally. Accidental catch (bycatch) refers to the capture of a species unintentionally caught together with target species during fishing operations, regardless of whether or not they end up on the market. This term may apply to other landed commercial species, non-landed commercial species (because they are too small or damaged), non-commercial species, and endangered, vulnerable, or rare species – as is the case for many sharks and rays. All these species, if discarded at sea, are defined as “discard."

Monitoring of catch rates in the Southern Adriatic

Between July and November, over the period from 2019 to 2021, a total of 174 fishing days were monitored, mainly in the northernmost area of the Southern Adriatic. The results showed that, on average, between 1 and 2 blue sharks are caught per 1,000 hooks, and that blue sharks account for an average of 15% of the total landings (roughly one blue shark for every seven swordfish landed). 

Most of the blue sharks caught accidentally measure between 150 and 170 cm, typical of young females and adult males. Sharks of this size are also the ones most commonly landed; smaller individuals (under 150 cm) and larger ones (over 200 cm) are generally released, as they are either not marketable or too difficult to handle, respectively.

How to reduce bycatch by modifying fishing strategies

Bycatch mitigation strategies include modifications to fishing gear and/or fishing practices. Initial tests have shown that the use of circle hooks improves the condition of animals at capture, while reversing the timing of fishing activities from night to day reduce bycatch to zero in the Southern Adriatic. The implementation of all mitigation measures depends on the collaboration of fishers, and further testing is needed to assess the impact on swordfish catches. The shape of the hook used can affect the capture of vulnerable species. Traditional J-shaped hooks are known for high bycatch rates of threatened or protected species, whereas replacing them with C-shaped circle hooks has proven particularly effective in reducing incidental captures of sea turtles, although evidence on their effectiveness for elasmobranchs remains mixed. 

Satellite tagging data have also revealed that blue sharks show a very stable pattern of vertical movement: during the day they prefer swimming at considerable depths, down to over 600 m, while at night they hunt near the surface, even at the water’s edge. This information was key to designing a mitigation strategy based on reversing the timing of fishing operations. Consequently, two types of tests were carried out between August and November 2021: circle hooks and reversal of the fishing strategy. 

The comparative test between traditional hooks and circle hooks demonstrated that circle hooks do not directly reduce the number of sharks accidentally caught, but they do improve their condition at capture, thereby increasing the chances of survival after release (a higher percentage of healthy animals caught on circle hooks, versus a higher percentage of weakened animals caught on traditional hooks). 

Tests of reversal of the fishing strategy proved more effective at reducing the number of blue sharks caught. Under normal fishing operations, longlines are set at night, when sharks swim close to the surface. During the test, longlines were set during the day, when blue sharks remain at greater depths. On fishing days when this strategy reversal was implemented, blue shark bycatch was reduced to zero.

What You Can Do!

The choice to consume certain seafood products has consequences not only for your health but also for the Planet. With just a few simple actions, you can help safeguard sharks and rays around the world. 

Our tips: 

• Avoid buying and eating shark and ray meat: to date, only a very small number of products on the market come from sustainable fisheries. 

• Look carefully at the labels on the fish you buy (by law, they must be traceable and labelled) and familiarize yourself with the names of different species: blue shark, catshark, and smooth-hound are all types of sharks. 

• Avoid products without labels, or with incomplete labelling, as they cannot be identified or traced. 

• Learn about the risks linked to regular consumption of shark meat: some species, such as blue sharks, contain persistent organic pollutants and heavy metals – including mercury – at levels above EU recommendations for human consumption. 

• Do not purchase beauty or health products that contain squalene – it may be derived from shark liver oil. 

• Do not buy souvenirs or other items containing shark parts, such as teeth. Sharks are generally not fished for this purpose, but buying these items may still support unsustainable fishing. 

• If you fish recreationally, release any sharks and rays you catch accidentally, following international guidelines you can also find here: SafeSharks 

• If you spot sharks or rays, take photos or videos and share them with WWF! You will help us not only to map these species but also to raise awareness among others. 

• When traveling, choose tour operators that run snorkelling and diving activities in ways that are sustainable for elasmobranchs.