Conservation Status

The Great Hammerhead Shark is one of the most iconic and recognizable species on Earth. They are a fascinating species with immense size reaching up to 20ft long and their unique flat elongated head shape. This species is really a marvel of nature and an ecologically important species. Most importantly they are in danger as a population and are rated as an endangered species. According to the IUCN this is a critically endangered species with huge population drops worldwide due to human activity.

The IUCN also states that the population declines reach up to an 80% in population size across their range. The conservation efforts for this species remain very difficult as they travel across international borders so it needs to be a worldwide effort. Their distribution has also decreased due to fishing pressure which makes sightings and also studying much more difficult.

Why Are They In Danger?

Speaking of fishing pressure, the shark fin trade is a huge part of the extreme fishing pressure this species experiences and greatly contributed to the decline of their population. Their large dorsal and high fin content make them a key target for shark fin soup which is sought after in Asian countries. This in combination with bycatch typically from gill net and longline operations as they swim in midwater which puts them right in the range for this type of fishing operation has severely depleted the population. Scientists have also found that even if they are released their survival rate after release is especially low which makes bycatch extra harmful for this species. 

The Great Hammerhead also doesn’t rehabilitate quickly as like many other shark species with their large size and apex predator status reproduction is costly and slow moving. They grow slowly from juvenile and have a late reproductive maturity meaning they need to survive longer to be able to reproduce. This in combination with the long gestation periods and few reproductions per female makes it difficult for them to keep up with a high mortality rate.

Why Is This Important.

Knowing all of this about them it is important to also understand why they are so important as sharks are often put into a box of scary predators. They are apex predators worldwide across many ecosystems and that is an important role. They make up the top of the trophic ladder consuming middle-predators like rays which limit populations. Without these apex predators there could be a top down trophic cascade which would allow mid predators to overpopulate and then likely eat too many prey and producers and then starve themselves.

Sources:

Secretary of Commerce, Acting Through the National Oceanic and Atmospheric Administration and the National Marine Fisheries Service. (2012). https://media.fisheries.noaa.gov/dam-migration/great_hammerhead_petition_2012-accessible.pdf

Great Hammerhead Shark. (n.d.). Oceana. https://oceana.org/marine-life/great-hammerhead-shark

CREATURE FEATURE: GREAT HAMMERHEAD. (2022, January 5). The Shark Trust. https://www.sharktrust.org/blog/creature-feature-great-hammerhead

(2017, May 18). Great Hammerhead Sharks | MarineBio Conservation Society. MarineBio Conservation Society. https://www.marinebio.org/species/great-hammerhead-sharks/sphyrna-mokarran

The Great Hammerhead Shark. (n.d.). Www.mokarran.org. https://www.mokarran.org/en/the-great-hammerhead/

‌NOAA Fisheries. (2022). Tagged Hammerhead Shark Travels Widely In Warm Pacific Waters. NOAA. https://www.fisheries.noaa.gov/news/tagged-hammerhead-shark-travels-widely-warm-pacific-waters