Are there sharks in the River Thames?

Whilst there have been sightings of fins peaking out of the water along points of the river Thames, these are more likely to belong to dolphins or porpoises who sometimes head upstream in search of food.  

Freshwater can be deadly to a shark – many can only exist in seawater, which means that they wouldn’t be able to travel far up the river Thames without becoming unwell.  

Our volunteer crew have never reported any shark sightings, but we do however, have some interesting wildlife that stop by at our moorings at Canbury Wharf, Kingston, including this gorgeous seal we nicknamed Ron that stopped by to say hello.  

Our new friend Ron the seal stopping by our moorings in Canbury Gardens, Kingston. 

However, there are a handful of sharks that have adapted to freshwater. These are categorised under the genus ‘Glyphis’ meaning river sharks, and some are named after well- known rivers like the Ganges Shark, the Borneo River Shark, or others like the Bull shark (also known as the Zambezi shark) which has adapted to survive in both fresh and saltwater conditions.  

Fortunately for the galeophobics amongst us, there is no such things as a Thames shark, but there are up to five species of seawater shark that swim in the waters of the Thames Estuary, one of the largest estuaries in the country, where the Thames meets the sea.  

Shark species that can be found in the Thames Estuary include the critically endangered tope shark or ‘soupfin’ shark and starry smoothound shark (named for the bright white spots that adorn its back that resemble stars); and the Spurdog Shark. It’s believed that Tope and Starry sharks both use the Estuary as a nursery and birthing area for their young.   

The Zoological Society of London are working with anglers in the Thames Estuary area to understand how significant the Thames Estuary is as a habitat for these sharks. The research will be used to ensure their long term survival in the wild.  

There are many endangered species that have made their home along the River Thames at various points, including the critically endangered European eel. Although their birthing grounds are in the Sargasso Sea, this species spend most of their lives inhabiting rivers and can spend up to 20 years in estuaries such as the Thames feeding and maturing.  

Every year young eels known as elvers arrive from the Sargasso Sea and swim en masse up the river Thames, sometimes called the elver run. This journey is hindered by the many barriers on the river, including weirs, which can stop or slow down their migration and is one of the contributing factors that has caused their endangerment. The population of their upstream migration, so vital in the lifecycle of this species, is a mere 10% of what it used to be since before the 1980s.

European eels spend most of their lives maturing and feeding in riverways.  

There has been a lot of conservation work to remove these barriers, removing redundant river structures, and adapting weirs and sluices that cannot be moved to ensure the migration can take place with minimal hindrance.  

Eel and fish passes have been introduced at many of the weirs and sluices along the River Thames and its major tributaries, to ensure that wildlife can pass through these obstacles and continue on their migratory path.  

Just 200 years ago, during the peak migration period, there were 1800 eels passing by Kingston bridge per second! Numbers have sadly dwindled due to migratory obstacles and over-fishing. 

Whilst eels may not be the most attractive fish, they are incredible animals. Unlike other fish, they are not reliant on the use of their gills – they can absorb oxygen directly through their porous skin. This provides them with the ability to travel across land in search of more water and food. 

Our School on the River education days take place at Teddington Lock and cover a range of topics including the biodiversity of the River Thames, and the many conservation and environmental projects that take place there too, inspiring future generations to care about our riverways.  

To learn more about our education activities and how to book a trip, head over to our webpage here:

https://thamesboatproject.org/educational-activities/

Or get in touch with us here:

https://thamesboatproject.org/contact-us/

Schoolchildren learning about reusable and recyclable materials on the riverside.