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Tees Seals Project 

This was a record year for the seal colony at Teesmouth. Not only was there a big jump in number of pups recorded (up to 36 from last year’s record of 26) but the peak numbers of both Harbour Seals and Grey Seals were the highest ever recorded.  This was the first year when the combined number of seals of both species that were hauled out at one time exceeded 200 and that happened not once but five times.  When it is considered that it is estimated that only about three quarters of the seals present are out of the water then the number of seals in the Estuary is likely to be over 250, at least on some occasions. 

Harbour seal pub

It is not all good news though.  Many of the Harbour Seal pups have been succumbing to a condition, best described as mouth rot.  This is a condition that has been recorded previously in Harbour Seal pups, but which suddenly became more prevalent around Britain and Ireland a few years ago. Defra-funded research is being carried out into potential causes of this pathology but in the meantime, when added to the natural level of pup mortality that would be expected anyway it means that most pups have died in their first few months.  However even this tragedy has taught us things about the Teesmouth seals.  For example, it was assumed that the very small, year on year increase in Harbour Seal numbers that has been occurring for the past 30 years meant that this was probably a self-contained population with births slightly exceeding deaths.  With small number of pups surviving to contribute to the numbers it means instead that the increase must be due to seals from elsewhere, which are now calling Teesside home.