Increase in dead seals due to fishing nets and cannibalism
An increase in the number of dead seals washing ashore in counties including Wexford, is being blamed on fishing nets and cannibalism within the seal population.
A survey by the Irish Seal Sanctuary began in 2012 with the support of the public who were asked to record the location of dead seals and to take photographs of the scene.
As part of the non-scientific survey, some post-mortem studies at University College Dublin identified injuries believed to be consistent with older bull seals attacking young members of the grey seal population.
The phenomenon may be responsible for injuries previously thought to have been caused by propellers.
In a dead seal database report covering the two years up to May 2016, the Irish Seal Sanctuary said that 104 carcasses were washed ashore in 77 cases reported to it by the public.
The numbers were down slightly from 171 dead seals recorded in 140 reports in the previous two years.
The latest report includes cases notified to the seal sanctuary from 13 counties with the biggest number of carcasses found in counties Dublin (26), Cork (19), Wexford (12) and Waterford (11).
While numbers showing evidence of being entangled in fishery nets were small, the report said a separate study of mammals caught in tangle nets showed much higher seal numbers than those reported to its survey. This indicates only a portion of seals caught in nets washing ashore.
It was not possible to tell if the litter entanglements happened before or after the seals died.
The database of dead seals showed the highest numbers in Waterford and Wexford were found in December and January which may or may not be coincidental to inshore herring and sprat fishery happening at the same time, the seal sanctuary said.
The two main seal species in Ireland, the common and grey seal, are protected under the country's wildlife laws.