The following information addresses some misconceptions that can arise with our understanding of the relationship between seals and the fishing industry. Seal populations continue to be slow to recover from a long history of sealing. Consequently, all species of seal in Tasmanian waters are protected. For full details of the species of seal found in Tasmanian waters, see our web pages on
seals.
A Population Explosion?
Contrary to sensationalist media reports, there has not been 'an explosion in seal numbers'. What is often interpreted as a 'plague' or a huge increase in the seal population is actually late summer migrations of seals from Bass Strait to southern waters. At the end of the breeding season, while females remain at the colonies to feed their pups, adult males and non- breeding animals migrate south, occupying haul-outs along the coast.
Observation of seals at different sites often leads to the mistaken idea that numbers are growing fast - in fact, the population recovery of Australian fur seals continues to be slow.
Do Seals Threaten Fisheries?
It's a popular misconception that seals eat 'twice their bodyweight of fish' per day. In fact, seals eat no more than 10% of their body weight in fish, squid, octopus and cuttlefish per day. Fish form a major part of the diet of Australian fur seals with redbait, leather jacket and jack mackerel the major species (see the food web of the seal and the sea below).
Seals have a key place in the marine ecosystem, a natural part of a complex and productive ocean. Some fishermen complain about seals, accusing them of taking all their fish. Occasionally fishermen suggest that seals should be culled and that this will increase fish stocks and there will then be more available for human consumption. However, closer examination of seal-fishery interactions at the ecosystem level suggests that removing or culling seals may in fact be detrimental to fish stocks rather than beneficial. Remove a top predator and the whole system runs the risk of collapse, just like removing a key player from a sports team. Each component of the ecosystem (or each player in the team) has an important role to play. So killing seals may not ensure a greater catch of targeted fish stocks!
We can find a way to share the sea with seals and their predators whilst accepting and appreciating their role.
The foodweb of the seal and the sea.
See also:
Management of Seals Onshore in Tasmania
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