Seals and Tasmanian Aquaculture

There is no question that seals are a serious potential problem for fish farms. There is also no question that relocating or killing seals is a bad response.

To a Tasmanian seal, whether it is a New Zealand fur seal or an Australian fur seal, farmed salmon is like a cross between a Big Mac and heroin, (although salmon may be a healthier food choice than a Big Mac).

Seals love to eat big, fat, slow, tasty, farmed salmon. Fish farmers hate to feed their fish to seals. Fair enough. The solution is simple. Keep the seals away from the farmed fish with effective cage technology. It makes sense and is a practical thing to do. 

For many years this fact seemed to escape the notice of Tasmanian fish farms. Instead of dealing with the basic problem, they implemented band-aid solutions, including trapping and relocating seals. The mammals were even killed – supposedly to protect divers or other farm workers, rather than the farmed fish, interestingly enough.

There are obvious animal welfare issues associated with relocating or killing protected animals such as seals. Recreational and commercial fishers claim that relocated seals become accustomed to people and associate boats with a free meal. For many years, both sectors have been calling for the practice of relocation to be stopped.

I have dived with thousands of seals over the last 36 years and I have encountered a variety of seal species. I have dived with seals in all southern states of Australia as well as in other countries, including the UK, Ireland, Canada, Argentina and Antarctica. I have dived with leopard seals in the Antarctic – a species that has actually attacked and killed divers – and Steller sea lions, which are the largest eared seal, growing to well over 1000kg, who make our local species look like kittens in comparison. I have also made dives with so-called problem or threatening seals, at the invitation of the aquaculture industry here in Tasmania. I think I have enough experience to make a judgement about the risks seals pose to divers and other fish-farm workers.

Many of the concerns are due to misinterpretations of seal behaviour. Just because a big seal zooms up to you does not mean that it is being aggressive or going to attack. It is understandable that people get anxuious about close encounters with seals, but unfounded fears are not a good reason to harm innocent animals. Personally, I would be much more concerned about the sharks that are attracted to fish farms than about any seal.

However, seals are big animals with big teeth. You do not want to get bitten by a seal, just as you don’t want to get bitten by a big dog (or most other animals). Usually the seal just eats some fish or bites a hole in some cage netting. Some people claim that seals pose a real threat to divers or other fish-farm workers. Seals who are sunning themselves on fish cages or other farm structures can get territorial, and there have been a couple of instances of people being bitten.

A view held by some in the aquaculture industry is that relocation and killing ‘problem seals’ is necessary to protect workers. In my view, if anyone was actually seriously injured by a seal on a fish farm, killing or relocating seals would not be a good enough solution: it fails to deal with the fundamental issue, and the company might be open to litigation if it had not done all that could reasonably be expected to prevent a recurrence.. Relocating or killing ‘problem seals’(if there is such a thing), is done after problems have become apparent, which may be too late to prevent anyone being bitten.

A better solution is to stop seals hanging around fish farms in the first place. Stop them having access to areas where they can get out of the water to bask in the sun and, most important of all, stop them having access to farmed fish to eat. If they couldn’t access any food at fish-farms, most seals would not bother to stop and there would be almost no risk of any sort of unwanted interaction.

Technologies exist to keep seals away. Laws protecting marine mammals in the US are probably even stricter than in Australia, so farms had to find alternatives to killing seals, and they did. Fish farms in Washington State in the US, for example, had been doing this for a long time when I visited a farm there in 1997. I kept informing the Tasmanian Government about these facts for years, sadly without any impact on public policy. Our state government still allows seals to be killed and relocated.

The key to keeping seals away from farmed fish is having secure cages with netting that actually keeps the seals away from the fish. Fish handling practices can also play a role, and care must be taken to ensure that fish are not lost during fish transfer operations.

Three of the big four Tasmanian fin-fish aquaculture companies already have technologies that appear to work well to exclude seals. Huon Aquaculture and Tassal have actively developed excellent cage technologies that protect fish and exclude seals. Van Diemen Aquaculture in the Tamar already uses system cages that offer good protection. Petunia is based in Macquarie Harbour where seals are not very abundant, and so far the farms appear to have avoided the attentions of seals.

Educating workers about normal seal behaviour, and better work and fish-handling practices, should reduce anxiety and unwanted interactions, although in my experience most farm workers are already well aware of these issues.

Another good reason for aquaculture companies to employ better technologies and procedures is that Australian consumers will not accept the killing of seals as a normal part of raising farmed fish. There would be a public backlash if the Tasmanian aquaculture industry started to kill seals on a regular basis. Tasmanian salmon growers mainly supply a domestic market where considerations of marine mammal welfare are important.

Seals are smart animals and many have learned to associate fish farms with food over a long period of time. This learned behaviour would not disappear overnight, even if appropriate cage technologies and fish-handling practices were used throughout the industry. There is currently an opportunity to break the link between seals and farm cages, but a united industry-wide approach. The Tasmanian Government should be encouraging this. Instead, its seal management strategy has resulted in normally protected seals being deliberately killed with government approval for no good reason.

The Tasmanian Government should scrap specialised regulations that allow seals to be killed on fish farms. Other legislation allows protected animals to be killed if they represent a threat to human safety. The government should ensure that fish farms are obliged to prevent seals from accessing fish or using farms structures as haulouts, and should aim for a consistent approach across the industry.

In the future, market forces in Australia will work to protect seals. Seals do not have to die so that fish can be farmed in Tasmania.

Jon Bryan
Marine Campaigner