A seal protection group has raised concerns about the use of a jet ski to scare seals out of the River Dee in order to protect salmon.
The Dee District Salmon Fishery Board has attached an “acoustic startle device” to a jet ski to reduce the number of seals swimming upriver to feast on the fish.
The board has tried other techniques to deter marine mammals from making the journey upriver, such as placing acoustic deterrent devices in the water. However, no approach so far has yielded consistently good results.
Ythan Seal Watch is now questioning the board’s use of a jet ski, claiming statically moored boats fitted with acoustic devices have worked in other rivers, such as Ellon.
Noise of jet ski being used to ‘scare’ them
Lee Watson, who runs the group, explained he is worried the jet ski may cause the protected mammals panic or physical harm.
An acoustic deterrent device (Add) emits a low-frequency sound that would get louder the closer the seal gets to it. Normally, they get to a certain level before they turn around and swim away.
Mr Watson says using a jet ski with an Add attached is not a “fair or safe” technique to use around a wild animal, because the engine will affect the seal before the Add does.
He said: “They’re using the jet ski to corral the seals up the river. Like anything else, it will cause the animal stress.
“The noise of the jet ski is being used to scare them away rather than the Add. We don’t think they’ve got the seals’ best interests at heart using this.
“As far as we’re concerned the noise of the jet ski is the deterrent and that’s not a fair or safe technique to use around a wild animal.”
The seals are in shallow water, so the group fears that being chased and panicked by a jet ski may lead to them being injured by scraping themselves on rocks or stones on the riverbed.
There’s a chance they may even exit the river further upstream and either be too scared to go back into the water or struggle to find their way downstream again.
He also highlighted that jet skis can also have a negative impact on fish, birds and any other animal that uses the river for feeding.
‘Putting their business first’
According to Mr Watson, an Add would normally be placed on a moored boat at a certain point in the river. He says the successful technique is used in other rivers and there have been no reports of seals in the river at Ellon since they started using an Add.
He says the group of conservationists cannot understand why the jet ski is needed to move the Add closer to any approaching seals.
Although they understand the fishery board’s need to protect salmon numbers, the group believes they are only interested in the fish and not the welfare of any other animals.
“It’s a business to them,” Mr Watson explained. “So they’re obviously going to put their business first.”
The group is also sceptical about whether or not the fishery board can identify different seals and know when they might be carrying or with pups.
There is a worry the jet ski might scare younger seals more severely or cause distress to pregnant seals.
Meanwhile, it is only a few determined and adamant rogue seals that make the journey so far up a river, and there could be other factors impacting the salmon numbers.
This has left Mr Watson believing the jet ski is “overkill” and that seals are being used as “scapegoats”.
He finished: “At the end of the day, seals are wild animals, and it is impossible to predict how any independent or individual seal would react to being scared by the noise of a jet ski engine.
“So I don’t see how they can confidently say it causes no harm to the seals.”
The Ythan Seal Watch group wants to watch the trial firsthand to see for themselves the impact it really has on the seals.
‘Slowly’ pushing seals downstream
Although only a small number of seals make the journey upriver, the fishery board is concerned about the impact they are having on struggling salmon population numbers.
The board says it follows protocol to ensure the seals are unharmed and the device is set at a frequency that only disturbs the seals.
Jamie Urquhart, Dee District Salmon Fishery Board’s protection manager, said the jet skis are used to “slowly push” the seals downstream, away from the salmon.
He told the BBC: “It emits a sound which is unpleasant to seals.
“Basically it deters seals and pushes them away from the noise. We slowly push the seal downstream and out of the river.”
Currently, the initiative is targeting the lower parts of the River Dee, particularly downstream of Drumoak.
Conversation