Some of Scotland’s sea trout stocks are in danger of being wiped out, unless the government acts quickly to improve both understanding and management of this elusive form of trout, according to leading scientists.
The 1st International Sea Trout Symposium took place in Wales last month – and its conclusions make grim reading.
Pointing out that sea trout stocks in certain areas have collapsed the Symposium convenors stated that: “Continued neglect of the science and management of this species….could threaten yet another valuable natural resource.” They called on governments and all stakeholders to stop taking this species for granted, and act now to protect and conserve stocks.
Sea trout fisheries may, according to the Symposium, offer even greater socio-economic benefits than those based on salmon. These shy and elusive fish also represent a ‘biological barometer’ par excellence in terms of monitoring the health of our ecosystems.
However, the Symposium lambasted current management of sea trout fisheries as “poorly formulated and inadequately protective.” Not only are stocks at risk from illegal fishing and injudicious stocking, but also from the adverse impacts of marine aquaculture.
“We know far less about sea trout than we do about wild Atlantic salmon,” commented Sea Trout Group spokesperson Fiona Cameron. “These amazing fish live in our coastal waters rather than travelling to the northern ocean to feed as the salmon do. Yet there are enormous gaps in our knowledge about exactly where they feed, and their territorial ranges.”
Even less is known about the precise nature of the biological and environmental triggers which mean that some trout spend their whole lives in fresh water as brown trout, while others migrate to salt water and become sea trout – though the Symposium heard that great advances are now being made in understanding this process.
“Many of the formerly abundant sea trout fisheries on the north west coast of Scotland and in the Northern Isles have collapsed over recent years,” said Ms Cameron. “While we accept that various environmental factors have contributed to this situation, we believe that increased infestation of the fish by sea lice from salmon farms is still a major problem – and one which it is within our means to control.
“The present situation, where no official body has responsibility for monitoring or policing sea lice management strategy or containment of farmed fish is unsustainable. A prestigious international Symposium, attended by 150 delegates from 15 countries, has concluded that the record of governments and agencies in protecting sea trout stocks has been lamentable.
“We have major concerns over the impact of sea lice, and also the adverse genetic effect of the large numbers of farmed fish which escape from cages – more than a third of a million fish in the last year for which there are published statistics. When these escapees find their way into rivers, they can interbreed with wild trout. This can lead to hybridisation which is essentially wasteful, as nearly all of the progeny are sterile.
“It is absolutely necessary that sea cage farming is controlled in a sustainable and accountable way. By doing this, we can lay an essential part of the groundwork to help rebuild wild fish stocks in the areas which have seen the most dramatic decline and promote the revival of valuable traditional fisheries. The Scottish Executive has the opportunity, in the forthcoming legislation on aquaculture, to show the way ahead in terms of regulating the impact of sea cage fish farms on our native wild fish, particularly sea trout.”
Ms Cameron added that the Sea Trout Group endorses the Symposium delegates’ call for substantial allocations of funding for research on sea trout stocks, and how they can best be managed.
“This is one of Scotland’s most characteristic and interesting native fish capable of supporting a lucrative angling sector, and yet we know far less about it than we do about many of our other animals. The sea trout is part of our heritage, and we should do everything within our power to ensure that we know how best to support and conserve stocks,” she said.
FISHINGmagic Note
(1)The 1st International Sea Trout Symposium was held at Cardiff University, Wales, from 6th – 8th July 2004.
(2)The native European trout represents a unique combination of life history diversity and range of habitat use in freshwater, estuarine and coastal waters. Although scientists are beginning to understand what causes some trout to migrate to salt water and become sea trout, a full understanding of this process is hampered by the lack of research funding.
(3)Catch statistics for sea trout are notoriously unreliable, with large gaps in the data. Much of this is due to the fact that automatic fish counter systems are normally unable to distinguish between sea trout and salmon. This means that baseline statistics on sea trout stocks are not available or dependable, making management plans difficult to develop.
(4)The formal proceedings of the Sea Trout Symposium will be published in 2006.
(5)The Preliminary conclusions of the Symposium will be presented to the Diadromous Fish Committee of ICES (The International Council for the Exploration of the Sea) this autumn.
