Up to 320,000 seabirds a year are being killed worldwide each year by being caught up in fishing lines, according to a study being presented to the World Conference on Marine Biodiversity on Tuesday.

Some species and populations of albatross, petrels and shearwaters are being pushed to the edge of extinction because many fishing fleets are not taking simple measures to prevent birds chasing bait, experts will warn.

Some fleets have drastically cut the carnage though methods such as bird-scaring lines and weighting of hooks. But others are failing to monitor the problem or implement steps that could reduce the problem to "negligible proportions", according to authors of a study that is attempting to set a global baseline against which progress could be measured.

Much of the available data is poor, say researchers from the RSPB and BirdLife International, whose work for the global seabird programme will be discussed at Tuesday's conference in Aberdeen. They say that information is absent on bird deaths around Iceland, the Faroe Islands and Norway, distant Asian fishing grounds and the Mediterranean.

Their estimates of bird deaths range from about 160,000-320,000, with the Spanish longline fleet fishing the Gran Sol grounds off south-west Ireland potentially killing more than 50,000 birds a year (mostly shearwaters and fulmars), and the Japanese tuna fleet killing 20,000 birds a year, seriously affecting albatross populations.

Orea Anderson, policy officer for the programme and lead author of the study: "It is little wonder that so many of the affected seabird species are threatened with extinction – their slow rate of reproduction is simply incapable of compensating for losses on the scale this study has demonstrated."

Co-author Cleo Small said: "Using simple bird-scaring lines and weighting of hooks as they enter the water could dramatically reduce the number of seabirds being killed.

"With the UK's overseas territories in the south Atlantic holding a third of the world's breeding albatrosses, the UK has a major responsibility to ensure seabird-friendly fisheries. As for the EU, the findings of this review places a heavy onus on the forthcoming EU plan of action for seabirds to deliver a robust set of remedial measures capable of reducing the impact of longline and other fisheries on seabird populations."

Some successes in reducing seabird deaths have been achieved, including around South Georgia in the south Atlantic, where tough measures are said to have brought about a 99% reduction. South Africa achieved an 85% drop in its foreign-licensed fleet in 2008, and, Brazil in April passed a law requiring stringent bycatch measures in its domestic tuna fleets.

The Albatross Task Force, set up by Birdlife International and the RSPB, is also working on mitigation measures with the fishing industries in South Africe, Namibia, Brazil, Uruguay, Argentina, Chile and Ecuador. Steps include dying fish bait blue to make it less visible to birds; setting lines at night when birds are less active; or setting them deeper underwater, through chutes; and controlling discards of unwanted fish.