Numbers of seven species of sea duck have dropped by up to 65% in Northern Europe in the last 15 years, including some that winter off the UK’s coasts, particularly long-tailed duck and velvet scoter.
The mysterious nature of sea ducks and the challenges in monitoring their numbers have meant that the situation had gone largely unnoticed.
The UK coast is one key area for sea ducks during winter. Counts at the Scottish estuary the Moray Firth show that in less than a decade velvet scoters have gone from several thousand to less than 100 and long-tailed ducks have plummeted ten-fold, to fewer than 1,000.
Similar declines were reported from the Baltic Sea at the end of 2011, strongly suggesting that these birds aren’t just going elsewhere, they’re disappearing. Whilst smaller species like Steller’s eider have attracted concern since 2000, some of the more shocking recent declines have been among common and widespread populations like the common eider, which has halved since 1993, and the long-tailed duck, which has declined by over 65%.
The causes remain unknown, however, though the widespread nature of the declines has prompted concern that it is linked to environmental change across much of the arctic and sub-arctic regions where most of these species breed.
This week Wildfowl & Wetlands Trust (WWT) conservationists are making the case for Europe’s sea ducks, and calling for international support at a meeting of the African-Eurasian Waterbird Agreement (AEWA).
WWT’s Richard Hearn will set out a strategy to AEWA Parties, asking for their input and support in developing international research and conservation action, that includes international surveys, tracking their migration routes and studies in the breeding areas, particularly Russia
Hearn says: “Till very recently the size and location of the flocks of ducks that live in our shallow seas remained a mystery. Often they’re beyond the horizon, out of sight of land, so you need to get up in a plane just to count them. From these surveys we’re finding that numbers are dropping off the edge of a cliff, yet we still barely understand the basics like their migration routes, breeding success or life expectancy in the wild. ”.
“What is clear is that this problem of rapid decline is widespread. We’re seeing it in the UK and other North Sea regions. And it’s the same story in the Baltic. We don’t want to ignore the proverbial canary in a cage. To address it we need to work at the whole population scale. AEWA has the international framework for doing this, so I’m here to present our plan and appeal for funding and support”.
Sea ducks occur in remote areas in both summer and winter, making their numbers and habits difficult to uncover. This hinders attempts to pinpoint the reasons behind these declines although there is no shortage of suggestions, including changes in nutrient levels of marine waters, changes to predator-prey webs in the arctic, over-fishing of mussels, by-catch in fishing nets, oil spills and changes in levels of predation.
WWT and other conservation institutions want a co-ordinated monitoring and research programme, underpinned by AEWA Single Species Action Plans, as required.
“Without further research and international co-operation, we may miss an opportunity to reverse the decline of these birds.”