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The story of biodiversity conservation often reads as a litany of dashed hopes and lowered expectations: more habitat destroyed, more factors like toxic chemicals and climate change emerging to compound threats, more species sliding toward extinction. But a new study by researchers from the University of Vermont and Duke University points out that there’s good news from the realm of species conservation too, and a lack of attention to conservation successes can actually trigger new problems.

The researchers analyzed population trends of 92 marine mammal species, and found that only 10 percent are known to be declining. Almost half – 42 percent – are increasing, and the remainder are stable (which could itself indicate that they are recovered) or show no detectable trend.

In fact, the last several decades have seen dramatic recoveries of some marine mammal species. The population of humpback whales off western Australia has grown from fewer than 300 individuals in 1968 to 26,000 today. The northern elephant seal has rebounded in the northeast Pacific from as few as 20 individuals in the 1880s to more than 200,000 today, a number that is probably close to their abundance before humans came in contact with them.

But paradoxically, returning marine mammals and other species aren’t always good news to people who have gotten used to their absence. “After generations away, these forgotten species can suddenly be seen as newcomers – or even pests,” says Joe Roman, a conservation biologist at the University of Vermont and the study’s lead author.

Gray seals, for example, have staged a dramatic comeback in the North Atlantic since the 1970s. Some residents of New England coastal towns blame the seals for fouling nearshore waters, attracting white sharks, and decreasing fish populations. In Canada, authorities have proposed killing 70,000 gray seals, purportedly to protect groundfish stocks, even though there is no scientific evidence linking the animals to fisheries declines.

The solution to these conflicts is “lifting baselines,” the researchers propose, meaning making the public aware of successful recoveries and how they relate to the historical population levels of species.

The idea is a play on, and counter to, “shifting baselines,” a term coined by fisheries biologist Daniel Pauly in 1995. That concept originally referred to perceptions of fisheries stocks but has acquired a more general sense, describing people’s tendency to psychologically adapt to degraded ecological conditions and perceive them as normal.

In the new study, the researchers propose four strategies to accomplish lifting baselines. First and foremost, they say, let’s celebrate conservation success stories and make sure the public is aware of them. In addition, conservationists should advocate delisting species that have recovered, both because this creates the public expectation that recovery is possible and because it frees up resources for protecting other species. They should emphasize the broader ecological and cultural benefits of returning species, in order to counter perceptions that these are “nuisance” animals. And they should try to anticipate and plan how to address conflicts with humans or other species that may occur when one species recovers.

Of course, not all endangered species are on the upswing, and there are far more declining species than recovering ones, the researchers hasten to acknowledge (perhaps proving their own point about how difficult it is to celebrate conservation successes when there is so much work left to be done). But looking on the bright side every once in a while isn’t a bad idea.

The other day, I watched a flock of crows harry a bald eagle across the skies over my semi-suburban Seattle neighborhood. I remember the first time I saw a bald eagle, in the late 1990s. It was perched in a snag near the shore of Lake Washington, and I felt astonished and lucky to have glimpsed this icon of endangeredness. But the truth is I’ve lost count of the number of bald eagles I’ve seen since then. So this time, it was fascinating to watch the interaction between the birds, but the fact that a bald eagle was involved seemed rather unremarkable – and that in itself is a remarkable thing. Consider my baseline – and my spirits – lifted. – Sarah DeWeerdt | 9 June 2015

Source: Roman J. et al. 2015 Lifting baselines to address the consequences of conservation success. Trends in Ecology and Evolution DOI: 10.1016/j.tree.2015.04.003

Header image: Gray seals (Halichoerus grypus) at a sandy haulout in Chatham Harbor, Cape Cod during the summer of 2013. Credit: David W. Johnston under permit by NOAA.