Should conservationists try to save all threatened species, or do there have to be sacrifices?
In a new book, Tickets For The Ark: From Wasps to Whales - How Do We Choose What to Save?, ecologist and author Rebecca Nesbit explores the moral complexities of conservation, asking what should we conserve, and why.
And in an age where extinction rates are at the highest since the dinosaurs bit the dust 65 million years ago, there are plenty of decisions to be made.
Photo: supplied
While we are losing species at an alarming rate, we must admit that we cannot save everything, Nesbit tells Kathryn Ryan.
“We simply don't have resources at the moment. Some species are going extinct before we've even discovered them.
“So we are going to be forced to choose and for a long time conservation has had various sins to answer for in human rights abuses, even when, for example, people were removed from their native lands to make way for national parks.”
In our decisions of prioritising what to save, we need to also think about what our goals are, Nesbit says.
“I'm going to think of a really classic tradeoff here that's particularly pertinent in New Zealand, is to keep some species still going for years to come. If that species is not going to face extinction in the very near future, then we need to kill large numbers of introduced predators.
“How do we make that decision? Do we want that species to continue or do we want not to have to poison all these individual animals?
“And that's a horrible, horrible choice to have to make but there is no easy answer, and I think my answer to the question about how do we make these decisions, part of that is having conversations, listening to diverse voices, and really thinking about what do we want to achieve and why.”
But the problem is often our emotions get in the way of us realising the importance of preserving unseen bacteria or ugly and infamous creatures, she says.
“I would love to set up a charity saving the horsehair worm and most people think I'm mad. Because we have a natural response of disgust to things like parasites, yet actually they play an incredible role in our ecosystems and are very, very important.”
For example, there are potentially up 2000 species of the horsehair worm and one in Japan has been found to help attract a source of protein for an endangered fish, called the kirikuchi char.
“[The horsehair worm] starts infecting mayfly larvae in a stream and when the mayfly becomes an adult, flies free, it will only live for a day or so before it dies, drops to the ground, that hairworm is still alive, gets eaten by a cricket and goes on to infect the cricket, grow in there, digesting every nonessential bit of tissue.
“But the really neat thing is that it plays with the cricket’s mind, because the hairworm needs to return to the water to complete its life cycle, the crickets are manipulated to become attracted to water.
“The cricket jumps into a stream, the horsehair worm wriggles free and the life cycle continues … so many crickets are jumping into the stream because they've been manipulated by hairworms that this has become a really important food source for this fish.”
Likewise, plankton species in the deep sea lock up the vast amounts of carbon a whale releases when it dies.
“Who thinks of these species? They are definitely underappreciated.”
But thinking about what is good or bad for our ecosystem will vary depending on the location, she says.
“The common wasps that are bringing great benefits in the UK, in New Zealand, can be causing great problems.”
It may also be time to rethink if the European conservation model of "keep everyone, everything out", which New Zealand uses, is working or whether we need to return to a sustainable use outlook, which indigenous societies use, she says.
“In much of the world, areas managed by indigenous peoples are either as good as protected areas or better than protected areas, yet they're receiving much less attention, much less conservation funding.
“So, it is an issue that a lot of what's supposedly protected aren't bringing the benefits, and sometimes they are not bringing the benefits for wildlife but bringing the disadvantages for local people.
“If you don't bring local people on board, if you deprive them of their livelihoods then you can't expect them to go along with the rules that you've made to try and protect this area.”
Societal issues are also very much intertwined with conservation and have a huge impact on the way we shape the natural world, she says.
“I think to some extent, we really, really need to address this issue of consumption and the inequality in consumption, that actually if you lived the lifestyles of many people on Earth, well, we could sustainably keep this level of human population.
“However, most people don't live like that and we can think of, for example, horrendous food waste. There are vast areas of land that are not available for nature because we're farming them and we're simply throwing that food in the bin, so I definitely think a huge amount can be done and needs to be done to minimise our impact.”
