Only 4% of parasites are harmful while the rest play important roles, here's why we need to save them
Parasites, which dwell on other organisms for food and shelter, are considered pesky. But without them, the world could plunge into instability, allowing wildlife populations to multiply as pests, warn scientists in a new study. While some parasites are microscopic, others are visible to the naked eye. An example of a parasitic disease is Malaria, which causes nearly 660,000 deaths each year. However, only 4% of parasites are known to infect humans. The rest are involved in keeping the wildlife population in check, thereby maintaining the natural balance.
But the world is losing these organisms. Dr Skylar Hopkins, from North Carolina State University, tells MEA WorldWide (MEAWW) that parasites face two kinds of threats. First, climate change or habitat degradation could reduce their abilities to survive and reproduce. Second, secondary extinction makes them vulnerable: when endangered species go extinct or rare, so do parasite species that inhabit them, explained Hopkins, who is involved in the study. Experts from across the globe are calling for efforts to save them.
However, there is one main problem: only 10% of parasites are known. They do not receive enough attention from conservation groups either. "I think we neglect parasite biodiversity for several reasons. For example, most people rarely see parasites in the wild, so it is easy to overlook them and to assume they are not particularly common or important. But there are millions of parasite species, and they do play important roles in ecosystems, just like predators do," Hopkins explains.
"If species don't have a name, we can't save them," says Colin Carlson, the other project co-lead and an assistant professor at Georgetown University. "We've accepted that for decades about most animals and plants, but scientists have only discovered a fraction of a percentage of all the parasites on the planet. Those are the last frontiers: the deep sea, deep space, and the world that's living inside every species on Earth."
Scientists chalk out conservation plans
Dr Hopkins and an international team of scientists have charted out 12 conservation goals they hope to achieve over the next decade. Some of the plans include describing half of all parasite species, adding them into global surveys, documenting declines and extinction, protecting endangered parasites, working on outreach activities and training. The plan does not include saving parasites that infect humans or domesticated animals.
To predict how parasites might respond to biodiversity loss, Chelsea Wood, an assistant professor at the University of Washington's School of Aquatic and Fishery Sciences, plans on studying museum specimens of fish to reconstruct the past and record changes — increase or decrease in population — over time.
"These pickled animals are like parasite time capsules," explains Wood, who is one of the authors of the study. "We can open them up and identify the parasites that infected a fish at its death. In this way, we can reconstruct and resurrect information that previously we didn't think was possible to get."
Implementing these plans will come with its fair share of challenges. "Conservation efforts are always challenged by resource constraints, and parasite conservation will be, too. So we recommend that parasite conservation efforts "piggyback" on existing conservation efforts as much as possible," says Hopkins. "Thinking about parasites while conserving hosts could do a lot for parasite conservation." The study is published in Biological Conservation.