Loss of rare species can harm ecosystems

Mar 19, 2012 By Lori Lennon
Matthew Bracken, assistant professor of biology, surveys biodiversity along a rocky shore in Nahant. Credit: Michael Hutson.

(PhysOrg.com) -- Here’s another reason to cheer for the little guy. A new study co-authored by Matthew Bracken, assistant professor of biology in Northeastern’s College of Science, has found that rare species from the bottom of the food chain can have a large impact on an ecosystem’s health.

The findings were published in March in the online edition of the scientific journal Ecology Letters.

Bracken and Brown University student Natalie Low conducted several experiments that analyzed the impact of removing seaweed and sessile animals, such as mussels and barnacles, from the rocky shores of Northeastern’s Marine Science Center in Nahant, Mass. The experiments were designed to mimic naturally occurring changes in biodiversity on rocky shores.

The findings were startling. “We have shown that the loss of these extremely rare species — which collectively represent less than 10 percent of the seaweed and animal biomass at the base of the food web — causes major declines in the abundance and diversity of animals, such as snails, crabs and other mobile animals,” Bracken said.

Prior research on the extirpation of rare species from a particular ecosystem focused on how the loss of top predators — often referred to as “keystone” species — affects plants and animals at the bottom of the . Bracken and Low, on the other hand, have shown that the loss of from the base of the food chain, which they call “cornerstone” species, can also reshape marine systems.

A pattern of decline emerged after only three weeks of experiments and persisted for the remainder of the five–week study. “Previous work on the effects of rare predator removals took months to years to show strong effects,” Bracken said. “We found strong effects of rare seaweed removals after only a few weeks.”

Explore further: Big science from small insects

add to favorites email to friend print save as pdf

Related Stories

A call for an evolved understanding of emotion

Jan 04, 2012

(Medical Xpress) -- Many scientists believe that all people experience and express the same biologically “basic” emotions — an idea they have attributed to evolutionist Charles Darwin and one ...

The grass is always greener

Aug 19, 2011

(PhysOrg.com) -- Recent study of grasslands shows that species variety more important to ecosystem services than previously thought.

Researchers find a keystone nutrient recycler in streams

Jun 28, 2011

(PhysOrg.com) -- Researchers from the University of Georgia Odum School of Ecology have found that certain neotropical stream ecosystems rely almost entirely on a single fish species known as the banded tetra ...

Recommended for you

22 elephants poached in Mozambique in two weeks

11 hours ago

Poachers slaughtered 22 elephants in Mozambique in the first two weeks of September, environmentalists said Monday, warning that killing for ivory by organised syndicates was being carried out on an "industrialised" ...

Pakistan releases smuggled turtles into the wild

17 hours ago

Pakistani officials and environmentalists on Monday released some 200 rare turtles into the River Indus after the reptiles were retrieved from a southwestern Chinese town where they were seized by customs ...

Big science from small insects

22 hours ago

Anniversaries are often a time to look back. But after taking stock of the past, it can be just as important to look to the future.

Dwindling wind may tip predator-prey balance

Sep 19, 2014

Bent and tossed by the wind, a field of soybean plants presents a challenge for an Asian lady beetle on the hunt for aphids. But what if the air—and the soybeans—were still?

User comments : 0