Navigation Links
Grazing snails rule the waves

Coral reefs and seashores largely look the way they do because large fish and urchins eat most of the seaweed that might otherwise cover them, but a major new study has found that the greatest impact of all comes from an unexpected quarter small marine snails.

The study published in the journal Ecology Letters is the largest of its kind ever undertaken into the ecological impacts of marine grazing animals: it was led by Associate Professor Alistair Poore, of the UNSW Evolution & Ecology Research Centre, who worked with an international team of 10 researchers.

It found that, on average, marine herbivores remove almost 70% of the plant material growing on the sea floor an effect far greater than grazing animals have on land plants.

"We found that across the globe marine herbivores profoundly reduce the abundance of marine plants, with the strongest effects in rocky seashores," says Poore.

"Icons like the Great Barrier Reef would look very different otherwise: the corals and rocks are usually free of seaweed, but that's only because animals eat all the plants as soon as they grow.

"Big animals such as fish and urchins have major impacts on reefs and kelp forests but what may surprise many people is that we found that the strongest impacts of all were snails controlling seaweeds on rocky shores."

The study team analysed results from over 600 experiments, conducted over the past 40 years across the planet, where ecologists have experimentally removed herbivores to understand their importance in structuring marine habitats.

Manipulating animals in their natural habitats is the most powerful technique to understand how ecological interactions work, they note.

"When these grazing animals are removed, the seaweeds quickly start to dominate," notes Poore. "One of the exercises we give our students to illustrate this is to visit a rocky shore at Sydney's Maroubra Beach and remove all the snails from a selected area. When we return a few weeks later, the rocks are covered in green seaweed."

Of particular interest to ecologists is the team's finding that the global data set rejects the long-standing idea that herbivores in the sea and on land have stronger impacts on plants in the tropics.

"For decades, ecologists have believed that biological interactions like predation or herbivory are more intense in the tropics compared to temperate areas," says Poore. "But we found no evidence of stronger herbivory close to the equator, nor increased herbivore impacts with increased temperature. Despite expectations, grazing on coral reefs did not have larger impacts than in several other marine habitats."

The study also found that in some ways, marine plants are winning the long evolutionary battle with their herbivores. Some groups of seaweeds and seagrasses can avoid herbivore damage with the help of chemical or physical defences or because they are poor quality food.


Contact: Bob Beale
University of New South Wales

Related biology news :

1. Grazing management effects on stream pollutants
2. AgriLife research: Multi-paddock grazing is superior to continuous grazing
3. Grazing as a conservation tool
4. SU biologist partners with National Park Service to study bison grazing in Yellowstone
5. How grazing lands influence greenhouse gas
6. ARS scientists study effects of grazing on grouse habitat
7. Alperujo -- a beneficial complement in diet of dairy sheep during non-grazing periods
8. Grazing animals help spread plant disease
9. Sea snails help scientists explore a possible way to enhance memory
10. In bubble-rafting snails, the eggs came first
11. Research into molluscan phylogeny reveals deep animal relationship of snails and mussels
Post Your Comments:
(Date:4/26/2016)... India and LONDON ... Infosys Finacle, part of EdgeVerve Systems, a product ... and Onegini today announced a partnership to integrate ... solutions.      (Logo: ... to provide their customers enhanced security to access ...
(Date:4/15/2016)...  A new partnership announced today will help ... in a fraction of the time it takes ... life insurance policies to consumers without requiring inconvenient ... Diagnostics, rapid testing (A1C, Cotinine and HIV) and ... weight, pulse, BMI, and activity data) available at ...
(Date:4/13/2016)... April 13, 2016  IMPOWER physicians supporting Medicaid patients ... a new clinical standard in telehealth thanks to a ... the higi platform, IMPOWER patients can routinely track key ... body mass index, and, when they opt in, share ... visit to a local retail location at no cost. ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016 Houston Methodist ... the Cy-Fair Sports Association to serve as their ... agreement, Houston Methodist Willowbrook will provide sponsorship support, ... connectivity with association coaches, volunteers, athletes and families. ... the Cy-Fair Sports Association and to bring Houston ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... today announced the launch of the Supplyframe Design Lab . Located in ... to explore the future of how hardware projects are designed, built and brought ...
(Date:6/23/2016)... Andrew D Zelenetz ... Published recently in Oncology ... touchONCOLOGY, Andrew D Zelenetz , discusses the ... is placing an increasing burden on healthcare systems ... With the patents on many biologics expiring, interest ...
(Date:6/23/2016)... , June 22, 2016  Amgen (NASDAQ: ... the QB3@953 life sciences incubator to accelerate ... The shared laboratory space at QB3@953 was created to ... key obstacle for many early stage organizations - access ... the sponsorship, Amgen launched two "Amgen Golden Ticket" awards, ...
Breaking Biology Technology: