Featured Research

from universities, journals, and other organizations

Overfishing of sharks is harming coral reefs, study suggests

Date:
September 18, 2013
Source:
University of Toronto
Summary:
A team of scientists from Canada and Australia have discovered that the decline in shark populations is detrimental to coral reefs. Where shark numbers are reduced due to commercial fishing, there is also a decrease in the herbivorous fishes which play a key role in promoting reef health.

Overfishing of sharks is harming coral reefs.
Credit: Peter Verhoog of the Dutch Shark Society

A team of scientists from Canada and Australia has discovered that a decline in shark populations is detrimental to coral reefs.

"Where shark numbers are reduced due to commercial fishing, there is also a decrease in the herbivorous fishes which play a key role in promoting reef health," said Jonathan Ruppert, a recent University of Toronto PhD graduate. Ruppert was part of a team engaged in long-term monitoring of reefs off Australia's northwest coast.

Team leader Mark Meekan, of the Australian Institute of Marine Science (AIMS), said that the results might, at first glance, seem strange.

"However our analysis suggests that where shark numbers are reduced, we see a fundamental change in the structure of food chains on reefs," Meekan said.

"We saw increasing numbers of mid-level predators -- such as snappers -- and a reduction in the number of herbivores such as parrotfishes," said Meekan. "The parrotfishes are very important to coral reef health because they eat the algae that would otherwise overwhelm young corals on reefs recovering from natural disturbances."

According to Ruppert, the study comes at an opportune time -- coral reefs are facing a number of pressures both from direct human activity, such as over-fishing, as well as from climate change.

The reefs studied are about 300 kilometres off the coast of northwest Australia where Indonesian fishers target sharks -- a practice stretching back several centuries and which continues under an Australian-Indonesian memorandum of understanding.

"The reefs provided us with a unique opportunity to isolate the impact of over-fishing of sharks on reef resilience, and assess that impact in the broader context of climate change pressures threatening coral reefs," said Ruppert. "Shark fishing appears to have quite dramatic effects on coral reef ecosystems.

"Given that sharks are in decline on reefs worldwide, largely due to the shark fin trade, this information may prove integral to restoration and conservation efforts."

Tracking studies show that, in many cases, individual reef sharks are closely attached to certain coral reefs. This means that even relatively small marine-protected areas could be effective in protecting the top-level predators and allowing coral reefs to more fully recover from coral bleaching or large cyclones which are increasing in frequency due to the warming of the oceans as a result of climate change.

The study will appear in the September 28 issue of journal PLOS One.


Story Source:

The above story is based on materials provided by University of Toronto. The original article was written by Kim Luke. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jonathan L. W. Ruppert, Michael J. Travers, Luke L. Smith, Marie-Josée Fortin, Mark G. Meekan. Caught in the Middle: Combined Impacts of Shark Removal and Coral Loss on the Fish Communities of Coral Reefs. PLoS ONE, 2013; 8 (9): e74648 DOI: 10.1371/journal.pone.0074648

Cite This Page:

University of Toronto. "Overfishing of sharks is harming coral reefs, study suggests." ScienceDaily. ScienceDaily, 18 September 2013. <www.sciencedaily.com/releases/2013/09/130918180429.htm>.
University of Toronto. (2013, September 18). Overfishing of sharks is harming coral reefs, study suggests. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2013/09/130918180429.htm
University of Toronto. "Overfishing of sharks is harming coral reefs, study suggests." ScienceDaily. www.sciencedaily.com/releases/2013/09/130918180429.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) — Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Newsy (July 30, 2014) — The Peace Corps is one of several U.S.-based organizations to pull workers out of West Africa because of the Ebola outbreak. Video provided by Newsy
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) — Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins