Featured Research

from universities, journals, and other organizations

Microbes, sponges, and worms add to coral reef woes

Date:
August 6, 2012
Source:
Wildlife Conservation Society
Summary:
Microbes, sponges, and worms -- the side effects of pollution and heavy fishing -- are adding insult to injury in Kenya's imperiled reef systems, according to a recent study.

This is a coral sample that shows a large borehole created by a sponge. Sponges proliferate in reefs with high levels of pollution, according to a new study.
Credit: M. Carreiro-Silva

Microbes, sponges, and worms -- the side effects of pollution and heavy fishing -- are adding insult to injury in Kenya's imperiled reef systems, according to a recent study by the Wildlife Conservation Society and the University of Azores.

The authors of the study have found that pollution and overfishing on reef systems have an ecological cascading effect -- the proliferation of microbes, sponges, and worms -- that further degrade corals, a discovery that underlines the complexity of reefs and possible solutions.

The study appears in the online edition of Marine Ecology Progress Series. The authors include M. Carreiro-Silva of the Center of IMAR of the University of Azores and Tim McClanahan of the Wildlife Conservation Society.

The paper examines how human activities can create unexpected complications in coral reef recovery and management. For instance, recent experimental studies by Carreiro-Silva and colleagues in Belize and Kenya demonstrated that a higher nutrient content in coral reefs associated with growing agriculture activity and urbanization increased the rate at which reefs eroded from microbes such as bacteria, fungi, and algae, as well as larger animals like sponges and worms. While the study cites previous work suggesting a faster erosion of reef calcium carbonate with high pollution levels, the experimental manipulations and use of reefs experiencing different levels of fishing and pollution strongly supports those previous conclusions.

An entirely new finding from this research is that worms are major eroders of reefs where fishing is heavy, while sponges play this same role in unfished reefs of the kind found in marine parks. This suggests that it is not only nutrients and pollution that are eroding the reef substratum. Marine consumers like fish and sea-urchins also appear to be influencing species that erode the reef substratum.

In heavily fished reefs, sea-urchins are the dominant grazers, and their grazing activity is so intense that only fast-growing early colonist species such as worms are able to grow inside the reef substratum. The lack of fish may also make these holes a safe haven for worms. In this scenario, worms then take over the role that sponges usually play.

"This change in the roles of worms and sponges shows how the affects of fishing can cascade down even into the hidden crevices of coral reefs," said Dr. Carreiro-Silva of the Department of Oceanography and Fisheries at the University of the Azores in Portugal and the lead author of the study.

In areas impacted with high levels of runoff and drainage from land, such as some of the oldest marine parks in Kenya, researchers have found the highest levels of reef decay; in these instances, the increased pollution produces an abundance of sponges that live in and erode reef cavities.

Dr. Tim McClanahan, senior conservationist for the Wildlife Conservation Society and co-author of the study added: "This problem is outside of the usual control of park managers and shows the importance of maintaining clean waters if reefs are to grow and keep up with the rise in sea levels."

The study authors are concerned about the cascading effects of pollution and overfishing on already stressed coral reef systems. Intensive erosion of carbonates has the potential to undermine reef growth and diminish reef structure over time, an increasing challenge as ocean temperatures and sea levels rise. The authors point out that reducing pollution, the influence of run-off, drainage of highlands and wetlands, and other sources of non-point pollution and land development in coastal areas are critical in conserving the ecological services provided by coral reefs.

Dr. Carreiro-Silva speculates that one unstudied but looming problem is the increased acidification of the ocean that will add to the growing intensity of impacts. Acidification created by increased emissions of carbon dioxide weakens coral skeletons and creates opportunities for species that like to live in hidden crevices and further dissolve the reef structure.

"Ultimately, the synergy between these different impacts may lead to the deterioration and eventual collapse of the reefs unless greater efforts are made to reduce the many sources of pollution and excessive use of coral reefs as fisheries," she added.


Story Source:

The above story is based on materials provided by Wildlife Conservation Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Carreiro-Silva M, McClanahan TR, Kiene WE. Effects of inorganic nutrients and organic matter on microbial euendolithic community composition and microbioerosion rates. Marine Ecology Progress Series, 2012 [link]

Cite This Page:

Wildlife Conservation Society. "Microbes, sponges, and worms add to coral reef woes." ScienceDaily. ScienceDaily, 6 August 2012. <www.sciencedaily.com/releases/2012/08/120806151413.htm>.
Wildlife Conservation Society. (2012, August 6). Microbes, sponges, and worms add to coral reef woes. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2012/08/120806151413.htm
Wildlife Conservation Society. "Microbes, sponges, and worms add to coral reef woes." ScienceDaily. www.sciencedaily.com/releases/2012/08/120806151413.htm (accessed October 22, 2014).

Share This



More Earth & Climate News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
White Rhino's Death In Kenya Means Just 6 Are Left

White Rhino's Death In Kenya Means Just 6 Are Left

Newsy (Oct. 20, 2014) Suni, a rare northern white rhino at Ol Pejeta Conservancy, died Friday. This, as many media have pointed out, leaves people fearing extinction. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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