Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



WATER WORLD
Achieving fish biomass targets
by Staff Writers
Washington DC (SPX) May 11, 2016


Lead author Dr. Tim McClanahan surveys high fish biomass on reefs off Vamizi Island in northern Mozambique. Image courtesy Emily Darling and WCS. For a larger version of this image please go here.

Scientists from WCS (Wildlife Conservation Society), University of Queensland, James Cook University, and Macquarie University have completed a massive study that will help communities and countries of the Western Indian Ocean measure and restore fish populations while identifying the best policies for achieving global sustainable and conservation targets.

The researchers utilized more than 25 years of data from fish surveys and research focusing on the effectiveness of fishing closures to generate predictive models of recovery that will help marine managers better assess the state of reef systems and their fish populations in the Western Indian Ocean. The findings use previous studies to predict the recovery time of depleted reefs to levels where fishing is sustainable or conservation objectives are reached.

The study titled "Modeling Reef Fish Biomass, Recovery Potential, and Management Priorities in the Western Indian Ocean" appears in the online journal PLOS ONE. The authors are: Tim McClanahan of the Wildlife Conservation Society; Joseph M. Maina of the Wildlife Conservation Society, the University of Queensland, and Macquarie University; Nicholas A.J. Graham of James Cook University and the University of Queensland; and Kendall R. Jones of the University of Queensland.

"This study covers 45 years of fish recovery in 18 of the region's best protected areas - an area of 7,000 square miles - to produce these unusually extensive findings. The study will help guide conservation actions for the entire Western Indian Ocean, a region filled with coastal communities that rely on fishing for their livelihoods," said Dr. Tim McClanahan, Senior Conservationist for WCS and lead author on the study.

"Fish biomass is key for maintaining the ecosystem services that keep reef systems functional; fishing and other human activities can disrupt these sensitive ecosystems. Fortunately, we can leverage previous research to identify predictors that will help guide governments at many levels in ways that can safeguard coral reefs, fish populations, and the communities that rely on them."

Using the data collected between 1987 and 2014, McClanahan and his collaborators developed and tested predictive models to determine which factors correlated to levels of fish biomass in the region's coral reefs, a few of which explained up to 66 percent of the observed variability in surveyed reef systems.

The most important predictor of fish biomass in the research team's models was fisheries management types or restrictions. Fishing closures with a high degree of compliance and enforcement consistently led to significant increases in fish biomass, as did strict gear restrictions. On the other hand, fished reef systems with no gear restrictions led to a significant decrease of fish biomass.

Distance between coral reefs and the nearest fish market made a big difference as well; a shorter distance generally corresponded to a lower fish biomass levels. Of less importance were water temperatures and some potential predictors such as habitat; water quality and current speeds were not modelled because most sites lacked these data.

The study generated a map of coral reef biomass in the whole Western Indian Ocean along with a recovery time estimate of 8.1 years for individual reef systems to reach 1,150 kilograms of fish biomass per hectare, the critical level to conservation coral reef ecosystems. The average estimated time for a depleted reefs to support both maximum species diversity and sustainable yields was between 1.74 and 2.9 years in duration. Recovery times varied by country and were dependent on the state of their resources. In the most resource-depleted countries, recovery could take as long as 20 years.

The authors also conducted a prioritization analysis to help select areas for increased management efforts. While prioritization exercises have traditionally employed conservation targets based on global treaties (for example, Aichi biodiversity targets), the study used empirical and ecologically informed fish biomass recovery targets, therefore enhancing the chances for management effectiveness in priority areas.

Prioritization minimized the time needed for fish biomass to recover to achieve a nation's sustainable and conservation goals. One analysis identified the ideal areas for protecting reefs to achieve protection of 20 percent of coral reefs for conservation or no-fishing zones and having 50 percent of reef systems contained in sustainable fishing zones. Consequently, nations are provided with a means to select reefs for these management goals that will lead to the most rapid recovery.

Finally, the study examines three potential management scenarios for achieving the conservation goal of protecting 20 percent of the region's reefs. The fastest way to achieve this goal was to get countries to collaborate on a regional conservation plan and protect areas with the highest fish biomass. National conservation plans would be nearly as effective and would not require the efforts of achieving regional collaboration.

A final option considered a plan whereby fishing communities protected the most resource-depleted reefs first. The authors suggested the some combination of the three approaches is likely to succeed by relying on all scales of governance rather than just one.

"Implementing management measures to restore fish biomass is the number one action coastal communities, nations and regions can take themselves to help coral reefs face the coming threats of global climate change," said Dr. Caleb McClennen, WCS Vice President, Global Conservation "The study provides three complementary pathways to achieving sustainable fisheries in the Western Indian Ocean region within a decade - articulating empirically sound actions that critical for the long-term viability of some of the world's most biodiverse and important coral reef systems."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
Wildlife Conservation Society
Water News - Science, Technology and Politics






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
WATER WORLD
Continental drift to thank for coral reef biodiversity
Zurich, Switzerland (UPI) May 6, 2016
A new study suggests both the fragmentation and convergence of continents 100 million years ago explains the rich biodiversity found among the coral reefs of Indonesia and Southeast Asia. Using a computer model, researchers were able to track the movement and evolution of corals and reef fish as Africa and Asia separated and India drifted northward into Asia. Scientists powered t ... read more


WATER WORLD
Haiti preparing for major earthquake, tsunami

China landslide death toll rises to 31

Kenya demolishes 78 risky buildings after deadly collapse

17 missing 2 dead after collision in East China Sea

WATER WORLD
Engineers create a better way to boil water

Molybdenum disulfide holds promise for light absorption

JILA extends laser 'combing' method to identify large, complex molecules

Squished cells could shape design of synthetic materials

WATER WORLD
Effect of ocean acidification on shellfish depends on other stressors

Chile fishing crisis traps tourists, empties markets

How much does groundwater contribute to sea level rise?

Continental drift to thank for coral reef biodiversity

WATER WORLD
The genetic history of Ice Age Europe

Influence of sea-ice loss on Arctic warming shaped by Pacific temps

Study finds ice isn't being lost from Greenland's interior

What lies beneath West Antarctica

WATER WORLD
Study reveals genetic origins of carrots' orange color

Rising Carbon Dioxide Levels Will Help and Hurt Crops

Edible silk coating keeps fruit fresh for a week, scientists find

EU won't sacrifice food safety for US trade deal: German minister

WATER WORLD
Landslides kill nearly 50 in Rwanda

World's shallowest slow-motion earthquakes detected offshore of NZ

Floods following drought worsen Ethiopian hunger

Survivor rescued 13 days after deadly Ecuador quake

WATER WORLD
Senegal's child beggars show limits of 'apptivism'

S.Africa may re-consider regulated rhino horn trade in future

Climate-exodus expected in the Middle East and North Africa

Severe drought forces Zimbabwe to sell off wildlife

WATER WORLD
Drawing the genetic history of Ice Age Eurasian populations

Hominins may have been food for carnivores 500,000 years ago

Neandertals and Upper Paleolithic Homo sapiens had different dietary strategies

Chimp study explores the early origins of human hand dexterity




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement