Subscribe to our free daily newsletters
. Earth Science News .

Subscribe to our free daily newsletters

Overfishing devastates spawning aggregations
by Staff Writers
Washington DC (SPX) Mar 10, 2016

File image.

Globally declining fish populations are a frequently cited ecological and commercial calamity, but relatively little attention has been paid to the specific threats faced by fish that gather and spawn in large groups, says Yvonne Sadovy, writing in an article for BioScience.

The marine scientist, affiliated with the University of Hong Kong and Science and Conservation of Fish Aggregations (SCRFA), outlines the challenges unique to these populations.

"Many aggregating species face growing threats to their populations from increasing harvest and lack of effective management," she says.

Appearing in temporarily high abundances, the fish are particularly vulnerable to overexploitation as a result of both increased catchability and lethal and nonlethal biological factors.

According to Sadovy, aggregations in small-scale fisheries in particular could be dangerously overfished by only a few active boats, but large-scale industrial fisheries are also susceptible.

The author also describes how changing economic conditions could contribute to rapid species declines. Many exploited fish populations were once safeguarded from collapses by costs of fishing that rose as fish numbers declined.

Given the high catchability of aggregate spawners and consumers' growing ability to pay premium prices for desirable species, this safety valve is vanishing. Instead, fishing pressure could be ramped up, leading to a "downward spiral toward extinction." The Chinese bahaba is a clear example.?

Insufficient or inappropriate management contributes to the problem, says the author: "Fisheries management was long (and largely still is) based on the concept of 'stocks,' with management units and monitoring typically treating localized demographic effects and local overfishing as unimportant."

Such approaches may neglect the complex migratory dynamics and life histories of many individual populations, reports the author. Also, biological factors can increasingly compromise reproduction in aggregations as fish numbers decline.

Sadovy does see an ongoing role for fishing of aggregate-spawning species, which she describes as being of great economic and food security value globally, but this can be continued only "if it is done right" and if management is truly precautionary.

In cases where insufficient management and enforcement are a problem, she proposes that "no fishing of spawning aggregations should occur until appropriate measures are implemented to ensure their sustainable use."

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
American Institute of Biological Sciences
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 DiggDigg RedditReddit GoogleGoogle

Previous Report
Fish populations revealed through seawater analysis
Kobe, Japan (SPX) Mar 08, 2016
A research group led by YAMAMOTO Satoshi, a research fellow at the Kobe University Graduate School of Human Development and Environment, has shown that measuring quantities of fish DNA in seawater can reveal how many fish inhabit that environment. This discovery could enable quicker and more effective surveys of fish distribution, and has potential applications in long-term monitoring. The ... read more

Among the believers: hope endures for MH370 relatives

Web users lament China's 'forest of steel' after lift death

Mutations, DNA damage seen in Fukushima forests: Greenpeace

Fukushima 'dark tourism' aids remembrance and healing

Scaling up tissue engineering

UMass Amherst team offers new, simpler law of complex wrinkle patterns

Electron-beam imaging can see elements that are 'invisible' to common methods

How metal clusters grow

Shark babies remain strong in future acidic oceans

Sea level rise threatens larger number of people than earlier estimated

New York oyster beds once protected against storms and wave damage

Fish populations revealed through seawater analysis

In search of Earth's oldest ice

Greenland's ice is getting darker, increasing risk of melting

How permafrost thawing affects vegetation, carbon cycle

Russian scuba divers set deepest under-ice dive record

South Africa says drought cost farmers $1 billion

Urgent need to transform key food producing regions in Africa by 2025

Impact of climate change on agriculture may be underestimated

Recoupling crops and livestock offers energy savings to dairy farmers

How rivers of hot ash and gas move when a supervolcano erupts

Shipwrecks, tree rings reveal Caribbean hurricanes in buccaneer era

Five years on, Japan tsunami scars visible and invisible

The maximum earthquake magnitude for North Turkey

Nigerian Army Council clears Boko Haram arms officer

S.African private army protects world's largest rhino farm

Rwanda prosecutors demand 22 years in jail in sedition trial

US top brass urge tighter W. Africa response to Islamist threat

ONR Global sponsors research to improve memory through electricity

Easter Island not destroyed by war, analysis of 'spear points' shows

Neanderthals and modern H. sapiens crossbred over 100,000 years ago

Neanderthals mated with modern humans much earlier than previously thought

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