Featured Research

from universities, journals, and other organizations

Jellyfish experts show increased blooms are a consequence of periodic global fluctuations

Date:
December 31, 2012
Source:
University of Southampton
Summary:
Blooms, or proliferations, of jellyfish can show a substantial, visible impact on coastal populations -- clogged nets for fishermen, stinging waters for tourists, even choked cooling intake pipes for power plants -- and recent media reports have created a perception that the world's oceans are experiencing trending increases in jellyfish. Now, a new multinational collaborative study suggests these trends may be overstated, finding that there is no robust evidence for a global increase in jellyfish over the past two centuries.

This image shows salp bloom off the coast of New Zealand.
Credit: Seacology

Blooms, or proliferations, of jellyfish can show a substantial, visible impact on coastal populations -- clogged nets for fishermen, stinging waters for tourists, even choked cooling intake pipes for power plants -- and recent media reports have created a perception that the world's oceans are experiencing trending increases in jellyfish. Now, a new multinational collaborative study, involving the University of Southampton, suggests these trends may be overstated, finding that there is no robust evidence for a global increase in jellyfish over the past two centuries.

The results of the study, which includes lead co-author Dr Cathy Lucas, a marine biologist at the University of Southampton, appear in the latest issue of Proceedings of the National Academy of Sciences.

The key finding of the study shows global jellyfish populations undergo concurrent fluctuations with successive decadal periods of rise and fall, including a rising phase in the 1990s and early 2000s that has contributed to the current perception of a global increase in jellyfish abundance. The previous period of high jellyfish numbers during the 1970s went unnoticed due to limited research on jellyfish at the time, less awareness of global-scale problems and a lower capacity for information sharing (e.g. no Internet).

While there has been no increase over the long-term, the authors detected a hint of a slight increase in jellyfish since 1970, although this trend was countered by the observation that there was no difference in the proportion of increasing vs. decreasing jellyfish populations over time.

Dr Cathy Lucas, who is based at the National Oceanography Centre, Southampton, says: "Sustained monitoring is now required over the next decade to shed light with statistical confidence whether the weak increasing linear trend in jellyfish populations after 1970 is an actual shift in the baseline or part of a larger oscillation."

To date, media and scientific opinion for the current perception of a global increase in jellyfish was evidenced by a few local and regional case studies. Although there are areas where jellyfish have increased; the situation with the Giant Jellyfish in Japan and parts of the Mediterranean are classic examples, there are also areas where jellyfish numbers have remained stable, fluctuated over decadal periods, or actually decreased over time.

Increased speculation and discrepancies about current and future jellyfish blooms by the media and in climate and science reports formed the motivation for the study. "There are major consequences for getting the answer correct for tourism, fisheries and management decisions as they relate to climate change and changing ocean environments," says Dr Lucas. "The important aspect about our work is that we have provided the long-term baseline backed with all data available to science, which will enable scientists to build on and eventually repeat these analyses in a decade or two from now to determine whether there has been a real increase in jellyfish."

"The realisation that jellyfish synchronously rise and fall around the world should now lead researchers to search for the long-term natural and climate drivers of jellyfish populations, in addition to begin monitoring jellyfish in open ocean and Southern Hemisphere regions that are underrepresented in our analyses," says lead author Dr Rob Condon, marine scientist at the Dauphin Island Sea Lab (DISL) in Alabama.

Given the potential damage posed by jellyfish blooms to fisheries, tourism and other human industries, the findings of the group foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.


Story Source:

The above story is based on materials provided by University of Southampton. Note: Materials may be edited for content and length.


Journal Reference:

  1. Robert H. Condon, Carlos M. Duarte, Kylie A. Pitt, Kelly L. Robinson, Cathy H. Lucas, Kelly R. Sutherland, Hermes W. Mianzan, Molly Bogeberg, Jennifer E. Purcell, Mary Beth Decker, Shin-ichi Uye, Laurence P. Madin, Richard D. Brodeur, Steven H. D. Haddock, Alenka Malej, Gregory D. Parry, Elena Eriksen, Javier Quiρones, Marcelo Acha, Michel Harvey, James M. Arthur, and William M. Graham. Recurrent jellyfish blooms are a consequence of global oscillations. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1210920110

Cite This Page:

University of Southampton. "Jellyfish experts show increased blooms are a consequence of periodic global fluctuations." ScienceDaily. ScienceDaily, 31 December 2012. <www.sciencedaily.com/releases/2012/12/121231180617.htm>.
University of Southampton. (2012, December 31). Jellyfish experts show increased blooms are a consequence of periodic global fluctuations. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2012/12/121231180617.htm
University of Southampton. "Jellyfish experts show increased blooms are a consequence of periodic global fluctuations." ScienceDaily. www.sciencedaily.com/releases/2012/12/121231180617.htm (accessed September 17, 2014).

Share This



More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) — The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) — Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) — Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) — Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 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