Tweet
Jellyfish 'may benefit from ecosystem instability'
By Mark Kinver Science and environment reporter, BBC News
The causes behind jellyfish blooms are difficult to disentangle, say the authors
A team of researchers have been trying to identify how jellyfish may benefit from marine ecosystems destabilised by climate change and overfishing.
There is concern that a rise in jellyfish numbers could prevent depleted commercially important fish stocks recovering to historical levels.
However, a study by European scientists says more data is needed to understand what is happening beneath the waves.
The findings are set to be published in the journal Global Change Biology.
Researchers from the UK and Ireland said samples collected from the Irish Sea since 1970 have recorded an increase in material from cnidarians (the division of the animal kingdom that includes jellyfish and coral), "with a period of frequent outbreaks between 1982 and 1991".
Continue reading the main story Related stories
"There does appear to have been an increase in abundance since 1994 for the Irish Sea," said co-author Christopher Lynam, a researcher at the Centre for Environment Fisheries and Aquaculture Science (Cefas).
The team added that previous studies had recorded changes to marine ecosystems as a result of various factors, such as the removal of top predators, and changes to the distribution and characteristics of plankton.
'Jellyfish joyride'
These changes have led to a growing concern that the oceans may become increasingly dominated by jellyfish because "many gelatinous zooplankton species are able to increase in abundance rapidly and adapt to new conditions".
Vast blooms of certain jellyfish can cause havoc in affected areas
In recent years, there have been a number of examples of sudden blooms of jellyfish in European waters - including the Irish, Mediterranean and Black seas - which have killed fish and closed beaches.
In 2007, an invasion of mauve stingers (Pelagia noctiluca) wiped out Northern Ireland's only salmon farm, killing more than 100,000 fish.
However, Dr Lynam was keen to point out that the team's study was dominated by the common moon jellyfish (Aurelia aurita), which was not responsible for wiping out the salmon.
The main concern, the team wrote, was the establishment of a "never-ending jellyfish joyride" in which the creatures become so established that it makes it almost impossible for commercial fish stocks to return to historical levels.
But Dr Lynam told BBC News: "I don't think that the hypothesis that jellyfish will come into an area and dominate, not allowing anything to come back again, is really supported.
"Such a nightmare scenario does not seem to be the case, when you consider the data and studies that have been carried out."
Complicated picture
He explained that the team looked at whether factors such as changes to the climate and overfishing were responsible for the increase in jellyfish abundance.
"It is quite a complicated set of possible linkages that need to be drawn, which we really only have a vague insight at the moment.
"For the recent period where we have good data, it appears as if sea surface temperature is the most important variable.
"This does not necessarily prove it of course, but it does appear to be benefiting jellyfish."
The team, using data provided by the UK Met Office, commented: "The regional seas of the northeast Atlantic have been warming for the past 15 years at a rate not experienced in recent centuries."
Overfishing has also been linked to the rise of jellyfish populations. Research suggests that commercial fishing during the 20th Century had resulted in a change in the Irish Sea's ecosystem.
The researchers wrote: "The overexploitation of herring during the late 1970s was followed by a period of ecosystem instability in the 1980s in which the frequency of occurrence of cnidarian material... rose to high levels, indicating outbreaks of jellyfish."
Dr Lynam added: "If you take out a lot of the plankton feeders, there could be more food for jellyfish so they might become more abundant. There may be feedback mechanisms that we are not aware of, so there does need to be further study."
But he cited examples in the North Sea and Black Sea where fish species had declined, leading to an increase in jellyfish abundance, but the introduction of measures such as limits on catches had resulted in a recovery of fish stocks.
The team urged for the monitoring of jellyfish to continue, and concluded: "The move to ecosystem-based fisheries management requires extensive ecological knowledge and an understanding of the risks posed by any indirect effects... of our utilisation of the sea's resources."
More on This Story
Related stories
Related Internet links
The BBC is not responsible for the content of external Internet sites
Share this page
In association with
More Science & Environment stories
RSS
Top Stories
Advertisement
<SCRIPT SRC="http://ad.adlegend.com/jscript?spacedesc=2107231_1099125_300x600_2107203_ 2107231&ML_NIF=Y&target=_blank&@CPSC@= http://ad.doubleclick.net/click%3Bh%3Dv8/3a44/3/0/%2a/i%3B230736217%3B0-0%3B0%3B19196841%3B4986-300/600%3B38761625/38779382/1%3B%3B%7Eokv%3D%3Bslot%3Dmpu%3Bsz%3D160x600%2C300 x250%2C300x600%2C336x700%2C336x850%2C336x280%2C468 x648%3Bsectn%3Dnews%3Bctype%3Dcontent%3Bnews%3Dsci ence%3Breferrer%3Dnewsscience_and_environment%3Bre ferrer_domain%3Dwww.bbc.co.uk%3Brsi%3DJ08781_10126 %3Brsi%3DJ08781_10139%3Brsi%3DJ08781_10153%3B%7Ess cs%3D%3f"></SCRIPT> <NOSCRIPT> <A HREF="http://ad.doubleclick.net/click%3Bh%3Dv8/3a44/3/0/%2a/i%3B230736217%3B0-0%3B0%3B19196841%3B4986-300/600%3B38761625/38779382/1%3B%3B%7Eokv%3D%3Bslot%3Dmpu%3Bsz%3D160x600%2C300 x250%2C300x600%2C336x700%2C336x850%2C336x280%2C468 x648%3Bsectn%3Dnews%3Bctype%3Dcontent%3Bnews%3Dsci ence%3Breferrer%3Dnewsscience_and_environment%3Bre ferrer_domain%3Dwww.bbc.co.uk%3Brsi%3DJ08781_10126 %3Brsi%3DJ08781_10139%3Brsi%3DJ08781_10153%3B%7Ess cs%3D%3fhttp://ad.adlegend.com/click?spacedesc=2107231_1099125_300x600_2107203_21 07231&ML_NIF=Y" TARGET="_blank"> <IMG SRC="http://ad.adlegend.com/image?spacedesc=2107231_1099125_300x600_2107203_21 07231&ML_NIF=Y" WIDTH=300 HEIGHT=600 ALT="Click Here" BORDER=0> </A> </NOSCRIPT>
Features & Analysis
Most Popular
Shared
Read
Watched/Listened
In association with
Elsewhere on the BBC
In association with
Advertising Partners
Programmes
Ads by Google
By Mark Kinver Science and environment reporter, BBC News
The causes behind jellyfish blooms are difficult to disentangle, say the authors A team of researchers have been trying to identify how jellyfish may benefit from marine ecosystems destabilised by climate change and overfishing.
There is concern that a rise in jellyfish numbers could prevent depleted commercially important fish stocks recovering to historical levels.
However, a study by European scientists says more data is needed to understand what is happening beneath the waves.
The findings are set to be published in the journal Global Change Biology.
Researchers from the UK and Ireland said samples collected from the Irish Sea since 1970 have recorded an increase in material from cnidarians (the division of the animal kingdom that includes jellyfish and coral), "with a period of frequent outbreaks between 1982 and 1991".
Continue reading the main story Related stories
"There does appear to have been an increase in abundance since 1994 for the Irish Sea," said co-author Christopher Lynam, a researcher at the Centre for Environment Fisheries and Aquaculture Science (Cefas).
The team added that previous studies had recorded changes to marine ecosystems as a result of various factors, such as the removal of top predators, and changes to the distribution and characteristics of plankton.
'Jellyfish joyride'
These changes have led to a growing concern that the oceans may become increasingly dominated by jellyfish because "many gelatinous zooplankton species are able to increase in abundance rapidly and adapt to new conditions".
Vast blooms of certain jellyfish can cause havoc in affected areas In recent years, there have been a number of examples of sudden blooms of jellyfish in European waters - including the Irish, Mediterranean and Black seas - which have killed fish and closed beaches.
In 2007, an invasion of mauve stingers (Pelagia noctiluca) wiped out Northern Ireland's only salmon farm, killing more than 100,000 fish.
However, Dr Lynam was keen to point out that the team's study was dominated by the common moon jellyfish (Aurelia aurita), which was not responsible for wiping out the salmon.
The main concern, the team wrote, was the establishment of a "never-ending jellyfish joyride" in which the creatures become so established that it makes it almost impossible for commercial fish stocks to return to historical levels.
But Dr Lynam told BBC News: "I don't think that the hypothesis that jellyfish will come into an area and dominate, not allowing anything to come back again, is really supported.
"Such a nightmare scenario does not seem to be the case, when you consider the data and studies that have been carried out."
Complicated picture
He explained that the team looked at whether factors such as changes to the climate and overfishing were responsible for the increase in jellyfish abundance.
"It is quite a complicated set of possible linkages that need to be drawn, which we really only have a vague insight at the moment.
"For the recent period where we have good data, it appears as if sea surface temperature is the most important variable.
"This does not necessarily prove it of course, but it does appear to be benefiting jellyfish."
The team, using data provided by the UK Met Office, commented: "The regional seas of the northeast Atlantic have been warming for the past 15 years at a rate not experienced in recent centuries."
Overfishing has also been linked to the rise of jellyfish populations. Research suggests that commercial fishing during the 20th Century had resulted in a change in the Irish Sea's ecosystem.
The researchers wrote: "The overexploitation of herring during the late 1970s was followed by a period of ecosystem instability in the 1980s in which the frequency of occurrence of cnidarian material... rose to high levels, indicating outbreaks of jellyfish."
Dr Lynam added: "If you take out a lot of the plankton feeders, there could be more food for jellyfish so they might become more abundant. There may be feedback mechanisms that we are not aware of, so there does need to be further study."
But he cited examples in the North Sea and Black Sea where fish species had declined, leading to an increase in jellyfish abundance, but the introduction of measures such as limits on catches had resulted in a recovery of fish stocks.
The team urged for the monitoring of jellyfish to continue, and concluded: "The move to ecosystem-based fisheries management requires extensive ecological knowledge and an understanding of the risks posed by any indirect effects... of our utilisation of the sea's resources."
Related stories
- Jellyfish attack destroys salmon 21 NOVEMBER 2007, NORTHERN IRELAND
- Fishing 'destabilises Black Sea' 05 JUNE 2007, SCI/TECH
Related Internet links
- Cefas
- Coastal & Marine Resources Centre
- Swansea University - School of Environment & Society
- Agri-Food and Biosciences Institute
- University College Cork
- Global Change Biology
The BBC is not responsible for the content of external Internet sites
Share this page
In association with
More Science & Environment stories
RSS
-
Nature talks end with 'weak' deal
An international biodiversity summit in Japan agrees a 10-year plan aimed at preserving nature, but conservation groups fear the deal is too weak. - Eutelsat suffers spacecraft loss
- Japan looks to Hanoi for minerals
Top Stories
-
Dubai bomb flew on passenger jets - Istanbul suicide blast injures 32
- Brazil votes for next president
- Westwood becomes world number one
- Baghdad church hostage drama ends
Advertisement
<SCRIPT SRC="http://ad.adlegend.com/jscript?spacedesc=2107231_1099125_300x600_2107203_ 2107231&ML_NIF=Y&target=_blank&@CPSC@= http://ad.doubleclick.net/click%3Bh%3Dv8/3a44/3/0/%2a/i%3B230736217%3B0-0%3B0%3B19196841%3B4986-300/600%3B38761625/38779382/1%3B%3B%7Eokv%3D%3Bslot%3Dmpu%3Bsz%3D160x600%2C300 x250%2C300x600%2C336x700%2C336x850%2C336x280%2C468 x648%3Bsectn%3Dnews%3Bctype%3Dcontent%3Bnews%3Dsci ence%3Breferrer%3Dnewsscience_and_environment%3Bre ferrer_domain%3Dwww.bbc.co.uk%3Brsi%3DJ08781_10126 %3Brsi%3DJ08781_10139%3Brsi%3DJ08781_10153%3B%7Ess cs%3D%3f"></SCRIPT> <NOSCRIPT> <A HREF="http://ad.doubleclick.net/click%3Bh%3Dv8/3a44/3/0/%2a/i%3B230736217%3B0-0%3B0%3B19196841%3B4986-300/600%3B38761625/38779382/1%3B%3B%7Eokv%3D%3Bslot%3Dmpu%3Bsz%3D160x600%2C300 x250%2C300x600%2C336x700%2C336x850%2C336x280%2C468 x648%3Bsectn%3Dnews%3Bctype%3Dcontent%3Bnews%3Dsci ence%3Breferrer%3Dnewsscience_and_environment%3Bre ferrer_domain%3Dwww.bbc.co.uk%3Brsi%3DJ08781_10126 %3Brsi%3DJ08781_10139%3Brsi%3DJ08781_10153%3B%7Ess cs%3D%3fhttp://ad.adlegend.com/click?spacedesc=2107231_1099125_300x600_2107203_21 07231&ML_NIF=Y" TARGET="_blank"> <IMG SRC="http://ad.adlegend.com/image?spacedesc=2107231_1099125_300x600_2107203_21 07231&ML_NIF=Y" WIDTH=300 HEIGHT=600 ALT="Click Here" BORDER=0> </A> </NOSCRIPT>
Features & Analysis
-
Crystal ball
An expert's view of the likely result of the US 2010 elections -
In pictures
Images from the closing weekend of the Shanghai World Expo -
Noble tradition?
The debate over bull fighting in France -
Cross Bones
London's long-forgotten burial ground for outcasts
Most Popular
Shared
- 1: Istanbul suicide blast injures 22
- 2: What was Jon Stewart's rally in Washington all about?
- 3: Flasher is bitten by victim's dog
- 4: Audio slideshow: Cross Bones
- 5: Bomb was flown on passenger plane
Read
- 1: Bomb was flown on passenger plane
- 2: Istanbul suicide blast injures 22
- 3: Japan looks to Hanoi for minerals
- 4: What was Jon Stewart's rally in Washington all about?
- 5: Hostages taken in Baghdad church
- 6: US child sued for bicycle crash
- 7: 'Witch's hat' stalls Tube trains
- 8: Honduras football attack kills 14
- 9: Athens marathon marks anniversary
- 10: A class of their own
Watched/Listened
- 1: Russia holds 'Millionaire fair' Watch
- 2: Device 'meant to explode on plane' Watch
- 3: Stephen Fry feeds baby white rhino Watch
- 4: Working out with San Francisco's cheerleaders Watch
- 5: Police probe Maldives wedding abuse Watch
- 6: One-minute World News Watch
- 7: EU budget deal 'protects' UK taxpayer Watch
- 8: Helicopter crash site assessed Watch
- 9: UAE Philharmonic faces fuding woes Watch
- 10: Suspected suicide bomb attack in Istanbul Watch
In association with
Elsewhere on the BBC
-
Get spooked
BBC Travel surveys the world's most spectacular Halloween destinations
In association with
Advertising Partners
Programmes
-
Fast Track Watch
Sweden's new luxury hotel high among the trees
In association with
Ads by Google
- Portable Folding Boats
Revolutionary Boat Design Folds to 4 Inches Flat! Eliminate Trailers.
www.Porta-Bote.com - New York Coupons
1 ridiculously huge coupon a day. It's like doing NYC at 90% off!
www.Groupon.com/New-York - Niantic Sportfishing
Osprey Sportfishing Offers Ocean Adventures at Low Rates. Call Now!
www.ospreyfishingcharters.com