Increase in Jellyfish Blooms

Hanad DualeJeff Falcone

Omar Laroussi

Jellyfish Blooms• Jellyfish are medusa of the phylum Cnideria

and Ctenophora (comb jellies)• Jellyfish blooms occur naturally but they are

increasing worldwide on average

• “On course to Woods Hole. Jellyfish are everywhere!”

• Hadera power plant

Causes

• Overfishing• Eutrophication• Climate Change• Translocation

Overfishing

Competing for the same lunch

Jellyfish and forage fish prey on zooplankton.

There is an inverse correlation between jellyfish biomass and forage fish biomass

Eutrophication

• Fertilizer and waste runoff causes a decrease in oxygen

• Most fish will die off since they cannot thrive with a substantial decrease of oxygen

• But Jellyfish will survive a reduction of oxygen and will actually thrive and experience a population explosion since their competitors and predators will be wiped out

Translocation/Invasive Species• Natural translocation:

Animals migrate on their own

• Human accidental translocation: Ship ballast

• Human purposeful translocation: Ignorance of danger

Dangers of Translocation/Invasive Species

• Invasive species are extremely dangerous for the following two reasons:

1. Good chance they wont have natural predators in their new habitat

2. Good chance they wont have tough competitors in their new habitat

Mnemoipsis leidyi

• Mnemoipsis leidyi is a ctenophore species indigenous to the Atlantic coast of the United States

• M. leidyi became infamous in the 1980s due to a devastating invasive bloom in the Black Sea

• Invasive blooms have occurred in several other locations globally including the Mediterranean, Agean, Caspian, Azov, Marmara seas

• Invaded the Black Sea in 1982• Thought to have arrived in ship ballasts• Triggered unprecedented loss in biomass and

species composition• Known to be an invasive species but evidence

shows that overfishing contributed to success of population

Climate Change

• The world ocean is now warmer then it has been in the last 50 years

• The world ocean is warming at a rate of 0.2°F every decade

• There is a lot of evidence that Jellyfish thrive in warmer water

In 1999 warm spring water temperatures lead to a midsummer bloom which persisted until december

In 1971 the bloom peaked in late summer and rapidly declined

The population of M. leidyi tends to increase with temperature

Why does it matter?

• Losses of tourist revenue• Power outages • Fishing industry• Human health effects

Losses of tourist revenue

• Blooms of Box Jellyfish and other venomous Jellyfish have killed bathers, resulting in loss of tourist

• Even blooms of non-toxic Jellyfish can bring about loss of vacationers

• It is estimated that the tourism industry in Queensland lost 65 million US dollars after a couple of deaths in 2002 from blooms of box Jellyfish

Power outages • Coastal power plants

have suffered serious damages in the past after machinery sucked in huge numbers of Jellyfish from blooms in the area

• This has caused power outages in some coastal cities.

• Repair jobs have cost some power plants millions of dollars.

Fishing industry

• Jellyfish blooms outcompete fish for food• Blooms also devastate fish eggs• Blooms also destroy fishnets, and even in

some instances capsize fishing boats • This causes enormous problems for the fishing

industry as well as the consumers

Human health effects• Many Jellyfish species

are venomous and can either kill or seriously injure humans

• There have been cases where toxic fish have made people sick, and some scientist have theorized that Jellyfish stings might be to blame

Flow of Energy

• Blooms cause a trophic cascade by overfeeding on phytoplankton

• As a prey source they are very low in nutrients• Alter seasonal cycle of plankton productivity• Jellyfish blooms frequently coincide with

fisheries collapse

Possible Solutions

• Stop overfishing

• Limit runoff

• Limit species relocation

• Allow mother nature to self heal

Stop overfishing

• Sustainable forms of fishing will leave more competition for Jellyfish and this will help combat the emergence of blooms

Limit runoff

• Use sustainable methods such as composting instead of fertilizers

• Improve waste water treatment

Limit species relocation

• Find better ways to combat animals getting into ballast

• Educate the public about the dangerous of species relocation and invasive species

Allow mother nature to self heal

• The black sea had some of the worst dead zones on Earth mainly caused by fertilizer runoff

• When the USSR broke apart and farmers couldn’t get a hold of fertilizers, the dead zones self healed as mother nature usually does

Works Cited • Weisse, T., M.-T. Gomoiu, U. Scheffel, and F. Brodrecht. "Biomass and Size Composition of the Comb Jelly

Mnemiopsis Sp. in the North-western Black Sea During Spring 1997 and Summer 1995." Estuarine, Coastal and Shelf Science 54.3 (2002): 423-37. Print.

• Brodeur, Rd, H. Sugisaki, and Gl Hunt. "Increases in Jellyfish Biomass in the Bering Sea: Implications for the Ecosystem." Marine Ecology Progress Series 233 (2002): 89-103. Print.

• T., Shiganova, Mirzoyan Z., Studenikina E., Volovik S., Siokou-Frangou I., Zervoudaki S., Christou E., Skirta A., and Dumont H. "Population Development of the Invader Ctenophore Mnemiopsis Leidyi , in the Black Sea and in Other Seas of the Mediterranean Basin." Marine Biology 139.3 (2001): 431-45. Print.

• Kideys, Ahmet, Abolghaseem Roohi, Siamak Bagheri, Galina Finenko, and Lyudmila Kamburska. "Impacts of Invasive Ctenophores on the Fisheries of the Black Sea and Caspian Sea." Oceanography 18.2 (2005): 76-85. Print.

• Darvishi, F., A. Esmaili Sari, and P. Farshchi. "Dietary Overlap between Invasion Ctenophora (M. Leidyi ) and Anchovy (C. Engrauliformis) in the Southern Parts of Caspian Sea." International Journal of Environmental Science & Technology 1.2 (2004): 89-95. Print.

• Purcell, Je, S. Uye, and W. Lo. "Anthropogenic Causes of Jellyfish Blooms and Their Direct Consequences for Humans: A Review." Marine Ecology Progress Series 350 (2007): 153-74. Print.

• Purcell, Jennifer E. "Climate Effects on Formation of Jellyfish and Ctenophore Blooms: A Review." Journal of the Marine Biological Association of the UK 85.3 (2005): 461-76. Print.

• Lynam, Christopher P., Mark J. Gibbons, Bjørn E. Axelsen, Conrad A.j. Sparks, Janet Coetzee, Benjamin G. Heywood, and Andrew S. Brierley. "Jellyfish Overtake Fish in a Heavily Fished Ecosystem." Current Biology 16.13 (2006): R492-493. Print.