Current topics in marine ecology


it was my turn to give a lecture on jellyfish ecology for M.Sc. students of biological oceanography. The lecture is set to introduce current topics involved in our department and our contributions to it as scientists.  For the round table, where students select a paper to be discussed, we had three papers. the one that was very interesting to everybody and highly debated  was a report paper on jellyfish fishery in Vietnam:

One of the graduate students told how she was impressed by  the fact that jellyfish might be of benefit because so far she has just heard negative aspects ascribed to jellyfish. NOOOO!!! in a different line of thinking, jellyfish were viewed as a potential target product and recently attempts were made to utilize jellyfish products even as part of “baby diapers” in nanotechnology (Times of Israel, 2014) or for pharmacy (e.g. Anticancer agents). Indeed, Japanese and Chinese have been eating JF for more than a thousand years. Edible JF represent a very low caloric values due to their high proportion of water, low amount of calcium binding protein, no detectable crude fat and cholesterol and trace amounts of sugar.

Figure of jellyfish fisheries and their processing in Thanh Hoa, Vietnam. (a) A fishing boat retrieving a net, (b) Deck of a fishing boat filled with jellyfish (Rhopilema hispidum, the most exploited species in Thanh Hoa, (d) On-beach processing of jellyfish, (e) Peeing off the surface skin of P. hispidum by a tool made of bamboo, (f) A processing pond for the bells at a jellyfish processing factory. (Fig.2 of Nishikawa et al. 2008)

Therefore, among East Asian populations, it is believed that jelly-food improves memory, helps to fight age-related cognitive decline, is beneficial in the treatment of rheumatoid arthritis and helps to prevent wrinkling of the skin. Recently even FAO, called for JF to be used in food, medicine and cosmetics. An increase in the demand for edible JF together with a reduction in the stock size of edible Asian species has led to the need for new resources overseas. Thus although JF have traditionally been caught in South-East Asia, new species have recently been taken into consideration to export to Asia from the USA, Mexico, Australia and India for food industry. So far, commercial use of JF has focused on just 12 species (Trade-Seafood Industry Directory, 2011) and mainly relied on field catches suffering from high inter-annual variation. Although JF fishery is a growing field in the USA, their importance for other marine organisms like sea turtles can derail their sustainable use from the field…..please take care of jellyfish fishery before it gets late!!!