Balance of nature illustrated: role of jelly fish (Introduction)

by David Turell , Wednesday, March 23, 2016, 22:54 (2955 days ago) @ David Turell

The lowly jelly fish has an important role at the bottom of the food chain. This is a very long article most of which is not to my point that the food chain explains the reason for the bush of life. This article shows why this ancient 600 million year old (roughly)animal needs to be studied and understood. We humans have a tendency to disrupt the ecosystems of nature without thought. Luckily, in the recent past, our activities have been recognized as having potential dangers. Just ask the Australians, who introduced all sorts of foreign animals to the detriment of the indigenous species:-http://www.nature.com/news/the-secret-lives-of-jellyfish-1.19613?WT.ec_id=NATURE-20160324&spMailingID=50988418&spUserID=MjA1NjE2NDU5MwS2&spJobID=882986144&spReportId=ODgyOTg2MTQ0S0-“It's been very, very hard to convince fisheries scientists that jellies are important,” says Purcell.-***-"A few years ago, they discovered that salmon prey such as herring and smelt tend to congregate in different areas of the sound from jellyfish1 and they are now trying to understand the ecological factors at work and how they might be affecting stocks of valuable fish species. But first, the researchers need to know how many jellyfish are out there. For this, the team is taking a multipronged approach. They use a seaplane to record the number and location of jellyfish aggregations, or 'smacks', scattered about the sound. -***-"Some studies show that the animals are important consumers of everything from microscopic zooplankton to small fish, others suggest that jellies have value as prey for a wide range of species, including penguins, lobsters and bluefin tuna. There's also evidence that they might enhance the flow of nutrients and energy between the species that live in the sunlit surface waters and those in the impoverished darkness below.-*** 
" When Cardona's team analysed 20 species of predator and 13 potential prey, it was surprised to find that jellies had a major role in the diets of bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus) and spearfish (Tetrapturus belone)2. In the case of juvenile bluefins, jellyfish and other gelatinous animals represented up to 80% of the total food intake. “According to our models they are probably one of the most important prey for juvenile bluefin tuna,” says Cardona.-
***-"Jarman, who works at the Australian Antarctic Division in Kingston, reported in 2013 that DNA analysis of the samples revealed that jellyfish are a common part of the penguin's diet4. Work that has yet to be published suggests the same is true for other Southern Ocean seabirds.-***-"In the deep waters of the South Pacific and Indian oceans, Jeffs has been studying the elusive early life stages of the spiny lobster (Panulirus cygnus). During a 2011 plankton-collecting expedition 350 kilometres off the coast of Western Australia, he and his fellow researchers hauled in a large salp (Thetys vagina), a common barrel-shaped gelatinous animal. The catch also included dozens of lobster larvae, including six that were embedded in the salp itself. DNA analysis of the lobsters' stomach glands revealed that the larvae had been feeding on their hosts5.-"Jeffs now suspects that these crustaceans, which support a global fishery worth around US$2 billion a year, depend heavily on this relationship. “What makes the larvae so successful in the open ocean,” he says, “is that they can cling to what is basically a big piece of floating meat, like a jellyfish or a big salp, and feed on it for a couple of weeks without exerting any energy at all.”-***-"As scientists gather more data, they hope to get a better sense of exactly what role jellyfish have in various ocean regions. If jellies turn out to be as important as some data now suggest, the population spikes that have made the headlines in the past decade could have much wider repercussions than previously imagined."-Comment: And dead jelly fish provide nutrients for bottom plants. The bush of life is very intertwine and necessary.