Concentrated waste plumes from fish farms could travel significant distances to reach coastlines, according to a study to be published in an upcoming issue of the journal Environmental Fluid Mechanics.
Domoic acid, a toxin most often associated with algal blooms, has been found in the sardines that died massively at Redondo Beach. Could it be the beginning of an unstable marine ecosystem due to more algal blooms? It’s too soon to say for sure. Read the article by clicking the link above.
There is something unsettling about quantifying the value of an ecosystem based on artificial currency units…all ecosystems should be equally prized, not for their carbon reserves or their economic value, but because, well, because they’re awesome.
Saying that, any protection is better than nothing.
“An international effort to protect coastal wetlands by assigning them carbon credits kicked off last week in Paris. The aim is to do for some wetland plants — mangroves, seagrasses and salt marshes – what carbon credits have done for trees.”
“Uhh, I didn’t do anything wrong!” This is the war cry of British Petroleum, many months after they agreed to help pay for the damage caused by their oil spill. The only reason they have so much leeway is that they supply the lifeblood of our economy. Read the whole article here.
Fish Oil Health Benefits: Worth pushing fish to the brink?
Fish oil health benefits are exaggerated, says a new study appearing in the Canadian Medical Association Journal. And yet, it warns, increased consumer demand for fish oil is pushing fish populations to the brink.
These animals live at depths of 900-1,300 metres in the ocean where there is no sunlight, and use their huge eyes to find prey in the darkness. Exceptionally large for ostracods at 25mm across, they tumble through the ocean never touching a hard surface.
Not only is this salty Asian delicacy a rich source of nutrients, it is also an important part of the marine ecosystem. Much like worms working soil in a garden, sea cucumbers are responsible for cleaning up the sea bed — moving, consuming and mixing marine sediments.
Used widely in Chinese medicine and cuisine, sea cucumbers are also a rich source of glucosamine and chondroitin which are used in a range of common food supplements.
As a result, natural stocks of sea cucumbers are now seriously depleted around the world but at Newcastle University (my uni!), UK, a team led by Professor Selina Stead (my sustainability lecturer!) is investigating how we might be able to use sea cucumbers to develop a more sustainable way of farming in the sea.
Dr Matthew Slater, an expert in sea cucumbers and part of Professor Stead’s team, said the aim was to investigate the sea cucumber’s potential as a natural, organic cleaner on fish farms around the world — including the UK — as well as a source of food.
The Plight of the Eel in Reaching Spawning Grounds in the Sargasso Sea
ScienceDaily (Feb. 1, 2011) — Eel stocks are currently undergoing a steep decline, although no one knows exactly why. This is why researchers from a number of institutions including DTU Aqua are in the process of examining the European eel’s (Anguilla anguilla) behaviour in order to understand what happens during its reproductive migration from Europe to the Sargasso Sea.
For centuries, the tusk of the narwhal has fascinated and baffled. Narwhal tusks, up to nine feet long, were sold as unicorn horns in ages past, often for many times their weight in gold since they were said to possess magic powers. In the 16th century, Queen Elizabeth received a tusk valued at ?10,000 - the cost of a castle. Austrian lore holds that Kaiser Karl the Fifth paid off a large national debt with two tusks. In Vienna, the Hapsburgs had one made into a scepter heavy with diamonds, rubies, sapphires and emeralds.
Scientists have long tried to explain why a stocky whale that lives in arctic waters, feeding on cod and other creatures that flourish amid the pack ice, should wield such a long tusk. The theories about how the narwhal uses the tusk have included breaking ice, spearing fish, piercing ships, transmitting sound, shedding excess body heat, poking the seabed for food, wooing females, defending baby narwhals and establishing dominance in social hierarchies.
But a team of scientists from Harvard and the National Institute of Standards and Technology has now made a startling discovery: the tusk, it turns out, forms a sensory organ of exceptional size and sensitivity, making the living appendage one of the planet’s most remarkable, and one that in some ways outdoes its own mythology.
Corals around Japan are fleeing northwards, according to a new study. One type has been spotted ‘sprinting’ at 14 kilometres a year, thanks to a lift from ocean currents. That means ocean ecosystems could shift rapidly in the face of climate-change impacts such as warming seas, the authors say.
The study, due to be published in Geophysical Research Letters1, is the first documentation of coral mass migration, but matches up with several other observations. As early as 2004 in Florida, for instance, staghorn and elkhorn corals were observed farther north than their usual ranges2, and in Australia, reef-dwelling fish have been found farther south than before.
Hiroya Yamano of the Center for Global Environmental Research in Tsukuba, Japan, and his colleagues checked out records of corals seen in Japanese waters since the 1930s. Here, sea surface temperatures in winter have increased by 0.7–2.4 °C over the past 100 years.
ScienceDaily (Jan. 17, 2011) — Sakhalin Energy Investment Company — part owned by Shell — has announced plans to build a major oil platform near crucial feeding habitat of the Western North Pacific gray whale population.
Only around 130 whales of the critically endangered Western population exist today, and their primary feeding habitat — off Sakhalin Island in the Russian Far East — is already besieged by multiple oil and gas exploration and development projects.
The construction and operation of an additional off-shore platform could have numerous negative impacts on the whales, potentially disrupting feeding behaviours and increasing the chance of fatal ship strikes. Also, a third platform heightens the risk of an environmentally catastrophic oil spill in this sensitive habitat.
"Just around 30 female western gray whales of breeding age remain — the population is already on the brink of disappearing forever," said Aleksey Knizhnikov, Oil & Gas Environmental Policy Officer for WWF-Russia. "The loss of even a few breeding females could mean the end for the population."
The researchers examined 17 species of shark, including the bull shark
Researchers in Australia have discovered a secret weakness of one of the ocean’s most impressive predators.
Sharks, it seems, are completely colour blind.
The scientists, who examined retinas of 17 different species of shark, discovered that the creatures had only one type of colour-sensitive cell, known as a cone cell, in their eyes.
Human eyes have three cone cell types, with each type dedicated to receiving either blue, green or red light.
This allows most people to tell the difference between different coloured objects.
This may help us to design swimming attire that is less attractive to them
Biologist Dr Nathan Scott Hart
The study, carried out by Nathan Scott Hart and colleagues from the University of Western Australia and the University of Queensland, Australia is published in the journal Naturwissenschaften.
Dr Hart said the research could help to prevent shark attacks on humans and assist in the development of fishing gear that may reduce the number of sharks that are caught accidentally in long-line fisheries.
"Our study shows that contrast against the background, rather than colour per se, may be more important for object detection by sharks,” he explained.
"This may help us to design long-line fishing lures that are less attractive to sharks as well as to design swimming attire and surf craft that have a lower visual contrast to sharks and, therefore, are less ‘attractive’ to them."
To reveal the secrets of shark vision, the team examined the retinas of 17 shark species caught in a variety of waters in both Queensland and Western Australia.
In humans, the retina is densely packed with light-sensitive rod and cone cells.
Rods are able to function in much lower light than cones - and these were the most common cell types found in all of the sharks.
In ten of the species they examined, the researchers found no cone cells at all.
In the seven species that did have cones - only a single type, highly sensitive to just one wavelength, and therefore one colour, was present.
If sharks’ retinas cannot distinguish between different colours of light, as this research suggests, they may be totally colour-blind.
Dr Hart explained that, because sharks live underwater and many are most active at dawn and dusk, they are operating in relatively dim light.
"Rods are what humans use to see at night," he said.
"But some sharks are active at all times of the day and they have more cones and fewer rods than the nocturnal or deeper diving species. Why they are apparently not interested in colour is a mystery and one we hope to find out through further research."
It seems clear from these findings that if sharks are “attracted” to an object in the water, this is probably because of its contrast against the surrounding water, rather than it’s colour.
"Bright yellow is supposed to be attractive to some sharks, presumably because it appears to the sharks as a very bright target against the water," said Dr Hart.
"So perhaps it is best to avoid those fluoro-yellow shorts next time you are in the surf."
Nature Studies by Michael McCarthy: Of all our conservation failures, this is the saddest - The Independent
A hoary old cliché, the dream that died, but perhaps we may be allowed to write the dream that is dying: for such is the situation facing anyone who has supported the noble aim of restoring salmon, the finest of all freshwater fish, to the River Thames. After more than 30 years of trying, and a colossal amount of thinking, effort, and expense, the current custodians of the dream, the Environment Agency, has more or less accepted that it is not going to be realised, and this year’s stocking of young fish in the river - in the hope that they might go down to the sea and then return as adults, to breed - will be the last. The salmon have not come back. A native breeding population has not been established, and only a tiny handful of adult fish are now turning up in the river each summer. The project, which many people set their hearts on, has effectively failed.
One of Britain’s best known seabirds migrates to different sides of the Atlantic depending on how successful its breeding season was, researchers have found.
Kittiwake on the nest.
Unsuccessful kittiwakes tend to spend their winter on the Canadian side of the Atlantic, while their more successful colleagues stay much closer to home, sticking to places in the east Atlantic, like the British, Spanish and Portuguese coastlines.
The team’s findings are likely to be useful for scientists trying to work out which of the birds’ wintering sites should be protected.
'We don't yet know why the birds that fail at breeding go all the way to Canada,' says Dr Maria Bogdanova from the Centre for Ecology & Hydrology, lead author of the report, published in Proceedings of the Royal Society B. ‘But it could be because they’ve got more energy and resources compared with birds that have had to work hard raising chicks.’
ScienceDaily (Jan. 21, 2011) — A team of biologists has discovered an entirely new group of algae living in a wide variety of marine and freshwater environments. This group of algae, which the researchers dubbed “rappemonads,” have DNA that is distinctly different from that of other known algae. In fact, humans and mushrooms are more closely related to each other than rappemonads are to some other common algae (such as green algae). Based on their DNA analysis, the researchers believe that they have discovered not just a new species or genus, but a potentially large and novel group of microorganisms.