Latest recipes

Pollution Makes Spain’s Male Fish Produce Eggs

Pollution Makes Spain’s Male Fish Produce Eggs


We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

Mullet in Spanish rivers are producing eggs because of pollution

Wikimedia/JoJan

Pollution in Spanish rivers has reportedly been making male fish grow eggs in their testicles.

Spanish biologists have discovered that pollution in the rivers of the Basque region is having an unexpected effect on the local fish populations, and the male fish have actually been developing eggs.

According to The Local, chemical pollutants from farming and industrial activities have been functioning as oestrogens and feminizing the male fish populations. A new study says even everyday products like contraceptive pills and detergent are surviving the water cleaning systems and making it through to the rivers and estuaries. As a result, scientists have found eggs developing in the testicles of male mullet fish. Mullet roe is a delicacy, but this new development does not seem like a product anybody would be too eager to eat.

"Our discoveries are significant as they enable us to know how far these pollutants have spread in our rivers and estuaries and what effects they have," said researcher Miren Cajaraville.

Scientists at the Cell Biology in Environmental Toxicology group are pushing for the Spanish government to adopt regulations that would prohibit the production of pollutants that cannot be cleaned away through water treatment facilities.

“We will be able to adopt ways of keeping them from reaching out waters,” Cajaraville said.


Fish reproduction

Fish reproductive organs include testes and ovaries. In most species, gonads are paired organs of similar size, which can be partially or totally fused. [1] There may also be a range of secondary organs that increase reproductive fitness. The genital papilla is a small, fleshy tube behind the anus in some fishes, from which the sperm or eggs are released the sex of a fish often can be determined by the shape of its papilla.


Dumped fishing gear is biggest plastic polluter in ocean, finds report

Lost and abandoned fishing gear which is deadly to marine life makes up the majority of large plastic pollution in the oceans, according to a report by Greenpeace.

More than 640,000 tonnes of nets, lines, pots and traps used in commercial fishing are dumped and discarded in the sea every year, the same weight as 55,000 double-decker buses.

The report, which draws on the most up-to-date research on “ghost gear” polluting the oceans, calls for international action to stop the plastic pollution, which is deadly for marine wildlife.

About 300 sea turtles were found dead as a result of entanglement in ghost gear off the coast of Oaxaca, Mexico, last year. And in October, a pregnant whale was found entangled in ghost gear off the Orkney coast. The fishing gear was jammed in the animal’s baleen, the filter-feeder system inside its mouth, and scientists said the net would have hugely impaired the minke whale’s feeding and movement.

Louisa Casson, an oceans campaigner at Greenpeace UK, said: “Ghost gear is a major source of ocean plastic pollution and it affects marine life in the UK as much as anywhere else.

“The UK’s waters do not exist in a vacuum as oceans have no borders. The world’s governments must take action to protect our global oceans, and hold the under-regulated fishing industry to account for its dangerous waste. This should start with a strong global ocean treaty being agreed at the United Nations next year.”

The report said abandoned fishing gear was particularly deadly. “Nets and lines can pose a threat to wildlife for years or decades, ensnaring everything from small fish and crustaceans to endangered turtles, seabirds and even whales,” it said.

“Spreading throughout the ocean on tides and currents, lost and discarded fishing gear is now drifting to Arctic coastlines, washing up on remote Pacific islands, entangled on coral reefs and littering the deep seafloor.”


Microplastics killing fish before they reach reproductive age, study finds

Fish are being killed, and prevented from reaching maturity, by the litter of plastic particles finding their way into the world’s oceans, new research has proved.

Some young fish have been found to prefer tiny particles of plastic to their natural food sources, effectively starving them before they can reproduce.

The growing problem of microplastics – tiny particles of polymer-type materials from modern industry – has been thought for several years to be a peril for fish, but the study published on Thursday is the first to prove the damage in trials.

Microplastics are near-indestructible in natural environments. They enter the oceans through litter, when waste such as plastic bags, packaging and other convenience materials are discarded. Vast amounts of these end up in the sea, through inadequate waste disposal systems and sewage outfall.

Another growing source is microbeads, tiny particles of hard plastics that are used in cosmetics, for instance as an abrasive in modern skin cleaners. These easily enter waterways as they are washed off as they are used, flushed down drains and forgotten, but can last for decades in our oceans.

The impact of these materials has been hard to measure, despite being a growing source of concern. Small particles of plastics have been found in seabirds, fish and whales, which swallow the materials but cannot digest them, leading to a build-up in their digestive tracts.

A perch with ingested microplastic polystyrene particles. Photograph: Oona Lönnstedt/Science

For the first time, scientists have demonstrated that fish exposed to such materials during their development show stunted growth and increased mortality rates, as well as changed behaviour that could endanger their survival.

Samples of perch, still in their larval state, were shown not only to take in the plastics, but to prefer them to their real food. Larval perch with access to microplastic particles ate only the plastics, ignoring their natural food source of plankton.

The study, published in Science on Thursday, found that the fish born into an environment rich in microplastics – defined as tiny pieces of less than 5mm in size – had reduced rates of hatching and development to maturity.

The perch studied also ignored the chemical signals that would normally warn them of the presence of predators, the researchers found.

These particles are now found in abundance across the world’s oceans, and are often common in shallow coastal areas, where they wash in from waste dumps and sewerage systems.

“This is the first time an animal has been found to preferentially feed on plastic particles, and is cause for concern,” said Peter Eklöv, co-author of the study. “Larvae exposed to microplastic particles during development also displayed changed behaviours and were much less active than fish that had been reared in water that contained no microplastic particles.”

Environmental campaigners have been calling for a reduction in the waste allowed to drift from rivers into seas and oceans, and for an end to the use of artificial microplastics in cosmetics. Greenpeace launched a campaign against microbeads early this year, and several companies have committed to phasing them out.

However, the study suggests that damage has already been done, and preventing the leakage of more microplastics into the oceans should be a matter of urgency, as once they are in our seas they are almost impossible to get rid of.

Perch exposed to microplastics in the study were eaten by pike four times more quickly than their naturally-reared relatives, when the predators were introduced into their environment. All of the plastic-exposed fish in the study were dead within 48 hours.

Microplastics visible in a pike. Photograph: Oona Lönnstedt/Science

This suggests that the impacts of microplastics are likely to be far-reaching and long-lasting, beyond the immediate effects on the fish’s digestive systems, which was previously the main cause of concern. Plastics may be causing differing behaviour in the fish, and inhibiting their evolved responses to danger, through mechanisms not yet fully understood.

The study adds to research that has found coastal fish species suffering marked declines in recent years, while the amount of plastic litter in the oceans has increased.

“If early life-history stages of other species are similarly affected by microplastics, and this translates to increased mortality rates, the effects on aquatic ecosystems could be profound,” warned Oona Lönnstedt, another of the report’s authors.

This article was amended on 4 May 2017 to add a note at the top indicating that the scientific paper on which it was based had been retracted.


Frittata Mistakes You Might Be Making

  • You forget to season the whisked eggs and other add-ins. Each ingredient needs to be seasoned to-taste with salt and pepper, that way you avoid having a bland dish. Already salty ingredients, such as bacon, don&apost require this step.
  • You forget to use the golden ratio when you&aposre making a frittata on the fly. An easy recipe to remember is 6 large eggs, ¼ cup of dairy, and 1-2 cups of add-ins like vegetables, meat, cheese, and herbs.
  • You over-bake. This is probably the most common mistake. A finished frittata should be custardy, fluffy, just set, and still pale in color — not browned and spongy.
  • You throw out the leftovers. Use a wedge to top toast or add to a side salad for an easy, repurposed meal.

Intersex fish found in Pennsylvania rivers spur search for chemicals

Pennsylvania’s Department of Environmental Protection has begun an extensive sampling of chemical contaminants in response to the discovery of intersex fish in three of the state’s rivers, a department spokeswoman said.

Male fish carrying eggs were found in the Susquehanna, Delaware and Ohio river basins, a sign that the water may be tainted with chemicals, the U.S. Geological Survey found in research released Monday.

Amanda Witman, a DEP spokeswoman, said the agency is testing two tributaries of the Susquehanna River: Juniata River and Swatara Creek.

The USGS research said that two fish species, smallmouth bass and white sucker, were exhibiting intersex characteristics due to exposure to endocrine-disrupting chemicals — hormones and hormone-mimicking chemicals that caused the male fish to produce eggs.

“The sources of estrogenic chemicals are most likely complex mixtures from both agricultural sources, such as animal wastes, pesticides and herbicides, and human sources from wastewater treatment plant effluent and other sewage discharges,” said Vicki Blazer, a fish biologist and lead author of the USGS study.

Estrogenic chemicals disrupt the endocrine system, which regulates the release of hormones such as estrogen and testosterone. This interferes with the fish’s ability to reproduce.

Some of the compounds and contaminants found were new, and researchers had to develop new laboratory test procedures to measure them, Witman said.

“The results will provide a much better understanding of the kinds, distribution and concentrations of these compounds,” she said.

This isn’t the first time intersex fish have been discovered in U.S. rivers. Since 2006, the USGS has found similar characteristics during several surveys of bass in the Potomac River.

In the Pennsylvania survey, Blazer and colleagues collected fish from 16 sites in the Susquehanna, Delaware and Ohio river basins. Intersex males were found at every site where smallmouth bass were collected and their condition was generally worse in places just downstream from wastewater treatment plants, the researchers found.

Bass seem especially prone to becoming intersex when exposed to estrogenic compounds, the study found. The researchers also sampled white suckers and redhorse suckers. Redhorse suckers didn’t have any intersex characteristics, but the team found an egg cell precursor, or stem cells that could potentially develop into eggs, in the blood of some white suckers.

The most common hormone found in water and soil samples was estrone, a potent endocrine-disrupting chemical often found in sewage from wastewater plants and the manure of animals such as cows, chickens and pigs, the researchers said.

“We weren’t expecting the issue to be as widespread as it was,” Blazer said. “The number of fish affected and the severity was surprising.”

Blazer said any of these chemicals could affect humans, especially chemicals that entered the water from pharmaceuticals and personal care products, such as fragrances. The fish showed the effects of the pollutants, she said, because spending all their time in the water means they are continuously saturated in the substances.

Upgrading wastewater plant technology and fencing rivers so animals can’t excrete directly into the water would help, she said.

Rep. James P. Moran, a Democrat whose district is northern Virginia, issued a statement, calling the findings “troubling” and “yet another example of the adverse effects on water pollution in this country and another reminder that lawmakers need to take chemical waste regulation more seriously.”

Pennsylvania’s environmental agency began a multiyear analysis of the Susquehanna River in 2012, though samples collected by researchers are still being evaluated. Samples will continue to be collected through this summer and those results will be available next year, Witman said.

“DEP’s plan is to continue the sampling until it has an understanding of how these compounds may or may not impact the aquatic life in all streams and rivers, not just the Susquehanna,” she said.

Must-read stories from the L.A. Times

Get all the day's most vital news with our Today's Headlines newsletter, sent every weekday morning.

You may occasionally receive promotional content from the Los Angeles Times.


5. Killin’ The Mood For Fish

Plastics in aquatic ecosystems don’t just become a problem when they wrap around an animal or end up blocking digestive systems. Plastics can also introduce chemical warfare to the bodies of fish, and scientists are actually finding that it is killing the reproductive health of many fish species.

Included in the chemical cocktail aquatic animals are hit with from pollution is something called “endocrine disruptors.” These impact the endocrine system, obviously, which can be detrimental to the immune system, reproductive system, development, neurological responses, and overall growth. Bisphenol A or BPA is found in many plastics entering the ocean and, unfortunately, it acts as an endocrine disruptor for fish. Scientists have observed BPA exposure to some freshwater fish species as a source of confusion for the fish, make it difficult for them to pursue their own species to mate. Clearly, a fish of one species attempting to mate with a fish of another species will not result in reproductive success for either.

Lines between fish species not only become blurred by plastics. This type of pollution is also impacting gender in some fish species as well. Chemicals in plastics are one of several types of pollution that are feminizing male fish. When fish are exposed to chemicals that mimic estrogen during development, their ability to develop into males is thwarted and female characteristics develop instead. There have also been scientific observations in which fish become intersex due to their exposure to BPA, among other pollutants. There have been promising results when water can be treated in a treatment plant that removes some of these chemicals. But the problem of plastic pollution is very widespread and difficult to address on a large scale. Until we can get a handle on it, the reproductive rates of some fish will continue to be at risk.


How to Cook Capon

You can prepare capon like any other poultry dish. Typically, capons are roasted and the procedure for doing so is similar to roasting a chicken due to its larger size, however, the cooking time will be longer.

Traditionally, roosters are braised. For instance, the classic French dish coq au vin involves braising a rooster in red wine. That is because their meat is tougher than chicken meat and they are usually slaughtered at an older age, which toughens the meat as well. As such, braising is also a good cooking technique for preparing capon.


Farmed Atlantic salmon

Provenance:Most commercially available Atlantic salmon is farmed, providing about 72 per cent of the world&rsquos total salmon harvest. Atlantic salmon is farmed across the globe but by far the two largest producers are Norway and Chile, whose coastlines provide optimum conditions for production. Farming takes place predominantly in open-net pens in sheltered waters such as fjords or bays. Scotland, Canada, the Faroe Islands, Tasmania, Ireland and Iceland also farm Atlantic salmon. The US is the world&rsquos biggest importer of Atlantic salmon, Germany, France and the UK are traditionally major markets, while China is the fastest-growing market. In China, fresh Atlantic salmon fillets are often served sashimi-style in Japanese sushi restaurants, but frozen, fresh or smoked salmon is increasingly found in modern retail outlets and through e-commerce channels. In Japan, Atlantic salmon is popular in a range of sushi dishes such as nigri and hosomaki. Most of the fish are imported, chiefly from Norway and Chile, though recently there are initiatives to farm Atlantic salmon in Japan and China.

Available fresh all year round, Atlantic salmon&rsquos mild flavour, fleshy texture and pocket-friendly price makes it a popular choice worldwide. In many important markets, Atlantic farmed salmon is listed in the top five species being consumed. While discerning pescaphiles might sing the praises of the flavour and provenance of wild-caught salmon, others say farmed makes better smoked salmon because of its higher fat content. Its versatility means it can be cooked most ways, from poached to pan-fried, and even cured, cold-smoked and hot-smoked.

The natural colour of salmon is dusty grey. Wild-caught salmon picks up its pink colouring naturally from the food chain, while farmed salmon gains its colour from the pigments in its feed. The colour of the fish can vary widely from russett to light pink according to the amount of pigment in the diet.

The Aquaculture Stewardship Council (ASC) is an independent non-profit organisation that sets a voluntary standard for responsibly farmed salmon. The certification process is carried out by third-party auditors and if certified, the ASC logo can be used on pack as a trusted indication that the seafood came from a truly responsible farmer who seeks to minimise environmental and social impacts. These include reducing pollution from pesticides and waste in the surrounding seas, limiting reliance on chemicals and medication, and improving working conditions.

Did you know?

Farmed salmon produces a fraction of the carbon generated by the beef industry. The carbon footprint for farmed salmon is 2.9 carbon equivalents per kilogram of edible product compared to as much as 30 for cattle.

Nick Wyke is a journalist and food writer who is passionate about local, seasonal and sustainable produce.


OSU researcher makes alarming 'intersex' fish discovery

CORVALLIS, Ore. -- An alarming discovery off the coast of France a mile below the ocean surface: Fish with both male and female organs.

It's the result, researchers say, of man-made pollution.

The study was co-authored by a professor at Oregon State University and is already making waves around the world.

While it is not the first time scientists have found these kinds of "intersex" fish, it is the first time they've found this condition in fish way out in the ocean far away from any polluting cities.

In 2009 USGS scientists made a similar discovery along the Columbia River just west of Hood River.

After testing a number of small mouth bass there, they found more than half of them were "intersex."

Now, for the first time, researchers from Oregon State University have found the same characteristics in fish that live about a mile deep in the ocean.

In addition to the "intersex" fish, the study also found the fish had tumors, liver conditions, all sorts or health problems they believe are linked to what we are putting into our waterways.

Toxins like PCBs, flame retardants, pharmaceuticals, even personal care products.

"In areas ranging from pristine, high mountain lakes of the United States to ocean waters off the coasts of France and Spain, we've now found evidence of possible human-caused pollution that's bad enough to have pathological impacts on fish," said Michael Kent, a professor of microbiology at Oregon State University.

"Everything you wash down the drain and put down the toilet it ends up eventually going through a treatment plant and then into the rivers and into the ocean. It's all collected," said Elena Nilsen, a researcher with USGS.

The researchers also pointed out that if we eat these fish that continue to build up toxins, they may become a "significant human health issue."


Watch the video: ΨΗΣΙΜΟ ΨΑΡΙΟΥ ΟΛΑ ΤΑ ΜΥΣΤΙΚΑ (July 2022).


Comments:

  1. Tedrick

    Can fill the gap ...

  2. Tojalkree

    normul

  3. Dair

    Wonderful phrase and about time

  4. Allan

    Sorry for interfering, but I need more information.

  5. Irven

    You're right.

  6. Feran

    Bravo, this phrase came in just the right place

  7. Worden

    I agree with you



Write a message