Fish females subjected to stress produce highly active offspring but the risk of abnormalities also increases, according to new research carried out by Dr Monica Gagliano, a research fellow with the AIMS@JCU joint venture, and Dr Mark McCormick from the ARC Centre of Excellence for Coral Reef Studies at the James Cook University.

The research focused on the Ambon damsel fish (Chromis amboinensis), a common reef species in the Indo-Pacific, and has deepened our understanding of how stress factors affect not only the adult fish themselves but also their offspring. Being more active than normal affects survival and more active offspring will therefore have important implications for fish populations in a changing environment.

In their laboratory testing, Dr Gagliano and Dr McCormick exposed fertilized Ambon damsel eggs gathered from the wild to various amounts of the stress hormone cortisol. Previous studies have shown that female Ambon damsels release cortisol from their ovaries when subjected to environmental stress. Fish that lived on reefs with few predatory fish around and little competition released less cortisol than those who lived in environments where they had to deal with a lot of competition and predators.

In addition to making the offspring more active, high doses of cortisol also increases the risk of developmental defects.

“If the mother fish is more stressed and she passes on more cortisol, then the offspring will have a faster developmental rhythm and therefore errors will be more likely in their development. One likely result of this is that the offspring are born asymmetrical,” Dr Gagliano said.

“These baby fish can’t make these important hormones until later in life, so their whole initial development is determined by hormones they obtain from their mothers,” Dr McCormick added.

Developmental errors can naturally cause serious problem for fish and lower their chances of survival. In 2008, Dr Gagliano and her colleagues showed that fish born with asymmetrical ear bones have a hard time handling the open ocean stage of their life and that a large percentage of these fishes die before being able to find a reef to settle on. The asymmetry hurts the fish’s hearing ability and makes it difficult for it to pick up reef-related sounds.

In her new research project, Dr Gagliano has been able to show that maternal stress has a large measurable effect on the shape of ear bones. Offspring subjected to a high dose of cortisol are more than twice as likely to have asymmetrical ear bones compared with those that received no dose of cortisol.

You can find more information in the study published in Oecologia.

Nearly 40 miles (60 km) of beaches along the Australian east coast has been declared a disaster zone due to the massive amounts of oil and chemicals that leaked out from a Hong-Kong registered cargo ship on Wednesday.

According to Queensland state official, the beaches along the Moreton Island[1], Bribie Island[2], and the southern area of the Sunshine Coast[3] have taken the hardest hit and the oil spill is the worst to affect Queensland in decades. You can see an animation showing the sequence of events here: http://www.msq.qld.gov.au/resources/file/eb697a008fb8b4f/Pacific_animation.wmv

The Hong-Kong registered ship, a 185 metre container ship named Pacific Adventurer, was enroute from Newcastle to Indonesia via Brisbane when it got caught in Cyclone Hamish and lost over 30 shipping containers in the heavy seas about seven nautical miles east of Cape Moreton. The falling containers damaged the ship which resulted in heavy fuel oil getting into the water.

As of now, the Environmental Protection Agency, Emergency Services, and local government are working together in an effort to limit the consequences of the spill. Massive cleaning up efforts has been launched and affected animals are being treated by trained wildlife carers. According to Australian Prime Minister Kevin Rudd, the clean-up effort could end up costing millions of dollars.

Queensland State Premier Anna Bligh says that Swire Shipping, the company owning the ship, could end up paying for the clean-up. “We are investigating the entire incident and if there is any basis for a prosecution, we will not hesitate to take that action – the total cost of the clean-up will rest with this company.” If found guilty of environmental breaches, Swire Shipping may also be facing fines of up to AUS $1,500,000 (US$ 977,000).

Initially, reports of the accident contained the number 20-30 tonnes of leaked oil, but the true number has now turned out be ten times this figure – a shocking 230 tonnes of oil. Oil is not only dangerous to wildlife in the short run; it is carcinogenic and can cause long-term effects.

The oil is however not the only problem; the shipping containers from the Pacific Adventurer where filled with ammonium nitrate fertiliser and environmental experts now fear that the nutrients will cause algal blooms and oxygen scarcity in the region. Radar-equipped aircrafts are therefore currently searching for the missing 620 tonnes of chemical fertilizer, in hope of finding as many containers as possible intact.

In a statement from Swire Shipping the company ensures that it and its insurers will meet all their responsibilities.

“The company very much regrets the environmental impact caused as a consequence of the vessel being caught in Cyclone Hamish. The company and its insurers will meet all their responsibilities. It has chartered a helicopter to survey the extent of the oil slick and to try to locate the containers. The company is in contact with Queensland government officials and has offered to provide any information that will help the clean up campaign to be targeted efficiently to minimise beach pollution and environmental impact. The companys oil pollution expert is arriving from the Middle East tonight to assist local authorities and technical experts with the clean up.”

You can find more information about the disaster on Maritime Safety Queensland, a government agency of Queensland Transport:
http://www.msq.qld.gov.au/Home/About_us/Msq_headlines/Headlines_pacific_adventurer

For information about volunteering or reporting sick or injured wildlife, contact the Queensland Environmental Protection Agency: http://www.epa.qld.gov.au

Statements and information from Swire Shipping can be found here:
http://www.swireshipping.com/web/news.jsp?fid=368

War on clams has been declared at Lake Tahoe, a large freshwater lake in the Sierra Nevada Mountains of the United States. Scuba divers have been enrolled in a 400,000 USD project aiming to completely rid the lake of all Asian clams. The anti-clam endeavour is scheduled to begin in mid-March and is a combined effort by the governments of Nevada and California.

The Asian clam (Corbicula fluminea) is native to Asia and parts of Africa where it inhabits streams, canals and lakes. In this part of the world it is a natural part of the ecosystems and is even known as the prosperity clam or good luck clam. The Asian clam was introduced to North America in the 1920s by Asian immigrants for whom it was an appreciated source of food. It would however take until 2001 before the first specimens were encountered in Lake Tahoe. Since the first finding, the clam has been collected from numerous locations Tahoe’s southeast shore and authorities now fear that it will pave the way for even more dangerous invasive species such as the Ukrainian Quagga mussel (Dreissena rostriformis bugensis) and the Russian Zebra mussel (Dreissena polymorpha).

”We’re concerned they could create a positive settlement situation for the quagga mussels,” says Steve Chilton, aquatic invasive species coordinator for the U.S. Fish and Wildlife Service. ”We’re basically looking at all avenues through which the quagga mussel could get into the lake and eliminate that risk factor as much as possible.”

Steps so far have primarily focused on mandatory boat inspections to ensure no mussels are attached to them when they launch into the lake, but scuba divers participating in the new anti-clam project will actually be removing Asian clams from Lake Tahoe’s southeast shore. Starting in mid-March, divers will place plastic sheets, so called bottom barriers, over selected clam beds in order to deprive the clams of oxygen and nutrients. Divers will also carry out ”diver-assisted suction”, e.g. manually vacuum clams off the bottom of Tahoe.

”This needs to be done. We have to get our hands around the Asian clam problem,” Tahoe Regional Planning Agency spokesman Dennis Oliver told the Reno Gazette-Journal. ”We need to find out what works and what works best. Once we know that, we can develop a program.”

Invasive mussel species are known to form huge populations in environments where they lack natural predators and can for instance clog water intakes, attach themselves to boats and docks, and litter sandy beaches.

North America is not the only continent with an Asian mussel problem; Corbicula fluminea has begun to spread throughout Europe as well. It was found in the Rhine as early in the 1980s and then gradually found its way into the Danube through the Rhine-Maine-Danube Canal. In 1998 the first specimens were found in the Elbe and the species is now also present in the rivers of Portugal.

The oceans of the world absorb a large part of the carbon dioxide released into the atmosphere by us burning fossil fuels, burning forests to make room for fields, etc. This have helped slow down global warming, but new studies shows that it might have a devastating effects on certain fish species such as clown fish. Tests performed on clown fish larvae have shown that increased levels of carbon dioxide can make them disoriented an unable to find a suitable home and avoid predators. The pH level in the ocean has dropped 0.1 since pre-industrial times due to the absorption of carbon dioxide and researchers believe that it will fall another 0.3-0.4 before the end of this century.

This increased acidicy of the water can cause serious problems for clown fish larvae, since clownfish larvae lose the ability to sense vital odours in more acidic waters – probably owing to the damage caused to their olfactory systems. Kjell Døving (Oslo University), co-author of the rapport that was published in US journal Proceedings of the National Academy of Sciences, says “They can’t distinguish between their own parents and other fish, and they become attracted to substances they previously avoided. It means the larvae will have less opportunity to find the right habitat, which could be devastating for their populations.“

The research indicates that other species might be affected in a similar way and might have a hard time finding their way to suitable habitats if carbon dioxide levels raises in the oceans.

About the study

The study was executed in such a way that the researchers checked how well clownfish larvae could detect smells in normal sea water (pH 8.15) and how well they could detect odours in more acidic water (at levels predicted to be a reality around the year 2100 and later). The test showed that at pH 7.8 the larvae stopped following scent trails released by reefs and anemones and started following sent trails they would normally avoid; scents that are associated with environments not suitable for clown fish. The larvae also lost the ability to use smell to distinguish between their parents and other fish. At pH 7.6 the larvae were unable to follow any kind of odour in the water, and instead swam in random directions.

The yearly manatee count revealed a record number of manatees this year. The survey counted 3807 manatees which is about 500 more than the previous record from 2001.

Manatee with calf

Experts do however say that it is too early to cheer and that one shouldn’t read too much into this as this year offered ideal conditions for spotting manatees. Cold temperatures made the manatees gather in warm clear waters around nuclear power plants and natural springs making them easy to spot. The previous record year 2001 – when about 1000 more manatees were counted than the year before and the year after – also offered similar conditions. It is important to remember that the count doesn’t reflect the actual number of manatees but rather a minimum number of manatees as not all of them can be found and counted.

Wildlife managers and manatee advocates do however call the number encouraging and say that it might indicate that the manatee population is slowly recovering as the number is higher then the numbers the previous record year. They say that the count supports population models suggesting manatees are increasing in Northwest Florida, along the Atlantic Coast and on the upper St. Johns River. Pat Rose, executive director of the “Save The Manatee Club” does however add that the numbers in Southwest Florida and the Everglades, home to about 40 percent of all manatees in Florida, are believed to be in continuing decline. Data on this region is however much more scare as it is hard to keep track on the animals in the dark waters found in this area.

Considering that scientists earlier estimated the manatee population in all of Florida to be below 1500 animals it can only be concluded that the conservation process have been a success and with 3807 animals it seems clear that the situation is much better than it once were, even if there still is much work to do to protect these gentle giants.

Wild-caught pets are often recommended against, since the harvest of wild caught specimen may deplete wild populations. In the Brazilian rainforest, the harvesting of popular aquarium species such as cardinal tetras have however helped prevent deforestation and made it possible for local residents to earn a living without resorting to logging, mining, cattle ranching, and slash-and-burn agriculture.

“All this is very counter-intuitive,” says Scott Dowd, an Amazon biologist at the New England Aquarium who has been researching the dark acidic waters of Rio Negro, a major Amazon tributary in Northern Brazil, for the past two decades. “You would think biologists would not want to take fish out of the rainforest. But the fish are the key to miminizing deforestation. The people’s other economic options – timber harvest, cattle ranching and gold mining – are environmental disasters.”
The Rio Negro region has been a major fish exporter for over half a century and 60 percent of local populations rely in this source of income for their sustenance. Since deforestation is known to be detrimental to the survival of financially valuable fish species like the cardinal tetra fish, the Brazilian government has protected the Rio Negro rainforest from logging and burning – at least until now. The situation may be about to change dramatically as more and more aquarium shops switch from wild-caught fish to farm-raised specimens. Wild-caught specimens are used to the dark, soft and highly acidic water conditions of Rio Negro, while farm-raised fish tend to be acclimatized to common tap-water conditions (i.e. clear water that is not very soft or acidic) and therefore easier to keep.

To prevent the market for wild-caught Rio Negro fish from collapsing, Dowd is participating in a “Buy a Fish, Save a Tree” campaign. “The local fisheries look like they are headed for collapse”, Down explains. “But there’s hope that this threat can be addressed. If you ask fish hobbyists if they care about the environment, a very high percentage say they care about it deeply.”

Dowd hopes that the “Buy a Fish, Save a Tree” branding will help Brazilian fish harvesters to benefit from the growing trend of cause labelling, such as Fair Trade and FSC (Forest Stewardship Council).

Another important step in making wild-caught Rio Negro fish a popular alternative to farmed-raised specimens is to adapt them to normal aquarium conditions, and the New England Aquarium is therefore helping local fishermen to efficiently acclimatize wild-caught tetras to a pH-value around 7.0.

Dowd also hope to take advantage of the Internet, by assigning lot numbers to every batch of aquarium fish caught in Rio Negro. “Imagine if you could go online and see a video of the actual fisherman who caught your tropical fish, says Dowd. “I want hobbyists to know directly how their choices can affect people thousands of miles away and how they can make a contribution to saving the rainforest. Things don’t look good, but we can begin to turn all of this around.”

Vast amounts of creatures looking like jelly balls have begun to appear off the eastern coast of Australia, and researchers now suspect that these animals may help slow down global warming by moving carbon dioxide from the atmosphere to the ocean floor.

The proper English name for this “jelly ball” being is salp. A salp is a barrel-shaped free-floating tunicate that moves around in the ocean by contracting and relaxing its gelatinous body. Just like the other tunicates, the salp is a filter feeder that loves to eat phytoplankton and this is why it has caught the attention of scientists researching global warming.

Phytoplankton are famous for their ability to absorb carbon dioxide from the top level of the sea, and a salp feasting on phytoplankton will excrete that carbon dioxide in the form of faeces. The faeces will drop to the ocean floor; thus lowering the amount of carbon dioxide present in the upper part of the ocean. Since the carbon dioxide found in this level of the sea chiefly hails from the atmosphere, phytoplankton and salps are a great aid when it comes to removing carbon dioxide from the air. Salps will also bring carbon down to the ocean floor when they die, which happens fairly often since the life cycle of this organism is no more than a few weeks.

Salp species can be found in marine environments all over the world, but they are most abundant and concentrated in the Southern Ocean near Antarctica where it is possible to encounter enormous swarms of salp. Over the last 100 years, krill populations in the Southern Ocean have declined and salp populations seem to be replacing them in this cold ecosystem. According to researcher Mark Baird of the Australian Commonwealth Scientific and Research Organization (CSIRO), the amount of salps in the waters off Australia are also on the increase, at least according to a survey carried out last month by CSIRO and the University of New South Wales.

While salp may help slow down global warming, their increase may also cause problems. Salp has a fairly low nutrient content and salps replacing nutrient rich krill in the Southern Sea may therefore prove detrimental for oceanic animals higher up in the food chain.

A six-month long investigation by the Florida Fish and Wildlife Commission (FWC) has led to the arrest of seven adults and one juvenile in Tampa. The arrested persons are believed to have been involved in various illegal activates concerning marine life, including catching protected sharks, sea horses, peppermint shrimp and bay scallops in Floridian waters, and exporting illegally obtained marine life to Europe. They are also suspected of having sold bait fish and bait shrimp as food for human consumption.

According to the FWC, the ring is believed to have operated for at least five years before attracting the attention of FWC. The ring lost a lot of animals due to poor maintenance, but the FWC still believes the group managed to sell $600,000 worth of peppermint shrimp alone.

The Florida Fish and Wildlife Conservation Commission came into existence on July 1, 1999. The Investigations Section of the commission conducts both overt (uniform) and covert (plainclothes) investigations, and one of their tasks is to target hard-core commercial violators by conducting long-term undercover investigations. In 2003, the Investigations Section made 554 arrests/warnings and seized 130 illegally possessed specimens of fish and wildlife including a cougar, tigers, leopards, primates, exotic deer, venomous reptiles, protected birds and exotic aquatic species.

The U.S. Bureau of Reclamation is now carrying out tests in hope of finding out if bacteria can aid them in their struggle against invasive mussel species that are threatening to spread across the West’s waterways.

During the summer of 2008, a preliminary test was executed at Davis Dam on the Colorado River at Laughlin in Nevada. In this dam, Quagga mussels (Dreissena rostriformis bugensis) were exposed to dead bacteria of the Pseudomonas fluorescens species, a non-infectious bacterium that is commonly found in water, soil and food.

Quagga Mussels

During the first test the mussels where exposed to bacteria in jars, but the next test will take place in 10-20 gallon aquariums to in order to more accurately mimic real dam conditions. Water will flow through the aquariums, but will not be released back into the river – it will instead be disposed of through an evaporation pond. A third experiment is also planned, where bacteria will be released in a domestic water intake line which is currently encrusted with a 2-3 inches thick layer of mussels (approximately 5-7.5 cm).

“We are always looking for new, more effective techniques for managing mussels, and this one looks very safe and very promising,” says Reclamation scientist Fred Nibling. “We’ll have a series of tests where we’re going to be testing off-line, off the river, so we can have the data to where we can apply for the permits to test elsewhere.

If the initial testing proves to be successful, the Bureau of Reclamation hopes to have a larger scale test approved by the Environmental Protection Agency.

The U.S. Bureau of Reclamation got the idea to use Pseudomonas fluorescens from Daniel Molloy, a researcher at the New York State Museum who discovered that both zebra and quagga mussels died if they ingest the bacterium. He confirmed the effect in 1998 and the method was patented by the museum. Eventually, the Californian firm Marrone Organic Innovations was awarded a National Science Foundation grant to commercialize the technology.

According to Molloy’s research, a mussel needs to ingest a high density of a strain of the bacteria in order for the bacteria to be lethal. If the density is high enough, a toxin inside the bacterium cell will efficiently devastate the digestive tract of the animal.

One advantage with Pseudomonas fluorescens compared to conventional anti-mussel treatments like chlorine is that mussels recognize chlorine as dangerous and close their feeding valves to keep the chemical out. They do however happily devour Pseudomonas fluorescens. Another important aspect is that research has found that Pseudomonas fluorescens does not kill fish or shellfish.

If large scale testing also proves successful, the Bureau of Reclamation say they wish to meet with municipal public works and water authority officials before the bacterium is put into general use. “We want to make sure they’re very comfortable and they have a chance to ask questions,” says Nibbling.

Zebra mussels

A study published in the online scientific journal PLoS Biology on October 27 with the provocative headline “Dams make no damn difference to salmon survival”[1] is now being questioned by a number of scientists, including several co-authors of the study.

According to the study, young fish running the gantlet of dams on the Snake and Columbia rivers did just as well as youngsters in an undammed river. Dams are widely regarded as one of the main reasons behind the sharp decline of salmon in North America’s western rivers and a study claiming that dams make no damn difference for salmon survival is therefore destined to receive a lot of attention from dam proponents and dam critics alike.

While a number of scientists, including several co-authors, are questioning the results and cautioning about what conclusions can really be drawn from them, lead-author David Welch stands by his report. “We’re not saying that the dams have never had an effect,” says Welch. “What we all have to ask ourselves is, if survival is up to the level of a river that doesn’t have dams, then what’s causing survival problems?”

Welch has already warned against overstating what the study proves, and continues to do so. According to Welch, the results of the study do however suggest that dams might not play such a big role in the fate of endangered Columbia River salmon today, and that the situation in the ocean – where the salmon live until it migrates upstream to spawn – is of higher importance than river conditions.

Michele DeHart, manager of the Fish Passage Center[2], strongly disagree with the conclusions drawn from the study. “There’s a huge mass of scientific literature that documents the impacts of dams. It’s just huge,” says DeHart. “It’s like saying, ‘Gosh, I just did this comparison and smoking does not cause cancer.’ Would you change your mind?”

In the study, the survival rate of young salmon and steelhead heading for the ocean (so called smolts) was measured in the rivers Columbia and Snake, which are heavily dammed, and in Fraser River, which has no dams at all. To the researchers’ surprise, the recorded survival rate was around 25 percent for all smolts, regardless of whether they travelled in dammed or undammed waters. If you take into account that smolt in the Columbia River actually have to travel a longer distance, it even looks as if smolt traversing dammed waters are doing better than their counterparts in the undammed Fraser.

Environmental groups are now claiming that comparing the different rivers with each other is like comparing apples and oranges, and co-author Carl Schreck, head of the Oregon Cooperative Fish and Wildlife Research Unit at Oregon State University, warns that the study could have failed to account for fish that die in the ocean due to the stress they have been subjected to while traversing dams in Columbia and Snake.

Ed Bowles, biologist and head of fisheries for the Oregon Department of Fish and Wildlife, says that it would be better to compare how similar fish, e.g. spring Chinook, do when they spawn in the same river – some above dams and some below.