Several types of commonly used fish egg disinfectants increase the risk of swim bladder disorder in fish, a new study from Israel reveals.

In an effort to prevent fungal growth, many fish breeders use various chemicals, such as methylene blue, hydrogen peroxide, acriflavine and chloramine-T to aquariums where eggs are kept. This practise is especially common among breeders who will not let the parents stay with eggs and fry. Many fish species carry out parental care and eggs from such species often depend on one or both parents gently fanning fresh water over them and manually removing any unfertilized eggs from the batch. Without such parental care, the eggs easily succumb to fungi unless the fish breeder adds some type of fungicide to the water.

The new Israeli study, which focused on Angelfish (Pterophyllum scalare), revealed that some of these chemicals may be responsible for a swim bladder disorder in developing fish. In fish suffering from this type of disorder, the swim bladder can not inflate properly and the fry fails to develop into a fully free-swimming adult. Among aquarists, such fish are commonly known as “belly sliders” due to their peculiar way of moving around the fish tank.

Methylene blue

Eggs hatched in the presence of 1, 2 and 5 ppm methylene blue exhibited significant increases in swim bladder non-inflation (11%, 9% and 33%, respectively; none in controls).

Time of exposure to methylene blue was a key factor. Exposure for up to 1 day post-hatch did not affect swim bladder non-inflation, but exposure from 2 days onwards significantly increased swim bladder non-inflation.

Hydrogen peroxide

Hydrogen peroxide at 250 ppm significantly increased swim bladder non-inflation (65% comparing to 27% in the control). Higher concentrations resulted in 100% mortality.

Acriflavin

Exposure to acriflavin at 2.25 ppm, but not 1.25 ppm, significantly increased swim bladder non-inflation (75% and 52% respectively; 20% in controls).

Chloramin-T

Chloramine-T did not significantly affect swim bladder non-inflation.

For more information, see the paper “C. Sanabriaa, A. Diamantb and D. Zilberga (2009) – Effects of commonly used disinfectants and temperature on swim bladder non-inflation in freshwater angelfish, Pterophyllum scalare (Lichtenstein)”. The paper has been published in the journal Aquaculture.

Researchers at Woods Hole Oceanographic Institution (WHOI) unveiled a hazardous cocktail of pesticides when analysing the brain matter of 12 marine mammals; eleven cetaceans and one gray seal stranded near Cape Cod, Massachusetts.

This is the most extensive study of pollutants in marine mammals’ brains and it confirms suspicions of marine mammals being the carrier of a vast array of different chemicals that have found their way into marine ecosystems.

Lead author Eric Montie analyzed the cerebrospinal fluid and the gray matter of the cerebellum in the twelve animals and found them to contain a long row of different man-made chemicals, including a group of especially widespread substances labelled “the dirty dozen” by environmentalists. Many countries banned the “the dirty dozen” as early as the 1970s due to their adverse effect on human health, but they are unfortunately still present in our environment.

Montie didn’t just test for the presence of certain chemicals; he also measured their concentration and found one instance where it was surprisingly high.

“The biggest wakeup was that we found parts per million concentrations of hydroxylated PCBs in the cerebrospinal fluid of a gray seal”, says Montie. “That is so worrisome for me. You rarely find parts per million levels of anything in the brain.”

PCBs are neurotoxicants known to disrupt the thyroid hormone system. Other examples chemicals found in the tested mammals are DDT (diklorodifenyltriklorethane), which can cause cancer and disturb reproduction, and PBDEs (polybrominated diphenyl ethers); a type of flame retardants known to impair the development of motor activity and cognition.

Co-author Chris Reddy, a senior scientist in the WHOI Marine Chemistry and Geochemistry Department, describes the new study as “groundbreaking because Eric measures a variety of different chemicals in animal tissues that had not been previously explored. It gives us greater insight into how these chemicals may behave in marine mammals.”

The results of this study was published online April 17 in Environmental Pollution.

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