A Hawaiian company wants to build the world’s first commercial Bigeye tuna farm, in hope of creating a sustainable alternative to wild-caught big eye.

Bigeye tuna, Thunnus obesus, is the second most coveted tuna after the famous Bluefin tuna and the wild populations have been seriously depleted by commercial fishing fleets. As Bluefin is becoming increasingly rare due to over-fishing, consumers are turning their eyes towards Thunnus obesus – which naturally puts even more stress on this species that before.

In 2007, fishermen caught nearly 225,000 tons of wild Bigeye in the Pacific. Juvenile bigeye tuna like to stay close to floating objects in the ocean, such as logs and buoys, which make them highly susceptible to purse seine fishing in conjunction with man-made FADs (Fish Aggregation Devices). The removal of juvenile specimens from the sea before they have a chance to reach sexual maturity and reproduce is seriously threatening the survival of this tuna species.

“All indications are we’re on a rapid race to deplete the ocean of our food resources,” said Bill Spencer, chief executive of Hawaii Oceanic Technology Inc. “It’s sort of obvious _ well, jeez we’ve got to do something about this.”

Techniques to spawn and raise tuna fry are still being tentatively explored by scientists in several different countries, including Australia and Japan. As of today, most tuna farms rely on fishermen catching juvenile fish for them, but Hawaii Oceanic Technology plans to artificially hatch Bigeye tuna at a University of Hawaii lab in Hilo.

Once the young tunas from the lab have grown large enough, they will be placed in the 12-pen tuna farm that Hawaii Oceanic is planning to build roughly 3 miles off Big Island’s west coast. Each pen will have a diameter of 50 metres (168 feet) and the entire farm will be spread out over one square kilometre (250 acres). If everything goes according to plan, this project will yield 6,000 tons of Bigeye per annum. The fish will not be harvested until it reaches a weight of at least 45 kg (100 lbs).

In an effort to avoid many of the common problems associated with large scale commerical fish farmning, Hawaii Oceanic Technology will place their pens at a depth of 1,300 feet (400 metres) where currents are strong. The company also plans to keep their pens lightly stocked, since dense living conditions are known to increase the risk of disease in fish farms.

Farming pens can cause problems for the environment if fish waste and left-over food is allowed to collect under the pens, suffocating marine life living beneath. Other problems associated with fish farming are the release of antibiotics into the water and the escape of invasive species.

Fish farms can also put pressure on fish further down in the food chain since vast amounts of food is necessary to feed densely packed fish pens, and Peter Bridson, aquaculture manager at the Monterey Bay Aquarium in California, is concerned about how much fish meal the Hawaiian farm will use need to feed its tuna.

“You kind of have to come back to the whole debate on whether these fish are the right thing for us humans to be eating,” said Bridson. “There are lots of other things which have a lower impact in terms of how they are farmed.”

Spencer shares this concern and says Hawaii Oceanic wish to eventually develop other ways of feeding their fish, e.g. by creating food from soybeans or algae. It might also be possible to decrease the need for fish meal by recycling fish oil from the farm itself.

“We’re concerned about the environmental impact of what we’re doing,” Spencer said. “Our whole goal is to do this in an environmentally responsible manner.”

As reported earlier this week, Danish television presenter Lisbeth Koelster was put on trial after deliberately pouring diluted anti-dandruff shampoo into a fish tank housing 12 guppies. The aim of the “experiment” was to demonstrate the level of toxic material in the shampoo. After being subjected to the shampoo, all but one of the fishes died and a Danish veterinarian who watched the show decided to press charges.

Koelster had pleaded not guilty, but the Glostrup court found her guilty of violating animal protection laws. Judge Thomas Lohse said Koelster had “deliberately committed an act of cruelty to animals” and violated animal protection laws. She was however not found to have violated any laws regarding experimentation on animals.

Koelster will not have to pay any fine since the event took place in 2004; four and a half year from now. The judge found this amount of time unreasonable and therefore decided not to fine her.

Is ritual slaughtering of animals on the beach to blame for two fatal shark attacks in the waters off Port St Johns this year?

After two young men died after being attacked by sharks, a task team was set up to investigate the attacks and their conclusion, presented in an official report released on Tuesday, is that the sharks were attracted to the beach by the smell of blood and other animal remains from the ritual slaughtering of animals.

Both the Zambezi shark (Carcharhinus leucas, also known as Bull shark) and the Tiger shark (Galeocerdo cuvier) are notorious scavengers and the smell of blood in the water attracts them to places where they can feast on animal remains.

Also conducive to the shark attacks was the beach’s proximity to the Umzimvubu River, “a well known nursery ground for Zambezi sharks”, said the Natal Sharks Board team of experts. In a statement issued jointly with the department of environmental affairs and tourism, the team said newborn and juvenile Zambezi sharks had been captured in the Umzimvubu River.

The team also stated that sewerage entering the river or the sea probably wasn’t a significant factor in the attacks.

Picture by: Andy Murch diver photographer  (CC3)

To prevent future attacks, the team recommended having the rituals moved away from this popular beach and not to be carried out on any other beach used by swimmers and surfers. In addition to this, signs ought to be erected warning visitors of the possibility of shark attacks. The team recommends any swimmers to stick together in groups and not to venture far out from the shoreline.

Tree deaths in two years; two of them in 2009

In January, Wild Coast Coast lifeguard Sikhanyiso Bangilizwe, 27, was fatally attacked by a shark off Port St Johns, making him the second lifeguard fatally attacked by sharks in this area in two years. Just two months after the January attack, a 16-year-old died of his injuries 30 minutes after being wounded by a shark in the same region.

After the death of Bangilizwe, his nephew, Lumka Bangilizwe, also a lifeguard, blamed the attack on an absence of shark nets and the animal rituals conducted there by traditional healers.

“Then what do you expect? Sharks smell all of that and come near where people are swimming,” he said claiming the municipality knew about the practice, but did nothing to stop it.

Environmental experts, meanwhile, suggested that untreated sewage entering the water might have attracted smaller fish which in turned lured the sharks near, but the municipality denied any spillage of sewage into the ocean.

An important step in the ground-breaking Clean Seas Tuna breeding program was taken today when millions of dollars worth of Southern Bluefin Tuna was airlifted from sea pens off South Australia’s Eyre Peninsula to an on-shore breeding facility at Arno Bay.

The Southern Bluefin Tuna is a highly appreciated food fish and the remaining wild populations are continuously being ravished by commercial fishing fleets, despite the species status as “critically endangered” on the IUCN Red List of Threatened Species.

The Australian tuna breeding program is the first of its kind and will hopefully help ease the strain on wild populations. The air transfer was made to provide the breeding program with an egg supply ahead of the spawning period.

As reported earlier, the Australian company Clean Seas Tuna managed to successfully produce Southern Bluefin Tuna fingerlings in March this year and they are now hoping to commence commercial production of the species no later than October.

WWF Australia’s fisheries program manager Peter Trott says any advancement that would reduce pressure on wild tuna stocks is welcome, but he also cautions against the environmental problems associated with large-scale aquacultures. It is for instance common to use other fish to feed farmed fish, which can put pressure on wild fish populations.

Researchers at Tokyo Institute of Technology have undertaken what is believed to be the very first CT scan of eggs inside a coelacanth fish.

“I was surprised to see that all the eggs were the same size,” said Dr Norihiro Okada, a bioscience professor at the university and a member of the research team. “I hope to do research into why this is.”

Each coelacanth fish was roughly 170 cm (67 in) long and weighed about 70 kg (154 lbs). After being captured off the coast of Tanzania, both fishes were frozen and send to Japan where the CT scan showed how each fish contained roughly 40 eggs; each egg being about 7 cm (almost 2 ¾ in) in diameter.

The eggs of a coelacanth are never released into the water because the offspring hatch while still inside their mother. The young fish sometimes reach a length of 30 cm (12 in) before leaving their mother’s body.

Coelacanths were long believed to have gone extinct around the same time as the dinosaurs, until scientists realized that these fishes actually turn up in the nets of African and Asian fishermen now and then. The first confirmed finding is from 1938 when a specimen was captured in the Indian Ocean.

Coelacanths are of special interest to evolutionary biologists since they are thought to represent an early step in the evolution of fish to amphibians. You can read more about this in our coelacanth article.

A sinking date has now been set for the retired military vessel scheduled to form an artificial reef off Key West in Florida. If everything goes according to plan, Gen. Hoyt S. Vandenberg – a 523-foot-long military ship that used to track Russian missile launches during the Cold War – will be sunk seven miles (11 km) south of Key West on May 27.

“Our sink window opens Wednesday, May 27, and that’s the date we’re currently targeting,” said Jim Scholl, Key West’s city manager and project administrator. “However, there are factors that could delay the scuttling, including weather and other unforeseen circumstances.”

A definite time for the sinking has not yet been set, but the event will probably take place during late morning, officials said.

During the sinking, a one-mile perimeter will be enforced on the water and in the air by the U.S. Coast Guard, the Florida Fish and Wildlife Conservation Commission, and other U.S. law enforcement agencies.

Gen. Hoyt S. Vandenberg is currently waiting in Key West Harbor.

To demonstrate the level of toxic material in a brand of anti-dandruff shampoo, a Danish television presenter poured diluted shampoo into a fish tank on a 2004 episode of the consumer affairs show she fronted.

Lisbeth Kloester, a television presenter on the Danish public channel DV1, is now on trial for causing unnecessary suffering to animals.

After being subjected to the shampoo, all but one of 12 guppy fish housed in the aquarium died within four days and a veterinary practitioner watching the show decided to press charges. Under Danish law, causing unnecessary suffering to animals is an offence and Kloester could face a fine if convicted.

Kloester has pleaded not guilty and her lawyer Tuge Tried said he expected his client to be acquitted at the trial on Tuesday.

“The allegations are this experiment caused the fish’s fear and suffering…but expert witnesses told the court on May 12 that this was not the case,” he said. “Fish are killed by suffocation in industrial fisheries and we throw live lobsters into boiling water, but we don’t press charges against fisherman or restaurant owners.”

A new cichlid species has been described from the Río Negro and Río Tacuarí basins in the Uruguay River drainage by Uruguay ichthyologists Iván González-Bergonzoni, Marcelo Loureiro and Sebastián Oviedo.

The fish has been given the name Gymnogeophagus tiraparae (picture here) after María Luisa Tirapare, a Guaraní woman who founded the town of San Borja del Yí (no longer existing) close to one of the collecting localities for this fish.

Gymnogeophagus tiraparae is found in larger rivers with clear water over both sandy and rocky bottoms where underwater vegetation is scarce. The fish is decorated with two horizontal series of moderately elongated light blue dots between the dorsal fin spines, and a series of light blue stripes between the soft rays, sometimes merging with the second series of elongated dots. Between the series of dots, the body of the fish displays a red ground colour. On this spotty fish, the caudal fin is also adorned with dots, which are vertically aligned on the distal border. The body has no transversal bands at all. Another important characteristic is how the adipose hump on the head is located deeper than the upper border of the dorsal fin.

The description was published in the most recent issue of the journal Neotropical ichthyology.

González-Bergonzoni, I, M Loureiro and S Oviedo (2009) A new species of Gymnogeophagus from the río Negro and río Tacuarí basins, Uruguay (Teleostei: Perciformes). Neotropical Ichthyology 7, pp. 19–24.

* Guaraní is a group of culturally related indigenous people of South America who speak the Guaraní language. They are chiefly found between the Paraguay River and the Uruguay River.

In a recent issue of the journal Zootaxa, researchers Gertrud Konings-Dudin, Adrianus Konings and Jay Stauffer have described and named three new species of cichlid from the genus Melanochromis; two of them being fairly widespread among aquarists keeping African cichlids.

All three species hail from the eastern shore of Lake Malawi and belong to the group commonly referred to as Mbuna cichlids among fish keepers.

The fish you may have been offered under the name Melanochromis sp. “northern blue” (picture here) has been given the full name Melanochromis kaskazini. Just like its old trade name suggests, this Malawi cichlid hails from the northern part of the lake and the word kaskazini was choosen since it is the Kiswahili word for “northern”. (Kiswahili, also known as Swahili, is an African language spoken along the continent’s eastern coast.)

The “blue” part of its old trade name is a reference to the colour of the males; they are cobalt blue, while the females are white with a yellow or orange anal fin. Melanochromis kaskazini looks quite similar to its close relative Melanochromis lepidiadaptes but the latter one sports a suit of mensural characters not seen in Melanochromis kaskazini.

The Mbuna cichlid previously sold in fish stores as Melanochromis sp. “auratus elongate” (picture here) is from now named Melanochromis mossambiquensis. The fish is named after the country Mazambique since it is found along the Mazambique shore of Lake Malawi; a lake shared between the countries Mazambique, Malawi and Tanazania.

In Melanochromis mossambiquensis, the female fish is adorned with yellow stripes on the belly and a midlateral and dorsolateral black stripe that is narrower than the submarginal black band in the dorsal fin. The yellow stripes do not cover the entire lower abdomen, and the caudal fin features black spotting. The male fish is brown/black with white dorsolateral and midlateral stripes, and he displays a suite of mensural characters.

The third Mbuna cichlid, which does not have any trade name, has been given the scientific name Melanochromis wochepa due to its small size. Wochepa means “small” in Chinyanja, also known as Chichewa, a Bantu language spoken in south-central Africa.  I have not been able to find a picture at this time.

Melanochromis wochepa males are blue without any white striping, while the females sport a submarginal dorsal band that is wider than the mid-lateral and the dorsolateral stripe, thin abdominal yellow stripes never covering the entire lower abdomen, and a suite of mensural characters. The vomer is steep-angled in both sexes.

For more information, see paper published in Zootaxa: Konings-Dudin, G, AF Konings and JR, Jr Stauffer (2009) Descriptions of three new species of Melanochromis (Teleostei: Cichlidae) and a redescription of M. vermivorus. Zootaxa 2076, pp. 37–59.

Have you ever tried to keep a seahorse alive in an aquarium only to fail miserably? Well, to add insult to injury, these creatures seem to be much sturdier than previously believed, because how else can you explain the amazing survival of a British seahorse found three miles inland in Weymouth, Dorset?

“I was just popping out to buy a paper and I looked down and saw this funny object by the pathway, said Karen Warr, 46, who discovered the unusual visitor outside her house. I got a bit closer I saw it was a seahorse. They are very distinctive. I did wonder what on earth it was doing there but I could see it was still breathing so I dashed inside and the only thing I could think of to pick it up with was a fish slice. I put it in the bowl I use for my scales and filled it with tepid water. It was still breathing but wasn’t moving much, it must have been in shock.”

How long the seahorse had been lying on the ground gasping for air is unknown, but Warr put her cat out three hours earlier; a cat fond of eating creatures from the sea. “’It couldn’t have been there then otherwise he would have eaten it”, Warr explained.

After saving the seahorse from suffocation, dehydration and the possible return of the hungry cat, Warr made a call to the nearest Sealife Centre. “I called the Sea Life Centre because they are only down the road and somebody came out to see me.”

The resilient seahorse, an adult female who has been given the name Pegasus, is now recuperating from her adventures in a dark quarantine aquarium at the Sea Life Centre where she is gradually being acclimatized back to saline conditions.

“They can go into shock if they are not treated carefully”, says Display supervisor Claire Little. “She seems fine now but we will continue to monitor her while she is in quarantine for the next 28 days. She has been quite lucky. They are fairly hardy creatures but it was obviously just very good fortune that she was found straight away and we were called.”

Exactly how a seahorse ended up three mile inland remains a mystery, but Warr and Little both agree that it was most likely dropped by a seagull.