Control of Reproduction in Farm Raised Fish. by Josh Frazier

Posted by Josh Frazier:  Agricultural Research Service scientist have created a technique to block reproduction in farm raised salmon and trout.  This blockade of reproduction is ultimately due to an extra set of chromosomes which switches energy that was once utilized for reproduction to overall growth.  Biologists have discovered that if they intrude in the early stages of development they can produced a fish displaying four sets of chromosomes.   These four set chromosome fish are then crossed with a normal fish thus producing an offspring displaying three sets of chromosomes.  These now sterile fish cannot reproduce with wild/native stock and with their fast growing capabilities are gaining attention in the sport fishing community.



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Ecosystem of Lake Michigan May Crash

By Lonewolf, Xavier: Charlie Kerfoot’s Doughnut has been disintegrating over time, and the prime suspect is European mollusk. Both the Charlie Kerfoot’s Doughnut and the invasive European mollusc existence in Lake Michigan were unknown until W Charlie Kerfoot and his research team revealed it in 1998. The team discovered that the algae doughnut is created during winter storms, which disturb sediments that releases nutrients. The team determined the components of the doughnut, which includes zoo-plankton and phytoplankton. The disappearance of Charlie Kerfoot’s Doughnut could lead to ecosystem downfall. Crumbling of zooplanton and phytoplankton, which makes up the base of the food chain, will cause a struggle for plankton consumer. The chain reaction will continue until it reaches the top of the food chain.

Ancient Coral Reef May Hold Picture of the Past

By Kyle Ekstrand:  9/7/2010 on  To make an accurate assessment of historical oceanic information, it is necessary to obtain an sample of an object which acts as a sort of record keeper from the past. Coral reefs act in this fashion—growing in ways which allow us to gauge the conditions of the ocean based on their growth. In an ongoing study to obtain historical oceanic statistics (temperature, salinity etc), a team of scientists equipped with a massive drill took core samples of ancient fossilized coral reefs from below the Australian Great Barrier Reef. It is suspected that some of the samples from the fossilized coral reef are older than 60,000 years. The team conducting the survey is hopeful that analysis of these samples will reveal a descriptive trend of information which may tell us just what kind of fluctuations the earth’s oceans have gone through in the past, and perhaps what to expect in the future. The study will reach conclusion by July of 2011.

Taming the Wild Tuna

Posted by Tom Foster:  September 4, 2010, NY Times.

Aquaculture scientists have just announced that they have made a step towards converting the Atlantic Bluefin Tuna to a farmed species. With its huge metabolism this poses some issues. Looking at the other farmed fish of the sea, there are problems already at hand. The farmed Atlantic salmon  are causing problems for the native run fish that originally lived in the waters used to culture them. They have also been posted by some as fish not to be eaten because of some harmful chemicals that are accompanied by fish farming. Cultivating these Tuna could arguably be worse for the ocean and humans than farming the salmon has been. Instead of fish meal which is fed to the salmon, Tuna are predatory fish that need forage to survive. It has been found that 5 to 15 pounds of forage fish such as herring and sardines are needed to produce 1 pound of Tuna. At this rate the effects of farming Bluefin could be catastrophic to forage populations. We are running out of these enormous fish. Is the answer to farm them or leave the species alone to possibly be harvested to extinction?

There’s a killer on the loose

Posted by Cory Graham, BBC-9/9/10:

An invasive species has just appeared in the UK. Dikerogammarus Villosus is a species of predatory shrimp that attacks and kills a variety of organisms, including other species of shrimp and even small fish, often leaving them unconsumed.  This is the first instance of this species in the UK and their introduction could have dire consequences for the local ecosystems. Scientists fear that D. Villosus could cause the extinctions of many native species and diminish biodiversity. The extent of the invasion is still unknown and scientists hope that it is not widespread.

Bountiful salmon run reminds us we know little about the fishery

By Nicole Farnham:  Vancouver, August 27, 2010:  Scientists still do not know what to expect when the fish return from the sea every year.  This month in August, the largest fish return took place; this has not happened since the days fisherman used rowboats.  Last year, only one tenth of what was expected on Sockeye Salmon returned to the Fraser River (around 1 million).  Now, one year later, 25 million fish show up to spawn in the Fraser River.  However, “one good year is not a comeback,” according Bruce Cohen.  There has been a study on the Sockeye Salmon since the early 1990s about how their population is decreasing.  There have been warnings about the effect of global warming, pollution, and sea lice may have an effect on these fish, but now scientists think it is to soon to actually have any ideas.  With such a big return of fish to the river it has really given scientists a chance for new research studies.  Creating a management plan for these fish will be hard because we still have so much to learn.  To see the original article:

An octopus mimic?

Posted: 27 August 2010 by BBC news:  A unique octopus adaptation has been discovered – impersonating a deadly fish to scare off predators.  By turning a mottled color and swimming in an undulating fashion, the octopus very closely resembles a local species of toxic flatfish.  Similar to mimics of the coral snake, monarch butterfly, and wasp, this species “co-opts” the defenses of another species without actually having having to incur the cost of the defense.  I am always amazed at the complexity and beauty of octopus behavior.  This is no exception!   To see the original article and a very cool video, click the link below:

Talented octopus dupes predators by impersonating fish

Photo courtesy of the BBC

Diving for Pearls gives young men from Kuwait a connection to the past

Published August 12, 2010 in the NY Times:  It seems Kuwait Oil has spoiled a whole generation of young men used to luxury, shopping malls, and affluence.  Elders from the community are concerned that they have a whole generation of people who have gone ‘soft’.  To avert this, they have created an annual pearl-diving expedition to connect young Kuwaiti men with their pre-oil past. Since 1986, each summer young men (mostly in their teens and 20s) board traditional sailboats and sail for 60 miles to the oyster beds to dive for pearls.  These pearls once drove the economy in Kuwait, which, of course, is now dominated by the Oil and Gas industry.  It’s funny that a fishery for the luxury of pearls is now a source of ‘toughening up’ for a whole generation of men.  Whether it works or not, it is great to see an old fishery tradition thrive. Here is a link to the original article:

Photo Credit: Moises Saman for The New York Times

The Latest on the Oil Spill – is it to blame for all of the fish kills?

Published Aug 24 in the NY Times:  Unfortunately, the Gulf of Mexico has been in trouble long before the big oil spill that occurred this year in April.  However, one of the side effects, it seems, of the oil spill, is that every fish kill is suspected to be related to the BP disaster!  Turns out, it is the same old problem that has been haunting the area for years – anoxic ocean waters due to algal blooms responding to an excess of nutrients from a combination of farmland runoff, septic tanks, and lawn fertilizers delivered by the rivers emptying in to the gulf.  These are known as Gulf ‘dead zones.’  This article reports that a fish kill (5,000-15,000 fish)  at the mouth of a shipping channel in the Gulf was due to hypoxic waters, rather than the oil spill.

Picture of a Fish Kill from US Fish and Wildlife Service

Here is a link to the article:

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