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The Bahamas recently signed a Memorandum of Understanding, regarding the building of two ocean thermal energy conversion plants (OTEC).  “The new plants will be the world’s only commercially viable OTEC plants that will produce fossil-fuel free electricity, potable water and sustainable food production in the form of aquaculture, mariculture and chilled soil agriculture.” 

The Bahamas Electrical Corporation (BEC) was happy to jump on a chance to reduce the country’s dependency on fossil fuel, with the involvement of the Ocean Thermal Energy Corporation. The plants will be the first to use ocean water in creating fresh water and clean energy.  


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OTEC Plant Diagramme (click to enlarge)
Something the capital city, Nassau, of The Bahamas has been desperate for.  Nassau, up until 2011 imported its fresh water daily by barge from Andros.  A ridiculous concept, considering more than 60% of the country’s population lives on this one island that accounts for 1.5% of the country’s landmass!

The OTEC plants are ideal for tropical environments, and once running will help other countries look towards future-clean technologies.   These ‘prototype’ OTEC plants, will lead to the addition of others, with advancements on efficiency and load capacity.   The BEC serves almost 85% of electricity in The Bahamas; resourcefulness is required in many of the isolated Out Islands.


 
 
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Bonefish
Little is known about bonefish spawning, despite the fact it is one of the most populous sport fish in the Caribbean.  
A group of researchers tagged bonefish in Eleuthera, with ultrasonic transmitters to track their movement.  Tagging over 60 bonefish in two years, they have learned some insight into the life cycle of a bonefish.

One of the most interesting facts discovered is that for a few days, twice a month (new and full moon) from October to May schools of thousands of bonefish to spawn.  It was observed that at twilight the schools move out of the shallows to the edge of the drop and spawn.  Scientists believe the releasing of fertilized eggs out at sea increases the dispersal and the tides only exaggerate this. 

Now that scientists know that bonefish spawn at drop-offs, efforts can be made to establish conservational areas, and more accurately observe bonefish populations.  It is extremely interesting a fish that spends its entire life in the shallows, mates in the deep ocean.

 
 
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Male (top) & Female: Blainville's Beaked Whale
Andros, is the largest island in The Bahamas, one of the largest barrier reefs in the world boarders its east coast before plummeting thousands of feet into the "Tongue of the Ocean."

The Tongue of the Ocean is a deep, enclosed trench that allows for unique submarine projects.  Because of this the Naval Undersea Warfare Centre already had the technology a research team from Duke University  would need to conduct their observational experiments.

While scientists already knew Blainsville's beaked whales prey on fish and squid at a range of 400-1000 meters.  These whales can hold their breathe for up to an hour diving as deep as 3300 feet!

Evidence of beaked whales using oceanic features to find prey has been found.  Scientists believe this is accomplished by using specific information, namely salinity, temperature to track.  This is the first time information on the feeding habits of Blainsville's beaked whales have ever been established.


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Satellite Image of Observation Area
Evidence of beaked whales using oceanic features to find prey has been found.  Scientists believe this is accomplished by using specific information, namely salinity, temperature to track.  This is the first time information on the feeding habits of Blainsville's beaked whales have ever been established.

Observing beaked whale behaviour at depths is important especially because of the increasing amount of noise pollution humans are unleashing on the ocean.  In 2000, beaked whales were found stranded throughout The Bahamas, the timing coincided with naval sonar exercises in the Tongue of the Ocean.  It should not take situations like this to raise awareness, but sometimes the dramatic affect works...

After the beachings, scientists begun analyzing acoustic data, using 82 hydrophones mounted to the seafloor in the Tongue of the Ocean.  They found that "scattering layers" (represent prey) were denser on the western side than the east.  In knowing this, if further naval marine experiments need to be conducted, they can attempt to minimize the noise in relation to whales.  

 
 
On December 12, 2011 two fishermen found an albino lobster off Dorset, UK.  A staff member from the Weymouth Sea Life Park said that only one or two have been seen in the UK in the last 20 years.  The specimen found was around 30 years old, an was a large specimen around 15.7"  (lobsters can grow up to 30" and live up to 50 years).  

Most lobsters colouring is produced by mixing of yellow, blue and red pigments, causing their bodies and claws to be redder and their legs to be greener.  (By the way, lobster are not red until they are cooked, they are generally brownish-green alive).  
White is in fact not the only unusual colour of lobster, there are also yellow and blue lobster.  The albino lobster's white-colour is caused by a lack of melanin.   The rarest, around 1 in 100 million lobsters are believed to be albino.  

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Blue lobsters are the most common discolouration found, an estimated 1 in 2-5 million lobsters are blue.  In 2009, a New Hampshire fisherman thought he'd caught a beer can at first after catching a blue lobster!  There are also yellow lobsters, at about 1 in 30 million, and have been found from Nova Scotia to Hawaii.  There are even calico lobsters, and occasionally split-coloured lobster that are different colours on different sides.  None are as rare as the elusive albino lobster though.

Interestingly, observers are waiting to see if the albino lobster,  festively named, "Santa Claws," will moult into another albino layer, or if albinism in lobster is a temporary condition.

 
 
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Diving Penguins
Scientists have been researching how penguins "decide" to return to the surface to breathe.  Studies have concluded they use wing-flaps, similar to how divers use kick-cycles to measure an average distance and time. 

 Observing more than 15000 penguins, some diving for food, others foraging holes in the ice, and others free diving.  On average the birds flap their wings 237 times on each dive.  Flapping underwater has the same affect as birds flapping in the air; it allows the penguin to dive and surface aqua-dynamically.  

Dr. Shiomi, from the University of Tokyo stated he believes penguins' dives are constrained by how much power their muscles can produce after every pre-dive breath.  Accordingly, penguins begin their ascent to the surface about 5.7 minutes into their dive, allowing enough energy to return for the next breath.

Although there are similarities to how humans have learned to measure underwater, the penguins' execution is fundamentally different.  Dr. Shiomi states, "that the [penguin's] decision [to return is] constrained not by elapsed time, but by the number of strokes and thus, perhaps cumulative muscle work."

 
 
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Robotic Fish (MIT)

Yesterday's article about Robotic Fish being implemented to monitor ocean pollution was one of my more popular posts.  Today's article is about another research team developing robotic fish for a different purpose...
Maurizio Porfiri, a researcher at New York University, Polytechnic Institute, has created a robotic fish that is intended to lead real schools of fish out of danger; like an oil leak, or hazardous waste.  

Fish are known for their keen visual awareness of movement, and scientists have used this information to learn what makes a leader in a school of fish.  Observation has lead scientists to believe that leaders beat their tails faster, swimming around energetically to gain the attention of its peers.  This visual display represents the information signalling whether fish should school, migrate or disperse.  

Porfiri spent a lot of time considering how to make the fish swim silently and move in "smooth-yet-jerky" movements like real fish.  The second hardest obstacle Porfiri has to overcome is the battery-life of his robotic fish.  He hopes soon the fish will harness the energy of eddies and vibrations in the water.  

Not only does this technology have the potential to help save fish from swimming into ecological disasters like oil spills or hazardous run-off, but also from newly increasing underwater turbine technology.  Lastly, it may have the potential to shepherd fish across the ocean, much like sheep dogs; creating the possible potential of free-range fish like cattle?

 
 
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Robotic Fish in Aquarium
By the end of this year, or in the beginning of 2012, a team of scientists plans to launch a shoal of robotic fish off the coast of northern Spain.  

The project, headed by Prof. Huosheng Hu of the University of Essex, School of Computer Science & Electronic Engineering, is dedicated to monitoring water pollution.

The robotic fish are 1.5 metres long, and can travel at top speeds of 3.6km/h (2.2mph).  They were specially designed to look natural in their environment, designed after careful consideration and fish observation.  

While autonomously navigating through the water, the robotic fish have sensors that detect the presence of water-borne pollutants.  

The data will be streamed, via WiFi to a main control centre at the University.  This allows the scientists to interfere with the autonomous navigation and have the fish send signals so they do not overlap surveys.  

Although the idea of a school of robotic fish independently collecting data seems a little sci-fi, there is no more efficient way yet to collect marine pollutant data.  Endless hours of streaming data, from changing locations and multiple sources will become a vital pollutant mapping technique.
 
 
Lately there have been reports of three new invasive species found in Floridian waters.  Yellow tang, panther grouper and spotted scat are all from the Indian and/or Pacific Oceans and have been spotted off the coast of Florida.  In most cases these non-native fish have been improperly released by aquarium hobbyists - not realizing how well the species will survive and repopulate.

Not all non-native species of fish flourish in foreign ecosystems, many species will die out before leaving a major impact.  But, in the case of lionfish, they have overcrowded the reefs, taking valuable nutrients from native species.

The most important thing is knowing there are invasive species in an area.  If a species can establish itself in a foreign ecosystem, it becomes nearly impossible to eradicate.  As of now, the lionfish is the only known invasive species to have such success in Florida and the Caribbean. 

Hopefully the tang, grouper and scat will come and go quietly without further unbalancing the highly stressed marine ecosystems of Florida and the Caribbean.
 
 
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Atlantic Bluefin Tuna
The western population of bluefin tuna spawn in the Gulf of Mexico and are primarily fished by North Americans.  The eastern population spawns in the Mediterranean Sea and is fished primarily by Europeans and North Africans.  Since the 1950s adult bluefin tuna populations have declined as much as 85% in the west and 67% in the eastern Atlantic.  

Researchers have been working on a new model to estimate the population of Atlantic bluefin tuna.  The reason why this new model is so revolutionary is because  the data included, accounts for the population overlap of eastern and western bluefin.  

There are three major sources of data being observed.  The first is the tracking tag that sends data corresponding with the fish's geographical location and migration (read more about it in my blog on Tuna Tagging).  Secondly the scientists will be studying earbone microchemistry, explaining that it is similar to a birth certificate; explaining the origin and family of specimen.  Lastly, fisheries' data will be taken into account to discover how many tuna are surviving to adulthood versus being caught.  

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Bluefin Tuna Migratation (click to enlarge)

Not much is known about bluefin tuna because they are a pelagic, migratory species - meaning they don't spend much time where people can observe their behaviour.  Although we do know that bluefin tuna can live to 35 years old and weigh over 1500lbs.  This study has also introduced scientists to the fact that bluefin born in the Mediterranean have a significantly lower age of reproduction than their Gulf of Mexico-counterparts.  

Originally it was believed that most bluefin caught in the west, were born and lived out their lives there, and visa versa in the east.  But, this study has brought to light that as much as 50% of bluefin caught in the west were spawned in the Mediterranean. The highest fish mortality rates in the Med, took place in 1998 and 2007 - we now know that this is a direct cause of a decrease in populations in the western Atlantic.  

The catch in the east has been cut by about half, so it is possible this trend will invert.  Since the decline of fishing in the wes, the eastern bluefin population can bounce back relatively quickly due to its early age of sexual maturity.  Whereas the populations on the west will take at least 15 years to bounce back, that is if efforts remain and continue to repopulate bluefin tuna. 

 
 
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Green Turtle Bycatch :(
American fisheries "accidentally" kill an average of 4600 sea turtles each year.  These turtles die as bycatch, a result of reckless fishing techniques.  Bycatch is the accidental capturing or injuring of a marine animal in fishing gear that is not the intended catch.  

Firstly, killing 4600 sea turtles a year is a complete disgrace considering they are on the endangered species list - and efforts to revitalize population are global.  Secondly, the number of 4600 bycatch sea turtles is discredited by the fact it's claimed a 90% decrease since 1990.  Insignificant because; there is no way of measuring if these numbers are accurate, since illegal bycatch would be disposed of at high seas and not accurately accounted for.  Secondly, its impossible to know if the turtles are properly released back to the wild - which often results in death.

Sea turtles are susceptible now more than ever to human interaction as our populations sky-rocket and pollution and traffic on the high seas increases.  The trouble is, it's impossible to create a realistic bycatch-quota without knowing the numbers of population.  If we could determine just much damage we have already done, then we would be able to determine the mortality rate that populations can sustain.  Until then, we just need to raise awareness and only eat sustainable seafood choices.