Reflective Post

Reflective Post

I chose to do my blog on oceans because it is something that fascinates me. There isn’t anything about this topic that bores me, so I decided to write about things that affect the oceans negatively to bring awareness to the potential danger and damage that humans put on the seas. My research discussions took me on both an intellectual and an emotional journey. It was a little difficult focusing on the things that damage something you love. It was an intellectual journey because I was able to report my topics in a way that would teach people about how human indifference is the oceans biggest enemy, and how we are responsible for its damage. I wanted to bring awareness to invoke change. This non-traditional format allowed me to include my own personal feelings into the research. Traditional formats don’t allow you to do that. I really enjoyed constructing this blog.

Bluefin Tuna Overfishing

About a month ago I stated watching a new show on the National Geographic Channel called “Wicked Tuna”. It’s a reality show that follows different tuna fishermen out of the fishing town of Glouster, Massachusetts. These men tuna fish for a living only using rod and reel. Most days some of them catch one a day and others can go days without catching any at all. Their livelihood can depend on a single fish. I love seeing huge fish, so I thought this was right up my alley. While watching the show I learned that the Bluefin tuna they catch in that area have to be at least 73 inches long in order for them to keep and sell them. This gives the fish a chance to grow up and spawn. I learned that this regulation is in place because the Bluefin tuna is on the brink of extinction due to overfishing. Even though this show focuses on the trill of the hunt, it made me want to dig deeper into the plight of this amazing fish.

The Bluefin tuna can reach a weight up to 1,500 pounds and can be up to 13 feet long, making it a giant among fishes. The Bluefin is among the fastest of all fishes, capable of speeds up to 55 miles per hour and able to migrate across entire oceans. While most of the 20,000 fish species are cold-blooded, possessing a body temperature that is the same as the water they swim in, the Bluefin tuna is one of the few warm-blooded fish. It is the premier choice for sushi and has become the most desirable food fish in the world. That is why it is probably the most endangered of all large fish species. Heedless overfishing is steadily pushing the Bluefin toward extinction, and the species may soon disappear unless entrepreneurial fish farmers can learn how to breed the tuna in captivity (Ellis, 2008).

The Japanese sushi and sashimi markets have intensified Bluefin tuna fishing around the world. Bluefin tuna are known as the “cocaine of the seas” because of the astronomical prices it fetches as a luxury sushi. At one time, researchers believed that there were two separate populations of North Atlantic Bluefin, one that bred in the Gulf of Mexico and stayed in the Western Atlantic and another that spawned in the Mediterranean and foraged in the eastern part of the ocean (Ellis, 2008). The International Commission for the Conservation of Atlantic Tunas, which is a regulatory body established in 1960, based its catch quotas for the Bluefin on this two-population concept(Ellis, 2008) . They set strict limits in the western Atlantic (where Bluefin were becoming scarce as early as the 1070s) while allowing much larger catches in the eastern Atlantic. But what they failed to realize at the time is that individual Bluefin can migrate across the ocean, and the foraging grounds of the two populations overlap. So because the ICCAT has failed to stop overfishing in the eastern Atlantic, Bluefin tuna stocks have collapsed throughout the ocean.



Things are worst in the Mediterranean. Employing ideas and technology developed in South Australia, fishers corral schools of half-grown tuna and tow them in floating pens to marine ranches where they are fed and fattened until they can be killed and shipped to Japan. There are rules banning fleets from taking undersize tuna out of the Mediterranean, but none that prevent catching immature tuna and fattening them in floating pens. Every country on the Mediterranean, except Israel, takes advantage of this loophole and maintains tuna ranches offshore (Ellis, 2008). They are catching half-grown tuna by the hundreds of thousands. If you had to design a way to guarantee the decimation of a breeding population, this would be it: catch the fish before they are old enough to breed and keep them penned up until they are killed. The tuna ranches, once seen as a solution to the problem are only making it worse.

But even if lower fishing quotas were in place, the Bluefin would still be endangered. The tuna fishery is rife with illegal, unregulated fleets that ignore quotas, restrictions, boundaries, and any other rules and regulations that might threaten their catch (Ellis, 2008). The Japanese market which devours about 60,000 tons of Bluefin every year, or more than three quarters of the global catch, is only too eager to buy the tuna, regardless of where or how it is caught(Ellis, 2008). They bring in thousands of illegal tuna every year and falsify their records.

As the tuna populations continue to fall, the Japanese demand is increasing; fewer tuna will mean higher prices, and higher prices will mean intensified fishing. Intensified fishing will, of course result in fewer tuna. It seems like an inevitable lose-lose situation for the Bluefin tuna. It appears that the only hope for the Bluefin is captive breeding. Captive breeding of the Bluefin could save the species, but the effort will be challenging. Research groups in Japan and Europe have bred the tuna in laboratories, and now an Australian company is attempting to perform the feat on a commercial scale (Ellis, 2008).

It would be good for the Bluefin tuna, and in the end, good for the consumer if tuna fishing was not practiced in such a remorseful manner, but such change would entail nothing less than a modification of the fundamentals of human nature. But there is a little light at the end of the tunnel. Some organizations have begun boycotted the sale of Bluefin tuna in some restaurants and stores, hopefully this type of progress will bring more awareness to this type of situation and keep it from happening to another species as well.

Works Cited

Ellis, R. (2008). The bluefin in peril. Scientific American, pp. 70-77. Retrieved April 27, 2012 from the Complete Academic Database.



Marine Oil Spills

I remember sitting in awe watching the underwater cameras that were filming the thousands of gallons of oil spilling into the ocean back in 2010 during the BP oil spill. The sight was horrific. I sat and thought about the ramifications that a catastrophe of this magnitude would have on the ocean and all the marine life in the area, not to mention the effect it would have on the food chain and fishermen who made a living in that area. I was angry with the human carelessness that had once again taken its toll on the seas.

A marine oil spill is the release of a liquid petroleum hydrocarbon into the ocean or coastal waters, due to human activity, and is a form of pollution. The marine environment is a key interrelated and complementary element that is crucial for the existence of the biodiversity, ecosystem and human life on this planet (Sinanaj & Xhelilaj, 2010). There are a number of factors which determine the precise nature and duration of a possible impact of an oil spill in a marine environment. The most significant factors are the category and quantity of oil and its behavior once spilled; the physical features of the affected region; weather conditions and seasons; the nature and the efficiency of the clean-up operation, the biological and economical characteristics of the area and their vulnerability to oil pollution (Sinanaj & Xhelilaj, 2010).

Oil pollution may severely impact the ecosystem and the biodiversity of the ocean and coastal areas resulting in possible danger to the marine life. The impact of an oil spill on marine life depends heavily on the physical and chemical characteristics of the particular oil and on the weathering process (Sinanaj & Xhelilaj, 2010). The toxic effect of oil on marine life depends on the length of exposure and the oil concentration in the ocean. Coral reefs are susceptible to oil spills because oil compounds can dissolve in water with exposes the corals to potentially toxic compounds. Adult fish, squid, shrimp, wild stocks of important marine animals and plants seldom suffer long-term damage from oil spill exposure.





The biggest impact is found on shorelines where animals and plants may be physically coated and smothered by oil or exposed directly to toxic components in the oil. Shellfish are more vulnerable that fish to oil spills because of their close association with contaminated sediments, this also goes for fish located in fisheries. Organisms such as plankton may also be seriously impacted by oil pollution. Studies have revealed toxic and lethal effects on them. Sea and shore birds such as shags, fulmars, kittiwakes, razorbills, and guillemots are generally the group of birds mostly at risk from oil spills since they are easily harmed by floating water (Sinanaj & Xhelilaj, 2010).

Birds that submerge for their food or which gather on the sea surface are especially at risk. Oil can blind an animal, leaving it defenseless. The ingestion of oil causes dehydration and impairs the digestion process. Animals can be poisoned and may die from oil entering the lungs or liver. The most common cause of contaminated bird’s death is from drowning, starvation and loss of body heat and it must be noted that great mortality occurs during most spills which sometimes have even caused the entire breeding colonies to be seriously depleted(Sinanaj & Xhelilaj, 2010). The majority of birds die without human intervention. Some studies have suggested that less than one percent of oil-soaked birds survive, even after cleaning.

Sea mammals such whales, dolphins, and seals in the open sea are threatened from oil spills as well. Since the BP oil spill in the Gulf of Mexico in 2010, which is the 5^th largest oil spill in the world, hundreds of dead dolphins and aborted dolphin babies have been found. Researchers say that the number of dolphins and whales killed by the disaster could be as much as 50 times higher than the bodies found. Not to mention the eyeless shrimp that fishermen have now been reporting that they have been catching. But marine mammals such as seal and otters that breed on the shorelines are more prone to be affected by the oil pollution. The most endangered mammal species are those which rely on fur to regulate their body temperature because if the fur becomes contaminated with oil, the mammal may die from hyperthermia or overheating.

The US consumes more oil than any other country in the world. For decades the US has focused on producing and importing more oil, instead of increasing efficiency, lowering consumption, and new technologies. Oil spills are only caused by human activity. This fact alone means that if we are going to drill into these habitats for oil than we can’t continue to be careless about it. More precautions have to be taken in order to ensure that our need for oil doesn’t encroach on the well-being of the marine life that inhabits the seas. This goes for every single country in the world. We as humans have to be more careful with our actions.

Works Cited

Sinanaj, S., & Xhelilaj, E. (2010). The behavior and effects of oil pollution into the marine environment and oceans. Journal of Maritime Studies, pp. 19-25. Retrieved April 25, 2012 from the Complete Academic Database.



Fish Communication

Fish Communication

     As a kid I used to stare at the fish tank in my house and think the fish were talking to each other when their mouths moved. I used to wonder what they were saying, stories they were telling each other. I would even make up some conversations. Eventually I grew out of believing that fish could talk. But I always knew that even if they weren’t actually speaking, they were still in fact communicating in some way. But the question was-How?



     Schools of fish communicate using pheromones. Pheromones are endogenous chemical signals secreted by organisms. They trigger an innate response in other members of the same species. The behaviors that are influenced by pheromones are sexual attraction, territorial demarcation, signaling alarm, and recruiting members together for feeding or defense purposes. “Some aquatic organisms may only respond to chemical cues during times of the day. Migratory adult sea lamprey are nocturnal and respond to migratory pheromones at night” (Johnson & Weiming, 2010). In some cases the communication reflects more than just the survival and reproduction of an individual organism, but also contributes to others in the species. Alarm substance pheromones are pheromones that alert and warn other group members of a nearby predator. Some fish species release a volatile substance when attacked by a predator that can trigger a flight response in members of the same species of fish. Pheromones are detected by the olfactory systems. These systems for detecting pheromones include olfactory sensory neurons, which are nerve cells with one end exposed to the external environment, often embedding in an otherwise impermeable skin or cuticle.



     “Experience and learning also alter behavioral responses of fishes to alarm substances. Several fish species exhibit learned predator recognition to alarm substances” (Johnson & Weiming, 2010). Minnows, which are small fresh water fish that belong to the carp family, are known to shoal in large numbers or schools. Their small size makes them easy prey for all the carnivorous fish and they rely on their speed and close shoaling habits to save them from predators. Minnows can react very quickly to danger signals. They release an alarm pheromone stored in specialized cells on its skin only when the skin is damaged, warning other minnows in the school that a predator has attacked. The flight response will cause the school of minnows to disperse in a frantic manner, then school up and gradually swim away from the source of the alarm pheromone. But not all schooling fish have traits of the flight response.

     In some cases different species that can produce alarm pheromones can pick up each other’s version of it so that if one fish of a different species is attacked other species in the area know to get away from the area. There have also been fish that once used the pheromone, but lost the ability to produce and detect it because it would interfere with their diet which consists of similar species, which is the case for piranha. “Some species undergo an ontogenetic shift where alarm substance responses are only elicited in young age groups, likely due to trade-offs between foraging and predation risk” (Johnson & Weiming, 2010).  It is said that alarm substance pheromones evolved for three main reasons. The first reason is that it came as a way to ensure survival of members of the same fish species because it warns them of the presence of a predator. They may have also evolved as a way to prevent fish from eating their own species, more specifically their offspring. If a fish bit a member of the same species it would have the same effect of them as if it was released from a fish under attack from a predator. The third possible reason for the alarm substance pheromone is that it has been recently hypothesized that predator fish have begun to be able to pick up the presence of the pheromone attracting them to injure fish and an easy meal. But as the number of predators in the area around an injured fish increases, so does the time it takes from first strike to until the time of ingestion. This allows the prey more time to free itself and possibly escape. Whatever the reason, pheromones are a vital part of a fish species survival.

     Knowing that pheromones play a huge part in the lives of fish species it makes me wonder about the age old argument of instinct versus intelligence. Can fish think or is everything solely based on nature’s cues passed down from generation to generation? Since evolution plays a huge role on a fish’s instincts, it has to affect fish species intelligence as well.

Works Cited

Johnson, N., & Weiming, L. (2010, October). Understanding behavioral responses of fish to pheromones in natural freshwater enviroments. Journal of Comparative Physiology A: Neuroethology, Sensory, Neural & Behavioral Physiology, pp.701-711. Retrieved February 23, 2012, from the Complete Academic Database

Great White Sharks

Great White Sharks

     I remember my favorite move as a child. It wasn’t a typical cartoon movie like most children love watching, I never liked those. My favorite movie was the American thriller Jaws. Most kids my age, and adults were terrified by Jaws but I was fascinated by the movie. I would sit and watch in awe. I couldn’t believe a fish could be so big and powerful. I wanted the shark to be my pet. Even to this day, 20 years later, my mother still jokes about how I loved to watch Jaws, but I was afraid of the movie Star Wars. She found it amusing that I wasn’t afraid of a movie that was based on a real animal that could quite possibly cause the damage that the great white shark did in real life. That was where my fascination with sharks started. The great white shark is probably the most known shark out of the entire species, but still so little is known about them.



     Every year the Discovery Channel has there highly anticipated “Shark Week” where they broadcast shows all about sharks. Every year they always air a show with massive adult great white sharks jumping out of the ocean while they hunt seals. But out of all of the shows they never show any juvenile great whites. I can’t recall ever seeing any information on them and it made me wonder, where are the baby great white sharks? So little is known about great white sharks. “Even basic notions, such as how large they actually grow, how long they live, how many are out there, and where they go to breed and pup, remain a mystery” (Cillican, 2011).

     Recently off Port Stephens, New South Wales, a great white shark nursery was discovered. Scientists discovered the nursery from a YouTube video entitled “Great White Shark Hunters”. Even though the video shows the illegal hunting of great white shark pups, scientists gained a lot of knowledge from the video. “Australia listed the great white as protected in 1999; internationally it is listed as vulnerable on the IUCN (World Conservation Union) Red List for Threatened Species, and it was also banned for trade by the Convention on International Trade in Endangered Species of Wild Fauna and Flora in 2004” (Cillican, 2011). Because of the video, scientists have begun to research the area. They found that the nursery area consists of a 50 kilometer stretch of broken coastline between Seal Rocks and Stockton Beach. This location is perfect for a shark nursery because the nutrient-rich conditions of the area attract schools of Australian salmon, mulloway, mullet and snapper, which are the favored meals of juvenile great white sharks. Scientists from the CSIRO laboratories began tagging juvenile sharks in the area in 2007. “The team has fixed a satellite tag to the shark’s dorsal fin, which records the date and time, water temperature, depth and light levels” (Cillican, 2011). Acoustic tags have also been surgically implanted into the shark’s abdomen. The tags transmit a unique number when the shark swims within 500 meters of an underwater acoustic listening station, which have been scattered throughout Australian waters. They have also started annual helicopter surveys of the nursery to estimate how many sharks migrate there.

     “Conservation and study around this juvenile shark crèche is vital-knowledge from the nursery could help hint at the health of future adult populations” (Cillican, 2011). The research taking place at and around the Port Stephens nursery is important in helping protect a species that many people probably never realized was endangered. About 120 sharks are killed every year due to the bay catch of commercial and recreational fishing. This is a crucial amount because great white sharks only give birth to 2-14 pups in a litter and only produce 4-6 litters in a lifetime.

     Making people aware of this situation is the first step in conserving one of the ocean’s most powerful and most vulnerable creatures. Most powerful because they are one of the sea’s greatest hunters, and most vulnerable because their numbers are so few compared to other species of sharks. This type of research is a window into the great white shark’s world. The more we know about them, the more we as humans can do to make sure that our actions don’t impose on their habitats or threaten their well-being. Our actions impact everything that goes on in the ocean. Our responsibility with that type of power is the key to their survival.

Works Cited

Cillican, J. (2011, Dec). Great white creche. Australian Geographic, pp.80-85. Retrieved March 3,2012,from the Academic Search Complete Database.

Dead Zones

Dead Zones

     For as long as I can remember we have always had a fish tank in our home. I remember one day noticing green slime growing on the glass inside the tank. I asked my dad what is was and he told me it was algae build up. I asked him why did it grow and he didn’t know but said he knew how to get rid of it. Later that day we went to the pet store and he bought a new fish. It was a Pleco fish. It was a weird looking brown fish with a suction cup type of mouth that was apparently good for eating algae. A couple days later I watched as the fish stuck itself to the glass and ate the algae. I was amazed. Watching the Pleco fish made me wonder what happens when algae builds up in the ocean and what could cause it. Growing up we have all learned about how the effects of our pollution affects the planet. I remember being taught all about the hole in the ozone layer, and about how important it is to recycle our glass, plastics and paper products. But the only thing I can even remember learning that pertained to pollution in the ocean was the obvious toxic waste from nuclear power plants, and to make sure you cut the plastic rings that come attached to soda cans so sea turtles won’t get caught in them and choke to death. So I decided to find out what really causes pollution in our oceans, and I found a major issue that affects our seas but is rarely talked about. That is our oceans’ dead zones. The phrase “dead zone” refers to coastal waters that are too low in oxygen to sustain life. The lack of oxygen is called hypoxia. Phytoplankton are microscopic plants that grow in the sunlit surface waters of the ocean. They play a large role in sustaining ocean ecosystems and global climate. These plants are the base of the marine food chain. Dead zones are sparked by phytoplankton blooms that consume available oxygen and create these oxygen-starved zones where aquatic life cannot survive.

     The chain of events that cause these dead zones begins on land. “Farmers often over fertilize their fields. The excess fertilizer, laden with nutrients like nitrogen, washes into creeks and rivers, where it’s eventually carried into coastal bays and the open sea” (Dybas, 2005). Other sources include discharge of untreated sewage, animal waste from farms, and rising emissions from vehicles and factories. Nitrogen-fixing bacteria convert atmospheric nitrogen into nitrogen compounds that some organisms can use as food which in turn triggers the proliferation of phytoplankton blooms that deplete oxygen in the water. As a result there may be more phytoplankton in the water but it is less nutritious for the marine animals that feed on it. “When the phytoplankton die, they fall to the sea floor and are digested by microorganisms. The process removes oxygen from the bottom water and creates low-oxygen zones” (Dybas, 2005). Most marine life cannot survive these conditions. While fish might flee this suffocation; slow moving, bottom dwelling creatures like clams, lobsters, and oysters are less able to escape. The hypoxic water appears normal on the surface, but on the bottom they are covered with dead and distressed animals, and in extreme cases, layers of sulfur-oxidizing bacteria which cause the sediment in these areas to turn black.

     “Dead zones range in size, from small areas of coastal bays and estuaries to huge areas of the open sea, where they can reach tens of thousands of square kilometers. Most are found in temperate waters, off the eastern coast of the United States and in the seas of Europe” (Dybas, 2005). They usually occur in the spring and summer months because that is when fertilizer runoff from farms is at its highest levels. Mix that with the warm ocean waters and it fuels the plankton blooms. There are over 400 dead zones in the world. The world’s two largest dead zones are located in the Baltic Sea and the Gulf of Mexico. Dead zones can trigger alarming and sometimes irreversible effects on the waters that they occur in. Hypoxic conditions found in dead zones cause food chain alterations, loss of biodiversity and in some cases high aquatic species mortality.

     The realization of the situation is that we really have to be aware of the fact that what we do on land affects everything in the ocean as well. I almost feel like this is a problem that will never go away because farmers will probably never under fertilize their crops because the objective is to yield more crops in order to make more money, so for them it may not be cost effective to consider the danger they are causing in the oceans. The driving force of this planet is water. Human indifference is the ocean’s biggest threat. As humans we must strive to remember that our careless actions affect everything in nature, even at the bottom of the deep blue sea.

Works Cited

Dybas, C. L. (2005, July). Dead zones spreading in world oceans. BioScience, pp. 552-557.Retrieved February 15,2012, from the Environment Complete Database.

Introduction

I can remember when I was younger, my family and I would go to the beach every summer. As my younger brothers would play in the sand, I would sit at the edge of the shore and just stare out into the ocean. I would always wonder what was past the waves, and what was hidden below. My fondest memories all involve the ocean and ocean life in some way: from sitting on the water’s edge as a child wondering if I will ever be able to explore its hidden beauty, to being an adult sitting with my father on his boat getting challenged to catch the biggest fish. Learning about the ocean has always been my favorite hobby, so when I got laid off from my job last year, I decided to go back to school and pursue a career in marine biology. My goal is to turn the hobby that I love into a career that I love as well.

In this blog I will discuss topics concerning the oceans that range from the oceans “dead zones” to the hidden evolution that is taking place underneath the deep blue sea. I hope to spark an interest in a subject that has had me fascinated since childhood, and to hopefully bring awareness to the remarkable things that take place in our oceans.