Eutrophication and Dead Zones

The Problem 

Eutrophication is the process by which excess chemical nutrients enter waterways. These nutrients cause algae to bloom in large numbers because they consume it as food. The algae blocks out the sunlight other animals, like the zooxanthellae that provide coral with nutrients, need for photosynthesis and for survival. Also, bacteria that consume the decaying algae require a large quantity of oxygen to grow, limiting the amount other organisms can use. Areas that become low in oxygen are considered hypoxic, and areas of no oxygen are anoxic. Low oxygen areas can create "dead zones," large areas where limited life is possible due to the absence of sufficient oxygen. Many organisms are effected by algal blooms, especially if the type of algae creates toxins that are harmful to its health. Massive fish kills can result, obviously harming tons of species, including humans who visit or live near the beach. Over 60% of the coastal rivers and waterways of the United States are affected by some form of eutrophication. 

The Causes

Nutrient pollution enters waterways because of sources like agriculture, aquaculture, septic tanks, wastewater, runoff, industry, and combustion from fossil fuels. Chemicals travel though the air, surface water and/or groundwater. Some of the most prevalent nutrients used are nitrogen and phosphorous. 

In order to fertilize the plants we grow, humans add millions of tons of chemicals into the environment every year. In 2008 alone,  54.9 million tons of raw materials with 21.5 million tons of nutrients were applied in only the United States. These numbers are continuing to increase each year. About 20% of these chemicals escape into the environment via groundwater or surface runoff into nearby areas. Feces excreted by livestock animals and waste from aquaculture also escape into the environment and add too many nutrients to the waterways. 

Wastewater from industry is not usually filtered for nutrients so they can easily end up in the ecosystem. Leaching from septic tanks and runoff from yards are also contributors to the problem. 

The burning of fossil fuels adds a lot of nitrogen to the air. This nitrogen can form acid rain and smog and also end up in the oceans. 

What Can You Do?

In order to minimize the harmful effects of eutrophication on marine species, we must limit our uses of fertilizer and other nutrient sources as much as possible. DON'T put fertilizer on your yard if you live close to waterways. DON'T fertilize if it looks like it's going to rain because then the nutrients will be lost and enter the environment. DO use native plants species in your yard because they are already adapted to the environment and will not need as many extra nutrients to grow. By limiting waste, we can make the world a better place!

Sources: 

http://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar09b_eutro.html

https://www.tfi.org/statistics/statistics-faqs

http://www.wri.org/our-work/project/eutrophication-and-hypoxia/sources-eutrophication

Shoreline Degradation and Effects on Marine Life

More people are seeking out coastal land for development so shorelines are slowly becoming devastated worldwide. Coastal areas that have the greatest number of people consequently have the largest level of shoreline degradation. Beaches are diminished by houses, sea walls, and other things that prevent the environment from staying natural and flowing normally. This has a tremendous effect upon wildlife that call these precious environments home. 

Natural environments, such as mangroves, are being ripped up so that homes, hotels, businesses, or other structures can be created. The removal of these native habitats has a negative effect on the environment because these types of plants hold together the sand and prevent erosion of the land. They are also important homes for many types of marine life. The mangroves in Bimini, Bahamas are important sites for juvenile lemon sharks because their large roots protect these young animals from being eaten my larger predators. Many other species of fish, crustaceans, mollusks, and other organisms also call this habitat home. However, there is a large resort now on the island that destroyed the vital mangrove habitat to create beaches and many of these species are now at risk. The hotel also has plans to create a golf course, which would destroy even more. 

The removal of one species can cause more and more species to die off because they are connected via the food web. They will no longer be able to feed off of other species and other organisms will be unable to eat them. The removal of one species can destroy countless others. 

One paper estimated the amount of shoreline degradation in the Stockholm archipelago of the Baltic sea to determine the effect on fish species in the area. Between 1960 and 2005, about 40% of the shoreline had been developed for human purposes. Each year, only about 0.5-1% of the shoreline was developed, showing that small changes over the years can still have a large impact overall. The shoreline habitats were home to many species now at risk, including northern pike, Eurasian perch, and roach. 

One of the major causes of development is the decision of home buyers. Once one person decides to put up a sea wall along their property, many others will follow and eventually the natural landscape will disappear. Many people are concerned about the environment and should be encouraged to keep it as natural as possible because it will be better for the environment, as well as prettier for them to look at.

Invasive marine species can also be more attracted to normal concrete than native species are, thus they are better able to increase in number while the natural species are outcompeted.

Some ways to help with the problems of degradation include habitat restoration, better management levels and habitat creation. Another way to help is to use more environmentally friendly building materials. For example, people could use ECOncrete instead of regular concrete when building sea walls. ECOncrete has a lower pH than normal concrete so more small coastal organisms can grow. It is also more porous so there is more surface area for these small creatures to bind to. There are also larger crevices for fish and other bigger creatures. Of course it is better to leave these areas natural, but if development needs to happen, people should use more ecologically friendly methods.

Sources: 

http://www.unep.org/dewa/vitalwater/article180.html 

http://inhabitat.com/searc-reintroduces-marine-life-in-coastal-cities-with-econcrete/

http://www.ncbi.nlm.nih.gov/pubmed/24943864

ley.com/doi/10.1111/conl.12114/abstract;jsessionid=54A50A3CB61A58F8A49D367199D8492F.f02t02

Pros and Cons of Aquaculture

Aquaculture refers to the farming of fish, shellfish, and other aquatic animals. Marine and freshwater species are grown in captive areas, including areas on land, such as tanks and enclosures, as well as in pens in natural environments like oceans, rivers and lakes. Fish farming produces many of the fish that we eat, use for bait, or buy for aquariums. It could potentially help to limit the loss of marine biodiversity because populations of endangered species could help to be restored.

A large variety of countries practice aquaculture, including our own, and it is a large source of trade worldwide. Different countries can produce fish and other countries around the world can benefit from them. Aquaculture is a source of jobs and revenue for many people. 

However, aquaculture has a variety of different effects on the environment and is fairly controversial. 

Pros of Aquaculture: 

• Growing fish and other species in organized areas allows researchers to closely examine them and learn more about them without having to go into the natural environment for research. People can study different species without having to disrupt the natural environment to do so. They can learn about them and about better ways to care for them.
• Large destructive nets do not have to be used to catch fish. As I mentioned in an earlier post, large trawl nets have horrible effects on ecosystems and can destroy miles of coral reefs that took hundreds of years to form. When fish are grown in captivity, these nets don't have to be used once a stable population forms. 
• Endangered species can be grown in captivity and put back into the wild to restore natural populations. People can capture animals whose populations are declining and ensure their survival up to a certain point. 
• People can get jobs in the aquaculture industry and earn money to help support their families. 

Cons of Aquaculture:

• Research on captive species is not always accurate because animals behave differently in captivity compared to in the wild. 
• Chemicals like antibiotics, anti-foulants and pesticides used in aquaculture can pollute the environment and have negative consequences. Eutrophication is also a possibility.
• Diseases can be easily spread among creatures in an aquaculture facility because animals are in such close quarters with one another. If one fish gets sick, many others could as well. There are also potential contamination issues with wild species if the contained animals escape.
• Other fish have to be used to create fish food so they still have to be caught in the wild.
• Land has to be used to grow fish in facilities, which is a potential waste of resources.

My Opinion: 

I am currently divided on my viewpoint of aquaculture. There are valid arguments on both sides of the issue, and I believe further research is required for me to make a definite decision. Aquaculture could potentially save fish and other marine species, but it is at the cost of energy and land resources to do so. At least in the short run, I would definitely favor the protection of species. 

Sources: 

http://www.nmfs.noaa.gov/aquaculture/what_is_aquaculture.html

http://www.worldwildlife.org/industries/farmed-seafood

http://www.fao.org/fishery/statistics/en

Harmful Effects of Whaling

In addition to sharks and other fish, marine mammal populations are also being reduced from human actions. Despite attempted regulations, countries such as Norway, Japan and Iceland still continue to practice whaling in large numbers. Although there was a ban passed by the International Whaling Commission (IWC) in 1986, these countries still continue to kill whales. Over 50,000 whales have been killed since the ban went into effect. 

Japan started a "scientific whaling program" soon after the ban was established so they could have a cover for their commercial whaling program. Instead of being used for science, the whale meat is sold or given to people at cheap rates so that people will be encouraged to buy it and support the industry. The Japanese have been killing hundreds of whales each year under for their supposed research. 

Iceland also used a "scientific program" to avoid the limits on whaling. In 2006, it resumed commercial whaling because they left the commission for a period of 10 years and reentered under new regulations. In just 2010, they killed 148 fin whales (which are endangered) and 60 minke whales. 

Norway did not respect the whaling ban at all until 1993 and set its own quotas for the killing of whales. They have a limit of killing up to 1000 minke whales per year, which is a very large number because they kill many breeding females which can have a drastic effect on the population and on future populations. 

Between Japan, Norway and Iceland alone, thousands of whales are killed each year. 

There are currently three types of whaling in existence: commercial, special permit and indigenous. 

Whaling results in so many harmful effects for the environment and should be limited as much as possible. Fewer people depend on whale meat for survival (however if they truly do, whaling should be allowed so they can sustain their populations, as long as it is done as minimally as possible) so there is less demand for the whales to die. Whaling is never really done humanely and it takes so many years for whales to grow that their populations cannot regrow very rapidly. 

Whales are important parts of marine ecosystems, yet, just as with sharks and various species of fish, they are being killed by humans in tremendous numbers. They are killed in vast numbers and in inhumane ways and whaling should be limited as much as it can be so that whale populations have a chance to make a comeback. 

Sources: 

http://www.ifaw.org/united-states/our-work/whales/which-countries-are-still-whaling

http://us.whales.org/wdc-in-action/whaling

https://iwc.int/whaling

http://wwf.panda.org/what_we_do/endangered_species/cetaceans/threats/whaling/whaling_facts/

https://iwc.int/environment

Environmental Repercussions of Overfishing

In addition to the issues I have previously discussed, overfishing plays a very large part in accelerating the loss of marine biodiversity. Although 200 million people depend on fisheries as a source of income and 20% of the human population use fish as their primary source of protein, there are few regulations to ensure that fish populations remain intact. In fact, fish populations are dropping at tremendous rates. In 1900 the ocean had over six times the amount of fish it did in 2009 and in some areas, like the North Sea, it was 17 times easier to catch fish. Populations of large commercial fish like cod, haddock and flounder have dropped by almost 95%. More than 70% of the fish species on the planet are at risk of elimination, if they haven't been destroyed already. 

The Causes

Many fisheries are improperly managed or use illegal practices to get fish (i.e. throwing bombs in the water so all the fish die and float to the surface- a method that destroys not only undesirable fish but also coral reefs). Some fisheries catch up to 50% of their product with illegal methods. Even if more laws are established to prevent overfishing, industries may not abide by them anyway. Although many countries have some sort of fishing regulations, ocean destruction is almost double that of forests.

The Effects 

When any species of fish is killed, the ecosystem becomes unbalanced. Species of animals that eat them, such as whales and dolphins or other fish, will also decrease in number or will also be eliminated. When species begins to die, ecological dead zones are created. 

If we kill off fish populations, we will no longer be able to use them for food. People would suffer from malnutrition or even famine. People will lose jobs and will thus be unable to make money and provide for their families. When the Northern Cod Fishery in Newfoundland, Canada collapsed in 1992, over 40,000 people lost jobs and the cod populations were never restored.

Potential Solutions

More enforcement needs to be established so companies will fish more sustainably and existing laws will be followed. It won't benefit industries in the long run to catch more fish now if the populations are destroyed in the next few years. Once existing laws are fully enforced, more should be created to ensure population stability. More of the ocean should be set aside for marine protected areas (MPAs). These areas are vital so that at least some of the species can remain safe. Currently, less than one percent of the ocean is protected.

Normal people can help solve the problem of overfishing as well. People can watch the seafood that they eat to make sure they are getting it from a sustainable place. Organizations like Seafood Watch provide info via apps and websites to show you what kinds of fish are safe to eat throughout the year. People and nations must work together to solve the problem of overfishing so that species can survive for the years to come!

Sources:

http://overfishing.org/ 

http://ocean.nationalgeographic.com/ocean/explore/pristine-seas/critical-issues-overfishing/

http://www.worldwildlife.org/threats/overfishing

http://www.un.org/events/tenstories/06/story.asp?storyID=800

Ocean Acidification

Humans today are relying very heavily on carbon dioxide to fuel our way of life. We expel tons of carbon into the atmosphere every year from industry, agriculture, and from our own daily activities. Carbon emissions stay trapped in the atmosphere and cause a greater level of insulation of the sun’s heat, causing the earth’s temperature to increase. This phenomenon commonly referred to as global warming.

The greenhouse effect explains how increased levels of carbon dioxide contribute to the increased temperatures of earth.

While many people are familiar with the concept of global warming, significantly fewer people know about an equally problematic result of carbon emissions: ocean acidification. About 30-40% of carbon emissions get sucked into the oceans and have drastic effects on ecosystems. Some of this carbon combines with water and forms carbonic acid. An increased amount of carbonic acid causes there to be more hydrogen ions and thus a lower pH because there is a higher acidity. From 1751 to 1994, the oceanic pH dropped from 8.25 to 8.14 with an almost 30% increase in hydrogen ion concentration.

Increased acidity could have many negative effects on the ocean and on sea life. It could cause organisms to have lower metabolic rates and less responsive immune systems, both of which could lead to death.

Acidification also adds to coral bleaching. Corals have a symbiotic relationship with an algae called zooxanthellae. The algae provides the corals with increased nutrients from photosynthesis while the coral provides it with a home. Due to increased acidity levels, the coral cannot sustain the algae so it expels it and the coral turns white because the algae give it color. Because it lacks the algae, the coral therefore cannot get as many nutrients and is therefore more likely to perish. The carbonic acid resulting from ocean acidification also causes calcium carbonate to disintegrate, which is the substance that corals use to create their skeletons. It is therefore harder for corals to grow and even if they do have algae with them, they are more likely to die.

Corals are the most diverse ecosystems in the ocean (25% oceanic animal species live in them even though corals make up less than 1% of the ocean floor) and if they perish, so will all of the species that call reefs home. Coral death would cause many organisms to be without homes and many food chains would be disrupted. The diversity in the ecosystem would greatly decrease, and many organisms which we might even use for food would also die. Many animals would die and humans would also be unable to get many kinds of food. 

Sources:
http://www.pmel.noaa.gov/co2/story/Ocean+Acidification
http://www3.epa.gov/climatechange/kids/basics/today/greenhouse-effect.html