The emphasis on environmental issues for the changes to our oceans has lagged behind the changes humans have made to land. It was not until the nineties that the notion of ocean health has grabbed the attention of the media and ordinary people. Historically, the oceans were one that countries have controlled to create wealth and power, use for fishing and transportation and war.
Today the fishing industry has progressed from dropping nets where they think the fish are located, to technology that allows them to figure out where the schools are most likely found, along with the use of bottom trawling and fish aggregating devices. Bottom trawling is a commercial fishing technique where the use of heavy nets and gear pulled along the sea floor and catches everything in the wake of the nets, and modifying the physical properties of the seafloor. Trawling displaces the sediment on the floor causing the floor to become smoother over time, possibly changing the continental slope in many areas; the continental slope is the transition between shallow continental shelves and deep basins.
There are five components of the fishing mortality: 1) pre-catch losses, 2) ghost-fishing mortality, 3) post-release losses, 4) collateral sources of mortality and 5) mortalities from fisheries. These byproducts of commercial fishing are not easily traceable and are not accounted for in the fisheries due to the lack of accurate data available but in 2011 the Committee on Fisheries of the Food and Agriculture Organization of the United Nations endorsed guidelines to identify and quantify the impacts of mortality from pre-catch losses and ghost fishing. Ghost fishing is equipment that when discarded into the ocean traps fish and sea life and smothers the habitat by covering the area making it inaccessible for the fish and pre-catch losses are when the fish collide with the gear and die as a result. Trawling is gear made up of two board heavy enough to keep the gear on the seaboard and as the board are trawled along they are forced open and kick up sand clouds that herd the fish inside the net. Drift nets are sheets of thin netting that allow them to drift with the current and catches fish by entanglement.
Oceans and Sustainability
Historically the Romans were the first around 200 AD to use floating object to catch dolphinfish; they figured this out from watching the fish congregate around floating structures like logs and debris in the waters. Around the late 1950’s the first tuna purse seiners were operating in the Pacific Ocean using floating objects such as logs and after this the commercial operations began to use the floating objects to capture large catches of tuna. A purse seine is a net that encircles and closes at the bottom to entrap the fish.
There are negative impacts on the ecological system by the use of floating aggregate devices (FAD’s). The use of FADs contributes to the overfishing of tuna stocks, because of the yellow fin tuna largely dominating the free-swimming schools the accidental capture of these yellow fin and smaller skipjack tuna could affect the yield of these species and lead to excessive reduction of stocks. In addition, these floating devices attract other types of fish that are trapped and can affect the biodiversity of the ocean; use of the devices can run the tuna out of the areas they are normally habituating into areas they never have gone before and can change their biology, such as their growth rate or reproductive success.
Sustainable ocean fishing will require the world to make changes, in a conference in June 2014 hosted by the U.S. Department of State an action plan to help achieve this goal was generated. Several action points to help curb overfishing at the conference are:
Set fishing rules based on the best available scientific data,
Develop fair and equitable procedures for allocating fishing rights,
Enforce the fishing rules and impose penalties,
Eliminate by 2020 fisheries subsidies that contribute to the overfishing problem and,
Require the fishing fleets to use gear and techniques that will reduce to a minimum the bycatch of other species.
These points brought forward in this conference are crucial to the correction of the past overfishing issues that have brought us to this situation with the health of our life sustaining oceans in jeopardy. Other problems with the sustainability of the ocean are the illegal and unregulated fishing in the oceans. President Obama has announced a seafood transparency and traceability program that will enable the US consumers to be able to know that the fish they purchase is harvested legally and sustainably.
During the 1936/37 fishing season in California the largest catch of sardines were recorded at 700,000 tons of sardines; scientist warned about the effects of overfishing and California once known for its rich harvest of sardines shrank and never recovered. The sardine catches, which were quite high until after the war, slowed to about one third of the previous year’s, the industry was devastated, fishing canneries started closing from Washington and down the coast of California. The loss of one collapse of a fishing area leads to many other issues in the ecological chain not just with the oceans but the rivers, forest, and of course the ocean chain of life.
Grouper is a valuable fish commodity to the entire world but few of the fisheries are monitored and the threat to grouper is that of the 163 species 20 species are at risk for extinction, due to overfishing and poor fishery management. Fishing that dominates the industry is based on abundance and consumer preference include cod, tuna, and mackerel, but according to the Food and Agriculture Organization of the United Nations groupers contribute to 275,000 tons of the global capture for fisheries production in 2009.
Devastatingly, harvested marine species have had population declines of as much as 90% for pelagic fish species, along with coastal reef reductions of more than 4% per year since the mid-1990s. These statistics explain the threat of loss of our oceans and we must be held accountable for our overuse of the ocean’s food. Steps are being taken as noted but the fact is we have to be more aggressive in regulating the fishing industry to provide for the future health of our oceans. Sustainable means we must regulate and control the amount of fishing and production of the fisheries if we are to provide for the economic welfare of the industry and provide food for humanity.
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