Aquaculture vs Climate Change

Aquaculture vs Climate Change

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Romi Novriadi

Batam Marine Aquaculture Center

Directorate General of Aquaculture

Ministry of Marine Affairs and Fisheries of the Republic of Indonesia

E-mail: Romi_bbl@yahoo.co.id

The meeting of marine and fisheries policy makers through the OUR OCEAN conference 2016 scheme implemented in Washington DC has resulted in several commitments to address some of the important issues that struck our sea, including: (1) a commitment to increase the potential of sustainable fisheries production / MSY), (2) increasing the protection and protection of marine fisheries resources, (3) reducing the number of pollutants, and (4) concrete action against climate change. This commitment is realized with the announcement of approximately 136 new conservation areas with initiative funding of more than US $ 5.24 billion and also a marine protected area that increased to 4 million km2.

Marine health has become a very important global issue because, apart from covering about 75% of the Earth's surface, it also stores about 97% of the earth's water, produces more than half the oxygen in the atmosphere and absorbs some carbon from the atmosphere. Therefore, one can imagine the impacts of climate change that include global warming, ocean acidification, increasing the amount of carbon dioxide, and rising sea levels on food security, particularly fishery resources. Efforts to maintain the sustainability of fishery resources also face challenges in the form of increasing the amount of plastic waste in the oceans until estimated in 2050, will be more plastics than fish in the ocean. The above conditions encourage us to immediately adapt and mitigate so that climate change does not cause a decline in fisheries production, especially to meet national consumption needs.

For the aquaculture fishery sector, climate change also has its own main effects caused by rising temperatures, changes in rainfall patterns and acidification of seawater. According to National Geographic data, climate change has resulted in an increase in global average temperatures of about 10 F (0.60 C) over the past decade and about 0.180 F (0.10 C) sea water temperature from surface to a depth of 2,300 feet (700 m). Physiology and endurance of fish, as poicilotermic organisms, are strongly influenced by abiotic and biotic factors including temperature as one of the abiotic factors.

Referring to some research results, temperature changes greatly affect the pattern of development, distribution, replication and virulence levels of pathogenic organisms. Even in high latitude areas, where in general pathogen development is limited by cold temperatures, an increase in mean water temperature gives longer growing and developing time. This condition makes the prevalence rate and virulence of the disease becomes higher as the prevalence of proliferative kidney disease disease in salmon industry in eastern Europe up to the increasing of flavobacterium columnaredi bacteria network of gill tissue.

It is interesting to note that rising temperatures can also increase the rate of metabolism which in turn also supports the optimum growth rate of fish. An increase in temperature of 0.180 F (0.10 C) in the last decade also has a very small chance of making water temperature one of the stress factors for most aquatic organisms. However, exposure to higher temperatures over long periods of time can have a detrimental effect on the fish's immune system. Therefore, environmental health management systems and prophylactic applications such as vaccination, administration of immunostimulants and probiotics are the best alternative to overcome the effects of this increase in temperature.

Another impact of climate change also involves increasing the concentration of carbon dioxide (CO2) in the atmosphere which ultimately also increases the amount of carbon absorbed by sea water. Since the industrial revolution, atmospheric CO2 concentrations have increased from 280 ppmv to 399 ppmv by 2014. Sea water absorbs about 1/3 of the emissions of anthropogenic CO2 in the atmosphere and converts it to carbonic acid. The more anthropogenic CO2 absorbed will increase the concentration of [H +] dissociating in the oceans, making the seawater more acidic as water pH levels decrease.For the aquaculture sector, clusters of organisms are most susceptible to the acidification of seawater due to their strong dependence on calcium carbonate (CaCO3) for shell formation. In addition to the group of aggressive, fish finned groups are also affected significantly from acidification of seawater. The morphology of otolith organs (organ for balance), growth rate, and rate of fish oxygen consumption may be impaired under more acidic environmental conditions.

Solutions that can be done to reduce the impact of acidification of seawater is to perform daily routine monitoring for early detection or by mapping to determine site-specific buffering. In shellfish culture, shell placement around the cultivation site can help buffer the pH of the water and increase the availability of carbonate in water, selective breeding to good quality feeding can also be done to reduce the negative impact of ocean acidification.

Increased sea levels and the possibility of high salinity water being introduced to areas with lower salt levels are also exposed as part of the impacts of climate change. This condition certainly affects the physiological changes of aquatic organisms with the level of tolerance to changes in salt levels are very low. In the context of aquaculture, of course climate change also affects the uncertainty of the availability of raw materials for the production of fish meal and flour. However, various alternative sources of protein have been offered, such as the use of soy flour for partial or total substitution of fish meal. Some assumptions suggest that vegetable flour has many disadvantages such as incomplete essential amino acid composition (methionine and lysine), to the issue of palatability and digestion can be overcome with better feed-making production systems.

The addition of phytase, an enzyme to increase carbohydrate digestibility as well as methionine supplementation, lysinean taurine in feed formulations has been applied and proven to provide a growth rate that is not much different from the use of fish meal. The results of this research should be used in addition to supporting the increased potential of sustainable fisheries production and to reduce the cost of production of cultivation until the end product from aquaculture activities become more economical.

In addition to climate change, environmental pollution, both by the industry and to the accumulation of plastic waste in the coastal area become a separate threat for the sustainability of aquaculture production. Attention to the plastic waste that can be consumed by filter feeder organisms and ultimately deposited in the human body even becomes an important issue discussed in the OUR OCEAN meeting, which was also attended by dozens of state leaders including Indonesia through the Ministry of Marine Affairs and Fisheries. Currently, concrete action to save environmental health is needed, including by not using mangrove for cultivation, optimal biosecurity application to environmental management application through Good Fish Cultivation scheme. Through the application of good management system, it is expected that the aquaculture industry can anticipate the various impacts that have been and will be caused by climate change **

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