Climate variability and change has the potential to alter the balance of marine systems. Global aquaculture<!–[if supportFields]> XE “aquaculture” <![endif]–><!–[if supportFields]><![endif]–> systems rely on small pelagic fish populations, fisheries productivity, fishmeal supply, and fish oil production. Aquaculture is dependent on fishmeal as food to serve as a primary source of protein, lipids, minerals, and vitamins. Fishmeal is produced using small pelagic fish such as sardines, anchovies, and mackerels. These species are short lived and fast growing, so their production is highly susceptible to environmental changes. Fisheries production has stabilized over the last decade, however aquaculture has continued to increase, particularly through production of low-value freshwater fish. Prediction of changes in fisheries yield that result from climate change are important to estimate. Merino et al. (2010) used bioeconomic models at two temporal scales with the objective of investigating environmental and human induced changes to aquaculture systems. Short-term economic hypotheses were that (i) there is no relationship between aquaculture production and fishmeal consumption, given that technological advances will reduce the dependency on fishmeal production; and (ii) fishmeal demand is linearly related to aquaculture expansion. Long-term models were based on two socioeconomic scenarios until the year 2080. The World Markets scenario was estimated using prices based on recent average and highest price records while The Global Commons scenario predicted limited expansion of aquaculture and population growth. —Lauren Lambert
Merino G., Manuel B., Christian M., 2010. Climate variability and change scenarios for a marine commodity: Modelling small pelagic fish, fisheries and fishmeal in a globalized market. Journal of Marine Systems 81, 196–205.
Merino et al. expect that climate change will have a negative effect on marine resources through reduced levels of primary production. Global aquaculture<!–[if supportFields]> XE “aquaculture” <![endif]–><!–[if supportFields]><![endif]–> production relies on both carnivorous and herbivorous species. The majority of carnivorous species include salmonoids from Chile and Norway, and shrimp from Thailand and China<!–[if supportFields]> XE “China” <![endif]–><!–[if supportFields]><![endif]–>. Herbivorous species, mainly from China, make up 55% of global aquaculture production. Carnivorous species are dependent on fishmeal, however the amount of fishmeal used for herbivorous species is rising because of the improved growth rates and profits. The models combine the uncertainties of future climate and market effects on global fishmeal production and consumption.
The first model used short-term impacts over a 10-year simulation to find the annual variable production rate of individual small pelagic fish stocks aquaculture<!–[if supportFields]> XE “aquaculture” <![endif]–><!–[if supportFields]><![endif]–>. The second was long-term (2080) and estimated environmental impacts on the same stocks by using primary production predictions as proxies for carrying capacities of fish stocks. The short-term simulation investigated the consequences of short-term climate change on fish and fishmeal systems. Biological, economic, and activity/investment components were observed through this simulation. The biological component computed expected yields and was modulated by expected primary production. The economic component estimated net profits for regional production systems by combining their costs with revenue from the global market. This was driven by outputs from the biological component, activity component, fishmeal price function, transformation, and shipping costs. The parameters of the global market are price records from 15 international fish markets. Activity and investment components express exploitation patterns in terms of catchability and fishing activity of specific stocks. The results of this simulation were presented in the form of bioeconomic indicators such as global exploitation index, estimate of global small pelagic fish caught, and a measure of traded fishmeal to global markets as well as average prices.
The fish stocks show fluctuation according to random variability in fish production. In years that fish stocks decline, the costs of obtaining fish at the same yield show a slight increase, and the small pelagic and fishmeal supply remains relatively constant. As fishmeal markets expand, fish production fluctuates as a result of climate change. Through this simulation, Merino et al.found that in years with negative environmental conditions the price of fishmeal would need to be increased while production levels stay the same. At the end of the 10-year simulation, the fish stocks global indicator was 23% of optimal levels. Under these same conditions, the combination of random negative environmental impacts and increases in demand will continue to reduce the size of the fish stocks.
Long-term simulations investigated the impacts of changes in primary production under two different management scenarios. These are short and long term models that use actual data from 1997–2004 for 3 regional production systems. The import and export data from the International Fishmeal and Fish Oil Organization (IFFO) was used to estimate the size of these fish stocks, fleets, and transforming industries. The global market only works under the condition that fish stocks are currently exploited at their maximum sustainability capacity and that the differences in fishmeal production are reflective sof the difference in available fish stocks, fleets, and technology. This allows for investigation of impact of climate variability on production systems that trade products in the global commodity markets. The Global Commons management scenario showed that resulting fish biomass, exploitation levels, fish yield, and market trade are similar to present conditions. The World Market scenario shows a decline in all parameters that were tested. The model showed that production appears to be sustainable over the 10-year period, but fishmeal prices will rise.
The results of the long-term scenarios show changes in biomass of small pelagic fish, index of global exploitation level, total production of small pelagic fish, and quantity of fishmeal in the markets. Sustainability of small pelagic resources is more dependent on how society responds to climate change than to the magnitude of the alterations. There is a link between global climate change and aquaculture<!–[if supportFields]>XE “aquaculture” <![endif]–><!–[if supportFields]><![endif]–> dynamics in relation to the demand for natural resources and limits of ecosystem services. Ecosystems are expected to respond to global warming through variations in primary production and species capacity parameters.