Syllabus Edition
First teaching 2015
Last exams 2025
Demand for Aquatic Food Production
Written by: Alistair Marjot
Reviewed by: Bridgette Barrett
Demand for Aquatic Food Resources
Global aquatic food consumption
The demand for aquatic food resources is experiencing a significant increase due to the combined effects of a growing human population and dietary changes
As populations expand and economies develop, there is a higher demand for seafood products to meet nutritional needs and culinary preferences
The main factors behind the increase in demand for aquatic food resources are as follows:
1. Growing Human Population
The global population has been steadily increasing over the years, resulting in a larger consumer base for aquatic food resources
2. Changing Dietary Patterns
As countries undergo economic growth, there is often a shift in dietary patterns towards increased consumption of protein-rich foods, including seafood
3. Nutritional Benefits of Seafood
Seafood is recognised as a valuable source of essential nutrients, such as omega-3 fatty acids, vitamins, and minerals, which contribute to human health and well-being
4. Urbanisation and the rising middle class
Urbanisation and the emergence of a middle class in many regions have led to changes in dietary preferences, with an increased demand for diverse and higher-value food options, including seafood
5. Global trade and supply chains
Advances in transportation and the expansion of global trade networks have made it easier to import and export seafood products, increasing their availability to communities
6. Aquaculture production
Aquaculture, the farming of aquatic organisms, has experienced significant growth to meet the rising demand for seafood
The relative contribution of aquaculture and capture fisheries
Photosynthesis and Aquatic Food Webs
Photosynthesis by phytoplankton forms the foundation of marine food webs, supporting a highly diverse range of organisms within marine ecosystems
Phytoplankton utilise sunlight, carbon dioxide and nutrients to produce organic matter through photosynthesis
The organic matter produced by phytoplankton serves as a vital food source for various marine organisms, including zooplankton, invertebrates and small fish
The energy derived from phytoplankton is then transferred up the food chain, sustaining larger predators such as marine mammals, birds, and humans
Areas of high marine productivity
Phytoplankton productivity is highest near the coast or in shallow seas due to specific environmental factors:
Upwellings occur when wind-driven movements bring cold, nutrient-rich water from the deeper ocean layers to the surface
Upwelling zones promote phytoplankton growth by providing an abundance of nutrients like nitrogen, phosphorus, and iron that are essential for their photosynthetic activity
Nutrient enrichment of surface waters in these regions stimulates the growth of phytoplankton, leading to increased productivity and biomass
The high productivity near the coast and in shallow seas create ideal conditions for the development of diverse food webs
In addition to upwellings, other factors such as coastal runoff and mixing of nutrient-rich freshwater also contribute to the enrichment of surface waters, supporting phytoplankton growth and food web complexity
These regions serve as crucial hotspots for marine biodiversity and play a significant role in the overall health and functioning of marine ecosystems
Worked Example
Give an example of an area of high marine productivity caused by upwellings and nutrient enrichment of surface waters
Answer
The coast of Peru and Chile is an excellent example of how upwellings and nutrient enrichment of surface waters support high productivity and diverse food webs. This region experiences one of the most productive marine ecosystems in the world, known as the Humboldt Current System or the Peru-Chile Current System.
The coast of Peru and Chile is influenced by the Humboldt Current, a cold, nutrient-rich ocean current that flows northward along the western coast of South America. The prevailing winds in this region, such as the trade winds and the southward-flowing Antarctic Circumpolar Current, drive coastal upwelling. Upwelling brings deep, nutrient-rich waters to the surface, providing an abundant supply of nutrients like nitrates, phosphates, and silicates that are essential for phytoplankton growth.
The nutrient-rich waters of the Humboldt Current System support massive phytoplankton blooms, particularly of diatoms and other fast-growing algae. These phytoplankton populations experience rapid growth due to the availability of nutrients and sunlight, leading to high rates of primary productivity. The high primary productivity supports a diverse range of organisms throughout the food web.
Last updated:
Did this page help you?