When a scientist says that productivity is a rate, he/she means that it is the rate at which organic matter is produced (National Geographic, n.d.). More clearly, in a scientific perspective, biological productivity is the annual rate of biomass production expressed in tons per hectare per year.
Before discussing the factors that influence productivity in various ocean environments like the surf zone, mid-ocean and the deep abyss, it is important to understand the fact that oceans account for only one-third of Earth’s productivity although they cover roughly two-third of the Earth’s surface area. In oceans, coastal regions are characterized with the greatest net primary production. Thorne-Miller (1999) states that diversity of species in surf zone is low but the species that remain in this ocean environment is unusually productive, making the surf zone one of the most productive marine habitats. Wave action is a major factor that influences productivity in the surf zone indirectly. It supplies “nutrients and suspended food particles to plants and animals attached to the rock” (p. 68). In addition, the wave action keeps seaweeds wet in times of low tide, leading to a favorable photosynthesis rate during the period of greatest light intensity. Thorne-Miller also says that seaweeds and invertebrates living in the surf zone have the capability to adapt to the challenging physical conditions there (p.68).
In the words of Foulger (2011), the major factors that determine productivity in mid-oceans include the local plate boundary configuration, temperature, and source composition such as volatiles. Productivity is notably improved by enhanced source fertility. A high fertile source will be characterized with a lower solidus, and this in turn would yield a higher level melting at a given temperature resulting in the thickening of the oceanic crust (p.87). Tyler (2003)