Industrial Energy (INDE)


INDICATOR BACKGROUND AND RATIONAL FOR INCLUSION

Within GAPI, energy consumption is divided into two categories: industrial energy and ecological energy. Industrial energy is energy as we commonly know it—resources such as petroleum and hydroelectric power that are used by aquaculture producers to support fish-farming activities. Ecological energy, however, is a measure of how much energy, or net primary productivity (NPP), is embedded in the feed that is consumed by farmed fish. The industrial energy indicator (INDE) evaluates only the industrial energy component.

The acquisition, processing, and transport of feed ingredients accounts for up to 94% of the total energy consumption of a conventional net pen aquaculture production system (Ayer and Tyedmers 2009; Pelletier et al. 2009). Energy use of non-conventional production systems (e.g., closed containment, bag technologies) is not so tightly tied to feed-related energy use, however. GAPI uses an average value (megajoules/mT) for different production systems. The INDE indicator also includes the production energy embedded in marine, plant, and livestock inputs.

INDICATOR FORMULA

Formula

INDE =       ∑(Proportion Fish/Livestock/Plant/Production System) x
             Knife Coefficient (megajoules/mT) x Total Feed Consumed (mT)

Knife coefficient = Average energy of fish, livestock, and plant compontents in feed (Tyedmers, pers comm. 2009; Ayers and Tyedmers 2009; Pelletier et al. 2009)

Units: Megajoules (MJ)

Sample Calculation

Sample Normalised Calculation:Tiger Pufferfish from Japan, 2007

Industrial energy consumption is calculated as the energy use (MJ) embedded in feed used to produce one mT of fish in that country. Using values from Life Cycle Analysis on salmon (a full “cradle to grave” analysis of environmental impacts), the knife coefficient represents the amount of industrial energy necessary for production of feed components and differing production systems (Ayer and Tyedmers 2009; Pelletier et al. 2009). The components are separated into livestock, plant, and marine. Energy input for each of these includes production, raw material processing/reduction, and feed milling.

ADDRESSING DATA GAPS

GAPI employed the following decision rules to treat gaps in feed sustainability data: