Why Small Pelagic Fish are important?
- Small pelagic fish, such as anchovy and sardine, may contribute up to 50% of the total landings of marine species (Freon et al. 2005).
- The areas occupied by these species include all oceans and several inland seas (Checkley et al. 2017).
- They are used for aquaculture feed, industrial oil, health supplements, and human consumption (Barange et al. 2014).
- Especially in developing areas of the world, they play a critical role in the nutrition of many vulnerable and poor communities (Isaacs 2016).
- In the Mediterranean, most small pelagic fish landings are consumed directly by humans or used in the canning industry.
- Anchovy and sardine are key forage for marine predators, including fish, squid, marine mammals, and seabirds.
- They are of increasing interest for conservation because of their perceived role as critical forage for charismatic megafauna (e.g., marine mammals and seabirds) in many regions (Checkley et al. 2017).
What are the characteristics of Small Pelagic Fish?
- Small pelagic fish comprise small-sized, plankton-feeder, shoaling, epipelagic species that reside in coastal areas.
- Their main characteristics are the short life span, fast growth and sexual maturity, and high fecundity (Freon et al. 2005).
- They are particularly abundant in highly productive upwelling areas, which can support large populations. In many ecosystems due to their abundance and their mid-trophic position in the food web, they may exert a major control on energy flows, both upwards to their predators and downwards to plankton prey. This type of energy flow control is called ‘wasp-waist’ (Cury & Shannon 2004).
- Small pelagic fish are very sensitive to environmental changes and extremely variable in their abundance. Their close dependence on the environment makes them suitable candidates for the study of climate change effects on the pelagic ecosystem.
- Due to the short life span, their interannual population size largely depends on the annual reproductive effort and the subsequent recruitment success.
- Mortality rates are extremely high during early stages (eggs, larvae) due to predation, lack of food and unsuitable environmental conditions (Freon et al. 2005).
- Small pelagic fish are characterized by long-term variations that occur at multi-decadal scale, probably as a response to environmental regime changes. When anchovy and sardine coexist in the same system, they usually fluctuate out of phase
- Several cases of small pelagic stock collapse have been reported worldwide (Daskalov 2002, Cury & Shannon 2004, Alheit & Niquen 2004), probably due to combined overfishing, environmental changes and/or environmental impact of human activities