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  2. Fishing down the food web - Wikipedia

    en.wikipedia.org/wiki/Fishing_down_the_food_web

    The mean trophic level is calculated by assigning each fish or invertebrate species a number based on its trophic level.The trophic level is a measure of the position of an organism in a food web, starting at level 1 with primary producers, such as phytoplankton and seaweed, then moving through the primary consumers at level 2 that eat the primary producers to the secondary consumers at level ...

  3. Trophic cascade - Wikipedia

    en.wikipedia.org/wiki/Trophic_cascade

    Trophic cascades are powerful indirect interactions that can control entire ecosystems, occurring when a trophic level in a food web is suppressed. For example, a top-down cascade will occur if predators are effective enough in predation to reduce the abundance, or alter the behavior of their prey, thereby releasing the next lower trophic level from predation (or herbivory if the intermediate ...

  4. Trophic level - Wikipedia

    en.wikipedia.org/wiki/Trophic_level

    The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way ...

  5. Marine food web - Wikipedia

    en.wikipedia.org/wiki/Marine_food_web

    The definition of the trophic level, TL, for any consumer species is [6] = + (), where is the fractional trophic level of the prey j, and represents the fraction of j in the diet of i. In the case of marine ecosystems, the trophic level of most fish and other marine consumers takes value between 2.0 and 5.0.

  6. Wild fisheries - Wikipedia

    en.wikipedia.org/wiki/Wild_fisheries

    Phytoplankton → zooplankton → predatory zooplankton → filter feeders → predatory organisms (usually constituting several trophic levels) Phytoplankton is usually the primary producer (the first level in the food chain or the first trophic level). Phytoplankton converts inorganic carbon into protoplasm.

  7. Forage fish - Wikipedia

    en.wikipedia.org/wiki/Forage_fish

    The position that a fish occupies in a food web is called its trophic level (Greek trophē = food). The organisms it eats are at a lower trophic level, and the organisms that eat it are at a higher trophic level. Forage fish occupy middle levels in the food web, serving as a dominant prey to higher level fish, seabirds and mammals.

  8. Glossary of fishery terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_fishery_terms

    The species it eats are at a lower trophic level, and the species that eats it are at a higher trophic level. Trolling – a method of fishing where one or more fishing lines, baited with lures or bait fish, are drawn slowly through the water behind a boat.

  9. Aquaculture - Wikipedia

    en.wikipedia.org/wiki/Aquaculture

    Increased shelter raises stocks of prey fish and small crustaceans by increasing recruitment opportunities in turn providing more prey for higher trophic levels. One study estimated that 10 square meters of oyster reef could enhance an ecosystem's biomass by 2.57 kg [150] Herbivore shellfish will also be preyed on.