When ocean fisheries began, the most sought-after species were top predators such as bluefin tuna, orange roughy, and Chilean sea bass.These fisheries have now collapsed, and fishermen have responded by "fishing down the food chain," that is, taking smaller species from lower levels.If the trend of overharvesting continues at these lower trophic levels, what will the likely effect on ocean food webs be?
A) There will be little effect, because lower levels of the food web are less important.
B) As lower levels are depleted, the top predators will be able to recover.
C) As lower levels are depleted, species from elsewhere in the ocean will replace them.
D) Fishermen will look for other species to exploit before the food web is affected.
E) The lower levels will also collapse, drastically changing food webs.

Question

Quizplus · Accepted Answer

Overharvesting of lower trophic levels can have a cascading effect on the entire food web, leading to the collapse of multiple species and a drastic change in the ecology of the affected area. This has been observed in various locations around the globe, leading to concerns about the sustainability of ocean fisheries.

When Ocean Fisheries Began, the Most Sought-After Species Were Top