Why have marine fish stocks been depleted significantly in the last 75 years?

90% of fish stocks are used up – fisheries subsidies must stop ... Year after year, we have been pushing the boundaries of the ocean's ... Nearly 90% of the world's marine fish stocks are now fully exploited, overexploited or depleted. ... underpinned the dramatic decrease of fish stocks in the last 40 years, ...

Explanation:

ish catches have declined markedly and are likely to fall further, a study has found, with warming oceans to blame. ... The findings come from a study that has used “hindcasting” methods to reconstruct the effects of global warming, overfishing and other impacts on fisheries over the 80-year period from 1930 to 2010

Explanation:

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.