Find out what do the terms ‘algal bloom’ and ‘red-tides’ signify

Explanation

Algal bloom. High quantity of nitrates and phosphates in water bodies due to surface run off leads to blooming of agae.
Red tide. Some dinoflagellates like Gomyaulax when present in high quantity in sea imparts red colour to water and are called red tide. However due to algal blooms and red tide animal life declines due to toxins and deficiency of oxygen inside water.