An obligatory parasite is a parasite that can not complete its life cycle without exploiting a suitable host
John Pierpont Morgan<span> Sr. (April 17, 1837 – March 31, 1913) was an American financier and banker who dominated corporate finance and industrial consolidation in late 19th and early 20th Century United States.</span>
It causes eutrophication which means that the algae have too much nutrients and take over the pond, use the oxygen so there is not enough left for marine life, which die as a result.
The answer would be the ozone layer. <span>A layer of ozone in the upper atmosphere absorbs </span>UV radiation<span> and </span>prevents<span> most of it from </span>reaching<span> the </span>Earth<span>. ... This means that more </span>ultraviolet radiation<span> can pass through the atmosphere to the </span>Earth's<span> surface, particularly at the poles and nearby regions during </span>certain<span> times of the year.
I hope that this helped you! Good luck. :)</span>
