Due to blooms of the type of algae Alexandrium that cause paralytic shellfish poisoning, mussel oyster and clam harvesting was recently shut down along some sections of the Maine coast.

Algae is starting to show up in my local pond, giving the water a murky quality that indicates microscopic life thriving in the warm, nutrient-rich water. Even the water in my fish tank has turned an amazing shade of green.

These are all examples of algae blooms and the exponential growth of algae. Frequently, in the spring, the warming water, increasing sunlight, and extra nutrients washed into local waterways by spring rain fuels this rapid algal growth.

via Algae blooms are prolific this time of year | SeacoastOnline.com (Editor's note: this link is no longer available).