this, the second largest island in Casco Bay Mosquitoes can be a nuisance, and much of the island is soft, sandy, swampy soil (due largely in part to the many underground springs), which are perfect conditions for mosquito breeding. Harbor seals can often be spotted from the shores of Chebeague, swimming or sunning themselves on the rocks of nearby uninhabited islands or on depth-marker buoys. Occasionally one might spot a porpoise breaking surface as well. Lobsters and lobstering are a big part of Casco Bay, and the ocean surrounding Chebeague is dotted by thousands of lobster pot buoys, the livelihood of many year-round residents in the area. Lobstering is a big commodity of Casco Bay. Locals often fish from the docks and piers for mackerel, bluefish, or striped bass, just a few of many abundant fish in the area, and crab traps hang from the docks. Blueberries All over the island, as Maine is often known for, are blueberry patches that supply an abundant amount of blueberries, ardently picked by the locals. However, they are slowly decreasing in size as land development continues. Clamming and red tide The many inlet coves around the island are home to abundant clam beds. During low tide, these fully exposed areas can be walked on and are often clammed by the locals, some of whom have made a living for decades harvesting steamers, hen clams, and razor clams from the muddy, clay-rich soil. Clamming is often shut down when the red tide—a harmful microscopic ocean organism that affects shellfish—"blooms" in the area. People who eat clams that are affected by the red tide (even steamed ones) can become violently ill; the algae can be fatal. This paralytic poisoning often causes death to humans, birds, larval and adult fish, and marine mammals. For many years, mussels—which grow in clusters, attached by "beards" to rocks and seaweed, pier pilings, buoys, and just about any stable structure in the ocean—were largely ignored as inedible. But during the 1980s and early 1990s, when clams were getting more difficult to acquire, mussels began to be considered good eating. Some consider these mollusks a bit more "gamey" in taste compared to clams but quite similar otherwise. Mussels can be reaped in much larger quantities, very quickly. Clams have to be dug out of the sand, by hand, with an angled pick; they very often withdraw deeper into their sand tunnel