Invasive species—sometimes called “alien invaders”—are organisms that are not native to the places where they live. They compete so successfully in new ecosystems that they displace native species, and disrupt important processes like food webs. In the ocean, alien invaders can cause serious damage to habitats where seafood is caught or harvested.
Enlist your family and help conquer these ocean invaders by including them in your meals!
Eat the Invaders gives you hints for fighting invasive species, one bite at a time. Here are some hints:
Wild pigs stop near the Kennedy Space Center on their daily foraging rounds. Photograph by NASAwild boar. Wild hogs, indigenous to Eurasia, are “omnivorous and smart.” Now found in forested areas throughout the southeast and western United States, wild boars are dangerous invasives: “On beaches, wild pigs eat sea turtle eggs. In the desert, they root up plants that may not regrow for generations. They eat farmers’ crops; they cause soil erosion. They are linked to an outbreak of E. coli in California spinach that made 200 hundred sick and killed three. They are known to carry or transmit more than 30 diseases and 37 parasites, including swine brucellosis, which can be fatal to people, and pseudorabies, which can kill endangered Florida panthers.”
Non-native prickly pear cactus dominates this view of the southern Italian coastline. Photograph by Tino Soriano, National Geographicprickly pear. These cacti routinely outcompete native plants for resources, taking over entire hillsides and valleys in the southwestern U.S.
Eat the Invader: Be sure to spray the plant with water before harvesting the berries (the red “prickly pears” themselves) and always use thick leather gloves—these are cacti, and they have sharp spines! The berries can be eaten raw or cooked, and the cactus pads are a traditional Mexican treat: nopales!
Common periwinkles are spiral-shelled snails about one-inch long. Photograph by Lamiot, courtesy Wikimedia. CC-BY-SA-4.0periwinkles. In the intertidal zone, this “small snail has few predators—at least on this side of the Atlantic. More than 700 common periwinkles can be found in a square yard along parts of the shore.” Feasting on nearshore algae, periwinkles outcompete native species for food and create an imbalance in the species of green algae.
Eat the Invader: “Winkles” are commonly eaten like clams in both Europe and Asia, so recipes are not hard to find. Try spaghetti and periwinkles to start!
Wakame is a big brown kelp native to the cold Pacific waters around Japan, China, and the Korean Peninsula. Photograph by CSIRO. CC-BY-3.0wakame. “Like all good invaders,” this seaweed is “tolerant and opportunistic, growing on stones, rocks and reefs, shells, ropes, pontoons, buoys, and ships’ hulls. In the early stages of its life cycle, it can grow on other algae and sea-grasses. As an adult, it grows into kelp “forests.” The large canopy it forms modifies the habitats of the species that end up below, reducing light levels and water movement. The fronds may attach their holdfasts to shellfish on the seabed, whether the shellfish or their prey like it or not.”
Eat the Invader: Wakame is incredibly popular in Asian cuisine, frequently found in miso soups and seaweed salads.
Bryan Chasney, of the Anacostia Watershed Society, found this red swamp crawfish during a biological inventory at the Gateways, a national park property on the Anacostia River. Photograph by Krista Schlyer, National Geographicred swamp crayfish. One of Nat Geo’s favorite “tiny travelers,” these invaders can impact the living and non-living parts of an ecosystem: The crayfish “eats tadpoles and bass and trout eggs. It also consumes plants that line the bottoms of lakes and streams. Its activity can make clear bodies of water more turbid and cause stream-bank erosion.”
