Multi-Component Evaluation to Minimize the Spread of Aquatic Invasive Seaweeds, Harmful Algal Bloom Microalgae, and Invertebrates via the Live Bait Vector in Long Island Sound

The goal of the project was to protect guard Long Island Sound from the introduction of non-native organisms that may be imported via fishing bait worms and the seaweed packing material known as wormweed (Ascophyllum nodosum). The project examined bait for non-native invertebrate animals, macroalgae (also known as seaweeds), and harmful, toxin-producing microalgae. Bait was purchased from retail bait shops at locations ranging from northeastern Long Island Sound along the Connecticut shoreline to the southwestern part of the Sound in Long Island. Using a combination of visual and microscopic inspection, and sophisticated molecular biological techniques to detect the presence of microalgal cells, the study questioned whether (i) non-native organisms were being imported via bait worms, and if so whether; (ii) non-native organisms vary according to purchase location, or; (iii) time of year. Overall, 14 species of macroalgae, two species of harmful microalgae (Alexandrium fundyense, and Pseudo-nitzschia multiseries), and 23 different categories of invertebrate animals were discovered among the wormweed. Only one of the microalgal species was not native to Long Island Sound. Overall, location (eastern vs. western, northern vs. southern Long Island Sound) did not affect the number of algal or invertebrate species. Temperature did affect algal diversity and abundance, however, both in post-collection incubation (5° < 15° = 25°) and seasonally (summer produced highest numbers). Invertebrates were most abundant in summer as well. The Gulf of Maine now harbors a diverse suite of non-native organisms. These may be exported to other areas of the U.S. via national bait wholesalers and cause ecological harm to the receiving ecosystem. In addition to potential ecological impacts associated with the import of non-native organisms, economic harm is also possible. For example, commercial shellfishing beds may be closed when harmful microalgae bloom in coastal waters. With ca. 470 retail bait shops in NY and CT, the chances of introduction of harmful non-natives is not trivial. For example, in our 18 month study of four locations, we discovered the harmful non-native microalga Pseudo-nitzschia multiseries in 58% of our samples.