


“Delaware Invasive Species Council (DISC) and Marine Threats from Exotics”Estuary Habitat WorkshopJanuary 16, 2003Bruce Richards, Ph.D.
Overview • Examples of Estuary and Marine Invasives • Pathways of Introduction • Delaware Invasive Species Council • Organization • Planning & Assessment • Sample Programs & Activities • Management Plan
Rapana • 1. Black Veins • 2. columella is smooth • 3. siphonal canal is short • 4. The edge of the outer opercular lip has small, elongate teeth • * Deep orange internal shell color • * Shell growth to 18.3 cm • * Round, large inflated body whorl
Hemi- Background • Adult crabs can reach over 35 mm, Carapace width • consumes: algae and animals (amphipods,snails, etc.) • Reproductive April to September • Embryo to zoea stage 20 to 25 days • females produce over 40,000 eggs • Tolerates low salinity 15 o/oo
Common Pathways • Aquaculture - Pacific Oyster & Oyster drill • Aquarium Trade - Goldfish & Washington state lakes • Biological Control- Grass carp & nuisance aquatic plants • Ships: Cargo, Ballast, hull fouling • Live bait Seafood retailing & processing
Ballast water • An estimated 11,507,000,000 gallons of ballast water are discharged annually in US coastal environments. • In one series of studies, 367 different taxa were found in the ballast water of 154 ships arriving in Oregon from Japan.
DISC Organization • 1. Chair, Vice-Chair & Sec./Treasurer • 2. Committee: • Research • Data Management • Public Awareness & Education • Bylaws • Emphasis has been placed on agricultural exotics
Planning & Assessment • What can we do? prevention, eradication, control, and restoration measures • Why are they here? address the intentional, unintentional, authorized, and unauthorized movement of organisms among and within states • How they got here?pathways and processes • What’s our to-do list? Inventory, monitoring, applied research, and the development of new management methods and technologies (including for prevention and exclusion
Programs & Activities • Website, Brochure, Field Trip • Annual Meeting • Committees and ad hoc groups • Inventory of invasive plants • Research Projects: • Deer preference study • DE/MD coastal bays assessment of marine species
Management Plan Goals • 1. Prevent new invasive species introductions, regulate intentional introductions. • 2. Limit spread of established invasives. • 3. Abate harmful ecological, economic, social & public health impacts resulting from infestations of invasives.