Objectives:The purpose of this proposal is to assist small ports and harbors in Massachusetts prevent or reduce marine invasions from vessel related activities. One or two ports will be selected to serve as the ‘pilot project’ for this proposal. The specific objectives are 1. to develop a database of vessels visiting the port, their origins (and destinations), potential invaders from bioregion sources, and environmental data on home and source ports, and 2. to use this information to design a process for assessing risk of marine invasions from vessel-related activities. A list of best management practices to reduce risks will be compiled from existing information and provided to the port(s). The protocol, database, and best management practices should be adaptable to other small ports in Massachusetts and New England.Methodology:The approach is to collaborate with port managers from one or more ports in Massachusetts and to identify vessel traffic (including commercial, fishers, recreation, and others) that may be a vector for introduced species. Using a variety of data sources, a database will be developed using available information on 1. ballast discharges to the port, 2. port environmental data (both the source and receiving ports), 3. potential marine bioinvaders (and current ones in the port), and 4. data on hull fouling and other vectors, associated species of concern, and related metrics to assist with risk estimates of levels of threat of invaders. At least two focus group workshops (scientists, port managers, and users) will be convened to review to data, identify additional information,and provide advice on the development of the risk assessment for the port. Best management practices used to manage invasions will be assembled as options for managing, reducing or preventing new invasions.Rationale:The presence of the highly aggressive sea squirt (tunicate, didemnum cf. lahillei) on productive scallop beds on Georges Bank has economic and ecological implications for the industry. This species is found on hard surfaces from the shallow subtidal areas to the deep waters near the continental shelf and nearshore from Maine to Connecticut. It may have been introduced by ballast water, hull fouling, and fishing, but few ports or harbors are taking actions to prevent its spread. In addition to ballast water, other vessel-related activities may introduce species into harbors and ports. At the national level, efforts to reduce ballast water introductions are well underway, but there is little information on the relative contribution of marine invaders from other vessel related activities such as sea chests, hull fouling, bolding tank discharges, vessel and gear cleaning, ballast tank cleaning, and other practices that may be unique to a particular port. For ports, such as the City of Gloucester, there is little specific documentation on the risks associated with vessel related activities, thus they are uncertain about what can be done to protect their resources from invasions. Furthermore, information on how other areas are addressing these issues (e.g. hull fouling) is scattered throughout the literature and not easily accessible. There is a need to identify important issues and to document levels of risk (even if they are not quantified) associated with vessel activities.