Assessment of Transoceanic NOBOB Vessels and Low-Salinity Ballast Water as Vectors for Nonindigenous Species Introductions to the Great Lakes

The Great Lakes NOBOB Assessment and Ballast Water Exchange Study was a $1.9M three-year research effort involving collaboration among six institutions and conducted by a U.S.-Canadian team of scientists. The program was jointly led by the National Oceanic and Atmospheric Administration's (NOAA) Great Lakes Environmental Research Lab (GLERL) and the University of Michigan's Cooperative Institute for Limnology and Ecosystems Research (CILER), both located in Ann Arbor, MI.

+ read NOBOB Final Report [PDF, 8.3 mb]

Goals and Objectives

Greater than 75% of vessels entering the Great Lakes in recent years declared that they have no pumpable ballast water on board ("no-ballast-on-board", or "NOBOB"). Such vessels are not subject to ballast management regulations. Previous studies have shown that the "empty" ballast tanks in NOBOB vessels often contain an unpumpable residual mixture of sediment and water accumulated from previous ballasting operations. Once NOBOB vessels off-load cargo at a Great Lakes port, they take on lake water as ballast and then move to another port within the lakes. Before adding new cargo, these vessels must discharge some or all of their new ballast water, and in the process, can potentially discharge nonindigenous species from the original residual ballast material in their tanks.

A few studies have reported data on the characteristics of biota in NOBOB tanks, and show the residual water and sediment in these tanks may contain thousands of live organisms, their resting stages (resting eggs and cysts), and microorganisms, including human pathogens. Resting stages have been largely overlooked, yet may represent a significant potential source for introductions. However, a thorough characterization and nonindigenous species risk assessment of NOBOB residuals on ships operating in the Great Lakes did not exist prior to this study.

The primary goals of the program were:

To provide the scientific knowledge needed to understand the risk of invasive species introductions posed by transoceanic NOBOB ("no-ballast-on-board") vessels operating in the Great Lakes
To provide a basis for identifying effective preventive measures and for developing policies and biological standards for ballast water treatment
To experimentally determine the effectiveness of open-ocean ballast exchange with special attention to low-salinity or fresh water initial ballast

In order to meet these project goals, we pursued the following three interrelated objectives:

Task 1: Characterize biological communities (invertebrates, phytoplankton, and microorganisms) present in NOBOB tanks and correlate these findings with ballast management practices and history.

Task 2: Measure the effect of adding Great Lakes water as ballast to NOBOB tanks on germination and growth of nonindigenous species present in ballast residuals and on their potential release from ballast tanks.

Task 3: Test the effectiveness of open-ocean exchange for vessels arriving to the Great Lakes from fresh and brackish water European ports.

Contacts

This program is co-managed by:

Dr. David Reid
NOAA-Great Lakes Environmental Research Lab (GLERL)
2205 Commonwealth Blvd.
Ann Arbor, MI 48105-2945
Ph: 734-741-2019
FAX: 734-741-2055
Email:david.reid@noaa.gov

Dr. Thomas Johengen
University of Michigan
Cooperative Institute for Limnology and Ecosystems Research (CILER)
2205 Commonwealth Blvd.
Ann Arbor, MI 48105-2945
Ph: 734-741-2203
FAX: 734-741-2055
Email:johengen@umich.edu

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