Northwest Fisheries Science Center (NWFSC) Environmental and Fisheries Sciences EFS - Aquaculture


Live Hauling
Live Hauling of Fish
In certain markets, live fish can be sold for substantially higher prices than fresh dressed fish. A significant live-haul industry has developed in the U.S. and fish are commonly hauled 1,500-2,000 miles (25-30 hours) to market. The most common species hauled are tilapia, channel catfish, and rainbow trout; a smaller amount of marine rockfish, hybrid striped bass, and carp are also hauled. The most significant advancement in hauling technology in the last 20 years has been the use of bottled oxygen gas or liquid oxygen to maintain adequate dissolved oxygen levels. These types of systems can maintain significantly higher DO levels than systems using air. Some common stressors include harvest and loading procedures (pumping or out of water transfer), shaking as the transport vehicle is moving, low frequency sound from the vehicle and water treatment systems, crowding, and poor water quality (high ammonia and carbon dioxide levels, low dissolved oxygen), high light levels, or extreme water temperature. The physical shape and construction of the hauling unit may have an important impact on localized low DOs, physical damage to the fish, and survivability. Very little information has been published on the chemical and physical conditions in transport systems during long-distance transport and this limited data may not be representative of current commercial systems.

This research will be conducted with NWFSC staff in cooperation with private fish farmers in the Pacific Northwest. Specific sub-objectives will include the following:

(1) Documentation of water quality during transport and impact on mortality and product quality

(2) Design of efficient aeration systems for oxygen transfer and carbon dioxide stripping

(3) Determination of the impact of transport tank design and aerator type on the thermal balance during hauling.

The impact of this project will be increased survival and product quality of transported fish as a result of adopting the recommended protocols and utilization of the models. Project outputs will include peer-reviewed publications, popular publications, and conference presentations.

Data Sets

Research Themes

Recovery and rebuilding of marine and coastal species
The Pacific Northwest is home to several iconic endangered species, including Pacific salmon and killer whales, and several rockfish species. Mandates such as the Endangered Species Act, MagnusonStevens Act, and the Marine Mammal Protection Act, grant NOAA Fisheries the authority to manage the recovery of depleted species and stocks. The NWFSC contributes to species recovery through research, monitoring and analysis, providing NOAA managers and regional stakeholders the tools and information they need to craft effective regulations and develop sustainable plans for recovery.

Research Foci

Evaluate the effects of artificial propagation on recovery, rebuilding and sustainability of marine and anadromous species
Artificial propagation has the potential to provide benefits both to species recovery and to seafood sustainability. Artificial propagation also poses risks to wild species and ecosystems. In the past, the use of artificial propagation has been an important risk factor for several threatened and endangered species, particularly Pacific salmon. Assessing the effects of artificial propagation is complicated by the fact that programs vary widely in size, rearing practices, and goals. The NWFSC conducts critical research on the influence of artificial propagation on population dynamics, growth rate, ecology of infectious disease, and the evolutionary fitness of wild fish and other marine organisms. Results of this research are needed to support the recovery of fish populations and have been especially valuable in providing critical information for recent, larger scale habitat restoration activities such as the Elwha Dam removal. NWFSC will continue to conduct science that informs the discussion about whether to allow fish to recolonize naturally after barrier removal, or to supplement populations with hatchery fish and on the impacts of aquaculture on fishing pressure and practices, and on the surrounding environment and ecosystem.


The culture of fish, aquatic invertibrates, and aquatic plants for the production of food
gas transfer
addition of oxygen and removal of carbon dioxide
heat transfer
conductive transfer of heat across the hauling container walls
water quality
Impact of excreted carbon dioxide and ammonia on survival and product quality


Impact of Aeration and Alkalinity on the Water Quality and Product Quality of Transported Tilapia - A Simulation Study
Aquacultural Engineering, 55, 46-58


Species Oreochromis niloticus
Nile tilapia


John Colt
Principal Investigator