American Fisheries Society Special Symposium: Environmental Impacts of Coastal Ocean Aquaculture

Leading researchers and national policy-makers participated in a symposium entitled 'Environmental Impacts of Coastal Ocean Aquaculture' in San Francisco, CA, on September 4, 2007. Convened as a part of the 137th Annual Meeting of the American Fisheries Society, the symposium was organized by James A. Morris, Jr., and Dr. Jeff Govoni of the NOAA National Centers for Coastal Ocean Science.

The objective of this symposium was to provide a comprehensive assessment and analysis of environmental impacts of coastal ocean aquaculture. This symposium included invited and contributed papers encompassing environmental impacts of both shellfish and finfish culture and forecasts of future aquaculture activities affecting global coastal ocean ecosystems. Dr. Michael Rubino, NOAA Aquaculture Program Manager, delivered the symposium's keynote address.

Symposium participants and presentations included:

 

NOAA's current and future role in developing sustainable marine aquaculture
(pdf, 141 KB)
Author: Michael Rubino, NOAA Aquaculture Program
Abstract: A federal agency under the U.S. Department of Commerce, the National Oceanic and
Atmospheric Administration (NOAA) is focused on creating domestic seafood supply to
meet the growing demand for all seafood products. Currently, 80% of the seafood
Americans consume is imported, and at least 40% of those imports are farmed seafood.
Domestic aquaculture can be an effective option to reduce dependence on seafood
imports, provide jobs for economically depressed coastal communities, and increase
regional food supply and security. In 2005 and 2006, the NOAA Aquaculture Program
successfully focused national attention on marine aquaculture as a vital tool in the
nation’s fisheries management toolbox. In order to advance, this national dialogue must
include a science-based examination of the benefits and challenges inherent in building
our nation’s capacity for domestic aquaculture production. Spurred on by the growth of
aquaculture worldwide, the role of aquaculture in meeting consumer seafood demand,
and the enhancement needs of commercial and recreational fisheries, aquaculture
continues to attract attention from researchers, fisheries managers, policy makers, and
the public. In addition to the inherent health benefits and potential economic benefits of
a more robust domestic industry, experts are focused on research challenges, including
genetics/escapes, pollution, disease, and feeds.

(top)

Some suggestions for leasing and regulation of aquaculture in the United States EEZ
(pdf, 306 KB)
Author: Robert R. Stickney, Texas Sea Grant College Program
Abstract: Commercial aquaculturists who might consider moving into the open ocean, and more specifically into the Exclusive Economic Zone (EEZ) of the U.S. have expressed little interest until a leasing program is established and the regulations governing such facilities are promulgated. Because of the high level of risk associated with open ocean aquaculture related to the potential loss of facilities due to storms, high startup costs, logistical problems and the need to find species that can be cultured at a profit, leases need to be structured so that the cost is reasonable and the duration is sufficiently long that the operator stands a chance to obtain a return on investment. Regulations need to be promulgated that protect the environment while at the same time allowing aquaculturists to employ adaptive management as they learn how to operate successfully in the EEZ.

(top)

Coastal aquaculture policy and regulation - An industry perspective
(pdf not available)
Author: Bill Dewey, Taylor Shellfish Company
Abstract: Public policy and related regulations for nearshore and offshore marine aquaculture in the U.S. are rapidly evolving at the federal, state and local levels. In an attempt to bring consistency to shellfish culture permitting the U.S. Army Corps of Engineers is currently developing programmatic permits for shellfish culture operations throughout the country. Congress is debating that National Offshore Aquaculture Act which will for the first time permit and regulate aquaculture in the U.S. Exclusive Economic Zone. The U.S. Environmental Protection Agency recently developed aquaculture effluent guidelines. The challenge is to find the appropriate balance that adequately protects the environment from adverse impacts while allowing industry to remain profitable and competitive. Policy that does not encourage aquaculture development and/or regulations that are overbearing and costly will drive aquaculture entrepreneurs elsewhere in the world where it is more welcome and less regulated. Aquaculture products from these other countries are then exported back into the U.S. resulting in a net adverse impact to the global environment. To find that balance it is critical that industry and scientists get involved in aquaculture policy debates at the federal, state and local levels.

(top)

Risk assessment of marine aquaculture
(pdf, 57 KB)
Author: Colin E. Nash, NOAA Fisheries, Manchester Research Station
Abstract: The paper provides a basic set of guidelines for risk managers and other decision makers to use all information available to assess the different ecological risks of marine fish aquaculture in a variety of marine ecosystems. Ten areas of substantive risk in the interaction between marine fish aquaculture are perceived by the public and public administrators to be of most concern. In no order of priority they are:  increased organic loading, increased inorganic loading, residual heavy metals, transmission of disease organisms, residual therapeutants, biological interaction of escapes with wild populations, physical interaction with marine wildlife, physical impact on marine habitat, using wild juveniles for grow-out, and harvesting industrial fisheries for aqua-feeds. Each of these 10 areas of risk is assessed for its degree of potential adversity, together with its mitigation, in an identical step-by-step process. Using a flowchart each template identifies the biological end points or entities and their attributes, both locally and far field, which might be affected for that respective area of risk. It also identifies appropriate methodologies that can be used for measuring or monitoring the effects of exposure to each specific risk. As the chances of any risk occurring can differ greatly in accordance with the natural characteristics of the local ecosystem and its geographic location, each template contains a biological overview of its respective risk and briefly discusses factors that may enhance or mitigate the risk’s occurrence.

(top)

Towards evaluating risks and consequences of disease traffic in marine ecosystems
(pdf not available)
Author: Kristen D. Arkush, Bodega Marine Laboratory, UC-Davis
Abstract: Conditions required for the artificial propagation of fish can facilitate pathogen transmission, particularly of microbial agents, with the result that pathogen prevalence is potentially greater than that found among wild fish populations which are often the initial source of the pathogen. This so called “pathogen amplification” combined with other perceived and real biologic and environmental impacts of fish farming are major obstacles to the future growth of marine aquaculture. Disease traffic also flows in reverse, with cultivated species at risk of exposure to pathogens from wild fish. In either case, potential impacts are difficult to predict. Key steps to defining risk are to obtain data on the host-pathogen interaction. The types of data required include at least a cursory knowledge of the pathogenesis, the principal mechanisms of transmission of the agent among members of the population, and estimates of the initial prevalence of the pathogen in wild fish populations that are viewed at risk. Some of these data have been documented for certain pathogens in specific marine fish species though these and other, as yet uncharacterized disease agents are discovered with the cultivation of new host species. Thus risk assessment strategies ought to be considered on a case-by-case basis.

(top)

A fish farm information system for analyzing operations and environmental impacts
(pdf, 1.6 MB)
Authors: Dale A. Kiefer, University of Southern California; Frank J. O’Brien, System Science Applications; and Jack E. Rensel, Rensel Associates Aquatic Science Consultants.
Abstract: We have developed a fish farm information system to assess the operations and impacts of fish farms. The system provides a three dimensional simulation of the growth and metabolic activity of penned fish as well as the associated flow and transformation of nutrients, oxygen, and particulate wastes in adjacent waters and sediments. The farm model resides within the EASy Marine Geographic Information System, and thus all environmental information from field measurements to satellite imagery are readily available for development and testing of the model. The model itself consists of 4 components, a simple 3-dimensional description of advective and turbulent flow, a PZN description of plankton dynamics, a carbon-based description of fish growth and metabolism within the farm, and description of benthic sedimentation and resuspension. The information system has been applied to a virtual offshore salmon farm located in the Strait of Juan de Fuca and a proposed cobia farm in the coastal water of Puerto Rico. The system will support work by administrators, who establish regulations, by operators, who wish to obtain permits and optimize operations of the farm, and by investors, who wish to assess risks and opportunities. For more information on this model, search for "aquamodel" on an internet search engine.

(top)

Impacts of bottom culture of bivalve shellfish on vegetated habitat
(pdf, 1.5 MB)
Authors: James A. Morris, NOAA Center for Coastal Fisheries and Habitat Research; Donald Field, NOAA Center for Coastal Fisheries and Habitat Research; and Charles H. Peterson, University of North Carolina at Chapel Hill.
Abstract: Shellfish culture gear typically becomes fouled with macro-algae providing a local increase in estuarine production and intense suspension-feeding by cultured bivalves is hypothesized to lower turbidity and promote submerged aquatic vegetative (SAV) and macroalgal growth nearby. It has been demonstrated that macroalgal fouling on aquaculture gear can provide habitat similar in structure, biomass, and habitat use as seagrass communities. In this study, we use high-resolution aerial photography to assess the increase in SAV habitat provided by submerged shellfish culture gear and presence of dense suspension-feeding shellfish in a North Carolina estuary. In addition, we conduct a 20 year retrospective analysis capable of quantifying the amount of seagrass and vegetated habitat before and during aquaculture influence. This study provides the first long-term assessment of shellfish culture impacts on seagrass and similarly vegetated habitat and provides indication of how estuarine productivity may have responded to enhanced shellfish culture activities.

(top)

Eutrophication impacts of fish cages in Eleuthera, Bahamas and Calebra, Puerto Rico
(pdf not available)
Authors: Larry E. Brand, University of Miami; Daniel D. Benetti, University of Miami; Jose A. Rivera, NOAA Fisheries; and Brian O’Hanlon, Snapperfarm, Inc.
Abstract: One potential environmental impact of coastal fish cages is nutrient enrichment of the local environment as a result of uneaten food and fish metabolic wastes. In shallow, lighted waters, these nutrients can lead to overgrowth of the natural ecosystem by algae. Monthly samples were taken around submerged fish cages stocked with cobia (Rachycentron canadum) and deployed in exposed areas in Eleuthera, Bahamas and Culebra, Puerto Rico. The samples were analyzed for the abundance of phytoplankton, benthic microalgae, and epiphytic algae as an indication of eutrophication potential. The data were compared by distance from the cages as well as upstream vs. downstream. In all cases, we found that the abundance of the different types of algae was not higher closer to the cages than farther away and at control stations. Similarly, the abundance of algae was not higher downstream than upstream of the cages. We conclude that the strong currents where these cages were located effectively advected and diluted the nutrients from these cages, preventing a buildup of nutrients and algae in the local environment.

(top)

Environmental monitoring of an experimental open ocean aquaculture facility in the western Gulf of Maine
(pdf, 2.6 MB)
Authors: Larry Ward, University of New Hampshire; Raymond Grizzle, University of New Hampshire; James Irish, University of New Hampshire; and Richard Langan, Atlantic Marine Aquaculture Center.
Abstract: The University of New Hampshire, in partnership with local fishing cooperatives, a commercial marine fish hatchery, and several regional research institutions, has operated an experimental aquaculture facility since 1999 ~10 km offshore of New Hampshire. The site is typical of the western Gulf of Maine, with a mixture of substrate types and exposure to strong storm events (~9 m significant wave height). Fish species grown include summer flounder (Paralichthyus dentatus), Atlantic halibut ((Hippoglossus hippoglossus), haddock (Melanogrammus aeglefinis) and Atlantic cod (Gadus morhua). Total fish biomass has ranged from 300 kg to 25,000 kg. Prior to aquaculture activities, ~18 months of environmental observations (water quality and benthic characteristics) were obtained in order to develop baseline conditions. At the outset of aquaculture activities, an environmental monitoring program was established and has continued until present, resulting in nearly a decade of observations. Results of the monitoring indicate there have been no major changes to the environment related to the aquaculture activities. The most recent surveys indicate some differences between predicted impacted, nearfield and far-field zones. However, these results are preliminary and are likely attributable to natural variability. Detailed descriptions of the results of the monitoring work will be presented.

(top)

Advances in marine stock enhancement: indications of widespread implementation of a responsible approach in attempts to avoid mistakes
(pdf, 1.6 MB)
Author: Ken Leber, Mote Marine Laboratory
Abstract: Understanding impacts of hatchery-releases on fish populations is central to determining fishery management strategies, yet few studies have evaluated the effectiveness of stocking or the consequences on wild stocks of interactions between wild and hatchery fish using controlled experiments. Following a decade of new publications in the scientific literature about the emerging science underlying a responsible approach to marine stock enhancement, progress is finally being made in determining whether and how stocking cultured organisms can be an effective fishery-management tool for coastal fisheries.

(top)

Technology advances towards environmental sustainability of aquaculture
(pdf, 6 MB)
Authors: Daniel Benetti, Larry Brand, Brian O’Hanlon, Orhun Refik, Rivera Jose, and Denlinger Bristol, RSMAS/MAF University of Miami
Abstract: Aquafeeds, diseases, pollution and escapees are major contentious issues related to sustainable aquaculture development. Aquaculture scientists, agencies and the industry are addressing these issues by improving quality while reducing fishmeal and fish oil use in feeds to reduce reliance on wild fish. Improved Feed Conversion Rates (FCR), Feed Economic Conversion (FEC) and Feed Conversion Efficiency (FCE or wild fish / farmed fish ratio) are being achieved. Proactive health management strategies such as probiotics and vaccines are being used as prophylaxis for diseases prevention and control. Likewise, water column and benthos pollution due to organic and inorganic wastes have been minimized as modern aquaculture operations are moving into exposed areas in the open ocean, where assimilation capacity is increased due to greater depths and stronger currents. To minimize possible risks of escapees to the wild populations, advanced underwater engineering is allowing for the deployment of systems that are predator resistant and sturdy enough to withstand harsh elements and strong storms. Besides, only native species with wild genes infusions are being cultured. GMOs and exotic species are not recommended. Industry, government, researchers, regulators and organizations are committed to improve sustainability and eco-efficiency of aquaculture for both environmental and economic concerns.

(top)

 

For more information, contact the NOAA Aquaculture Program.