Canadian Aquaculture R&D Review 2011

Aquaculture – Environment Interactions

Benthic transport of aquaculture tracer material

Predicting the dispersal of feed pellets and faecal waste through the use of hydrodynamic modeling is necessary to estimate the benthic zone of influence surrounding farm systems. Validating model predictions can help with site selection and provide research and monitoring tools for regulating the aquaculture industry. In order to accurately validate models, transport coefficients of waste material ranging in size and chemical makeup were determined using a sedimentation column and an annular water-flow flume. Sinking rates and resuspension thresholds of fish feed pellets increased with increasing pellet size. Feed pellets formed aggregate formations at lower velocities decreasing their overall speed at lower flows. At higher flows, larger pellets moved faster than smaller pellets, likely due to their subdued saltation behaviour. The sinking rates of faecal pellets appear to be 40-60% lower than those of fish feed pellets. Transport of faeces was variable within an individual experiment due to the break-up behaviour of faecal pellet texture. This study provides some information regarding resuspension thresholds for feed pellets and faecal material. With the continuance of such research it should be possible to shed further light on the dispersal patterns around fish pens and to develop methods to ensure the sustainability of the aquaculture industry.

Sept. 2009 – Mar. 2010 • Funded by: DFO – Program for Aquaculture Regulatory Research
Project team: Terri Sutherland (DFO), Carl Amos (NOCS), Dave Higgs (DFO), Ian Forster (DFO), March Klaver (DFO)
Contact: Terri Sutherland ( Terri.Sutherland@dfo-mpo.gc.ca)

Video characterization of potential aquaculture impacts on hard-bottom

Although monitoring tools have been developed for benthic aquaculture assessments associated with soft-substrate settings, knowledge gaps exist regarding hard-substrate methods. The objective of this project is to identify methods for monitoring, quantifying, and evaluating potential impacts to hard-bottom substrates and increase the science knowledge base to support DFO ecosystem-based environmental regulation and decision making. High-definition videos and still photos were collected at stations along constant depth contours for a distance up to 1 km from farm netpens. Reference transects were oriented perpendicular from shore, across increasing water depths, to examine patterns of benthic community composition with depth. Additional work is required to establish reference stations as different zonation patterns exist between high-grade and low-grade seafloor slopes. Videos and images are currently being analyzed, and the information gained will be integrated with acoustic multibeam surveys to characterize the seafloor and biological communities associated with aquaculture operations. Depositional hard-bottom environments can be very complex and are sometimes made up of a mosaic of hard (rocky slopes), mixed (boulder fields), and/or compact seabeds (gravel shell-hash). A suite of technologies may be required to delineate natural and impacted seabeds of a heterogeneous nature and to determine what threshold effects of environmental change can be used practically for habitat management purposes.

Sept. 2010 – Mar. 2011 • Funded by: DFO – Program for Aquaculture Regulatory Research
Project team: Terri Sutherland (DFO), Gehan Mabrouk (DFO), Danny Ings (DFO), March Klaver (DFO), Carol Grant (DFO), Lisa Noble (DFO)
Contact: Terri Sutherland (Terri.Sutherland@dfo-mpo.gc.ca) /aquaculture/rp-pr/parr-prra/index-eng.html

Data collection in support of zone of impact modeling for Lake Huron cage farms

This project has begun the collection of data required to perform waste deposition modeling and zone of impact delineation at commercial cage sites in Lake Huron. Fine-scale bathymetric data, current speed and direction data, and farm production records were collected from three of nine commercial fish farm sites in the North Channel of Lake Huron. These data are required for DEPOMOD, which is a particle tracking model developed for and in use in the marine environment. DFO's Central & Arctic Region is testing if this tool provides accurate predictions of deposition in the freshwater environment and to modify or seek a new tool if it does not. Such a tool would permit applicants and regulators to assess the potential production capacity of a site within the assimilative capacity of the local environment.

We conducted a sensitivity analysis of the model DEPOMOD to confirm model response to changes in the input parameters. Starting with bathymetry, current data and production from an existing farm, each model parameter was then systematically varied along a range of values that slightly exceeds the range of values available in the published literature. Sensitivity analysis is a crucial first step to determine where best to focus resources for measurement of input parameters for greater model accuracy. We found that DEPOMOD is highly sensitive to changes in the coefficient of horizontal dispersion, amount of feed wasted, spacing between cages or between cage groups, and to the digestibility of feed. The model is moderately sensitive to increases in water depth below the cages and to carbon content of the feed. Within the hydrodynamic environment offered in the North Channel, the model is not sensitive to the coefficient of vertical dispersion, and the settling speeds of feed and fish waste. Some parameters affect the distribution of carbon sedimentation to the lake bed, while others impact only the magnitude of carbon flux.

DEPOMOD performance is being validated through a comparison of predictions against measured fluxes. Flux measures have been collected by deploying sediment traps around farm sites and also through the collection of sediment samples. Initial results indicate that the model over-predicts carbon sedimentation in close proximity to the cage edges and under-predicts carbon sedimentation at greater distances from the cages. No measurements of flux were obtained directly below the cages. Complex shoreline currents and uncertainty in sensitive parameters such as the coefficient of horizontal dispersion and the digestibility of feed, as well as the need for natural sedimentation rates in the area are ongoing challenges for model validation.

Apr. 2008 - Mar. 2011 • Funded by: DFO – Program for Aquaculture Regulatory Research, Ontario Ministry of Foods and Rural Affairs
Project team: Cheryl Podemski (DFO), Doug Geiling (DFO), Emil Laurin (DFO), Jian Zhang, Paul Azevedo, Steve Naylor (Ontario Ministry of Foods and Rural Affairs)
Contact: Cheryl Podemski ( Cheryl.Podemski@dfo-mpo.gc.ca)

Development of predictive modeling tools to assist with freshwater cage licensing

This project is taking advantage of a proposed expansion of the cage farm industry in Saskatchewan to test the suitability for the freshwater environment of DEPOMOD, a particle tracking model. Wild West Steelhead, already the largest Rainbow Trout cage farm in Canada, is poised to increase production through the addition of a new cage site in Lake Diefenbaker. This will be the first use of the innovative new I-cage technology in freshwater. Researchers have produced detailed bathymetric charts for the existing Cactus Bay and the proposed Kadla Coulee site, and have characterized water currents through the deployment of acoustic doppler profilers. The farm has provided detailed production records which, together with the bathymetry and current data, are being used to parameterize the model and produce deposition predictions.

Suitability testing of DEPOMOD included parameter sensitivity analysis, model parameterization and validation. Validation of DEPOMOD predictions against measured sedimentation fluxes is ongoing. Monthly during the ice-free season of 2008 and 2009, researchers deployed sediment traps around the Cactus Bay site and at upstream reference locations. DEPOMOD underpredicted waste dispersal and deposition with an overall model error (mean absolute relative error (MARE)) of +40% (N=65). Overall accuracies from the present study are less than the accuracy reported in previous research (e.g., MARE=13-20%). However, these authors only considered traps under cages for their validation. Similar MARE were obtained in the present study when considering only traps under cages. This error range is smaller than other solid waste dispersion models (e.g., GIS model accuracy with MARE of +58.1%, KK3D model accuracy +48.9%) and MERAMED (average MARE of 51%, and range 29-100%). Because the model was sensitive to coefficients of dispersion and literature values for this parameter are variable, measurements of coefficients of dispersion appropriate for typical freshwater cage sites may be an objective for future research. The effects of solids flux on sediment chemistry and benthic invertebrate community structure is being investigated through coring sediments along transects radiating from the Cactus Bay site.

The proposed Kadla Coulee site presents an opportunity to obtain good pre-and post-operational data to detect environmental impacts, and to further test DEPOMOD predictions. To create a baseline data set, water chemistry, zooplankton and phytoplankton populations as well as sediment chemistry and benthic invertebrate community structure have been monitored at the proposed Kadla Coulee site. The new farm is expected to start production in the summer of 2011, and environmental sampling will continue.

Apr. 2008 - Dec. 2009 • Funded by: DFO – Aquaculture Collaborative Research and Development Program (ACRDP), Wild West Steelhead
Project team: Cheryl Podemski (DFO), Paula Azevedo (DFO), Jian Zhang (DFO), Cynthia Wlasichuk (DFO), Doug Geiling (DFO)
Contact: Cheryl Podemski ( Cheryl.Podemski@dfo-mpo.gc.ca) /aquaculture/acrdp-pcrda/index-eng.htm

Assessment of environmental impacts and recovery from freshwater cage culture

The impacts of cage-culture are difficult to assess because they cannot be readily quantified in the large, open systems typical of many farms. Confounding influences, such as other industrial activities, the presence of multiple cage farms, cottage or municipal wastes, local fisheries, or species introductions make it difficult to unequivocally assign responsibility for environmental degradation. An experimental approach in a controlled ecosystem where both pre- and post- aquaculture data are collected is the strongest approach to objectively evaluating the potential impacts of freshwater aquaculture on lake ecosystems.

Researchers at the Experimental Lakes Area operated an experimental Rainbow Trout farm on Lake 375 from 2003-2007. For a period of 2 years prior to production, throughout production, and for 3 years after production, L375 and the control lake (L373) have been closely monitored. During the first year of cage production, only minor changes in water chemistry occurred and no changes occurred in algal production, zooplankton, or fish communities. Changes were observed in the sediments and benthic communities under the cage, but these changes were restricted to the area directly underneath the cage. During the second year of production, changes in the sediment chemistry were again largely restricted to areas directly under the cage, while changes to infaunal invertebrate communities extended to an area 15 m distant from the cage edge. There was an increase in water column total phosphorus, and algal production also showed a significant increase through years 2-5 of production, averaging approximately 4x higher than pre-farming production. Algal production remained elevated during the first year after fish farming, but declined in 2009 and returned to background levels in 2010. The zooplankton community was largely unaffected by cage culture. The Opossum Shrimp (Mysis sp.) population declined significantly in both L373 and L375 in 2008; the L373 population rebounded the following year but this did not occur in L375 until 2010, two years after cessation of farming. The native Lake Trout population exhibited increased growth, condition factor and abundance in response to aquaculture. The size of the Lake Trout population in L375 nearly doubled over the 5 years of aquaculture production. The response of the Lake Trout population to the removal of the farm is now being monitored to determine for how long increased growth and condition will continue. The forage fish community, which was not as closely monitored as Lake Trout, showed increased catch per unit effort for many species. The use of stable C and N isotopes to track the assimilation of cage-associated materials has shown that the wild fish community, as well as many of the invertebrate species in the lake have been utilizing waste from the cage as a food source. An isotope mixing model suggested that as much as 30% of the diet of minnows was of farm origin.

This project has demonstrated that with appropriate siting, freshwater cage aquaculture can be an environmentally sustainable activity, and the project continues to make important contributions even after removal of the farm. One potential management technique that could be employed by the industry to reduce accumulation of wastes and the associated changes in invertebrate communities under farms is fallowing – to rotate production periodically between different areas to allow assimilation of wastes. This strategy is employed by the marine finfish industry in a variety of jurisdictions. The continued monitoring of the recovery of sediments under the ELA farm provides a valuable opportunity to measure the rate of assimilation of waste material and help to inform the development of fallowing practices for freshwater.

2001-2011 • Funded by: DFO – Aquaculture Collaborative Research and Development Program (ACRDP), Northern Ontario Aquaculture Association
Project team: Cheryl Podemski (DFO), Ken Mills (DFO), Paula Azevedo (DFO), Paul Blanchfield (DFO), Mike Paterson (DFO), Ray Hesslein (DFO), Michael Turner (DFO), Dave Findaly (DFO), Jian Zhang (DFO), Cynthia Wlasichuk (DFO), Sandra Chalanchuk (DFO), Lori Tate (DFO), Adam McFee (DFO), Alain Dupuis (DFO), Karen Kidd (UNB), Marilynn Kullman (UNB), Shelley Wellman (UNB), Rebekah Rooney (U of Manitoba), Kelly Hille (U of Manitoba), Michelle Wetton (U of Manitoba), Corben Bristow (U of Ottawa)
Contact: Cheryl Podemski ( Cheryl.Podemski@dfo-mpo.gc.ca) /aquaculture/acrdp-pcrda/index-eng.htm

Treatment of particulate and dissolved wastes from a flow-through aquaculture facility

Sedimentation and screening are primarily used for solid waste removal in flow-through aquaculture facilities. These physical treatment methods remove settleable solids and particulate bound nutrients from the wastewater, but they do not treat the dissolved fractions such as total ammonia nitrogen, phosphate and biochemical oxygen demand (BOD5) that can harm the receiving aquatic environment.

The Centre for Alternative Wastewater Treatment has partnered with the Haliburton Highlands Outdoors Association in Haliburton, Ontario, which operates a flow-through salmonid hatchery. The purpose of the partnership is to study the ability of a subsurface flow constructed wetland to treat the concentrated wastewater flow that is produced during daily vacuuming of the hatchery's raceways. Constructed wetlands remove suspended solids and particulate bound nutrients by sedimentation and filtration and treat the dissolved fractions of the wastewater through microbial processes of decomposition and nitrification-denitrification.

The constructed wetland has been receiving vacuumed wastewater since the autumn of 2008. The graph shown depicts average reductions of total suspended solids (TSS), carbonaceous biochemical oxygen demand (cBOD5), chemical oxygen demand (COD), ammonia, and total phosphorus and phosphate during 2009–2010 when wastewater was flowing horizontally through the system.

During 2010-2011, the wetland is being operated with vertical dosing of wastewater to improve TSS, cBOD5, and ammonia removal.

May 2008 – May 2011 • Funded by: DFO – Aquaculture Collaborative Research and Development Program (ACRDP), New Directions Research Program, OMAFRA, Ontario Trillium Foundation
Project team: Brent Wootton (Fleming College), Gordon Balch (Fleming College), Bruce Anderson (Queen's University), Chris Metcalfe (Trent University), Robin Slawson (Wilfrid Laurier University), Alison Snow (Queen's University), Lauren Sansford (Queen's University), Mike Mitzel (Wilfrid Laurier University), Cassandra Helt (Wilfrid Laurier University)
Contact: Brent Wootton ( bwootton@flemingc.on.ca)

Carrying capacity modeling for bivalve aquaculture: biodeposition

Small mussel socks with and without two species of tunicates and control socks were constructed to evaluate biodeposition (sedimentation rates) associated with mussels and fouling organisms in field conditions over a 2 week period in September/October 2008. In short, biodeposition rates of mussel socks with tunicates were about double those without tunicates. Sinking rates of tunicate faecal pellets varied greatly but averaged about 2.35 cm sec^-1, about twice that of mussels. These data were used within an existing hydrodynamic-based depositional model - DEPOMOD - to predict benthic loading within a culture site. Benthic loading was predicted to be much greater although more restrained spatially when tunicates are present. Refinement of this and related models will ultimately allow for better predictions for aquaculture management within an ecosystem-based management framework for sustainable aquaculture.

Apr. 2008 – Mar. 2009 • Funded by: DFO – Program for Aquaculture Regulatory Research
Project team: C.W. McKindsey (DFO), M. Lecuona (DFO), M. Huot (DFO), A.M. Weise (DFO)
Contact: Chris McKindsey ( Chris.McKindsey@dfo-mpo.gc.ca) /aquaculture/rp-pr/parr-prra/index-eng.html

Monitoring and modeling phosphorus contributions in a freshwater lake with caged-aquaculture

Water quality risk management for cage-aquaculture in Ontario is currently based on in situ sampling, meaning results are based on phosphorus concentrations at the time of measurement. The current water quality regulatory framework lacks a predictive element with which to address the dynamic nature of nutrient loadings in 'open' ecosystems. The need for sustainable environmental management of cage-aquaculture farms is of primary importance if the industry is to move forward while preserving the ecological integrity of the Great Lakes.

A phosphorus mass-balance model was applied to a freshwater lake with cage-aquaculture on Manitoulin Island, Ontario. The objectives of the study were to: 1) determine the relative contributions of phosphorus from other sources (e.g., dwellings, tributaries, groundwater, inlet exchange, atmosphere) by implementing a sensitivity analysis; 2) determine if the lake can support the expansion or addition of a fish farm; 3) provide practical information to regulators (e.g., to compliment the Decision Support Tool (DST)) and make sound science-based decisions for lake management.

Preliminary results show that feeder tributaries are the most sensitive parameter in terms of phosphorus loading to Lake Wolsey, followed by the inlet exchange rates with the open lake, and, finally, by the contributions of the farm itself. Information from this project will: 1) provide improved understanding of the relative phosphorus contributions of a fish farm to a freshwater lake in Ontario; and 2) assist water quality managers by supplying scientific information to aid in the decision-making processes related to determining policy and regulatory approaches to sustainable aquaculture management in Ontario.

Jan. 2008 – Dec. 2011 • Funded by: Environment Canada
Project team: Richard. D. Moccia (U of Guelph), Jacqui Milne (U of Guelph)
Contact: Richard. D. Moccia ( rmoccia@uoguelph.ca) • http://www.aps.uoguelph.ca/aquacentre

Evaluation of ecosystem-level effects of bivalve aquaculture activities: mussel culture in Gaspé

A regional priority in Québec is to better understand the functional relationship between increased organic sedimentation due to suspended bivalve aquaculture and benthic responses to better predict the benthic ecological carrying capacity of sites for suspended bivalve aquaculture. This project constituted a scoping study in Gaspé in the fall of 2008 to evaluate the impact of current aquaculture practices on the benthic environment. As a first step in a larger future research, this work was limited to infaunal and sediment samples to evaluate if patterns relating to mussel farming exist. Benthic samples were taken below and between mussel lines in each of 3 stations within mussel farms and at each of 3 reference stations. All organisms recovered were identified. Although sites differed from one another, there was no evidence of an influence of bivalve culture on benthic communities. It is suggested that this is due to the low density of mussel culture in the area and great natural organic enrichment from a near-by river. Directed manipulative studies would have to be undertaken to determine the level of loading that would modify benthic communities in this environment.

Apr. 2008 – Mar. 2009 • Funded by: DFO – Program for Aquaculture Regulatory Research (PARR)
Project team: Chris McKindsey (DFO)
Contact: Chris McKindsey ( Chris.McKindsey@dfo-mpo.gc.ca)

Dose-dependent relationships for biodeposition from farmed mussels and benthic responses

One of the most evident impacts of bivalve culture is its influence on the seabed and the development of a sustainable aquaculture industry requires the ability to predict such impacts. Several knowledge gaps need addressing to develop predictive models to this end. These include: valid estimates of biodeposit production by cultured species, the functional response of benthic communities to increasing organic enrichment due to biodeposition from cultured bivalves, and the development of appropriate indicators of benthic community condition. We are addressing some of these gaps by using modeling approaches to estimate biodeposit production and its influence on the seabed, evaluate predictions through a series of in situ experiments, and parameterize an index of benthic condition for Eastern Canada conditions. Preliminary results from large in situ mesocosm studies done in the Magdalen islands in 2010 show that sediment biogeochemical parameters and oxygen concentration change predictably with increasing organic loading from mussel biodeposition. Analysis of biological communities is on-going. Proposed work in 2011 will repeat and expand upon this work in Prince Edward Island, provide realistic estimates of biodeposit production, and develop a model to predict benthic condition for different culture scenarios.

Apr. 2010 – Mar. 2013 • Funded by: DFO – Program for Aquaculture Regulatory Research (PARR)
Project team: Chris McKindsey (DFO – IML), Andrea Weise (DFO – IML), François Roy (DFO – IML), Philippe Archambault (ISMER), Luc Comeau (DFO), Cédric Bacher (IFREMER)
Contact: Chris McKindsey ( chris.mckindsey@dfo-mpo.gc.ca)

Influence of Eastern Oyster aquaculture on eelgrass populations and their recovery

International and regional scientific consensus has been achieved on the critical ecological position of eelgrass (Zostera marina) in providing fish, bird and invertebrate habitat as well as nursery habitat for juvenile fauna. Eelgrass also plays an important role in enhancing nutrient cycling and sediment stabilization. Worldwide seagrass declines have been associated with anthropogenic stressors, especially those linked to decreased underwater light levels or reduced water clarity associated with increased nutrient and sediment loading. Recently, the project team has demonstrated localized reductions in eelgrass distribution, growth rate and photosynthetic capacity linked to shading from oyster culture equipment used in the southern Gulf of St. Lawrence.

Based on these observations, DFO Habitat Management and the regional oyster industry have requested advice regarding the temporal and spatial recovery patterns of eelgrass in areas exposed to suspended bag, as well as off-bottom (i.e., table) culture. This project is designed to gain a better understanding of eelgrass recovery processes, while developing best management practices to guide industry in mitigating any effects. Multi-year field experiments examining the recovery dynamics of eelgrass exposed to both culture methods are underway, with additional experiments on lease fallowing strategies planned for the coming field season.

Apr. 2010 – Mar. 2013 • Funded by: DFO – Aquaculture Collaborative Research and Development Program (ACRDP), L'Étang Ruisseau Bar Ltd.
Project team:Marie-Hélène Thériault (DFO), Simon Courtenay (DFO/Canadian Rivers Institute), Marc Skinner (DFO/Canadian Rivers Institute), André Mallet (L'étang Ruisseau Bar Ltd.), Claire Carver (L'étang Ruisseau Bar Ltd.)
Contact:Marie-Hélène Thériault ( marie-helene.theriault@dfo-mpo.gc.ca) /aquaculture/acrdp-pcrda/index-eng.htm

Development of off-shore aquaculture in the southern Gulf of St. Lawrence: bottom mapping

A Wide Angle Seafloor Sonar Profiler (WASSP) (multi-beam) and the OLEX sea mapping software has been installed aboard the Opilio, the Gulf Region research vessel. During every research mission since the installation, marine bottom information is being gathered simultaneously as various project leaders conduct their research aboard the Opilio. The real-time 3D seafloor profiler is providing bathymetric contour mapping. A good understanding of the physical characteristics of the seabed is a key element in habitat characterization.

In the Gulf Region, the lobster group has a WASSP and OLEX system on their inshore vessel. At the end of November, after the Opilio has completed the 2009 missions, the bottom mapping data acquired on the Opilo will be downloaded and combined with the near-shore data obtained using the lobster group's inshore vessel. Presently, it is planned to download the data at the end of each year to create yearly marine bottom maps. Every time the Opilio sails, the contour maps are up-dated, therefore yearly maps will provide a means to document the changes as they occur. Users will be able to compare the marine bottom maps from one year to the next.

Apr. 2008 – Mar. 2009 • Funded by: DFO - Program for Aquaculture Regulatory Research (PARR)
Project team: Leslie-Anne Davidson (DFO)
Contact: Leslie-Anne Davidson ( Leslie-Anne.Davidson@dfo-mpo.gc.ca) /aquaculture/rp-pr/parr-prra/index-eng.html

Tracking aquaculture's interactions with wild species

A multi-year investigation was designed to determine if the natural carotenoid pigments – astaxanthin and canthaxanthin – that are added to salmon feed for nutritional and pigmentation purposes can be found in wild species living near salmon cage sites. These pigments give wild and farmed salmon flesh its red or pink colour, and are important for proper growth and development. Wild salmon obtain this pigment through their natural food, such as krill and other crustaceans. Consumption of dispersed aquaculture feed could result in higher concentrations of these pigments being found in species living close to cage sites. Therefore, samples of local invertebrates (American Lobster, scallops, sea urchins, Rock Crabs, Horse Mussels, and the common Northern Sea Star) were taken from three adjacent sites (less than 100 m) to salmon cages and three sites four to six kilometres distant from the nearest cages. These wild species were chosen for their abundance, long residence time, ease of capture, and commercial value. Initial results show that canthaxanthin can be detected in the reproductive and digestive tissues of several species (crab, lobster, sea urchins). In most invertebrate samples from locations closest to the cage sites canthaxanthin was detected at concentrations ranging from 2.5 to 7.9 ppm. However, this pigment was not detected in the same species collected four to six kilometres away from these aquaculture sites. The pigment astaxanthin, by contrast, was found at low levels in all samples both near and far from the salmon cage sites. But, since it is available from natural sources in the environment, its presence does not necessarily indicate exposure to aquaculture feeds. While these pigments have not been shown to do any harm to the wild species sampled, the study of canthaxanthin's distribution through the ecosystem may provide a valuable tool to objectively evaluate how aquaculture activities interact with the environment and to further understand nutrient flow within and around cage sites.

Oct. 2008 – Mar. 2009 • Funded by: DFO – Program for Aquaculture Regulatory Research (PARR)
Project team: Andrew Cooper (DFO – SABS), Shawn Robinson (DFO – SABS)
Contact: Andrew Cooper ( Andrew.Cooper@dfo-mpo.gc.ca), Shawn Robinson ( Shawn.Robinson@dfo-mpo.gc.ca)

Characterizing the zone of influence downstream of longline mussel leases

Cultivated bivalves can deplete available food resources faster than the ecosystem can replace them through primary production and tidal currents. In contrast to other parts of the world, there are no minimum partition requirements between mussel leases in PEI, and little is actually known about the zone of influence downstream of leases. This project proposes to characterize food particle depletion within this zone of influence and investigate to what extent the layout of mussel crops can modulate this zone. Predicting the zone of influence is relevant to the siting of new leases and to the development of bay management plans. We found localized depletions in food particles, from 5 to 3 μg chlorophyll-a L^-1, in areas where current velocities are low (< 10 cm s^-1). However, the depletions rarely extended beyond lease boundary, an outcome that provides little support to the implementation of a partition between mussel leases.

2009 - 2010 • Funded by: DFO – Program for Aquaculture Regulatory Research (PARR)
Project team: Luc Comeau (DFO), Reacute;mi Sonier (DFO)
Contact: Luc Comeau ( Luc.Comeau@dfo-mpo.gc.ca) •

Harbour Porpoise presence patterns at an aquaculture cage site in the Bay of Fundy

Finfish aquaculture is a prominent industry in the Bay of Fundy, Canada. The distribution of Harbour Porpoise (Phocoena phocoena) in the bay during the summer and fall may be impacted by the presence of offshore cages and the activities of workers on the site. Harbour Porpoise presence near and within an aquaculture cage site was studied using visual observations during the summer of 2006 and by monitoring echolocation signals using T-PODs during the summer and autumn of 2006 and 2007. At least one Harbour Porpoise was sighted per hour 61% of the time among or near the cages. Porpoises occasionally surfaced within the cage site when workers were present. Mother-calf pairs used the within-cages area proportionately more than adults and juveniles. The porpoises were temporarily displaced by the high disturbance activities such as cage cleaning with pressure hoses, but quickly returned to the area when the disturbance ended. Echolocation activity was lowest during the day, increased in the evening, and peaked between midnight and dawn. This pattern was evident on the offshore and onshore side of the cages and, to a lesser extent, at a non-aquaculture location farther along the coastline (2007 only). In August of both years, the echolocation patterns were similar, even though in 2007 there were no fish in the cages and much less worker activity than in 2006 when all 15 cages contained Atlantic Salmon (Salmo salar). Echolocation activity near a T-POD typically lasted for no more than 10 min or for at least 1 h, suggesting that the porpoises were either passing by the area or staying to feed, respectively. The presence of the aquaculture cage site under study did not appear to be displacing Harbour Porpoise from the area except during short intervals when high disturbance activities such as a food delivery by barge or cage cleaning were occurring.

Jan. 2009 – Dec. 2009 • Funded by: Fisheries and Oceans Canada (Species at Risk Program), Natural Sciences and Engineering Research Council
Project team:M.L. Haar (UNB), L.D. Charlton (UNB), J.M. Terhune (UNB), Ed Trippel (DFO – SABS)
Contact: Ed Trippel ( Ed.Trippel@dfo-mpo.gc.ca)

Development of aquaculture management plans for PEI aquaculture areas

The current expansion of oyster aquaculture on PEI requires an increase in the off-bottom lease acreage. This trend within the industry is facilitated by the conversion of existing bottom culture leases to off-bottom and is supported by joint federal/provincial/industry funding programs such as the Strategic Oyster Aquaculture Renewal (SOAR) Program. This conversion process is governed by the PEI Lease Management Board, which has stated that certain areas require Aquaculture Management Plans to be in place before any further lease conversions can be considered.

A series of consultations with leaseholders, local watershed management groups, First Nation organisations and wild fishery associations were held to identify the opportunities and challenges for further aquaculture development in this area. Federal and Provincial government stakeholders, such as Transport Canada, Fisheries and Oceans Canada and the PEI Department of Fisheries, Aquaculture and Rural Development for example, were also consulted.

The result of these consultations is a strong, industry-led Aquaculture Management Plan for the Foxley/Trout River system that clearly demonstrates the commitment of local shellfish aquaculturists to environmental sustainability in their farm management practices and will facilitate the continued expansion of oyster aquaculture.

Apr. 2010 – Mar. 2011 • Funded by: PEI Atlantic Shrimp Corp., Fisheries and Oceans Canada (DFO), PEI Department of Fisheries, Aquaculture and Rural Development
Project team: Peter Warris (R&D, PEI Aquaculture Alliance), Crystal MacDonald (Carpe Diem Consulting)
Contact: Peter Warris ( rd@aquaculturepei.com) http://www.aquaculturepei.com

Development of phytoplankton depletion criteria for assessing mussel culture carrying capacity

Given the high intensity of suspended mussel culture in some areas and the potential for interactions with other users of coastal waters, an ecosystem-based perspective is needed to ensure that aquaculture is carried out in a sustainable manner. The spatial extent and magnitude of seston and phytoplankton depletion associated with different husbandry practices and oceanographic settings are being studied through a broad international collaboration. The objectives of this work are to:

1. develop a reliable method for rapidly mapping the spatial scale of phytoplankton depletion within and outside suspended mussel farms;
2. obtain field data (depletion maps, water flow, and mussel stocking) from a wide range of geographic and aquaculture settings (long-line, raft, and bottom culture grow-out and spat collectors) to develop a statistical model for predicting phytoplankton depletion; and
3. identify critical phytoplankton depletion limits (thresholds) for assessing the ecological carrying capacity of suspended mussel farms.

Data from this project are also contributing to the development and testing of mussel farm-scale and ecosystem models in several countries and can be used for optimizing mussel production at the coastal ecosystem-scale.

Apr. 2008 – Mar. 2013 • Funded by: Fisheries and Oceans Canada (DFO), Danish Council for Strategic Research, Research Council of Norway, Netherlands Ministry of Agriculture, Nature and Food Quality, Spanish Ministry of Science and Innovation
Project team: Peter Cranford (DFO), Øivind Strand and Tore Strohmeier (Norwegian Institute of Marine Research), Pauline Kamermans and Karin Troost (Netherlands Institute for Fisheries Research, Wageningen University and Research Centre), Maria Joseacute; Fernández-Reiriz and Uxio Labarta (Instituto de Investigaciones Marinas), Pedro Duarte (Universidade Fernando Pessoa), Jens Petersen (The Danish Shellfish Centre), Proinsa mussel farms (Spain)
Contact: Peter Cranford ( Peter.Cranford@dfo-mpo.gc.ca)

Tracking the resuspension and transport dynamics of aquaculture wastes and their associated sediments for predictive model development and refinement

Scientific understanding of the far-field impacts of aquaculture is limited, especially with regard to the resuspension and transport of aquaculture wastes. A monster IN situ Size and SEttling Column Tripod (m-INSSECT) was deployed for one month in Bliss Harbour, NB, starting on August 16th, 2010. The tripod was instrumented with a LISST 100x type C, a digital floc camera (DFC), an in-situ settling column (DVC), a Nortek aquadopp, a McLane water transfer system (WTS), and a conductivity, temperature, and depth (CTD) sensor. The LISST 100x and DFC measure particle sizes from 2 μm to several mm, while the DVC is used to determine particle size versus settling velocity relationships. The aquadopp in its tripod configuration measured both the shear stress exerted on the seabed from waves and currents and backscatter, which can be used as a proxy to determine the change in suspended sediment concentration. The WTS filters 24 water samples in-situ and gives detail on the suspended mass concentration during each sampling interval. Finally, the CTD measured the salinity and temperature of the water. In addition, bottom sediment cores were collected and coupled to a GUST erosion device to determine the mass of material eroded, particle size, and trace metal and organic carbon concentration under differing stress conditions. Evaluation of the data will serve to refine or develop aquaculture waste transport models.

2010 • Funded by: DFO, CIAS
Project team: Brent Law (DFO), Tim Milligan (DFO), Gary Bugden (DFO), Vanessa Page (DFO), Tina Lum (DFO), Fred Page (DFO), Randy Losier (DFO)
Contact: Brent Law ( Brent.Law@dfo-mpo.gc.ca)

Carrying capacity in Norwegian aquaculture (CANO)

Norway has many fjords suitable for shellfish culture, but they are highly stratified, with deep nutrients and low summer production. Pilot studies have shown that inducing local upwelling of nutrients by pumping freshwater to depth stimulates phytoplankton production, creating improved food conditions for cultured mussels. Field, laboratory, and modeling studies were conducted in a Norwegian fjord by international participants in order to quantify the potential of this approach. We conducted several modeling studies to examine the density and location of mussel farms to take advantage of enhanced phytoplankton production. This project allowed development of a fully spatial model for ecosystem-based management of aquaculture. This model has already been applied to several sites in eastern Canadian waters.

2007 - 2010 • Funded by: Institute of Marine Research
Project team: Jon Grant (Dalhousie University), Øivind Strand (IMR Bergen)
Contact: Jon Grant ( jon.grant@dal.ca) • http://www.imr.no/cano/start

Management of husbandry practices to maintain water column environmental carrying capacity for bivalve culture

Bivalves are filter-feeding organisms that extract suspended food particles from the water column with an extraordinary filtration capacity. Densely stocked bivalves can deplete available seston faster than the ecosystem can replace it through primary production and water renewal. Both industry and regulatory agencies recognize a need to identify the stocking density at which the demand for food particles is well matched to the supply. Internationally, laudable research efforts are being made to develop simple standards and elaborate numerical models, with a common goal of assessing whether farming operations have exceeded the environmental carrying capacity of a system. However, knowledge gaps are becoming apparent, such as the influence of husbandry practices on the time it takes a population of cultivated bivalves to filter a body of water. Our broad objective is to further the development of carrying capacity indicators for longline mussel farming areas. Specifically, we will integrate the husbandry factor as a forceful variable in model simulations and predictions, with the end objective of developing a decision support tool that is state-of-the-art as far as aquaculture planning goes.

2010 – 2012 • Funded by: DFO – Program for Aquaculture Regulatory Research (PARR)
Project team: Luc Comeau (DFO – GFC), Jon Grant (Dalhousie University)
Contact: Luc Comeau ( Luc.Comeau@dfo-mpo.gc.ca)

Ecosystem modeling of sustainable aquaculture

Although sustainable aquaculture is an important management goal, the definition and measure of sustainability has been elusive. Ecosystem modeling has become a well-developed approach in prediction of culture production, and has progressed into operational models in many countries. These models consist of circulation models coupled to biogeochemical models which include shellfish feeding and growth. We have produced these models for several bays in eastern Canada, including measures of sustainability based on chlorophyll depletion by suspension-feeding shellfish. The focus of sustainability is preservation of coastal ecosystem function and integrity. Most recently, the work has an increasing context of integration into coastal zone management and GIS.

Jan. 2009 – Nov. 10 • Funded by: NSERC
Project team: Jon Grant (Dalhousie University), Ramon Filgueira (Dalhousie University)
Contact: Jon Grant ( jon.grant@dal.ca)

Mussel aquaculture regulatory effectiveness monitoring: validation of the environmental assessment and monitoring program in St. Ann's Harbour

The largest single mussel aquaculture application in the Maritimes was approved in 2003 for St. Ann's Harbour, Nova Scotia after an assessment of environmental risks and the implementation of a rigorous environmental monitoring program (EMP). The mussel leases in St. Ann's Harbour are approximately 70% developed and an intensive environmental sampling program was conducted to test both the impact assessment predictions and the effectiveness of the EMP design. Existing site monitoring data and pre-development data were also utilized in a retrospective analysis of aquaculture/ecosystem interactions. Data collected during this study were used to provide advice on how shellfish aquaculture monitoring programs may be made more spatially and statistically meaningful using the same sampling effort as currently used in the site EMP (e.g., number of seabed samples collected). A technical report containing project results and conclusions is currently in press by the project team, which included representatives from DFO Science, DFO Habitat Protection and Sustainable Development Division, Dalhousie University, the Nova Scotia Department of Fisheries and Aquaculture, and industry. The recommendations contained in this report are provided to increase the scientific certainty of monitoring results while permitting the mussel aquaculture industry to remain economically viable.

Apr. 2009 – Mar. 2011 • Funded by: DFO – Program for Aquaculture Regulatory Research (PARR)
Project team: Peter Cranford (DFO – BIO), Joe Crocker (DFO – BIO)
Contact: Peter Cranford ( Peter.Cranford@dfo-mpo.gc.ca)

Mussel culture carrying capacity in St. Ann's Bay

St. Ann's Bay is an ideal site for longline mussel culture with productive Gulf waters and low rural population density. Parts of the bay have been cultured, and ongoing monitoring by DFO and Nova Scotia Department of Fisheries and Aquaculture has been used to assess benthic health. As with many mussel culture sites, there are minimal benthic impacts. We sought to use an ecosystem approach to culture carrying capacity via ecosystem modeling to assess the degree of chlorophyll depletion due to suspension-feeding mussels. Studies of the bay are not often seasonal, and a time series of water quality is important in initializing the model. In order to make models of carrying capacity more operational, we used satellite remote sensing to define seasonal changes in chlorophyll in the nearshore. By simulating chlorophyll levels in the presence and absence of mussels, we were able to define culture levels that did not severely impact water quality, maintaining the integrity of the ecosystem for other consumers.

2009 – 2010 • Funded by: DFO – Aquaculture Innovation and Market Access Program (AIMAP), Nova Scotia DFA, Enterprise Cape Breton Corporation
Project team: Robin Stuart (Englishtown), Jon Grant (Dalhousie University), Ramon Filgueira (Dalhousie University)
Contact: Jon Grant ( jon.grant@dal.ca)

Indicators of coastal ecosystem health

There is much interest in indices of ecosystem state or health, and many of these incorporate measures of biodiversity. A lot of the focus revolves around aquaculture impacts, and there is a need to describe the health of the far-field, i.e., beyond the limits of the cultured areas. Although describing system state following perceived impacts is useful, it would be more valuable to make predictions of system health in advance of activities such as aquaculture development. In this project, we sampled benthic biodiversity in several bays, and examined sediment characteristics as predictive variables. A critical difference from previous studies was controlling for spatial sample location in the regression model. This allowed for a reduction in the number of samples, and changed the relative influence of sediment variables as predictors. The technique has many implications for sample design as well as approaches to predictive power in system-wide studies. Moreover, we were able to conduct some of the research in collaboration with coastal communities as stakeholders in the data collection and decision process.

2008 - 2011 • Funded by: NSERC Strategic Project Grant
Project team: Jon Grant (Dalhousie University), Mike Dowd (Dalhousie University)
Contact: Jon Grant ( jon.grant@dal.ca)

An investigation of reproduction between wild and farmed salmon in Newfoundland

Since the late 1970s, salmon aquaculture has grown into a global industry, producing over 1 million tonnes of salmon per year. The majority of this biomass is held in open net pens in coastal areas, areas through which Atlantic Salmon migrate on their way to and from the ocean. Atlantic Salmon abundance has been declining for several decades, preceding the arrival of intensive salmon aquaculture in Newfoundland's coastal waters. It is very difficult to assess the effects salmon farming has had on the highly dynamic, migratory wild salmon populations, due to other environmental and anthropogenic variables such as oceanographic and climate conditions, habitat loss, and human interactions in coastal areas.

The finding that the effects of salmon farming on wild salmon do not increase linearly with the tonnage of farmed salmon highlights the need for a better scientific understanding of the situation. In Newfoundland, the introduction of farmed salmon originally from the Saint John River strain to the Bay d'Espoir area raises the question of potential effect of escapes on wild stocks. With the support of the aquaculture partner (Gray Aqua Group) and the Council of the Conne River Micmacs (Miawpukek Mi'kamawey Mawi'omi), this project aims to answer the question of mating success between farmed mature fish and wild spawners from Newfoundland river stocks. Fertilization rates and gamete quality will be assessed in both farmed and wild mature fish and crosses will be completed to evaluate fertilization and hatch rates. The effect of the water quality (river waters) will be tested to better understand the potential reproductive effect of salmon escapes from local farms on wild spawners in their natural environment.

Apr. 2010 – Apr. 2012 • Funded by: DFO – Aquaculture Collaborative Research and Development Program (ACRDP), Gray Aqua Group
Project team: Dounia Hamoutene (DFO), Danny Ings (DFO), Gehan Mabrouk (DFO), Lynn Lush (DFO), Kimberley Hobbs (DFO), Clyde Collier (Gray Aqua Group Ltd.), Brian Dempson (DFO), Ian Fleming (Memorial University), Ross Hinks (Miawpukek Mi'kamawey Mawi'omi)
Contact: Dounia Hamoutene ( Dounia.Hamoutene@dfo-mpo.gc.ca) /aquaculture/acrdp-pcrda/index-eng.htm

Finfish aquaculture site development: fate of fish waste

New finfish aquaculture sites being developed in Newfoundland are often located over deep waters (> 100 m) with hard bottom substrates that are difficult to monitor for regulatory purposes. One of the primary aims of monitoring at finfish sites is to determine the potential influences of organic input on benthic habitats. To investigate the fate of wastes associated with fish farming and the potential influences on benthic communities at sites on the south coast of Newfoundland, we initiated a study to validate DEPOMOD. This model was developed by the Scottish Association for Marine Science and it predicts the dispersion of particles from cage sites. Site specific current data, bathymetry, cage orientation, feeding regime and feed properties are all input into model runs. Data used to validate DEPOMOD were collected during two periods: late July to late August and late August to mid-October of 2010. We sampled using sediment traps to estimate organic input along transects extending from an Atlantic Salmon farm and a Rainbow Trout farm. Additionally, we collected video data along transects on both sides of the sediment traps to determine the benthic community response to organic input. The model predictions will be compared to the observed organic flux. Also, video data of the benthos will be analyzed and compared to the data on organic flux around cages.

May 2010 – Mar. 2013 • Funded by: DFO – Aquaculture Collaborative Research and Development Program (ACRDP), Cold Ocean Salmon Inc., Northern Harvest Sea Farms
Project team: Danny W. Ings (DFO), Gehan Mabrouk (DFO), Fred Page (DFO), Dwight Drover (DFO), Dounia Hamoutene (DFO), Randy Losier (DFO), Sharon Kenny (DFO), Terry Bungay (DFO)
Contact: Danny Ings ( danny.ings@dfo-mpo.gc.ca)

Oceanographic study of the south coast of NL

The province of Newfoundland is experiencing a significant influx of investment in salmonid farming. Since 2004, 50 new marine sites for Atlantic Salmon and 6 new sites for Steelhead Trout have been licensed in the Bay d'Espoir-Fortune Bay area. An additional 17 sites were under review in 2008. The increasing biomass, the increase in the number of companies operating, the diversity of production strategies, and the increasing concentration of farm sites, particularly in outer Bay d'Espoir, challenges biosecurity and the sustainability of this growth. Currently there is a lack of data and understanding of the oceanography of the outer Bay d'Espoir area that precludes establishment of scientifically validated production and management areas to guide site licensing, production planning, and sustainable management of the industry. The project will establish the infrastructure and the foundation for Newfoundland to be able to carry out an oceanography program to collect and model the physical environmental data - currents, dissolved oxygen, temperature, and salinity - and map the environmental parameters and potential zones of influence that will be used to establish production management areas. A great deal of oceanographic data has been collected to date and its analysis is ongoing. The results of the drifter program, a component of the whole oceanography work, were presented in a DFO CSAS workshop on Nov. 2010.

Apr. 2008 – Mar. 2013 • Funded by: DFO – Program for Aquaculture Regulatory Research (DFO – PARR)
Project team: Gehan Mabrouk (DFO), Fred Page (DFO – SABS), Dwight Drover (DFO), Randy Losier (DFO – SABS), Paul McCurdy (DFO – SABS), Mike Foreman (DFO), Dave Senciall (DFO)
Contact: Gehan Mabrouk ( Gehan.mabrouk@dfo-mpo.gc.ca)