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Environmental Impacts of Salmon Farms: Lessons from New Brunswick Inka Milewski Science Advisor Conservation Council of New Brunswick June 27, 2011 Shelburne, Nova Scotia

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Environmental Impacts of Salmon Farms Known potential impacts include: Increased suspended solids, turbidity and sedimentation Nutrient loading Degradation of water quality from hazardous materials Impacts to fish and fish habitat Disease transmission Invasive species, which could alter ecosystem dynamics Interference with traditional use of resources Disruptions of wildlife and wildlife habitat, including migratory birds and species at risk Impacts of odour and noise on humans Source: Transport Canada. 2011. Environmental Assessment Screening Report for proposed sites in St. Marys Bay

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Environmental Impacts of Salmon Farms By volume, largest component of waste released from a salmon farm is organic (fecal and uneaten feed) waste and nutrient (nitrogen and phosphorus)

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Carbon and nitrogen releases to the LEtang Inlet, New Brunswick 2002 SourcesCarbon (mt per year) Nitrogen (mt per year) Salmon Farms 22 farms (APL 4.44 million fish) 949 2372.5 259.1 657.0 Sewage plant (servicing 1200 people)51.110.9 Pulp Mill138.74.1 Fish plant (sardine processing plant)1525.7273.7 Runoff from land299.310.95 Precipitation-18.2 Source: Strain and Hargrave. 2005. Salmon aquaculture, nutrient fluxes and ecosystem processes in southwestern New Brunswick. In. Hargrave (ed.) Environmental Effects of Marine FInfish Aquaculture: The Handbook of Environmental Chemistry Vol 5.

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Impacts of Organic (Carbon) Waste Sediments and the water column above become oxygen depleted and toxic Diversity of animals in and on the sediment drops; white bacterial mats cover the bottom Food chain connecting the benthic (bottom- dwelling) and pelagic (free-swimming) communities becomes uncoupled

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Increase in annual seaweed biomass increased incidence of toxic phytoplankton blooms localized oxygen depletions loss of perennial submerged aquatic vegetation (e.g., rockweed, eelgrass) a shift from filter-feeding (clams, mussels) to deposit- feeding (worms) animals increased disease in fish, crabs, and/or lobster Impacts from Nutrient (nitrogen and phosphorous) Waste

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Crow Harbour/Penn Island, New Brunswick Study 2002-2004

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Control site Former Fish Farm Site Crow Harbour/Penn Island, New Brunswick Study 2002-2004 July 2000 site ~ 295,000 smolt put into 21 net pens covering an area of ~19 ha April 2002 harvesting began July 2002 final feeding August 2002 last fish harvested August 24, 2002 benthic survey began ~ 5 months after most intensive feeding period and 3 weeks after last fish harvested Sampled again on August 27, 2003 and August 23. 2004

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Sediment core sample coming on board and testing

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2002 Crow Harbour benthic samples 2002 Control Site benthic samples Black sediments indicate a lack of oxygen and the presence of anaerobic bacteria.

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Reference/Control site 2003 Penn Island/Crow Harbour farm site 2003 Penn Island/Crow Harbour farm site 2004

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Sediment Eh at a former fish farm in Crow Harbour and a reference site (mean values of 3 samples) 2002-2004 Sediment Depth Hypoxic Anoxic

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Surface Sediment Sulfides at a former fish farm in Crow Harbour and a reference site (2002-2004)

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Reference Site Farm Site Number of species and diversity did not recover at the farm site after two years

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Environmental Monitoring of Salmon Farms only one environmental measure is monitored sulphides in sediments DFO has not defined a sulphide limit that results in mandatory regulatory action ; HADD authorization may be required at 4500-6000 M 40-60% biodiversity reduced at 500 to 1500 M sulphides 60-70% reduced at 1500-3000 M 70-90% reduced at 3000-6000 M 90% reduced > 6000 M

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Environmental Monitoring of Salmon Farms In New Brunswick Prior to 2006, remediation plans were required when sulphides reached 1300 M In 2006, remediation required when benthic sulphides reach 1500 m Site must do more monitoring and submit report when sulphides are 3000-4500 M and may be required to get HADD authorization from DFO Annually, 20% of NB farms require remediation plans

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2006 Salmon Farm Sites

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2006 NB Action Level 2001 NB Action Level

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2009: 2111.7 M sulphides 2010: 1442 M sulphides Control site Former Fish Farm

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Nova Scotia Environmental Monitoring Program (EMP) First EMP began in 2002 Plan was updated in March 2011 EMP is focused on monitoring sulphides EMP approach is increased risk requires increased monitoring Sites with 50% of sampling stations with 1500 M sulphides need more sampling and must adjust their Best Management Practices (BMP) to improve site performance Sites with 50% of sampling stations with 3 000 M of sulphides need more sampling and operator must submit a mitigation plan for maintaining or increasing production levels Sites with 70% of sampling stations with 6 000 M sulphides must work with regulators to examine mitigation options; some site may require DFO authorization to allow a (HADD) harmful alteration, disruption or destruction of fish habitat on the site

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2011 NS more monitoring and enhanced management

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2011 NS more monitoring and enhanced management level

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Nova Scotia Environmental Monitoring Results Brier Island/Westport

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Beyond the farm impacts Bay-wide (Cumulative) Effects from multiple salmon farms Sampled 1994-1999 examined sediment carbon, microbial biomass and biological diversity 1994-95 results showed area was strongly impacted 1996-1997 salmon farming stopped due to ISA outbreak; Re-sampled in 1997 and 1999; carbon and bacteria levels declined, no recovery in the biological community farm operations had an effect on benthic habitat beyond the farm area Pohle et al. 2001. Assessment of regional benthic impact of salmon mariculture within the Letang Inlet, Bay of Fundy. ICES Journal of Marine Science 58: 417426. 2001

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For Lime Kiln Bay, salmon farms release 3.3 times more nitrogen and 1.6 time more carbon is cycled naturally in the water column and sediments. substantial changes to the functioning of the ecosystem have occurred due to the presence of the salmon farms Even in a larger, less intensively farmed area like the Campobello / Deer Island, fluxes of carbon and nitrogen from salmon aquaculture are 10 and 16 %, respectively, of those due to natural processes. Local impacts can be much greater than those measured on large scales Source: Strain and Hargrave. 2005. Salmon aquaculture, nutrient fluxes and ecosystem processes in southwestern New Brunswick. In. Hargrave (ed.) Environmental Effects of Marine FInfish Aquaculture: The Handbook of Environmental Chemistry Vol 5. Beyond the farm impacts Bay-wide (Cumulative) Effects from multiple salmon farms

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Regulations and Management of Impacts? Inadequate and Incomplete information for managing ecosystem effects are currently incomplete multiple measures will be the most effective for managing ecosystem effects of aquaculture management focused primarily on near-field and site-specific regulatory applications far-field and cumulative effects could occur and will require new or modified management tools Benthic monitoring is less suitable for farfield monitoring finfish aquaculture has the potential to alter the trophic (food web) status of bays Mass balance calculations can be used to estimate the portion of aquaculture wastes to a system compared to nutrients from other sources

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Our Oceans and Coasts in Trouble A decline in many fish stocks has occurred on the Atlantic and Pacific coasts as a result of commercial overexploitation. Industry and development have, or are threatening to, impact most ecosystems. The coastal zone is particularly vulnerable and is of concern as these areas are considered highly productive ecosystems.

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Need for sustainable aquaculture Activities that do not degrade the ecosystem on which they depend including: preserving the form and function (ecological relationships) of natural systems preventing nutrient, chemical and biological pollution ensuring no net loss of protein Source: Bardach, 1997: Sustainable Aquaculture. New York; John Wiley & Sons Costa-Pierce, 2002. Ecological Aquaculture: The evolution of the blue revolution Oxford: Blackwell Science