Invasive species

Invasive species are defined as plants, animals and micro-organisms that have been accidentally or deliberately introduced into habitats outside their normal range. Invasive “alien” species are those harmful species whose introduction or spread threatens the environment, the economy and/or society including human health. Ontario’s definition of an invasive species may also include species native to Ontario that have been introduced to a new geographic region due to human activity. These species are able to proliferate because in their new environment they are often free from the predation and competition that would normally limit their distribution and abundance.

The Invasive Alien Species Strategy for Canada (Environment Canada, 2004) identifies numerous pathways for the introduction or spread of aquatic invasive species and diseases that are relevant to FMZ 18. These pathways each represent individual challenges preventing the introduction and spread of species within the zone. The pathways identified include:

  • shipping (e.g. in adjacent FMZ 20 – St. Lawrence River)
  • recreational boating
  • use of live bait
  • aquarium and water garden trade
  • live foodfish
  • unauthorized introductions
  • canals and water diversions

Ontario’s Invasive Species Strategic Plan (OMNR, 2012) currently provides provincial direction for addressing invasive species introductions.

FMZ 18 lakes and rivers are particularly susceptible to the introduction of invasive species. Many of the lakes are connected to Lake Ontario and the St. Lawrence River via many of their tributaries. This connectivity increases the risks associated with species that become established within the Great Lakes. In addition, anglers and recreational boaters are active and mobile within the zone, increasing the potential for the spread of invasive species. The prevalence of waterfront property owners also increases the potential spread of aquatic invasive species through aquariums and water gardens.

The introduction of a new species can have significant effects on the aquatic ecosystem. The spread of zebra mussels (Dreissena polymorpha) has increased water clarity and decreased the nutrients available to lower levels of the food chain. This has likely decreased the overall productive capacity of the lakes and contributed to observed fish community shifts, creating more favourable conditions for some species (e.g. bass, muskellunge) and less favourable conditions for others (e.g. walleye). As water clears, the amount of habitat for the light-sensitive walleye is reduced and predation on young walleye is likely to increase. Water clarity is thought to have a very dramatic effect on the productivity of walleye in inland lakes (Lester et al., 2004).

Current threats include round goby (Neogobius melanostomus) which have had significant negative impacts including reductions in species diversity through competition with and predation on, other fish species in areas where they have become established. Other negative impacts associated with round goby are an increased contaminant burden and potential human health concern for anglers who eat their predatory sport fish; and the potential link between zebra mussels, round goby and botulism outbreaks that have killed hundreds of thousands of waterfowl and fish in the Great Lakes (OMNR, 2009b). Round goby also feed heavily on invasive zebra mussels and are thought to re-introduce nutrients into the food chain that were previously filtered out by zebra mussels (Bunnell et al., 2005).

Many new invasive species threats have also been identified. Spiny water flea, Eurasian water-milfoil and phragmites are present in many FMZ 18 lakes. The potential for introduction of asian carp, northern snakehead, ruffe, and other aquatic invasive plants (fanwort, water chestnut, water soldier, etc.) all pose significant threats to native biodiversity and aquatic ecosystems.

Invading Species Awareness Program

In the early 1990’s, the Ontario Federation of Anglers and Hunters (OFAH) and MNRF established the Invading Species Awareness Program. The program has established the following objectives:

  • raise public awareness of invasive species and encourage their participation in preventing their spread
  • monitor and track the spread of invading species in Ontario waters through citizen reports to the Invading Species Hotline and the Invading Species Watch Program
  • conduct research on the impacts and control of invasive species

Fish disease

Many fish diseases are caused by parasites, viruses and/or bacteria that can be considered within the context of invasive species. Throughout the summer of 2007 and 2008, tens of thousands of common carp died within the Trent-Severn Waterway, in adjacent FMZ 17. In addition to bacterial infections, koi herpes virus (KHV) was identified in many of the samples tested. The detection in 2007 represented the first confirmed case of KHV in Ontario. KHV is a fish disease caused by a virus that affects only common carp, goldfish and koi. Fish can become infected with the virus as it is passed through close physical contact. When stressed, fish that have become infected with this virus may become sick. Survivors of a disease outbreak may become carriers of the virus, passing it to other fish.

KHV is believed to have moved throughout the world via the ornamental fish industry. The virus was first found in the United States in 1999 and has been associated with large scale common carp and koi die-offs in New York State. It is not known how or when KHV arrived in Ontario waters.

In addition to KHV, there are a number of other fish pathogens that have been discovered in Ontario, in recent past. Viral Hemmorrhagic Septicemia (VHS) was first identified in 2005 after a die-off of freshwater drum (sheepshead) in the Bay of Quinte in FMZ 20. The virus has now been found in at least 28 species of fish in the Great Lakes including: walleye, yellow perch, muskellunge, smallmouth bass, rock bass, black crappie, round goby, emerald shiner, bluntnose minnow and spottail shiner. VHS has been linked to significant die-offs of muskellunge in the St. Lawrence River and Lake St. Clair. VHS has not yet been found in fishes from the inland waters of FMZ 18.

Lymphosarcoma is a native viral disease affecting esocids (muskellunge and northern pike) of spawning age. The disease is highly contagious and is usually fatal to fish within one year. Lymphosarcoma is believed to spread by direct skin contact during spawning. Lymphosarcoma was monitored via Muskies Canada angler diary program and it was estimated that 15% of the Kawartha Lakes muskellunge were affected by the disease. This infection rate has remained consistent for the past 20 years. Current infection rates are not believed to represent a threat to the sustainability of the fishery, but continued monitoring efforts are required.

Largemouth Bass Virus (LMBV) has been identified in bass in Lake St. Clair and the western portion of Lake Erie. In areas where LMBV has been a factor in bass die-offs, the larger individuals in the population have been more susceptible.

National Aquatic Animal Health Program

The Canadian Food Inspection Agency (CFIA) is dedicated to safeguarding food, animals and plants. The CFIA has the lead for fish disease control in Canada and works with DFO, which has the lead for fish research including disease diagnostics and testing at a federal level. The CFIA has recently established a National Aquatic Animal Health Program (NAAHP), a science-based regulatory program for aquatic animal diseases which includes diseases designated reportable or notifiable in Canada because of their potential impact on trade and our economy. Specifically, the activities of CFIA under the NAAHP include: protecting the health of the fisheries resources, maintaining a list of regulated aquatic animal diseases, implementation of surveillance and monitoring programs geared towards the early detection of fish diseases, control and eradication of aquatic animal diseases as appropriate, and establishing requirements for import and export and sustaining and increasing export market opportunities.

Responses to invasive species

Governments are actively working to reduce the threat of invasive species at both a provincial and national level. The Canadian Council of Fisheries and Aquaculture Ministers formed the Aquatic Invasive Species Task Group which developed the Canadian Action Plan to Address the Threat of Aquatic Invasive Species (CCFAM, 2004), an action plan under An Invasive Alien Species Strategy for Canada (Environment Canada, 2004). At a provincial level, Ontario’s Biodiversity Strategy identifies the implementation of the national strategy and action plans as a priority. Ontario has been working with other agencies and stakeholders to identify current initiatives underway to implement the national strategy, identify gaps, and outline actions to address the gaps.

MNRF also has the legislative authority to determine rules associated with the bait industry and the use of bait by anglers under the Ontario Fishery Regulations (OFR). MNRF is currently undertaking a review of its bait policy (as it pertains to baitfish and leeches) to among other things, help address the potential for the spread of invasive species through the bait pathway. Baitfish licence holders must also prepare a Hazard Analysis and Critical Control Point Plan (HACCP) to address the threat of invasive species associated with their operations.

The unfortunate reality is that, once an invasive species becomes established within an ecosystem, there are few effective options for control, and eradication is often an unachievable goal. The focus must be on preventing the spread of invasive species and fish pathogens. In some instances, MNRF has implemented measures to prevent the introduction and spread of non-native species. These include bans on the sale of crayfish and more recently restrictions on the movement of live baitfish by licenced harvesters to prevent the spread of VHS. MNRF has prepared Regulatory Guidelines for Bait and Gear Restrictions (toolkit) to streamline the use and description of angling regulations. Currently, there are no specific live bait restrictions in FMZ 18 aside from those that apply across the province. Should further regulations on the use of bait be desired, the regulatory guidelines will provide a starting point for consideration.

Reponses to fish pathogens

Once a disease becomes established, the focus switches to measures to control or slow down the spread of the disease. The government’s approach in dealing with viral hemorrhagic septicemia (VHS) is an example.

In 2007, the Minister of Natural Resources established interim measures to control the harvest and transport of baitfish. These measures were necessary to address immediate risks involving the potential spread of VHS into inland waters but they also had a significant impact on baitfish harvesters.

Measures included among others:

  • implementing a VHS Management Zone that contains VHS-positive waters in an area bounded by the provincial road network. The VHS-positive waters include lakes Ontario, Erie and Huron (including Georgian Bay) and their connecting waterways and tributaries up to the first impassable barrier, excluding fishways
  • allowing walleye spawn collection from the VHS Management Zone only if the fish are stocked into the zone and the receiving fish culture facility is located in the zone
  • allowing baitfish harvesters and dealers in the VHS Management Zone to harvest baitfish, but restrict movement of live baitfish out of the zone

Invasive species and diseases management in FMZ 18

Invasive species and fish pathogens represent one of the most significant potential stressors on aquatic ecosystems and fisheries resources in FMZ 18. MNRF and the Advisory Council identified a number of challenges to the management of invasive species and diseases in FMZ 18.

Management challenges:

  • invasive species and diseases threatening the entire aquatic ecosystem of a given fishery and potential detrimental shifts in fish communities
  • susceptibility of lakes and rivers within FMZ 18 to the introduction and spread of invasive species and pathogens

The MNRF with the advice of the Advisory Council developed objectives and strategies to address the challenges and help reach the following invasive species and diseases management goal.

Goal:

Prevent the introduction and/or control the spread of invasive species and pathogens within FMZ 18.

Objective 1:

Reduce the risk of the introduction and spread of invasive species and pathogens through each of the identified pathways.

The most cost-effective means to prevent the initial introduction of invasive species and pathogens that cause disease, is to reduce the risk of the introductions in the first place. Many regulations and best management practices help prevent the spread of invasive species; however, there remains an ongoing need for increased public awareness regarding the threats of invasive species and associated regulations.

Strategies to address the objective include:

  • respond effectively to large-scale die-offs by implementing the District’s Fish Die-off Response Protocol
  • respond effectively to the introduction of new invasive species
  • support the implementation of an Aquatic Invasive Species Action Plan for Ontario
  • support the development of effective legislation to prevent the introduction and spread of invasive species and fish pathogens (e.g. ballast water control measures)
  • continue to work with bait harvesters and dealers to ensure their Hazard Analysis and Critical Control Point (HACCP) plans are effective and implemented correctly
  • monitor for the presence of aquatic invasive species and pathogens as a component of the BsM program and promote detection monitoring in all lakes within the zone
  • identify the transfer of live fish as a major risk of introduction and spread of invasive species and pathogens, to enable enforcement activities that ensure ecological sustainability of various fisheries
  • support a surveillance program to enable the early detection of invasive fish pathogens

The goal, objectives and strategies have been summarized in Table 12.

Table 12: Invasive species and diseases management summary

Adapted from tabular format.

Objective 1.

Reduce the risk of the introduction and spread of invasive species and pathogens through each of the identified pathways

Strategies
  • Respond effectively to large-scale die-offs by implementing the District’s Fish Die-off Response Protocol.
  • Respond effectively to the introduction of new invasive species.
  • Support the development and implementation of an Aquatic Invasive Species Action Plan for Ontario.
  • Support the development of effective legislation to prevent the introduction and spread of invasive species and fish pathogens (e.g. ballast water control measures).
  • Continue to work with bait harvesters and dealers to ensure their Hazard Analysis and Critical Control Point (HACCP) plans are effective and implemented correctly.
  • Monitor for the presence of aquatic invasive species and pathogens as a component of the BsM program and promote detection monitoring in all lakes within the zone.
  • Identify the transfer of live fish as a major risk of introduction and spread of invasive species and pathogens, to enable enforcement activities that ensure ecological sustainability of various fisheries.
  • Support a surveillance program to enable the early detection of invasive fish pathogens.
Performance measures
  • # of large-scale die-offs and introductions responded to.
  • # of monitoring/ surveillance/ stewardship projects initiated.
  • # of regulations/plans implemented and/or supported.

Progress reviewed by

  • Every BsM Cycle

Invasive species and diseases monitoring and assessment

The provincial BsM program and the Invading Species Awareness program are the primary survey methods used to collect invasive species data in Ontario. These programs will be able to report on the trends and status of invasive species at the fisheries management zone scale.

The MNRF District Fish Die-off Response Protocols are the primary survey methods used to collect fish disease data in Ontario. These protocols will be able to report on the trends and status of fish diseases at the FMZ scale.

Strategies:

  • utilize the BsM program (and its invasive species sampling) to track invasive species distribution
  • support ongoing efforts of the Invading Species Awareness Program to detect invasive species within FMZ 18
  • utilize District Fish Die-off Response Protocols to manage, and report on fish disease outbreaks