The Management of Invasive Species in Marine

1

• The Management of Invasive Species in Marine
  Coastal Environments
• Module 5
• Incursion Management

2
Module 5 Objectives

• Describe the strategies available for managing
  marine and coastal invasive species, once they
  have become established
• Highlight the differences between the various
  incursion management strategies
• Introduce the techniques used in incursion
  management
• Describe the decision-making process for
  selecting the appropriate strategy

3
Strategies

• Eradication
• Control
• Impact mitigation
• Do nothing

4
(No Transcript)
5
Containment
Dont wait until it is too late immediate
action can save large amounts of time and money.
6
Darwin Marina / Black striped mussel
7
Developing the Strategy
Three categories

• Mechanical/physical e.g. removals by hand
  (divers), mechanical harvesting or the creation
  of physical barriers
• Chemical - e.g. chemical dosing, toxic baits,
  application of an inorganic or organic herbicide,
  larvicide or other pesticide
• Biological e.g. a target-specific pathogen,
  parasite, predator, biopesticide, genetic
  manipulation, reproduction manipulation or
  habitat modification (e.g. salinity change by
  salt dosing or freshwater inundation).

8
Approaches to Control
9
Mechanical Control

• Labour-intensive and often expensive -especially
  where there are dense infestations or when an IAS
  is wide-spread and occurs in remote or
  inaccessible areas.
• Advantage of being target specific and that
  non-target and environmental impacts are usually
  minor.
• Often the best choice when infestations are small
  and easily accessible, because individual IAS may
  be specifically targeted.

10
Chemical Control
Involves

• Application of chemicals (agents) directly to
  water column, sediments or target species
• Killing or Sterilising target species
• Range of options available for various
  applications
• Legal and safety/health constraints
• Limited applicability

11
Biological Control
Involves

• Control/eradication of target species by another
  organism
• insect, bacteria, virus
• biological product (hormone)
• genetic or sterility manipulations
• Host-specific pathogen, parasite or predator
• Negligible side effects on native species

12
Biological Control
Disadvantages

• The time and expense required to identify, screen
  and test candidate control agents
• The time required for the released agent to
  multiply and cause the required effect
• Uncertainty about the level of control the agent
  will ultimately bring to bear on the targeted
  population
• The potential for the agent to exert an
  unexpected effect on native species or
  communities
• The population regulation mechanism underlying
  the principle of biological control, which does
  not anticipate eradication but reduces the
  invading population density and fitness, with the
  prey/host or predator/parasite relationship
  achieving a dynamic balance.

13
Biological Control

• Self sustaining methods
• Classical biological control the introduction of
  a natural enemy from the original range of the
  IAS
• Habitat management enhancing the populations of
  native predators and parasitoids
• - Adding to the IAS enemies (reared or cultured
  and released in large numbers) when an outbreak
  of the IAS has happened

14
Biological Control

• 2. Non-self sustaining methods
• Inducing host resistance against the IAS
• Biological chemicals. These are chemicals that
  are naturally produced by living species, and
  effective against certain introduced species
• The use of pathogens, parasites or predators that
  will not be able to reproduce or survive in the
  environment
• Mass release of sterile males

15

• Caution
• It is critical that national legislation
  provides for tight controls and legal
  requirements, including risk analysis as an
  integral part of decision making on whether
  introduction of a classical biological control
  agent should be authorised.
• Such risk analysis should include all risks,
  including those for native biological diversity
  (including endemic species) in the area where the
  agent would be released.
• A control agent approved for one country should
  hence not automatically be approved for another
  country.

16
Assessing the Feasibility of Available Options
Need to analyse the following

• Background information relating to the species in
  question. This should include biological,
  ecological and biogeographic information, as well
  as the previous invasion history of the species.
• Extent of the invasion, including size/density of
  the population, and geographic area covered.
• Available methods for the management option being
  evaluated.
• Case studies of other attempts at managing
  invasions with similar characteristics or
  conditions.
• Resources available, including man power,
  equipment and budget
• Cost-benefit and risk analysis.

17
Eradication
Objectives

• To restore the managed area to the condition it
  was in before the introduction of the alien
  species.
• To accomplish the above by removing all evidence
  of the introduced species.
• To maintain the managed area free of the
  introduced species following the eradication
  programme.

18
Control
Control involves reducing the numbers of an IAS
to below pre-set levels, or containing its
population within a defined area.

• Preferable when eradication is not appropriate or
  feasible
• Can be used for short-term relief from impacts,
  or for holding pattern while other options are
  investigated
• Typically more practical, less damaging options
• More affordable in the short-term
• But require long-term funding

19
Mitigation and Monitoring
Last Resort Strategies

• Impact Mitigation
• Monitoring / measuring change

20
Key Points

• The ultimate goal of IAS management is to
  minimise threats to biodiversity, human health
  welfare and economies
• Once a species has become established, there are
  four options eradicate, control, mitigate or do
  nothing
• Waiting for all possible information before
  deciding on how to deal with a newly-reported IAS
  can be disastrous.
• Use all sources of information about the IAS
  (local, national and international) to help
  decide how best to manage it
• An open and transparent process is more likely to
  win public and governmental support
• One agency or organisation should be responsible
  for the entire process, with complete authority
  to make decisions and execute them
• Correctly identifying the alien species is the
  first step in deciding how to manage it

21

• Local fishermen have reported that a different
  fish species has
• been turning up in their catch during the current
  fishing season.
• This species appears to be well-established and
  occurring in
• large densities and its presence has resulted in
  a decrease in
• their normal catch.
• How would you find out whether it is an invasive
  species or an invasive alien species, while
  finding this out what steps can you take?
• Would you get the general public to assist? How?
• How would you choose/ evaluate a method of
  control?
• If you were to choose biological control, what
  factors should you consider?
• If you were to choose chemical control, what
  factors should you consider?
• What if all attempts to eradicate the species
  have failed, what can you do?