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9.5 Pests, introduced species, diseases and algal blooms



Definitions of what constitutes Pests, Introduced Species, Diseases and Algal Blooms may need to be first agreed based on a review of regional and national studies. The term ‘pest’ generally refers to marine plants or animals that are not native to the region but have been introduced by human activities such as shipping; they have the potential to significantly impact marine industries and the environment.  Any other non-indigenous species introduced to the marine environment by humans is considered to be an ‘introduced species’.  When considering the spatial frame of reference, it should be viewed from the perspective of the habitats affected.  So if the pests, introduced species, diseases and algal blooms are confined to coastal and estuarine habitats, for example, then the best 10% would refer to coastal and estuarine habitats affected least and the worst 10% would refer to coastal and estuarine habitats affected most.  To score the pests, introduced species, diseases and algal blooms experts will follow these steps:

  1. Estimate a consensus score for the impact of pests, introduced species, diseases and algal blooms in the Best 10% and Worst 10% of the relevant habitats (eg. relative to 1900).  Score both the area and degree of impact caused by pests, introduced species, diseases and algal blooms; for example if it is estimated that pests, introduced species, diseases and algal blooms are not found in 10% of the habitats where they do occur elsewhere in the region, then the Best 10% will have a score of 10.  Conversely, if it is estimated that an introduced species has completely displaced an indigenous species in 10% of the area of habitats where they previously occurred, then the Worst 10% will have a score of 1.

  2. Estimate a consensus score for the impact of pests, introduced species, diseases and algal blooms in Most areas (eg. relative to 1900).

  3. Assign a Confidence grade for the Condition estimates (High, Medium, Low).

  4. Estimate the trends for each of Best 10%, Worst 10%, Most (Improving, Declining, Stable) over the last 5 years.

  5. Assign a Confidence grade for the Trend estimates (High, Medium, Low).

  6. Identify the main anchor references, and any commentary/notes in any relevant column for the habitat.

 

Pests, Introduced Species, Diseases and Algal Blooms

Grading statements for Pests, Introduced Species, Diseases and Algal Blooms

Very Good (7-8)

The incidence and extent of diseases and algal blooms are at expected natural levels, there are insignificant occurrences or numbers of pests, and the numbers and abundance of introduced species is minimal.

Good (5-6)

Incidences of diseases or algal blooms occur occasionally above expected occurrences or extent, and recovery is prompt with minimal affect on ecosystem function. Pests have been found, but there have been limited ecosystem impacts. The occurrence, distribution and abundance of introduced species are limited and have minimal impact on ecosystem function.

Poor (3-4)

Incidences of disease or algal blooms occur regularly in some areas. Occurrences of pests require significant intervention or have significant effects on ecosystem function.  The occurrence, distribution and abundance of introduced species triggers management responses, or have resulted in significant impacts on ecosystem functions.

Very Poor (1-2)

Disease or algal blooms occur regularly across the region. Occurrences of pests or introduced species are uncontrolled in some areas, have displaced indigenous species and are seriously affecting ecosystem function.