3. Consequence table for Seagrass values Degrees of Severity Consequence Positive Negligible Moderate Major Extreme to value (Enhance) (Maintain) All scales: All scales: Local scale: Local scale: Local scale: scale: Damaged or No discernible lasting Loss of up to 20% Loss of 20% to 50% of Permanent or None Localised – degraded seagrass impact on local, of a single a single seagrass modification of seagrass loss meadow is regional or meadow. Seagrass meadow, with full 50% to 100% of a (even improved or widespread seagrass species are able to recovery likely within 5 single seagrass permanently) is rehabilitated. health. recruit and years. meadow, making it unlikely to result in recolonise the area unsuitable for extreme Seagrass habitats Activity does not the following Regional or seagrass for more consequences on are identified, impact on seasonal season. The widespread scale: than 10 years. the overall value of Pioneering, managed, recovery and meadow is likely to Loss of up to 20% of a seagrass, unless highly variable monitored, resilience (such as recover within 1 critical meadow, or of Regional or the meadow is meadows or protected and short term year. multiple meadows, for widespread critical or part of a species conserved. increase in turbidity up to 1 year. Loss of 20% to larger scale, (such as during seasonal Regional or 50% of a critical cumulative loss. Halophila) Water quality is flowering period). widespread scale: meadow, or of improved to ensure No discernible multiple meadows, Regional or seagrass lasting impact on a for up to 5 years. widespread scale: requirements are critical meadow, or Loss of more than being met. on multiple 50% of a critical meadows. Impacts meadow, or of are confined to a multiple meadows, single non-critical for more than 5 meadow. years.
3. Consequence table for Seagrass values Consequence to value Degrees of Severity Positive (Enhance) Negligible (Maintain) Moderate Major Extreme Pioneering, highly variable meadows or species (such as Halophila) All scales: Damaged or degraded seagrass meadow is improved or rehabilitated. Seagrass habitats are identified, managed, monitored, protected and conserved. Water quality is improved to ensure seagrass requirements are being met. All scales: No discernible lasting impact on local, regional or widespread seagrass health. Activity does not impact on seasonal recovery and resilience (such as short term increase in turbidity during seasonal flowering period). Local scale: Loss of up to 20% of a single meadow. Seagrass species are able to recruit and recolonise the area the following season. The meadow is likely to recover within 1 year. Regional or widespread scale: No discernible lasting impact on a critical meadow, or on multiple meadows. Impacts are confined to a single non-critical meadow. Local scale: Loss of 20% to 50% of a single seagrass meadow, with full recovery likely within 5 years. Regional or widespread scale: Loss of up to 20% of a critical meadow, or of multiple meadows, for up to 1 year. Local scale: Permanent or modification of 50% to 100% of a single seagrass meadow, making it unsuitable for seagrass for more than 10 years. Regional or widespread Loss of 20% to 50% of a critical meadow, or of multiple meadows, for up to 5 years. scale: None – Localised seagrass loss (even permanently) is unlikely to result in extreme consequences on the overall value of seagrass, unless the meadow is critical or part of a larger scale, cumulative loss. Regional or widespread scale: Loss of more than 50% of a critical meadow, or of multiple meadows, for more than 5 years.
Seagrass-value-assessment-guidelines.docx