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.
More stable species or meadows (such as shallow Zostera, Cymodocea, Halodule, Thalassia) 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 seagrass health. Local scale: Frequent, disturbance over a small percentage of the total meadow area (such as boat propeller damage) which results in a small section of the meadow being damaged but does not impair its overall health or ecosystem function. Local scale: Temporary loss of up to 10% of a local meadow, but no discernible impact on dependent species as other nearby meadows are able to meet their needs. The local meadow is likely to recover within 1 year. Regional or widespread scale: No discernible lasting impacts on a critical meadow, or on multiple meadows. Impacts are confined to a single non-critical meadow. Local scale: Temporary loss of between 10 and 20% of a single seagrass meadow, with full recovery likely within 3 years. Regional or widespread scale: Temporary loss of up to 10% of a critical meadow or multiple meadows. Full recovery is likely within 1 year. Local scale: Loss of 50% to 100% of a local seagrass meadow for more than 5 years. If the activity ceases, natural recovery may occur within 10 years. Loss of 20% to 50% of a single seagrass meadow, with full recovery likely within 3 years. Regional or widespread scale: Temporary loss of 10% to 20% of a critical meadow, or of multiple meadows. Full recovery is likely within 3 years. Local 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 20% of a critical meadow, or of multiple meadows, for more than 5 years. Even if the activity ceases, natural recovery is unlikely within 10 years.