Flapper Skate protection: NatureScot advice to the Scottish Government

Flapper skate sensitivity to pressures and activities - (Potential threats)

We have assessed the sensitivities of flapper skate during three distinct life stages: adult, juvenile and egg. The pressures that we consider the three life stages to be most sensitive to are shown in Table 1. The sensitivity information^[2] is based on a combination of the 2013 FeAST^[3] assessment for Table 1: Sensitivity of flapper skate to key pressures and activities associated with those pressures. Potential risks from activities are in a separate Table in Annex 2.

flapper skate, more recent research and expert judgement. This is because there is limited published information with direct evidence from studies of flapper skate.

There are a variety of activities that can be associated with the pressures listed and may therefore impact on flapper skate egg-laying habitat; these are also included in Table 1. This information draws on our knowledge of the Inner Sound and our understanding of existing human activities or potential activities that could occur, but is not exhaustive.

The presence of the eggs highlights that adults and juveniles must also be present in this area, at least during the period of egg-laying and hatching. However the length of time adults and juveniles are associated with this habitat is unknown, and evidence suggests they utilise different habitats (see Annex 1 for further details). Therefore, we consider the eggs and egg-laying habitat to be most at risk and are the focus of most of our advice for this location.

From our current understanding of existing activities within the Inner Sound and the sensitivity of the feature to abrasion and siltation, we have identified demersal mobile/active gear (dredging) to represent the greatest potential threat to this habitat and to the skate eggs. Further details on the activities (including other fishing activities and potential disturbance from divers) that may occur in the Inner Sound and cause negative impacts are included in Annex 2.

As stated previously, the complex topography of boulder and cobble habitat used for egg-laying is likely to confer a degree of protection. However, dredging over this habitat has the potential to damage eggs and the structure of the habitat itself and therefore impact recruitment of skate to the population. Some eggs may survive the passage of a dredge due to their position in the crevices between large boulders and a dredge may "bounce" over this habitat (Boulcott and Howell 2011). Eggs on cobble habitat would be at greater risk.