Method | 10419926

Before investigating barnacle distribution an ethical review and risk assessment were considered.

Before the survey, tide times were checked to allow enough time to cover as much of the beach as was possible down to the mean low water mark. A risk assessment covered areas that could cause hazard or harm and actions were outlined to minimise these risks. The survey was carried out by a group of three to ensure someone would be present in case of an emergency and someone would be free to summon help if needed.

Study subjects were looked at in situ. This method reduced harm that may have been caused by removal. Due to the nature of the rocky shore it is difficult to avoid trampling some organisms such as seaweed and barnacles, however care was taken to tread carefully and minimise any damage. Where algae were moved to investigate underneath, they was replaced carefully to avoid harm or desiccation to organisms that may have been using them as refuge.

In order to investigate barnacle distribution in relation to height, a line transect was used from a high position on the beach to the low water mark. The method was adapted from Field Studies Councils, A Practical Fieldwork Manual (Field Studies Council, 2009).

Equipment used included range poles, clinometer, compass, tape measure, recording sheets, magnifying glasses and identification guides.

The transect line was chosen to start at point which was representative of the highest part of the beach and followed a line which was as straight as possible to the low tide mark. The line covered similar substrate and where different substrate intersected the line it was moved sideways as little as possible to keep to the same substrate.

A 0.5m2 quadrat was used to record barnacle, fucoid and limpet percentage cover at each sample station (Figure 3).

Figure 3 Quadrat sampling. (10419926a, 2015).

Three sample quadrats were taken at each station. The samples stations were placed at each drop in vertical height of 0.5m. The distance and slope angle between each station was recorded. Sampling ceased at the low tide mark where the height was 0m.