Boat-based Surveys

Dolphin Survey Boat Trips’ Sulaire and Anna Lloyd are both used as CBMWC research vessels from New Quay harbour. Boat surveys usually follow a set route within the Cardigan Bay Special Area of Conservation (SAC). A volunteer researcher from CBMWC joins each boat trip and is responsible for systematically recording effort (position and environmental information) and sightings data (of large marine animals) on a series of survey forms.

The effort form

An effort line is completed every 15 minutes or every time one of the following survey conditions changes:

  • Speed
  • Boat course (more than 10°)
  • Effort type
  • Precipitation
  • Sea state
  • Wind direction
  • Wind force

There are four effort types:

  • CW – casual watch. The researcher is observing from the wheelhouse or passenger area
  • DS – dedicated search. The researcher is observing from the roof (but not a line transect)
  • ID – photo-ID work is occurring
  • LT – line transect. The researcher is on the roof and the boat is following a predetermined route through the SAC

The researcher uses a handheld GPS (Global Positioning System) to gather the positional data (latitude and longitude) and also speed, course and time.

For each effort line the researcher also records any precipitation (e.g. rain or mist), visibility, sea state, swell height, wind direction and force, cloud cover and glare and any other boats that are observed in the area.

The sightings form

The sightings form is only used when a large marine animal (e.g. bottlenose dolphin, Atlantic grey seal, harbour porpoise, whale, basking shark or leatherback turtle) is seen. The following information on the sightings form is filled in immediately:

  • Latitude and longitude, taken from the handheld GPS
  • Angle from boat
  • Distance in metres to the animal

Once this data is complete, then the rest of the sightings form is filled in.

  • Species
  • Total number
  • Number of adults, juveniles, calves and newborns
  • Behaviour and/or direction of travel
  • Any large congregations of birds seen in close proximity to the sighting and their approximate number and behaviour

For the latest boat-based sightings click here