Wight Barfleur

Intelligence Report – July 2022

Wight Barfleur is a highly trafficked Special Area of Conservation (SAC).

General Key Finding

The Wight-Barfleur SAC experiences high levels of transiting cargo and pleasure vessel traffic.

Vessel Tracking Key Finding

Fishing vessel traffic on AIS is predominantly transiting through the SAC. There appeared to be a limited number of vessels carrying out trawl operations in the area (AIS Analysis highlighted three vessels).

Remote Sensing Key Finding

Remote sensing indicated the Wight Barfleur SAC had a moderate presence of ‘dark vessels’ (based on AIS data only) with 21 detections. Synthetic Aperture Radar (SAR) imagery identified eight (8) dark targets between 44 and 154 m in length.

Observed Activity

AIS Analysis Alerts:0
Machine Learning Alerts:0
High Risks:0


SAR analysis was able to identify presence of ‘dark vessels’ (those not transmitting on AIS) to support site use assessments.

High resolution Electro-optical imagery was obtained and detected targets could be identified with high confidence. Vessel tracking identified three (3) vessels with possible fishing activities in the SAC and provided further insight into how vessels operate within the MPA.


The combination of high-resolution SAR with vessel tracking data (VMS, iVMS and AIS) would aid monitoring to help understand likely operations. Currently there are no management measures in place for commercial fishing activity related to the designated features in the SAC.

Future site assessments for the SAC will consider current site use and potential pressures towards designated features. This may lead to consideration of management measures and associated enforcement activities.

The image to the right shows ‘dark vessel’ detections in and around the Wight-Barfleur Reef Special Area of Conservation (SAC), an area of bedrock and stony reef located in the central English Channel.

Each orange marker denotes a ‘dark vessel’ detection from SAR swaths and EO images taken over the SAC between April and July 2022.

There were eight ‘dark vessel’ detections (not reporting on AIS) present in the Area of Interest, three in the 3 NM buffer and five inside the SAC. Their size ranged between 44 to 154 m and had profiles which aligned with possible fishing vessels. It is possible that these vessels are transmitting on VMS, and it is recommended to carry out further checks to confirm this.

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Extended Findings

Over the monitoring period there were eight dark vessel detections within the SAC and surrounding 3 NM buffer which had size and profiles consistent with possible fishing vessels. SAR data was collected between April and June inclusive, with the highest number of detections occurring in April and May in the central and western sections. It is possible that these vessels are transmitting on VMS, and it is recommended to carry out further checks to confirm this.

The high-resolution SAR picked up numerous small dark targets. The profile and size of these detections were associated with pleasure vessel traffic.

Vessel tracking sources did not identify any high-risk behaviour in the MPA during the monitoring period. Three vessels were identified with likely trawling activity in the SAC, they are reported for situational awareness. Predominantly, vessels identified in the SAC were in transit along the English Channel.

EO imagery was useful for identifying vessel types with high confidence; detected cargo vessels passed through the SAC in transit east to west. This behaviour, along with north to south passing pleasure vessel traffic characterises the primary marine spatial use of the site.

Risk Assessment

The main finding within the Wight Barfleur SAC was the prevalence of medium to large sized ‘dark vessels’ (not transmitting on AIS), the lack of AIS use increases the risk of collision in this highly trafficked area. Based on the number of detections identified during the monitoring period, the primary risk areas for activity were in the central and western parts of the SAC.

The majority of vessels identified on tracking data were either small pleasure vessels with class B AIS transponders or large cargo vessels transiting. Fishing is currently permitted in the SAC, if future restrictions for mobile gear are introduced the large numbers of passing merchant vessels will reduce the opportunity for dark vessel activities to go unnoticed and any passing vessel could play a role in aiding monitoring of the SAC.

Next Steps

In the Wight Barfleur SAC fishing activity is currently permitted subject to licence. Therefore, the main risk identified from remote sensing sources originated from dark vessel activity (based on AIS data) which presented a low risk over the Wight Barfleur SAC. It is recommended to carry out further checks to see if these detections are broadcasting on VMS. Vessel tracking and EO data sources did not identify any risks. It is recommended to request and enforce that all licenced vessels are transmitting on AIS and VMS to support Monitoring, Control and Surveillance (MCS).

Due to the sizes of the dark vessels identified in the SAC and the likelihood that these vessel operations often occur over longer time periods (longer persistence over time), SAR is considered a valuable tool for use over the SAC. The large size of the SAC is well covered by SAR swaths and can give an indication of presence and absence of dark vessels cost effectively. This is particularly true when compared to other remote sensing options such as EO which provides smaller coverage relative to the cost. It is recommended to use SAR to identify dark vessels and follow up initially with VMS tracking data. Use of patrol vessels when available and regularly transiting vessel traffic, such as ferries would aid monitoring.

Vessel tracking did not identify any high-risk behaviour, but the data provided a clear understanding of vessel activities for those vessels visible on AIS and VMS. In conjunction with high resolution SAR this would enable effective monitoring and risk detection over the Wight Barfleur SAC.