A.3 - Identification of potential marine protected sites

Preliminary information on the sea bottom structure suggests that there are 3 potential areas in Latvian EEZ where priority habitats for protection may be found and should therefore may be designated as Natura 2000 sites.
Due to the size of potential areas, the complexity of the tasks as well as time constraints inflicted by the need of three to four field seasons, the activity has been split up between four teams.

Results in the Mid-term of the Project:

Side-scan-sonar

After Public Procurement procedure, a Service Contract was signed to use the research vessel “Mintis”. Surveys on the field were implemented in October 2022. Three types of survey line spacing were chosen for this job – 2km line spacing for general understanding of the area, 1km line spacing in areas where more detailed data was deemed necessary and line spacing 500 metres for areas of high interest. During data collection, multibeam sonar swath was opened to a maximum possible 140o angle. Obtained acoustic data was classified into 5 sediment classes according to EUNIS guidelines. Sediment classes can be further translated to benthic habitat types. Results show good correspondence of data and obtained multibeam and bathymetric data adds three-dimensional structure to observed habitats.

Avio-counts

After Public Procurement procedure, service Contract with Latvian Ornithological Society was signed. First avio-counts on feather throwing birds in all three pilot-territories were implemented during 8th to 9th August 2022. All together the length of the surveyed transects during avio-counts reached 1215km. In first avio-counts evidence has been obtained regarding the occurrence of the globally endangered duck Clangula hyemalis, which was determined in large amounts. The large number of individuals of Hydrocoloeus minutus shows that at least two of pilot-territories could reach the criteria for the protection of birds in accordance with the Birds Directive. Findings of the incidence of Alcidae indicate that these species are present in marine waters of Latvian exclusive economic zone in larger numbers than previously assumed.

Video recordings, scuba diving and acoustic points

After public procurement LIAE hired the research vessel “Brabander” for support of habitat mapping activities in the sea. In the year 2021, 14 days of 20 planned in agreement were spent on mapping of Southern territory collecting 324 video observations of benthic habitats and 534 acoustic points of depth observations. Additionally, 32 benthic samples were collected by scuba divers in the shallowest parts of project territory (till 33m depth). Other parts were significantly deeper and no diving activities were possible or reasonable.

In 2022, 20 days of 20 mentioned in agreement were spent in the Southern territory, allowing to complete the video surveys in the area. 354 video observations and 981 acoustic measurements were collected. The results show Stony reef habitats covered with keystone species Mytillus trossulus, accompanied by Amphibalanus improvisus, Cordylophora caspia and other less visible species. Video observations often show also more mobile species, like, mysids and fish (Myoxocephalus scorpius, Platchtys flesus and even Gadus morhua), indicating the importance of Stony reefs as complex habitats used by all trophic level inhabitants for feeding, hiding and breeding.

Fish surveys

The first seasonal survey was implemented on the commercial fishing vessel “Vergi” in the period from 10th to 28th August 2021 (summer season). Due to unfavourable weather conditions, the survey was done in three separate periods (in total 9 days at sea) and covered all three selected study areas, according to the initial plan. Due to technical problems, hydroacoustic recordings were performed only at the beginning of the survey, as well as pelagic trawling (3 hauls in total).

The second procurement (4 lots for the Project tasks) was announced on 31st March 2022 and was aimed to provide vessels for spring and summer gillnet surveys, and summer and winter hydroacoustic surveys in 2022. Based on the previous experience and vessel rent price estimates it was decided to split gillnet and hydroacoustic surveys separately. Work schedule, dates and performed actions are given in the table below.