WTSWW’s marine monitoring work gathers evidence for critical datasets, used to strengthen the resilience of Wales’ network of protected marine sites and the protection of the marine species found within these sites. Long-term, uninterrupted datasets are particularly important to assess broad population trends, filling knowledge gaps, and informing decisions about use of the marine environment.

Cardigan Bay dominates the coastal profile of Wales – a long sweeping arc which joins the Lleyn peninsula in the north with Pembrokeshire in the south. It is a huge lee shore that faces the prevailing winds coming in off the Atlantic.

With nearly 350,000 breeding pairs of Manx Shearwaters, over 40,000 Puffins, thousands of Guillemots, Razorbills and Kittiwakes and hundreds of Fulmars, Skomer is an internationally important seabird island.

It is located less than a mile off the beautiful Pembrokeshire coast making it a great place to visit for the day or stay overnight.

Please note, Puffins start arriving in mid-April. They are present from May-July. The first ones start leaving in mid-July and all Puffins are gone by the end of July. Please see our seasonal timeline below for what to see each month.

First confirmed in the UK in 2012, ash dieback, also known as 'Chalara' or Chalara ash dieback, is a disease of ash trees caused by a fungus called Hymenoscyphus fraxineus.

Surveys should be carried out by professional ecologists, registered with IEEM. When surveys involve protected species, such as bats, great crested newts or dormice, the surveyor should hold a license from Natural Resources Wales.