Regular population counts have been carried out at St Abb’s Head since the late 1970’s giving a reasonable set of data to identify trends in recent times.

Guillemots increased rapidly in that time and the breeding population tripled between 1978 and 1998.  Since then, counts have shown a levelling off and some recent signs of a decline.

Shags also tripled between 1978 and 1992, but then high winter mortality caused a population crash back to 1978 levels.  Since then, the trend has been steadily upwards and, apart from 2004, breeding success in recent years has been good.

Over the same period, Kittiwakes have shown a boom and bust pattern.  Breeding numbers almost doubled between 1978 and 1990 but then declined by two-thirds over the next 15 years.  Breeding success has also been poor in recent years suggesting that the decline may continue into the near future.

In 2004, seabirds experienced a very poor year at St Abb’s Head.  For example, the nesting populations for Fulmar and Kittiwake were the lowest for over 40 years.  This appeared to be caused by a food shortage made worse by poor weather conditions at crucial times in the nesting period.  In fact, population declines and low breeding success were widely reported from many colonies in the northern North Sea suggesting a widespread ecological event.  One possibility is that an increase in sea surface temperature led to a change in plankton and sandeel distribution with the overall effect of reducing sandeel abundance within the seabird’s normal foraging range.

Research and conservation work
The first population counts were carried out in the late 1950’s, with more regular counting since the late 1970’s.  In more recent years, breeding success has also been monitored for some species.  The data is used by the Joint Nature Conservation Committee to produce an annual report that summarises the fortunes of seabirds throughout the UK.

In 2002 and 2003, Colin Beale, a PhD student from Glasgow University carried out research into the relationship between human disturbance and seabird breeding success.  He found that breeding success for both Guillemots and Kittiwakes was significantly reduced by the presence of people.  He suggested that nesting birds experienced stress, causing raised heart rates.  This resulted in an additional energetic cost to the birds that could lead to nest desertion.