CJS

CJS Focus on Marine & Coastal Environments

Published: 25 May 2015

logo: Marine Conservation Society

In Association with: the Marine Conservation Society


logo: Scottish Seabird CentreThe Bass Rock

 

Whether driving the coastal roads or approaching by sea, the Bass Rock is an iconic landmark on the outer edge of the Firth of Forth that is just breath-taking as it gleams in the summer sun.

 

Stop for a moment and look through binoculars, and you realise that the dazzling white that covers this Rock is not guano but a hub of life, as thousands of gannets (our largest European seabird) have occupied virtually every suitable nesting site.

 

The airspace is alive as they soar overhead; some just swirling in extending columns using the thermals, others with offerings of

Nest material (Maggie Sheddan)
Nest material (Maggie Sheddan)

seaweed or plastic, even netting hanging from their bill for their continuous nest building. Juvenile gannets returning to the Bass for the first time since fledging, fly circuit after circuit around the Rock absorbing their birth colony, never landing, just observing, and sleeping on the seas close-by.

 

Gannets have been recorded as far back as the 6th century. For many centuries an industry in harvesting guga flourished, bringing valuable income not only as a food source, but feathers and the fat extracted from them was highly valued. In 1592 one of the first laws for conservation was introduced to protect the future of the colony. By Victorian times with the meat falling out of favour, wanton shooting almost decimated this colony.

 

Thankfully with these times long gone, the colony has grown in strength with Dr Bryan Nelson (who lived on the Rock for four seasons in the 1960s) studying these magnificent seabirds and bringing us the immense understanding of their behaviour that we have today.

 

Three-hundred-and-forty-million years old, this giant volcanic plug, composed of homogenous trap rock called phonolite or clinkstone, is on the cusp of rich feeding grounds of the North Sea. With sheer cliffs rising 120m out of the sea, this is what makes it the ideal habitat for the North Atlantic gannet (Morus bassanus).

 

gannet chick (Maggie Sheddan)
Gannet chick (Maggie Sheddan)

As the weeks pass, the white down on a gannet chick is replaced by the dark speckled plumage of the guga. By 12 to 13 weeks, static on this tiny ledge, its only exercise is to wing flap to strengthen the muscles. Rain stimulates this, creating a wave of dark wing flapping across the Rock (an impressive sight) but as rivers of water can cascade down the rock face after heavy storms, these factors combined can cause substantial mortality to the young on the prime sites.

Until recent times, sheep grazed upon the seven acres, Bass mutton being highly-prized. With the advancement of the gannetry, erosion has taken its toll and today little vegetation remains. Even the shags and gulls are being displaced.

 

In 2014, an aerial count confirmed that the Bass Rock is now the largest Northern gannet colony in the world with 75,259 AOS (apparently occupied sites), a dramatic increase of 24% since the last count in 2009. But why such a substantial increase when other seabirds in some areas have declined?

 

Gannets have been recorded foraging several hundred miles from the Bass Rock, although in summer feeding can be closer on the rich tidal banks. Because of their ability to travel such distances, and that they are able to take a variety of prey, they fare better than many other seabird species.

 

Guga first jump (Maggie Sheddan)
Guga first jump (Maggie Sheddan)

For the moment this is good news but despite current growing population numbers, balance of the food chain is vital. Fishing policies and environmental issues are closely monitored for changes that could have a negative impact on food supplies. This is why research and ongoing studies are vital to monitor these changes.

 

Leeds and Glasgow Universities are continuing studies this year. One will be deploying geo-locators on breeding birds to establish any changes in the foraging patterns, and what prey species is prevalent in their diet.

 

With various renewable energy schemes on the horizon, it is important that data is collected to establish possible changes in foraging zones; the potential for any disturbance to their flight paths; or disturbance to the marine habitat that could impact on resources. Winter geo-locators were deployed that brought interesting results showing that female gannets were travelling further during winter, resulting in birds returning in healthier breeding condition than those that did not travel that far. Eggs, too, are gathered every few years to monitor pollutants within.

 

Aerial shot of Bass Rock (Stuart Murray)]
Aerial shot of Bass Rock (Stuart Murray)

Whether I’m landing photographers, naturalists or just on a maintenance trip (scrubbing the landing, often with a young seal watching) my excitement and passion never tires. Many ask ‘when is the best time to land on the Rock?’ To be honest, anytime, but for me, the end of July through to late September when the young are yipping, vying for food, tossing sticks in the air, taking that first jump to their uncertain future.

 

Adults still display and nest build, the noise is extreme, the odour exceptional and the softer seasonal light is wonderful.

 

The Bass Rock, just 3 miles from the Scottish Seabird Centre (a mere 35 minute train journey from the city of Edinburgh) truly is a wildlife wonder.

 

Daily boat trips around the Bass Rock can be booked via the Scottish Seabird Centre

There are also exclusive, specialist, half-day landing trips for photography and wildlife enthusiasts.

www.seabird.org

 

Maggie Sheddan Senior Bass Rock Guide


Updated information February 2017

 

2016 saw the continuing studies from both Leeds and Glasgow Universities. We expect the updates from them in the next few months.

Lothian Ringing group accompanied by a couple of the research team ringed gugas (the fledged young), before they left the Rock in early September. With almost a hundred ‘chicks’ ringed this has been the first time young birds have been ringed for many years now. A report of one being washed ashore in Portugal was met with mixed feelings. It was wonderful to see this fledgling had made it that far south although sadly the thought is it succumbed to violent storms at that time. What was good was to now have a record of one of these fledglings. It shows he value and importance of ringing and although this one didn’t make it how far and where have the other 90 odd reached and will we ever see them return to the Bass? 


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