Climate change is happening now and affecting the things we love. As part of Show The Love week we are looking at how nature, in particular seas and seabirds around Scotland’s coasts, is being affected. In the first blog Peadar O’Connell looked at exactly what climate change is and why it is such a threat to our much loved wildlife. The second blog focused at what impact it is having on our seas. In this final blog Peadar addresses the impacts of climate change on seabirds.
Show The Love: climate change and seabirds
The sounds are fading from our coasts and cliffs; climate change is having frightening impacts on seabirds around the globe.
Seabirds are the most threatened group of birds in the world. In the past couple of years two more Scottish seabirds (puffin and kittiwake) have joined the long-tailed duck, velvet scoter and Leach’s storm petrel on a list of species that are at a “high risk of global extinction”. To put that into perspective this list also contains panda bears and snow leopards. There are also six species of UK seabirds on the national Red list with puffins, kittiwakes and shags recently added. Since 1986, the breeding numbers of the 12 regularly monitored species of seabirds in Scotland declined by 50% (in just 30 years!) and there have been huge declines in individual species like kittiwakes (72%), shags (68%) and Arctic skuas (76%). The results of these declines is easy to see, the cliffs are growing quiet. There are many reasons why this is happening with seabirds facing many different pressures but maybe the most insidious of all is climate change.
The prehistoric looking shags, suffering huge declines due to increasingly violent winter storms.
Today, climate change is affecting seabirds principally in two ways that we know of. Indirectly by changing the availability of prey for seabirds and directly by causing more severe storms in both the summer breeding season and in the winter. As mentioned in the previous blogs (here and here) in this series, climate change is implicated in more extreme weather events; this includes stronger storms and more rainfall. This is bad news for seabirds, which often live on the edge of the possible even during the good times. This increases the risk to birds nesting on cliff edges and along the coast where their nests can be washed away. More regular winter storms are thought to be the main driver of the decline in shags. Severe weather also makes finding and catching food more difficult and can cause chicks to die of exposure.
Kittiwakes are globally threatened. In Scotland they suffer from changes to their food supply as well as the risk of their nests being washed away during summer storms.
A less obvious impact of climate change is the impacts of increasing temperature and acidification on the marine food web. What is becoming very clear is that some species of seabirds including puffins and kittiwakes are struggling to find enough food to feed their chicks in certain parts of Scotland. This can be more or less severe in different years, for example there have been years of nearly complete breeding failure in the Northern Isles leading to fewer birds in the following years. But what’s causing this? It seems that changes in the ocean temperatures around the UK are affecting the primary prey of some of these seabirds, the sandeel. Sandeels are small silvery fish that, as their name suggests, spend a lot of their time buried in the sand in waters up to about 100m deep. Seabirds on the east and north coast of Scotland especially seem to rely heavily on these fish to feed their young chicks. Sandeels have declined, at least in parts of Scotland, and have become more difficult for the seabirds to find. Check out RSPB’s Project Puffin website for some fascinating citizen science research into the diet of puffins carried out last summer, plus some photos of puffins.
A puffin with a bill full of sandeels from the Isle of May, some populations, such as those in the Northern Isles, are struggling to find enough food to feed their chicks.
Sandeels bury themselves in the sand over most of the winter and do not feed. They survive on their fat stores by slowing their metabolism, similar to bats or hedgehogs in winter. However, the temperature increases due to climate change is affecting their ability to retain a slow metabolism over this period. A higher metabolism means they use up their fat reserves more quickly and don’t have the energy to breed or perhaps even survive to the summer. On top of this the food sandeels prefer to eat (a nutritious cold water plankton called Calanus finmarchicus) is being replaced by less nutritious species as the temperatures rise, and if that wasn’t bad enough the plankton that is taking over has a different life history so it is not abundant enough at the right time of year for the sandeels to feed on. So, we have changes in the environment leading to changes in the plankton that affects the sandeel that impacts on the seabirds and that is before we even look at the other pressures affecting seabirds, sandeels, plankton and their habitats.
The impacts of climate change are obviously not restricted to Scotland. Seabirds all around the north Atlantic are in decline; puffins in Iceland have all but disappeared from previous strongholds due to a lack of food. In the Antarctic things are just as bad; penguins are heavily dependent on cold conditions and as temperatures rise there have been huge declines in some species (10 of the 18 species are at risk of extinction) as they struggle to find food and suitable breeding locations. Low-lying islands, the last refuges for millions of seabirds, are sinking beneath rising sea levels and storms, particularly in the Pacific and Indian oceans. The list, unfortunately, goes on.
Terns are at particular risk of their nesting sites being flooded by rising sea levels. Arctic terns are also heavily dependent on sandeels to feed their chicks and have undergone huge declines in Orkney and Shetland.
So, what can be done to help seabirds? Along with others we have been working to give seabirds the best possible chance to adapt to the changes that are already occurring but this is extremely challenging as seabird protection requires government commitments, proper resourcing and diverse stakeholder participation.
Primarily seabirds need three things to help make them more resilient to climate change: safe places to breed, safe places to feed and the ability to survive into adulthood. Island restoration and the eradication of invasive predatory species (like mice and rats) introduced by man onto islands can increase the resilience of seabird colonies giving them a far stronger opportunity to cope with other changes and hardships. Biosecurity measures are vital to keep these invasive predators off the islands in the first place. Marine protected areas provide safe havens so long as they are managed effectively and resourced appropriately so that monitoring and enforcement can take place. These areas can protect both breeding and feeding areas for seabirds.
An ecosystem approach to both fisheries and marine planning ensures economic gain isn’t prioritised over sustainable and healthy environments, which underpins all marine activities. For example, we must ensure fishing for small fish like sandeel doesn’t increase the pressure on the birds, sea mammals and larger fish that rely on them. When planning developments like renewable energy infrastructure, which is vital to achieving a low-carbon economy, we must ensure turbines are placed in suitable areas so that seabird populations and other marine life are not put at risk – this is all possible. The only way we can save our seabirds, marine life and ultimately ourselves is to do something about climate change before it is too late, and that means now!
Although it is easy to start to feel like climate change is too big to deal with, it is not – we have the technology at our disposal, but we need to change our behaviour. We also need to convince our governments to act, and fast. Otherwise, we will be entering a world that is unrecognisable to those of us alive today, and the scale of biodiversity loss will be immense.
If we do not make tough demands of our governments they will not deliver the necessary actions, so it is critical that we all become informed, involved and act to address this threat. A first step is to Show the Love by making, wearing and sharing a green heart. There are lots of other things to do here to show family, friends and your elected representatives that you care.
Later this year, in Scotland, the Scottish Government will be introducing a new Climate Bill to the Holyrood Parliament. We, and our seabirds, need the new emissions targets in this Bill to be ambitious and world-leading, and for it to include strong new action to reduce those emissions to zero by mid-century. Please look out for our Climate Bill campaign work later this year and our partner Stop Climate Chaos Scotland’s website – and keep showing the love for all you hold dear that you don’t want to lose because of climate change.