Today's blog is by RSPB's Senior Conservation Scientist Steffen Oppel on the importance of protecting ocean areas for wildlife.
By the year 2020 (which is...now!) the Convention on Biological Diversity had aspired to designate 10% of our oceans as protected areas for the benefit of wildlife. This target has also been used by national governments to assign marine areas under their jurisdiction a protected status, with the focus mostly being on achieving the 10% coverage than protecting the most biodiversity.
For the last 30 years researchers have collected lots of data by attaching small electronic devices to seabirds that tell us where the birds go once they disappear from view over the horizon. Together with the BirdLife Marine team we have been using this huge amount of information derived from seabird tracking data to identify which areas of the ocean should be protected, and whether the already existing protected areas (briefly referred to as 'MPA's for Marine Protected Area) are actually in sensible locations. Two new studies from the UK Overseas territories summarise some of this work.
Attaching a small GPS logger to the tail of a seabird - when retrieved after a week this logger has recorded the exact locations where the bird has been.
The first study, led by Susana Requena, focussed on the waters around the islands of Tristan da Cunha in the South Atlantic. These islands are home to several million breeding seabirds, which use almost the entire South Atlantic Ocean between Argentina and Namibia to find food. To identify the most important areas within the jurisdiction of Tristan da Cunha - a 200 nautical mile radius around the islands - we assembled bird and seal tracking data and calculated which areas are used much more than expected by chance. The results show that the underwater sea mounts, mountains that are not quite high enough to emerge as islands from the sea, are among the most frequently visited foraging areas in Tristan waters and should be protected from any harmful exploitation.
Another UK Overseas Territory in the South Atlantic that is also home to millions of seabirds is South Georgia. The cold and highly productive waters around South Georgia are not only attractive to seabirds and seals, but also to industrial fishing fleets. To ensure that these do not harm the biodiversity, an MPA was established that has tight regulations which industry is allowed to fish where and when. Do these regulations actually protect the biodiversity?
Hundreds of thousands of Great Shearwaters returning to their breeding island in Tristan da Cunha
In a new paper led by Jonathan Handley, we compiled the seabird and seal tracking data from South Georgia and examined where globally significant concentration areas for wildlife were. Encouragingly, many of these concentrations were covered by the existing MPA, with regulations banning any fishery at the time when the areas are most heavily used by birds and seals. The MPA in South Georgia is therefore a good example how the industrial exploitation of marine resources can be managed to minimise negative effects on marine birds and mammals.
All this work contributes to making the foraging areas of seabirds safer - but that is only part of the story. Many seabirds still get killed by invasive species when they come to nest on islands. The birds on South Georgia are now safe from rats and mice thanks to a successful eradication. In 2020 we wanted to help the seabirds on Gough by eradicating mice - but due to a global pandemic and travel restrictions this work became impossible. We will return in 2021 to ensure that seabirds from Gough can soon not only forage but also nest in safety!
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