Blog by Kieren Alexander, Site Manager for RSPB Old Hall Marshes
Work is progressing nicely on the beneficial reuse project at Horsey island, with almost 25% of the material delivered by the Sospan Dau so far.
The Sospan Dau is being skippered by a joint venture of Van Oord and Boskalis Westminster who have undertaken many such projects around the globe and are experts in this type of operation. They are able to access the disposal location at every high tide once they have found enough of the correct material from the Harwich Haven authority channel deepening source site, in this case sand and shingle. The material is then pumped ashore using a short length of floating pipe held in place by ropes and a small tugboat. This allows accurate disposal of the material and into the area it should be placed.
You can track the boat here:
MarineTraffic: Global Ship Tracking Intelligence | AIS Marine Traffic
However, the best view is from the air and we were able to access Horsey last week and take this Drone footage. This shows the Sospan Dau approaching the island and discharging the material.
At the moment the material resembles a large flat sand and shingle pancake. It will be shaped and sculpted by tide and wind over winter, moving landwards and westwards and in time building up the existing beach.
Although it doesn’t look like it now, the existing beach at Horsey is manmade, it was created in the 1990’s by the original Sospan Dau after a similar scheme where material was transported from a deepening project carried out by Harwich Haven Authority and the Environment Agency. It was after this that little terns colonised the beach and made this an important colony. However, the same forces that created the beach are also slowly causing it to be less suitable for nesting birds, it is slowly flattening out and lowering. This makes it much more vulnerable to storm events and high tides over the breeding season, which can lead to the complete loss of a breeding season. This work will make this scenario much less likely in the future in this location.
In case you missed it, here is the link to first part of Horsey Island Recharge Project blog.
Blog by Lizzie Bruce, NW Norfolk Reserves Warden
Ten years ago, the Titchwell Marsh Coastal Change project was completed to protect the freshwater habitats from coastal erosion and rising sea levels. The project realigned and strengthened the sea defences that surround the freshwater marsh and reedbed and a new area of tidal saltmarsh, a natural sea defence, was created on the northern side of the Parrinder Bank. The completion of the Coastal Change project has safeguarded the freshwater habitats from saltwater incursion for generations to come.
The time is now right to restore and enhance the freshwater habitats within for the wetland species that are dependant upon this habitat.
The freshwater marsh is home to the iconic avocet and acts as an important service station for migrating waders. In August, using two amphibious excavators, the single freshwater marsh compartment was split into three with new water control structures installed. This will allow the freshwater marsh to be managed on a constant rotational basis ensuring a plentiful supply of food for breeding avocets, migrating waders and wintering wildfowl. In addition, a series of new nesting islands has been created and a new predator fence installed to improve the breeding success of avocets and common terns but could also attract new breeding birds for the reserve, such as sandwich terns.
The second part of the project aims at restoring the freshwater reedbed. The reedbed at RSPB Titchwell Marsh was integral in ensuring the bittern didn’t become extinct in the UK when their population dropped to just 11 booming males in the 1990’s. However, despite the overall conservation success of this species in the UK with more than 200 booming males today, RSPB Titchwell Marsh has not recorded a breeding pair for 10 years.
This project will restore the freshwater reedbed by repairing eroded banks, recreating a network of ditches and ponds, and installing new water control structures. The restoration work will improve the habitat to not just benefit bitterns but enhance the wetland for other species such as bearded tits, water voles, eels and a variety of invertebrates.
An exciting element of the reedbed restoration will be one of the first of its kind in the UK; to create ‘Spoonbill Islands’ for the small but growing breeding population of spoonbills in the UK, and on the Norfolk coast. A series of islands surrounded by a moat have been created which will then be planted with a mixture of trees to create scrubby islands for spoonbills to nest in.
Spoonbills were once a common sight in East Anglia featuring in medieval banquets. But as the Fenlands were drained, these distinctive birds lost their home and became a desirable species for egg collectors and hunters, resulting in them becoming extinct in 1668. As the Dutch population rapidly grew, in 1999 the first pair for 300 years bred in the UK, but it took a further 11 years for a colony to form at Holkham National Nature Reserve in Norfolk. They have since become a regular site on the Norfolk coast including at Titchwell Marsh.
The project commenced in August 2021 and will be completed by the end of October, in readiness for the arrival of the wintering wildfowl.
Blog by Kieren Alexander, Site Manager for RSPB Old Hall Marshes
Work will shortly commence on an exciting project at Horsey Island in Essex to secure and enhance the most important little tern colony in Essex. Using sand and shingle materials from the major channel deepening conducted by Harwich Haven.
Funded by the EU Life+ project and the Environment Agency and with a major contribution from Harwich Haven Authority. This project aims to secure the future of the most important little tern colony in Essex, ensuring that it is secure from climate change and sea level rise for the next 50 years.
Horsey Island is a private island in the north of Essex, it was first recharged in the 1990’s using sand and shingle from a previous deepening operation conducted by Harwich Haven Authority. More recently it has evolved into the most important little tern colony in Essex, ably wardened by the Ranger employed by Tendring District Council. Its unique offshore location means that it is relatively free of disturbance from people and mammalian predators this has allowed little terns to thrive and develop a productive colony.
However, over time the beach has moved westward and landwards and gradually flattened out. This has meant the beach is increasingly vulnerable to high tide events especially over the breeding season. This means that to ensure that we can continue to provide habitat for little terns we need to recharge the recharge.
Drone footage of the beach at Horsey Island, taken before the recharge operation. Credit: RSPB & Jim Pullen
This is done by dredging sand and shingle then transporting it to the island, it is then deposited either via blowing it out over the bow or connecting a pipe and pumping it directly on to the foreshore. This is then moved around by the wind and tides until it settles on the existing beach raising the beach. This type of scheme is also known as a beneficial reuse scheme.
Not only will this project secure the future of the little tern colony, but it will also help to reduce erosion of saltmarsh, also a valuable and protected habitat. It will also maintain Horsey’s role as a wave break in the embayment, absorbing wave energy and helping to maintain the socio and economic and recreational opportunities this wonderful part of the Essex coast supports.
The work is due to commence on or around the 30th of September and will last approximately a month. We will be updating the blog during the operation to track progress.
Blog by Mhairi Maclauchlan, RSPB Cumbria Coast Reserves Warden
Hello, I’m the Warden for the Cumbria Coast Reserves and I’ve been asked to give a summary of our long term tern numbers at Hodbarrow. Hodbarrow is a large lagoon in the south of Cumbria formed from a former iron ore mine. It’s calm waters and iron ore slag islands provide ideal habitat for nesting birds in particular seabirds such as terns, ringed plover, oystercatcher amongst many more.
Previously my colleagues have written about the work being carried out at Hodbarrow over the last year thanks to EU Life on The Edge funding. In addition to what is happening presently it’s very important for to look at historic trends in the data, examine the reasons for those trends and use these to help shape our management. Using historic data as well as data collected by the dedicated wardens we have had in place over the last 5 years, we can see how numbers have changed. When looking at data we tend to look at population size and productivity.
Numbers of nests only give us a small glimpse into the breeding season it can also be useful to investigate the productivity of those nests. When we say productivity, we mean the success of each individual nest to raise young to fledging age and the numbers of fledglings coming from each nest. Fledging survival to breeding age isn’t guaranteed but we still think of that nest as productive. Numbers of nests, in simple terms, show us what birds arrived to breed on the habitat we have however productivity shows us how many chicks were produced from those nests that will now be part of the population.
Focusing on Hodbarrow you can see from the graph below that Sandwich terns would arrive and not progress to nesting or fledging stage and have shocking productivity.
After several years of this trend in the winter of 2015/16, we installed an in-water fence to stop predators such as fox accessing the island and decimating the nesting birds. This was also the start of our employment of summer wardens who were responsible for managing disturbance and large gull predation. As you can see after these measures were implemented birds were able to settle and breed as well as successfully get chicks fledged.
South Cumbria Populations
It can be very tempting to focus in on your site and what is happening locally, when in reality birds don’t see a boundary or a fence on the map. A few years ago, we came to the realisation that we had to look at Hodbarrow numbers (successes and failures as well) in terms of South Cumbria, national and even international populations rather than focus on purely Hodbarrow numbers. This gave us a wider and better understanding of what was driving our population changes.
There are two main tern colonies in South Cumbria – Hodbarrow and Foulney. They are geographically very close to each other as the tern flies.
We work closely with the Wildlife Trust who manage Foulney, sit on working groups with them and we have also worked together throughout Life on The Edge funding.
We see the birds at Hodbarrow as very much part of the South Cumbria population. Often the overall number in the population of birds in South Cumbria stay the same however they utilise both sites. One year they can all be at Hodbarrow and another year the population can then move over to Foulney.
The graph below shows the population changes for little terns over 30+ years. You can see from the graph that from 1996 – 2003 little tern numbers were concentrated at Hodbarrow and similarly from 2008-2012 Foulney held most of the birds, however overall, the population number stays roughly the same.
The trends in the Cumbrian population shows that even though there are years where birds aren’t present on a specific site, we still have to make sure the habitat is great and that work carries on to provide tip top potential nest site which they may utilise during the season or in subsequent years.
Interestingly, we have even seen this trend with colonies further afield. In 2018, we had the best ever year for Sandwich terns at Hodbarrow / South Cumbria however this involved birds re-locating from Cemlyn, Wales. Within days of a mass desertion at Cemlyn due to increasing otter predation a large influx of birds arrived at Hodbarrow. We can only surmise that these birds may have made the journey up the coast and the dates certainly provided evidence in favour of this.
Guest Blog by Chris Goding, Hodbarrow Field Officer
Following Dave Blackledge’s introduction to the recent LOTE funded habitat works at RSPB Hodbarrow, life at the reserve continues apace. I am one of two Field Officers here over the breeding season, with shared responsibility for surveying adult numbers and productivity of our key species (notably Sandwich, common, and little terns). We also monitor predation events and engage with members of the public about the RSPB’s work at the reserve, its history, and the wildlife found here.
Work was finished on the new island in January this year, complemented by an extension to the eastern side of the main island. The new island has seen modest but encouraging interest from breeding birds, and is currently home to a ringed plover pair (with two chicks) and a single oystercatcher nest as well as 2 common tern nests.
We are hopeful of increased use of the island in future years once the substrate matures. At the time of writing this blog, there are at least 20 common tern pairs on the new extension to the main island, making use of the increased space provided where a small island has been joined to the ‘mainland’, forming a miniature peninsula.
Current trends point to a successful season all round!
The peak count of little tern adults so far this season is 87, with at least 40 pairs, more than triple the number of pairs last year! Twenty six little tern chicks were spotted during a ringing session on the 11th June, the highest count since at least 2017, so we are hopeful of an excellent year for the species here. They appear to be responding particularly well to the application of slag to the concrete surface at their favoured spot, which helps to prevent the accumulation of rainwater around the nests.
Fifty common tern pairs (with a minimum of 40 chicks so far) points to a good year for this species too. Alongside this, at least 300 black headed gull chicks and 200 Sandwich tern chicks means the colony is a busy place.
With time yet for these numbers to increase we are expecting a productive season at Hodbarrow this year.
Photo credits: Oystercatcher by Katie Nethercoat (rspb-images.com)