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Displaying items by tag: wave height

A research project led by coastal and ocean scientists in NUI Galway and the Marine Institute involves the deployment of a combination of smart buoys and time-lapse imaging to measure storm impacts and support the development of coastal flood and erosion defences.

The project, Brandon Bay on the Dingle Peninsula, Co Kerry, involves:

  • A new waverider buoy provided by Sustainable Energy Authority of Ireland to measure wave height, wave direction, wave period, surface currents, and water temperature as well as storm impact
  • Data being made available to view or download on the Marine Institute supported website Digital Ocean, a web portal to view data collected in and around Ireland's maritime zone.
  • The installation of a shoreline monitoring system along Brandon Bay at three sites, which will capture images of the beach every 10 minutes during daylight hours over the next 12 months, to identify the time periods when wave run-up is high enough to reach the dune toe and potentially cause coastal erosion. This research is funded by Geological Survey Ireland.

Dr Eugene Farrell, Discipline of Geography and Ryan Institute's Centre for Ocean Research and Exploration (COREx), NUI Galway, said: "We want to improve existing coastal change models by developing better insights into why does change occur and how much change will occur if we dial up climate projections for rising sea levels and storminess. To answer these questions we require process-response coastal models and these are only possible if nearshore observations from wave buoys such as the one in Brandon Bay are deployed over long time periods to capture all the seasons.

"We already know that changes along the coast from elevated storm surge and wave run-up result in changes in seabed and beach elevations. The data captured by the waverider will play an integral part in dismantling the important connections between different storm types such as size, direction, duration, clustering and coastal response that allows us to share real time ocean observations that can be used to address coastal erosion and coastal flood protection.

The wave buoy pictured after deployment in Brandon Bay on the 1, December 2020. Photo: Eugene Farrell, NUI GalwayThe wave buoy pictured after deployment in Brandon Bay on the 1, December 2020. Photo: Eugene Farrell, NUI Galway

Alan Berry, Manager of Marine Research Infrastructures at the Marine Institute said, "The wave buoy at Brandon Bay will enable researchers to observe and understand how our ocean is changing and determine how to respond to current and future patterns of change. Open access to this data on Ireland's Digital Ocean website is valuable to climate researchers in Ireland and across Europe."

The Brandon Bay long-term waverider project is co-led by Dr Eugene Farrell, Discipline of Geography, Sheena Parsons, Earth and Ocean Sciences, and Dr Stephen Nash and Andi Egon, Civil Engineering in NUI Galway, and Alan Berry and Conall O'Malley from the Marine Institute with support from the Sustainable Energy Authority of Ireland.

In September 2020, a Coastal Change Technical Working Group was established within the Irish government and tasked with overseeing the development of a scoping report on a national coastal change management strategy. They have envisaged that the scoping report will address issues related to 'baseline and other data capture and research requirements to inform developing, implementing and monitoring a national coastal management strategy, to include potential damages assessment'.

Dr Eugene Farrell adds: "We feel it is our responsibility as coastal scientists to provide the requisite baseline information and recommendations to guide future research along the coast in order to fill knowledge gaps. This is an integral part of the Brandon Bay Waverider project and can be used as a demonstration project so that future investment in coastal infrastructure can be identified.

"Cumulatively, our approach requires a large team of experts to work together. The Maharees in Brandon Bay is already becoming a hub for coastal science thanks to the active community group in the area, the Maharees Conservation Association. There is an urgent need to increase our understanding of coastal change so that that we can better protect our coastal communities and design conservation plans for coastal ecosystems whose dynamic boundaries move in response to changing climate conditions."

The Brandon Bay Waverider project is supported by the Marine Institute, NUI Galway and MaREI, the SFI Research Centre for Energy, Climate and Marine research and the Sustainable Energy Authority of Ireland.

Wave data results from the Brandon Bay Waverider project can be viewed here

Photo: The wave buoy pictured after deployment in Brandon Bay on the 1, December 2020. Photo: Eugene Farrell, NUI Galway


About the Waverider Buoy

The data from the buoy is being used to validate a state-of-the-art high-resolution coastal erosion modelling system comprising of wave, tide and sediment transport models that is under co-development in Civil Engineering, Earth and Ocean Sciences and Geography disciplines at NUI Galway and the Marine Institute since early 2019. The key attraction of these specialised numerical ocean models is their predictive capability. The model predictions are first tested against real-time observations in the bay and then tested for different climate change scenarios such as rising water levels or increasing wave heights.

For example, once the model is validated using the wave buoy observations the project team can test outcomes using the OPW sea level rise scenarios: (1) conservative Mid-Range Future Scenario which uses a sea-level rise of 0.5m by the year 2100 and (2) a High-End Future Scenario, which uses the maximum projected sea-level rise of 1.05m for the year 2100.

Superimposed on these changing sea levels the group can investigate how extreme storms and wave heights will impact the coast and determine how these impacts will be manifested on the coast, such as rates of shoreline retreat or increasing vulnerability of coastal communities and infrastructure.

The yellow spherical wave rider is one metre in diameter, is equipped with an antenna and light and is anchored to the seabed by a mooring. The light will flash yellow for five seconds every 20 seconds in hours of darkness. An accelerometer mounted within the buoy registers the rate at which the buoy is rising or falling with the waves. This type of 'heave, pitch, and roll buoy' is the most commonly used buoy for measuring waves in deep water. It measures the surface height and slope in different orthogonal directions to yield the horizontal and vertical displacements of the buoy.

The Brandon Bay Waverider Acknowledgements

Marine Institute & Sustainable Energy Authority of Ireland

The Marine Institute, supported by the Sustainable Energy Authority of Ireland, have been instrumental in the execution of this project. They have been very generous with their time (research-in-kind) and sharing their expertise and equipment. We would especially like to acknowledge the leadership of Alan Berry, Section Manager, Marine Research Infrastructures and Conall O'Malley, both from the Marine Institute.

The Marine Institute is a State agency responsible for marine research, technology development and innovation in Ireland whose remit is: "to undertake, to coordinate, to promote and to assist in marine research and development and to provide such services related to research and development, that in the opinion of the Institute, will promote economic development and create employment and protect the marine environment." This project exemplifies how scientific progress can be made when academics link up with management agencies like the Marine Institute.

The Sustainable Energy Authority of Ireland is Ireland's national energy agency aiming to create a cleaner energy future by making Ireland's energy sustainable, secure, affordable and clean. SEAI supports the Irish offshore renewable energy sector by advising the government on policy, offering grant support schemes, developing test site infrastructure, and providing information through the Ocean Energy Ireland portal. The Brandon Bay wave rider provided by SEAI will be part of the wave monitoring network of coastal buoys operated on behalf of SEAI by the Marine Institute.

The Marine Institute work with P&O Maritime Logistics who co-led the technical parts of the deployment including the installation of the base station and also the actual deployment.

NUI Galway

The NUI Galway Research Office provided funding support. This office is part of the Office for the Vice President for Research and works closely with the Innovation Office, the Researcher Development Centre and other professional services supporting the NUI Galway research community. We would especially like to acknowledge the support of Aengus Parsons, Director of the Research Office and Professor Lokesh Joshi, Vice President for Research for their support.

MaREI

MaREI is the SFI Research Centre for Energy, Climate and Marine research and innovation co-ordinated by the Environmental Research Institute (ERI) at University College Cork and also based in NUI Galway. We would especially like to acknowledge the support of Dr Stephen Nash in Civil Engineering in NUI Galway. The data from the wave buoy are an integral part of an ongoing MaREI funded PhD programme in NUI Galway.

Maharees Conservation Association and partners

The ongoing coastal and ocean research is not possible without the support of the Maharees community. We are very excited to contribute to our scientific understanding of coastal and ocean dynamics in the bay area with the hope that the results will support ongoing efforts by the community to build their resilience to pressures from storms and people. We would especially like to acknowledge Mr Paddy Buckley and his family for allowing us to install the base station in their home in the Maharees. The NUI Galway team would also like to thank Kerry County Council, National Parks and Wildlife Service and OPW for supporting coastal research in the area.

Published in Marine Science

#MCIB - The families of two fishermen found dead at sea off the Skerries last April may never uncover the circumstances that led to their demise. But the official report into the incident indicated that the absence of lifejackets was a significant contributing factor.

Ronan Browne (26) and David Gilsenan (41) were reported missing on the evening of 1 April after failing to return from a trip tending to lobster pots.

Their vessel, Lady Linda, was found the following morning upturned in an oil slick off Clogherhead with no sign of the crew.

It wasn't until a week later that their bodies were discovered caught in the vessel's fishing gear some five miles east of Clogherhead, as previously reported on Afloat.ie.

Post-mortem results found that both men died from drowning, with Gilsenan also showing signs of hypothermia.

With no eyewitnesses to the incident, the report by the Marine Casualty Investigation Board (MCIB) indicated a number of possible causes from eqiupment malfunction or shifting of lobster pots on deck, to the wave height and weather conditions on the day, which were reportedly deteriorating when the boat left port.

It also said that Browne and Gilsenan "were lifelong friends, both men were experienced and qualified marine engineers in the fishing vessel industry. Both men were experienced in boat handling and fishing and had worked together on many occasions."

But the report emphasised the lack of personal flotation devices (PFDs) on board, and noted that emergency equipment was stored under the deck and not easily accessible.

The MCIB's recommendations include a review of the code of practice for fishing vessels under 15m to establish "revised stability critera" and ensuring that all boats are fitted with automatic radio beacons that deploy upon capsize.

In a separate incident, lack of proper maintenance led to an unlicenced boat taking on water off Co Kerry last August.

The Claire Buoyant was carrying one crew, five passengers and 21 sheep from Beginish Island to Ventry when the vessel began to lose stability.

Skipper Eoin Firtear - who the MCIB described as having "limited sea-going experience" - and his five passengers were rescued by passenger ferry. All sheep were jettisoned overboard, with 18 eventually recovered.

The report reminded that the carriage of livestock should only be undertaken in appropriately certified vessels.

Published in MCIB

Sharks in Irish waters

Irish waters are home to 71 species of shark, skates and rays, 58 of which have been studied in detail and listed on the Ireland Red List of Cartilaginous fish. Irish sharks range from small Sleeper sharks, Dogfish and Catsharks, to larger species like Frilled, Mackerel and Cow sharks, all the way to the second largest shark in the world, the Basking shark. 

Irish waters provide a refuge for an array of shark species. Tralee Bay, Co. Kerry provides a habitat for several rare and endangered sharks and their relatives, including the migratory tope shark, angel shark and undulate ray. This area is also the last European refuge for the extremely rare white skate. Through a European Maritime and Fisheries Fund (EMFF) project, Marine Institute scientists have been working with fishermen to assess the distribution, diversity, and monthly relative abundance of skates and rays in Tralee, Brandon and Dingle Bays.

“These areas off the southwest coast of Ireland are important internationally as they hold some of the last remaining refuges for angel shark and white skate,” said Dr Maurice Clarke of the Marine Institute. “This EMFF project has provided data confirming the critically endangered status of some species and provides up-to-date information for the development of fishery measures to eliminate by-catch.” 

Irish waters are also home to the Black Mouthed Catshark, Galeus melastomus, one of Ireland’s smallest shark species which can be found in the deep sea along the continental shelf. In 2018, Irish scientists discovered a very rare shark-nursery 200 nautical miles off the west coast by the Marine Institute’s ROV Holland 1 on a shelf sloping to 750 metres deep. 

There are two ways that sharks are born, either as live young or from egg casings. In the ‘case’ of Black Mouthed Catsharks, the nursery discovered in 2018, was notable by the abundance of egg casings or ‘mermaid’s purses’. Many sharks, rays and skate lay eggs, the cases of which often wash ashore. If you find an egg casing along the seashore, take a photo for Purse Search Ireland, a citizen science project focusing on monitoring the shark, ray and skate species around Ireland.

Another species also found by Irish scientists using the ROV Holland 1 in 2018 was a very rare type of dogfish, the Sail Fin Rough Shark, Oxynotus paradoxus. These sharks are named after their long fins which resemble the trailing sails of a boat, and live in the deep sea in waters up to 750m deep. Like all sharks, skates and rays, they have no bones. Their skeleton is composed of cartilage, much like what our noses and ears are made from! This material is much more flexible and lighter than bone which is perfect for these animals living without the weight of gravity.

Throughout history sharks have been portrayed as the monsters of the sea, a concept that science is continuously debunking. Basking sharks were named in 1765 as Cetorhinus maximus, roughly translated to the ‘big-nosed sea monster’. Basking sharks are filter feeders, often swimming with their mouths agape, they filter plankton from the water.

They are very slow moving and like to bask in the sun in shallow water and are often seen in Irish waters around Spring and early Summer. To help understand the migration of these animals to be better able to understand and conserve these species, the Irish Basking Shark Group have tagged and mapped their travels.

Remarkably, many sharks like the Angel Shark, Squatina squatina have the ability to sense electricity. They do this via small pores in their skin called the ‘Ampullae of Lorenzini’ which are able to detect the tiny electrical impulses of a fish breathing, moving or even its heartbeat from distances of over a kilometre! Angel sharks, often referred to as Monkfish have a distinctively angelic shape, with flattened, large fins appearing like the wings of an angel. They live on the seafloor in the coastal waters of Ireland and much like a cat are nocturnal, primarily active at night.

The intricate complexity of shark adaptations is particularly noticeable in the texture of their skin. Composed of miniscule, perfectly shaped overlapping scales, the skin of shark provides them with protection. Often shark scales have been compared to teeth due to their hard enamel structure. They are strong, but also due to their intricate shape, these scales reduce drag and allow water to glide past them so that the shark can swim more effortlessly and silently. This natural flawless design has been used as inspiration for new neoprene fabric designs to help swimmers glide through the water. Although all sharks have this feature, the Leafscale Gulper Shark, Centrophorus squamosus, found in Ireland are specifically named due to the ornate leaf-shape of their scales.