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Displaying items by tag: marine wildlife

 

Atlantic Dolphins choose to eat high-energy fish to suit their energetic lifestyles, scientists have found.
A study of dolphins off the French coast shows that dolphins shy away from less calorie-dense prey in favour of high-energy food. This dispels a myth that dophins are opportunistic feeders that take any food that comes their way.
The study was carried out by Dr Jerome Spitz and other scientist at the University of La Rochelle in France, who looked at the eating habits of short-beaked common dolphins ( Delphinus delphis ).
This species are the most common type of dolphin in nearby Atlantic waters. The team studied the stomach contents of dolphins caught accidentally in tuna drift nets to see what they ate. They then compared what they found in the dolphins' stomachs with what surveys of trawling fish catches indicated as plentiful in the same waters.
What they found was that dolphins actively select their prey based on its energy density, preferring deep-sea species like lanternfish instead of fish that have lower energy densities.
The dolphins studied turned their noses up at fish with under 5kJ of energy per gram, and sought out rarer breeds of fish that had a higher energy rate.
Two favourites were less common species of  lantern fish, the Kroyer's lanternfish  and the Glacier lanternfish  which have 7.9kJ and 5.9kJ per gram respectively.

Atlantic Dolphins choose to eat high-energy fish to suit their energetic lifestyles, scientists have found.

A study of dolphins off the French coast shows that dolphins shy away from less calorie-dense prey in favour of high-energy food. This dispels a myth that dophins are opportunistic feeders that take any food that comes their way. 


The study was carried out by Dr Jerome Spitz and other scientist at the University of La Rochelle in France, who looked at the eating habits of short-beaked common dolphins.

This species are the most common type of dolphin in nearby Atlantic waters. The team studied the stomach contents of dolphins caught accidentally in tuna drift nets to see what they ate. They then compared what they found in the dolphins' stomachs with what surveys of trawling fish catches indicated as plentiful in the same waters.


What they found was that dolphins actively select their prey based on its energy density, preferring deep-sea species like lanternfish instead of fish that have lower energy densities.
The dolphins studied turned their noses up at fish with under 5kJ of energy per gram, and sought out rarer breeds of fish that had a higher energy rate.


Two favourites were less common species of  lantern fish, the Kroyer's lanternfish  and the Glacier lanternfish  which have 7.9kJ and 5.9kJ per gram respectively. Other less energetic predators, like sharks, are less fussy and take anything that's going.

 

Published in Marine Wildlife

Mr. Sean Connick, T.D., Minister of State at the Department of Agriculture, Fisheries and Food, today (June 29th) launched a milestone report on the effects of climate change on Ireland’s marine ecosystems. The document - Irish Ocean Climate and Ecosystem Status Report 2009 – details a number of significant observations recorded in recent years including: increases in sea surface temperature, increased wave heights off the south west coast and an increase in the number of warm water species in Irish waters, ranging from microscopic plankton to swarms of jellyfish. This report is one of three projects funded as part of the Marine NDP Research Programme (Sea Change) under the Environmental Policy Research Measure.


“It could be argued that one of the greatest challenges our marine food industries - such as fishing and aquaculture - are the effects of marine climate change,” said Minister Connick. “These changes will be primarily driven by the Atlantic Ocean. Research is therefore urgently required to improve our capability to predict marine climate change so that we can preempt and deal with the economic, social, political and environmental consequences that might follow.”

One key finding of the report is that increases of sea surface temperature of 0.6°C per decade have been taking place since 1994, which are unprecedented in the past 150 years. This in turn is linked to an increase in microscopic plants and animals, along with species of jellyfish. Further up the food chain, increased numbers of most warm water fish species have been observed in Irish waters, along with sightings of exotic species such as snake pipefish. Declines in number of seabirds have also been observed which may have a climate link.

“Ireland is strategically placed to play a key role in monitoring ocean-induced changes in our climate and environment,” said Dr. Peter Heffernan, CEO of the Marine Institute. “Geographically the warm southern waters of the Atlantic drift come closer to Ireland than any other country in Europe, where they merge with the cooler northern waters off the coasts of Galway and Mayo. It is here that the predicted biological shifts in marine species diversity or abundance are most likely to occur, making Ireland an ideal laboratory for the study of marine climate change.”







In the long term, the Irish Ocean Climate and Ecosystem Status Report 2009 report predicts that global mean sea level may rise by up to 0.88 m by 2100. This, when combined with the increase in wave heights of 0.8 m that have already been observed off southwest Ireland, could lead to an increased threat of coastal erosion and flooding.

‘We assembled a team who extensively reviewed and analysed our extensive marine databanks on oceanography, plankton and productivity, marine fisheries and migratory species such as salmon, trout and eels with the specific aim of identifying any pattern that might be linked to climate change,” said Dr. Glenn Nolan of the Marine Institute who managed the team. “In some instances these data were painstakingly assembled over a considerable period of time, indeed one of the time series extends back over five decades.”

A second report which reviews the effect of ocean acidification in Irish waters “Ocean Acidification: An Emerging Threat to our Marine Environment - 2010” has also been completed which highlights the growing threat to marine life and fragile ecosystems around the coast as a direct consequence of increased carbon dioxide (CO2) levels in the atmosphere. The report recommends that a nationally coordinated multidisciplinary marine climate change and ecosystem monitoring programme be established that will enable better evaluations to be made of the threats posed to the marine environment and economy by ocean acidification. It emphasises closer links between climate change, ocean acidification and environmental policy development especially in relation to mitigation strategies to reduce carbon emissions.

Sea Change – A Marine Knowledge, Research & Innovation Strategy for Ireland, identified climate change as a priority area for research over the period 2007 to 2013 and this report represents a significant contribution towards achieving the objectives of the marine research programme. It addresses the need to increase our understanding of the drivers and regulators of climate so as to improve the accuracy of advice to Government while at the same time provide key inputs into the national climate change programme of the EPA. It will also improve the reliability of predictive models, and allow researchers to downscale global climate model predictions to the regional/local scale.  As an island nation, it is important to continue to support investment in marine climate change research. This in turn will strengthen Ireland’s ability to develop knowledge-based scenarios on climate change impacts on the various marine sectors and include these in all future social, economic and environmental strategies.

The complete Irish Ocean Climate and Ecosystem Status Report 2009 and Report summary are downloadable from:

http://www.marine.ie/NR/rdonlyres/E581708D-6269-4941-836F-6B012DD7A4BD/0/IrishOceanClimateandEcosystemStatusReport2009.pdf

http://www.marine.ie/NR/rdonlyres/7528902D-2467-4F3E-BF21-39D81AEA4D37/0/SummaryIrishOceanClimateandEcosystemStatusReport2009.pdf

The Ocean Acidification Report can be downloaded from:

http://www.marine.ie/home/publicationsdata/publications/Marine+Foresight+Publications.htm

Published in Marine Wildlife

Scientists at the Marine Institute, Galway, are working with anglers around Ireland to study the migration and diving behaviour of porbeagle sharks (Latin name - Lamna nasus) in the northeast Atlantic. Porbeagle sharks are one of the top marine predators around Ireland, but very little is known about their movement patterns in the northeast Atlantic.

Like most pelagic sharks around the world, the porbeagle shark is vulnerable to fishing pressure due to its high commercial value, slow growth rate and complicated reproductive cycle. However, there is currently no protective legislation for the species, primarily due to a lack of basic information on its biology and ecology.

Marine Institute fisheries scientist Dr. Maurice Clarke said, "Understanding the biology and spatial ecology of the porbeagle shark is key to the conservation of the species and for establishing successful ecosystem-based management strategies in the northeast Atlantic".

To study the movement patterns of porbeagles, scientists are using pop-up satellite tags. These tags are fitted harmlessly to the back of the shark and collect information on the animals' location and depth distribution, together with data on the environment in which the sharks live. Then after nine months the tags pop-up to the surface and transmit the data to polar-orbiting satellites.

With help from expert shark angler, Peter McAuley, three tags were deployed off Downings, Donegal, in September 2008. These data have provided new insight into the migration and diving behaviour of porbeagle sharks around Ireland. One shark, a juvenile male, migrated over 2400 km to Madeira off the west coast of Morocco during the wintertime. Another shark migrated to the Bay of Biscay, a region that is considered a hotspot for other shark-like species such as albacore tuna. The results also showed that porbeagle diving behaviour is linked strongly to the day-night cycle and the monthly lunar cycle.

Daragh Brown of BIM commented that, "These results are really interesting and since there isn't a whole lot known about porbeagle behaviour or habitat preference, even small amounts of data can really advance our knowledge".

This year, Marine Institute scientists are hoping to tag large adult females to find out the location of porbeagle birthing grounds. Currently nothing is known about where these large predators give birth.

The Marine Institute is currently working with the Irish Elasmobranch Group, French Research Institute for Exploration of the Seas (IFREMER), and the Association for the Conservation of Sharks (APECS) to find further funding for the project that will end in 2011. They aim to establish links between the fishing industry, recreational anglers and the public to increase research and awareness for the conservation of these sharks.

Dr. Edward Farrell (Irish Elasmobranch Group) said, "Pelagic sharks have received much global attention recently. Given the increasing pressures that threaten their survival, there is a pressing need for new research to underpin effective management measures".

 

Published in Marine Wildlife

A four-year survey of jellyfish population and movements in the Irish Sea continues this summer, with the public being asked to report sightings of any jellyfish that they see on the water. The EcoJel project is a collaboration between UCC and Swansea University and aims to see whether jellyfish in the Irish Sea could be a potential resource, either as an export product to countries where jellies are a delicacy, or as an attraction for divers who enjoy diving with jellyfish blooms.

The survey also hopes to deepen understanding of jellyfish blooms, which have caused beach closures and fish kills in the Irish Sea in recent years.

For more information, or to report sightings, check out  www.jellyfish.ie

Published in Marine Wildlife
Tagged under

On Saturday May 1st, the Irish Seal Sanctuary made its last journey from Garristown in North Dublin to release three seals in Courtown’s North Beach, Co Wexford. The weekend marked the beginning of a new era for the ISS who are setting up a new head quarters in Courtown. Irish boaters play an important role in identifying and advising the seal sanctuary of stranded or injured seals around the Irish coast. More here

 

Useful links on this story:

http://www.irishsealsanctuary.ie/iss_via/html/main.htm

http://www.irishtimes.com/newspaper/ireland/2010/0503/1224269588723.html

 

Published in Marine Wildlife
Tagged under

The finding of “a well-established, high-density colony” of the freshwater Asian clam in the river Barrow at St Mullins, south Co Carlow, has alarmed fisheries officials and wildlife experts. Michael Parson has the full story in The Irish Times. Dr Joe Caffrey of the Central Fisheries Board said the invasive species posed a threat to salmon, trout and other native species such as the freshwater pearl mussel. The “invader” could damage the food chain in Irish rivers and fatally harm the gravel beds which are used by fish as spawning grounds.

Published in Marine Wildlife
Page 53 of 53

Dublin Bay

Dublin Bay on the east coast of Ireland stretches over seven kilometres, from Howth Head on its northern tip to Dalkey Island in the south. It's a place most Dubliners simply take for granted, and one of the capital's least visited places. But there's more going on out there than you'd imagine.

The biggest boating centre is at Dun Laoghaire Harbour on the Bay's south shore that is home to over 1,500 pleasure craft, four waterfront yacht clubs and Ireland's largest marina.

The bay is rather shallow with many sandbanks and rocky outcrops, and was notorious in the past for shipwrecks, especially when the wind was from the east. Until modern times, many ships and their passengers were lost along the treacherous coastline from Howth to Dun Laoghaire, less than a kilometre from shore.

The Bay is a C-shaped inlet of the Irish Sea and is about 10 kilometres wide along its north-south base, and 7 km in length to its apex at the centre of the city of Dublin; stretching from Howth Head in the north to Dalkey Point in the south. North Bull Island is situated in the northwest part of the bay, where one of two major inshore sandbanks lie, and features a 5 km long sandy beach, Dollymount Strand, fronting an internationally recognised wildfowl reserve. Many of the rivers of Dublin reach the Irish Sea at Dublin Bay: the River Liffey, with the River Dodder flow received less than 1 km inland, River Tolka, and various smaller rivers and streams.

Dublin Bay FAQs

There are approximately ten beaches and bathing spots around Dublin Bay: Dollymount Strand; Forty Foot Bathing Place; Half Moon bathing spot; Merrion Strand; Bull Wall; Sandycove Beach; Sandymount Strand; Seapoint; Shelley Banks; Sutton, Burrow Beach

There are slipways on the north side of Dublin Bay at Clontarf, Sutton and on the southside at Dun Laoghaire Harbour, and in Dalkey at Coliemore and Bulloch Harbours.

Dublin Bay is administered by a number of Government Departments, three local authorities and several statutory agencies. Dublin Port Company is in charge of navigation on the Bay.

Dublin Bay is approximately 70 sq kilometres or 7,000 hectares. The Bay is about 10 kilometres wide along its north-south base, and seven km in length east-west to its peak at the centre of the city of Dublin; stretching from Howth Head in the north to Dalkey Point in the south.

Dun Laoghaire Harbour on the southside of the Bay has an East and West Pier, each one kilometre long; this is one of the largest human-made harbours in the world. There also piers or walls at the entrance to the River Liffey at Dublin city known as the Great North and South Walls. Other harbours on the Bay include Bulloch Harbour and Coliemore Harbours both at Dalkey.

There are two marinas on Dublin Bay. Ireland's largest marina with over 800 berths is on the southern shore at Dun Laoghaire Harbour. The other is at Poolbeg Yacht and Boat Club on the River Liffey close to Dublin City.

Car and passenger Ferries operate from Dublin Port to the UK, Isle of Man and France. A passenger ferry operates from Dun Laoghaire Harbour to Howth as well as providing tourist voyages around the bay.

Dublin Bay has two Islands. Bull Island at Clontarf and Dalkey Island on the southern shore of the Bay.

The River Liffey flows through Dublin city and into the Bay. Its tributaries include the River Dodder, the River Poddle and the River Camac.

Dollymount, Burrow and Seapoint beaches

Approximately 1,500 boats from small dinghies to motorboats to ocean-going yachts. The vast majority, over 1,000, are moored at Dun Laoghaire Harbour which is Ireland's boating capital.

In 1981, UNESCO recognised the importance of Dublin Bay by designating North Bull Island as a Biosphere because of its rare and internationally important habitats and species of wildlife. To support sustainable development, UNESCO’s concept of a Biosphere has evolved to include not just areas of ecological value but also the areas around them and the communities that live and work within these areas. There have since been additional international and national designations, covering much of Dublin Bay, to ensure the protection of its water quality and biodiversity. To fulfil these broader management aims for the ecosystem, the Biosphere was expanded in 2015. The Biosphere now covers Dublin Bay, reflecting its significant environmental, economic, cultural and tourism importance, and extends to over 300km² to include the bay, the shore and nearby residential areas.

On the Southside at Dun Laoghaire, there is the National Yacht Club, Royal St. George Yacht Club, Royal Irish Yacht Club and Dun Laoghaire Motor Yacht Club as well as Dublin Bay Sailing Club. In the city centre, there is Poolbeg Yacht and Boat Club. On the Northside of Dublin, there is Clontarf Yacht and Boat Club and Sutton Dinghy Club. While not on Dublin Bay, Howth Yacht Club is the major north Dublin Sailing centre.

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