Bottlenose dolphins in Florida, new study


This video says about itself:

Bottlenose Dolphin (Tursiops truncatus)

* Family: Delphinidae,

* Genus: Tursiops,

* Class: Mammalia,

* Order: Cetacea,

* Type: Mammal,

* Diet: Carnivore,

* Average life span in the wild: 45 to 50 years,

* Size: 10 to 14 ft (3 to 4.2 m),

* Weight: 1,100 lbs (500 kg),

* Group name: Pod,

**Did you know? Bottlenose dolphins have been observed to breach up to 16 feet (4.9 meters) out of the water, landing with a splash on their back or side.

More info here.

From Wildlife Extra:

Florida dolphins use their own forms of social media to choose their friends

Just like human beings, dolphins form highly complex and dynamic social networks, according to a recent study by scientists at Harbor Branch Oceanographic Institute (HBOI) at Florida Atlantic University.

The researchers studied the interactions between some 200 bottlenose dolphins in the Indian River Lagoon (IRL), a 156-mile long estuary located on Florida’s east coast.

They discovered how the dolphins mingle and with whom they spend their time. They may not have Facebook or Twitter but they do have association patterns as well as movement behaviour and habitat preferences.

The IRL lagoon is long and narrow and composed of three distinct water bodies; Mosquito Lagoon, Banana River, and the Indian River. There are five inlets and one lock (Cape Canaveral lock) connecting the IRL to the Atlantic Ocean.

Researchers from HBOI have been conducting photo identification studies of IRL bottlenose dolphins since 1996, identifying more than 1,700 individual dolphins.

In their paper recently published in the journal Marine Mammal Science, the team found that individual dolphins exhibited both preference and avoidance behaviour – so just like humans, they have dolphins they like and associate with and ones they avoid.

The study also found that IRL dolphins clustered into groups of associated animals, or “communities,” that tended to occupy discrete core areas along the north-south axis of the lagoon system.

“One of the more unique aspects of our study was the discovery that the physical dimensions of the habitat, the long, narrow lagoon system itself, influenced the spatial and temporal dynamics of dolphin association patterns,” says Elizabeth Murdoch Titcomb, research biologist at HBOI who worked on the study.

“For example, communities that occupy the narrowest stretches of the Indian River Lagoon have the most compact social networks, similar to humans who live in small towns and have fewer people with whom to interact.”

In addition to providing a unique glimpse into dolphin societies, the study provides important insight and knowledge on how dolphins organise themselves, who they interact with and who they avoid, as well as when and where.

It also gives scientists and resource managers the roadmap needed to understand how dolphin populations perceive and use their environment, and how social networks will influence information transfer and potentially breeding behaviour and disease transmission.

Fukushima disaster killing dolphins


This video from Japan says about itself:

Fukushima Update -150 Dolphins Dead After Beaching Themselves in Japan

11 April 2015

Beached dolphins in Japan were found covering a six-mile stretch of beach in the Ibaraki region Friday morning. Nearly 150 of the cetacean mammals had beached themselves in the Ibaraki Prefecture along the eastern coast of the main island of Honshu. Less than one third of the dolphins were rescued.

This video says these beached animals were melon-headed whales.

By Royce Christyn:

Dead Dolphins In Fukushima Stranding Found With White Radiated Lungs

1 week ago

Japanese scientists are saying they have never seen anything like what they discovered after autopsying a massive group of dolphins that ended up dead after being discovered stranded on a beach near the site of the 2011 Fukushima disaster.

Their lungs were white, which, according to scientists is an indication of loss of blood flow to the organs which is an indication of radiation poisoning.

The translated article comes from EneNews.

Scottish common dolphin news


This video from the USA is called Short-Beaked Common-Dolphin (Delphinus delphis) off Southern California Coast.

From Wildlife Extra:

Double the sightings of common dolphins in the Hebrides

There has been a substantial increase in common dolphin numbers off western Scotland in recent years, and this is to be studied by Hebridean Whale and Dolphin Trust in a new season of marine research expeditions beginning in May.

The Trust’s encounter rate with common dolphins has more than doubled over the past 12 years. The causes – and broader effects on the marine environment and other species – are still unclear.

Common dolphins come to the Hebrides each spring to take advantage of seasonal food stocks. They are gregarious, often approaching boats to bow-ride and play in the wake, and are smaller than the region’s resident bottlenose dolphins.

The species also travels in large groups – sometimes forming super-pods of thousands of individuals.

The finding of increased numbers – recently presented to the European Cetacean Society – has emerged from the charity’s unique long-term monitoring of whales, dolphins and porpoises in the Hebrides.

Hebridean Whale and Dolphin Trust is now recruiting volunteers to work alongside marine scientists in its annual summer surveys, which it hopes will shed further light on the dramatic changes.

“An increase in common dolphins means that those wishing to encounter dolphins in the wild are in luck – but further research is needed to explain why this is happening, the extent to which this has been caused by human activity, and the implications for other cetacean species,” says Dr Conor Ryan, Sightings and Strandings Officer at Hebridean Whale and Dolphin Trust.

Despite their name, common dolphins – known in Gaelic as leumadair or ‘jumper’ – were once only occasionally seen in the Hebrides, preferring more southern waters generally warmer than 10°C.

With climate change causing sea surface temperatures in the Hebrides to rise at a rate of 0.5°C per decade, it appears that such warmer water species are starting to colonise new areas in the north or closer to shore.

Yet even as this shift potentially creates new opportunities for common dolphins, it may be generating competition for food with other dolphin species or seabirds.

One predicted consequence of warming seas is colder-water species such as the white beaked dolphin being forced to retreat further north.

So far, the Hebridean Whale and Dolphin Trust has found no evidence of displacement of the white beaked dolphin – but continued monitoring is needed to establish whether or not the influx of common dolphins is having a negative effect on such species.

“Dedicated volunteers onboard our specialised research yacht, Silurian, have enabled us to build up a unique and valuable database, enabling researchers to examine changes in cetacean populations – and providing vital data for protecting these species and their habitats, including in the recent designation of Scottish Marine Protected Areas,” says Kerry Froud, the Trust’s Biodiversity Officer.

“Our research expeditions depend on volunteers. In return, they offer the opportunity of a lifetime to contribute to a better understanding of cetaceans and basking sharks, whilst enjoying the beautiful scenery of Scotland’s west coast and experiencing exhilarating sailing.”

For more information, email volunteercoordinator@hwdt.org, call 01688 302620 or see www.hwdt.org.

Dolphins in Ireland, video


This 10 February 2015 video is about a pod of common dolphins near Cork, Ireland.

Famous dolphin swimming in Scotland


This video says about itself:

26 April 2014

A lone bottlenose dolphin – This is a well known dolphin that has been named Clet. He is well known and was first documented in France. In recent years he has spent time on the South Devon, Cornish, Isles of Scilly and Welsh coasts. It is important to be very careful when around lone bottlenose dolphins, they often choose to interact with boats, but poor/thoughtless boat handling can lead to them being severely injured or even killed. It is not advisable to swim with them as they are much more powerful than you and have a habit of trapping people in the water. Always keep in mind that they are not your plaything.

From Wildlife Extra:

Internationally famous dolphin turns up in Scotland

An internationally famous solitary Bottlenose Dolphin known as Clet has been identified making a surprise appearance in Scotland’s Sound of Mull, according to researchers from the Hebridean Whale and Dolphin Trust.

The rare sighting of a lone bottlenose dolphin following a ferry between Oban and the Isle of Mull triggered some rapid detective work at the conservation charity.

Bottlenose dolphins are not unusual in the Hebrides, even during winter – but the species usually occurs in small groups, with individuals rarely being seen alone.

By studying the dolphin’s distinctively scarred dorsal fin and using photo identification techniques, the Trust’s experts identified the animal as one that made international headlines with its unusual behaviour when it was last seen in September. That was in Galway in Ireland, some 600 kilometres away from the Sound of Mull.

“To our knowledge, this is the first time that Clet has been recorded in Scotland, and in fact this is the furthest north he has been recorded to date,” says Dr Conor Ryan, Sightings Officer at Hebridean Whale and Dolphin Trust.

“Bottlenose dolphins are usually considered to be resident to certain areas, so long-distance international movements such as this one has made challenge our understanding of this species, and also challenge our ability to protect them using Marine Protected Areas alone.”

The male dolphin was named by locals from Cap Sizun, Brittany in France, where he habitually follow[ed] the fishing boats between 2008 and 2010. He then travelled to Cornwall, Devon and Wales before appearing in West Cork in Ireland and spent several weeks interacting with boats.

The Irish Whale and Dolphin Group then recorded his movements along Ireland’s west coast to Valentia, County Kerry.

The last recorded sighting of Clet was on 28 September 2014 at Inis Óirr off Galway Bay. Although not confirmed, he was thought to be responsible for a dolphin attack on a group of swimmers in Salthill, Galway.

The RNLI ensured that the swimmers were able to get to shore without harm, but unfortunately the incident resulted in some sensational news headlines.

Solitary dolphins such as Clet do not pose a threat to people in boats, but can be aggressive towards swimmers.

The biggest danger to solitary dolphins is injury from boats, as the animals appear to seek out vessels to interact with. The deep gash on Clet’s dorsal fin may be from coming to close to boat propellers.

Pádraig Whooley, Sightings Officer for the Irish Whale and Dolphin Group, says: “We think it’s remarkable that Clet’s movements can be tracked to the Irish south and west coasts from France via English and Welsh waters, using images from the general public.

“The addition of Scotland after a two-month interval brings his known tally of passport stamps to five countries and counting, and shows the need for international collaboration when trying to monitor these highly mobile marine mammals.”

Wildlife photographer Nic Davies, who recorded Clet close to shore from Craignure on the Isle of Mull this week, said: “I was out photographing otters when I heard a loud blow sound just out from the shore, and then I spotted the dolphin heading at speed towards a departing ferry.”

Clet may remain in the Sound of Mull area for weeks or even months, as he has done in other areas. Hebridean Whale and Dolphin Trust is asking boat owners to be respectful and to give Clet the space he needs.

That way, hopefully the dolphin will continue to enthral onlookers from the shore and from the ferries he has been bow riding in the Sound of Mull.

Hebridean Whale and Dolphin Trust asks the public to report sightings of all whales, dolphins and porpoises – collectively known as cetaceans – and basking sharks at www.hwdt.org.

The charity’s extensive Community Sightings Network uses such sightings as a key way of strengthening understanding of the local marine environment and of these spectacular animals.