Showing posts with label dolphin. Show all posts
Showing posts with label dolphin. Show all posts

Friday, January 5, 2024

FOSSILS OF THE NORTH SEA

A lovely 12 cm creamy orange Bottlenose Dolphin, Tursiops sp. lumbar vertebrae found in the Brown Bank area of the North Sea, one of the busiest seaways in the world.

Bottlenose dolphins first appeared during the Miocene and swam the shallow seas of this region. We still find them today in warm and temperate seas worldwide though unlike narwhal, beluga and bowhead whales, Bottlenose dolphins avoid the Arctic and Antarctic Circle regions. 

Their name derives from the Latin tursio (dolphin) and truncatus for their characteristic truncated teeth

We find their remains in the sediments of the North Sea. There are two known fossil species from Italy that include Tursiops osennae (late Miocene to early Pliocene) from the Piacenzian coastal mudstone, and Tursiops miocaenus (Miocene) from the Burdigalian marine sandstone.

Many waterworn vertebrae from the Harbour Porpoise Phocoena sp., (Cuvier, 1816), Bottlenose dolphin Tursiops sp. (Gervais, 1855), and Beluga Whale, Delphinapterus sp. (Lacépède‎, 1804‎) are found by fishermen as they dredge the bottom of the Brown Bank, one of the deepest sections of the North Sea.  

The North Sea is a sea of the Atlantic Ocean located between the United Kingdom, Denmark, Norway, Germany, the Netherlands, Belgium and France. An epeiric sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north.

The fishermen use small mesh trawl nets that tend to scoop up harder bits from the bottom. This technique is one of the only ways this Pleistocene and other more recent material is recovered from the seabed, making them relatively uncommon. The most profitable region for fossil mammal material is in the Brown Bank area of the North Sea. I've circled this area on the map below to give you an idea of the region.

Brown Bank, North Sea, Pleistocene Dredging Area
In May 2019, an 11-day expedition by European scientists from Belgium and the United Kingdom was undertaken to explore three sites of potential geologic and archaeologic interest in the southern North Sea. 

It has long been suspected that the southern North Sea plain may have been home to thousands of people, and chance finds by fishermen over many decades support this theory. 

A concentration of archaeological material, including worked bone, stone and human remains, has been found within the area around the Brown Bank, roughly 100 km due east from Great Yarmouth and 80 km west of the Dutch coast. The quantities of material strongly suggest the presence of a prehistoric settlement. As such the Brown Bank provides archaeologists with a unique opportunity to locate a prehistoric settlement in the deeper and more remote areas of the North Sea, known today as Doggerland.

Until sea levels rose at the end of the last Ice Age, between 8-10,000 years ago, an area of land connected Great Britain to Scandinavia and the continent.  It has long been suspected that the southern North Sea plain was home to thousands of people, and chance finds by fishermen over many decades support this theory. 

Over the past decades a concentration of archaeological material, including worked bone, stone and human remains, has been found within the area around the Brown Bank, roughly 100 km due east from Great Yarmouth and 80 km west of the Dutch coast. 

The quantities of material strongly suggest the presence of a prehistoric settlement. 

As such the Brown Bank provides archaeologists with a unique opportunity to locate a prehistoric settlement in the deeper and more remote areas of the North Sea, known today as Doggerland.

Prospecting for such a settlement within the North Sea is a challenging activity.  Multiple utilities cross the area, bad weather is frequent, and visibility underwater is often limited.  Given these challenging conditions, researchers on the Belgian vessel, RV Belgica, used acoustic techniques and physical sampling of the seabed to unravel the topography and history of the areas chosen for the survey.  

During the survey, the team used a novel parametric echosounder from the Flanders Marine Institute (VLIZ). This uses sonar technology to obtain images of the sub-bottom with the highest possible resolution and was combined with the more traditional “sparker” seismic source to explore deeper sediments.  On the Brown Bank, the Belgica also deployed a grab and a Gilson dredge for sampling near-surface stratigraphy. Video footage was collated using VLIZ’s dedicated video frame and a simpler GoPro mounted on the Gilson dredge. A video showing the equipment in operation on the expedition can be seen at https://youtu.be/sGKfyrDCtmw

Additional reading: http://www.vliz.be/en/press-release/update-research-prehistoric-settlements-North-Sea

Wednesday, September 7, 2022

PLAYFUL PORPOISE: K'ULUT'A

Dall's Porpoise
These delightfully friendly and super smart fellows are Dall's porpoise. 

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, a blowhole is known as a ka̱'was, whether on a dolphin (porpoise) or whale and a porpoise is known as a k̓ulut̕a

In the Pacific Northwest, we see many of their kind — the shy, blunt-nosed harbour porpoise, the social and herd-minded Pacific white-sided dolphin and the showy and social Dall's porpoise.  

Of these, the Dall's porpoise is a particular favourite. These speedy muscular black and white showboats like to ride the bow waves of passing boats — something they clearly enjoy and a thrill for everyone on board the vessel. If you slow down, they will often whisk away, but give them a chance to race you and they may stay with you all afternoon. 

Harbour porpoises are the complete opposite. You are much more likely to see their solid black bodies and wee fin skimming through the waves across the bay as they try to avoid you entirely. Harbour porpoise prefer quiet sheltered shorelines, often exploring solo or in small groups of two or three. 

We sometimes see these lovely marine mammals represented in the art of the First Nations in the Pacific Northwest, particularly along the coast of British Columbia. You will know them from their rather rectangular artistic depiction with a pronounced snout and lacking teeth (though they have them) used to portray killer whales or orca. 

As a group, even considering the shy Harbour porpoise, these marine mammals are social and playful. Humpback whales are fond of them and you will sometimes see them hanging out altogether in the bays and inlets or near the shore. 

They are quite vocal, making lots of distinctive and interesting noises in the water. They squeak, squawk and use body language — leaping from the water while snapping their jaws and slapping their tails on the surface. They love to blow bubbles, will swim right up to you for a kiss and cuddle. 

Each individual has a signature sound, a whistle that is uniquely their own. They use these whistles to tell one of their friends and family members from another.

Porpoise are marine mammals that live in our world's oceans. If it is salty and cold, you can be pretty sure they are there. They breathe air at the surface, similar to humans, using their lungs and inhaling and exhaling through a blowhole at the top of their heads instead of through their snouts. 



Saturday, May 14, 2022

PORPOISE: KULUT'A

Dall's Porpoise
These delightfully friendly and super smart fellows are Dall's porpoise. 

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, a blowhole is known as a ka̱'was, whether on a dolphin (porpoise) or whale and a porpoise is known as a k̓ulut̕a

In the Pacific Northwest, we see many of their kind — the shy, blunt-nosed harbour porpoise, the social and herd-minded Pacific white-sided dolphin and the showy and social Dall's porpoise.  

Of these, the Dall's porpoise is a particular favourite. These speedy muscular black and white showboats like to ride the bow waves of passing boats — something they clearly enjoy and a thrill for everyone on board the vessel. If you slow down, they will often whisk away, but give them a chance to race you and they may stay with you all afternoon. 

Harbour porpoises are the complete opposite. You are much more likely to see their solid black bodies and wee fin skimming through the waves across the bay as they try to avoid you entirely. Harbour porpoise prefer quiet sheltered shorelines, often exploring solo or in small groups of two or three. 

We sometimes see these lovely marine mammals represented in the art of the First Nations in the Pacific Northwest, particularly along the coast of British Columbia. You will know them from their rather rectangular artistic depiction with a pronounced snout and lacking teeth (though they have them) used to portray killer whales or orca. 

As a group, even considering the shy Harbour porpoise, these marine mammals are social and playful. Humpback whales are fond of them and you will sometimes see them hanging out altogether in the bays and inlets or near the shore. 

They are quite vocal, making lots of distinctive and interesting noises in the water. They squeak, squawk and use body language — leaping from the water while snapping their jaws and slapping their tails on the surface. They love to blow bubbles, will swim right up to you for a kiss and cuddle. 

Each individual has a signature sound, a whistle that is uniquely their own. They use these whistles to tell one of their friends and family members from another.

Porpoise are marine mammals that live in our world's oceans. If it is salty and cold, you can be pretty sure they are there. They breathe air at the surface, similar to humans, using their lungs and inhaling and exhaling through a blowhole at the top of their heads instead of through their snouts. 



Thursday, September 16, 2021

NORTH SEA DOLPHIN VERTEBRAE: HATSAWE'

A lovely 17 cm deep chocolate brown fossil Bottlenose Dolphin, Tursiops sp. vertebrae found in the Brown Bank area of the North Sea, one of the busiest seaways in the world.

Bottlenose dolphins first appeared during the Miocene and swam the shallow seas of this region. 

We still find them today in warm and temperate seas worldwide though unlike narwhal, beluga and bowhead whales, Bottlenose dolphins avoid the Arctic and Antarctic Circle regions. 

Their name derives from the Latin tursio (dolphin) and truncatus for their characteristic truncated teeth. In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest — and part of my heritage — dolphin are hatsawe'. 

On the north end of Vancouver Island, we have pods of 50-100 Pacific White-Sided dolphins, cousins of the Bottlenose, who frolic and jump alongside your boat if you are out on the water. Similar to their southern cousins, Pacific White-Sided dolphins feed on salmon, herring, pilchards, anchovies, needlefish, squid, shrimp, pollock, sablefish, rock cod and other small fish — a tasty menu that reflects my own. 

Bottlenose dolphins are the most common dolphin species in the Pacific Northwest but do not often venture farther north than Oregon. We have two populations of bottlenose dolphins here, the California coastal population and those that prefer to live offshore. It is as exciting to see them playing in our oceans today as it is to see the fossil remains of their ancestors from the Brown Bank sediments of the North Sea. 

Brown Bank, North Sea, Pleistocene Dredging Area
There are two known fossil species from Italy that include Tursiops osennae (late Miocene to early Pliocene) from the Piacenzian coastal mudstone, and Tursiops miocaenus (Miocene) from the Burdigalian marine sandstone.

Many waterworn vertebrae from the Harbour Porpoise Phocoena sp., (Cuvier, 1816), Bottlenose dolphin Tursiops sp. (Gervais, 1855), and Beluga Whale, Delphinapterus sp. (Lacépède‎, 1804‎) are found by fishermen as they dredge the bottom of the Brown Bank, one of the deepest sections of the North Sea.  

The North Sea is a sea of the Atlantic Ocean located between the United Kingdom, Denmark, Norway, Germany, the Netherlands, Belgium and France. An epeiric sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north.

The fishermen use small mesh trawl nets that tend to scoop up harder bits from the bottom. This technique is one of the only ways this Pleistocene and other more recent material is recovered from the seabed, making them relatively uncommon. The most profitable region for fossil mammal material is in the Brown Bank area of the North Sea. I have circled this area on the map below to give you an idea of the region.

Found by Fishermen in the North Sea. Using a small mesh trawl net is often the only time these come up from the seabed, hence they are uncommon. ​Size: 17.0cm. Age: 30-40,000 Years old.