The video showcases the migration patterns of various marine creatures, focusing on how ocean currents and environmental factors influence their movements. It explores the fascinating life cycle of jellyfish and their growing populations due to declining predators, emphasizing their potential role in supporting fish stocks.

A journey to the mid-Atlantic ridge uncovers the dynamic ecosystem around seamounts, highlighting how nutrient-rich waters create thriving marine life. The video documents interactions among species such as barracuda, triggerfish, and blue sharks, alongside the dramatic feeding behaviors of whales, hand-in-hand with seabirds and dolphins, capturing the intricate food web in action.

Main takeaways from the video:

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Marine ecosystems are deeply influenced by geographic features like seamounts.
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Whale hunting tactics demonstrate their key role in marine food chains.
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Preserving marine habitats is crucial in sustaining diverse marine species.
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Key Vocabularies and Common Phrases:

1. deliberately [dɪˈlɪbərətli] - (adverb) - Consciously and intentionally; on purpose. - Synonyms: (intentionally, purposefully, knowingly)

Others quite deliberately to where there is food.

2. elemental [ˌɛlɪˈmɛntl] - (adjective) - Primary or basic; relating to the essential aspects of something. - Synonyms: (basic, fundamental, essential)

I'm drawn to the elemental beauty of jellyfish.

3. seamount [ˈsiːˌmaʊnt] - (noun) - A mountain rising from the ocean seafloor that does not reach above the water's surface. - Synonyms: (undersea mountain, underwater peak, submarine hill)

These underwater mountains are known as seamounts and they can be hugely fertile areas.

4. buoyancy [ˈbɔɪənsi] - (noun) - The ability or tendency to float in water or air or some other fluid. - Synonyms: (floatability, lightness, ability to float)

Gases burst from their swim bladders which control their buoyancy.

5. circumnavigated [ˌsɜrkəmˈnævɪˌɡeɪtɪd] - (verb) - Traveled all the way around something, especially the Earth. - Synonyms: (navigate, sail around, traverse)

These blue sharks have more than likely circumnavigated the North Atlantic.

6. predatory [ˈprɛdəˌtɔri] - (adjective) - Relating to animals preying naturally on others. - Synonyms: (carnivorous, hunting, rapacious)

Unlike basking sharks, most others are predatory sharks, that is, they have teeth and strong jaws to eat fish.

7. articulated [ɑːrˈtɪkjuleɪtɪd] - (adjective) - Consisting of segments united by joints for motion. - Synonyms: (jointed, connected, segmented)

That's two fully loaded articulated trucks.

8. intimidating [ɪnˈtɪmɪˌdeɪtɪŋ] - (adjective) - Having a frightening or threatening effect. - Synonyms: (daunting, frightening, unnerving)

At up to 10 meters and 5 tonnes, these are intimidating animals to meet in the open ocean.

9. Dms (Dimethyl Sulfide) [ˌdaɪˈmiːθəl ˈsʌlfaɪd] - (noun) - A sulfur compound emitted from the ocean, known to affect the smell and is used by some marine species for navigation. - Synonyms: (sulfur compound, ocean chemical, marine scent)

Phytoplankton give off a gas known as dimethyl sulfide, DMS and seabirds have an incredible sense of smell.

10. plankton [ˈplæŋktən] - (noun) - The small and microscopic organisms drifting or floating in the sea or freshwater, consisting chiefly of minute plants. - Synonyms: (microorganisms, aquatic organisms, marine life)

Living for just a few months, they strive to reach maturity, chasing the bounty of the early summer plankton bloom

🔴 LIVE - Exploring the North Atlantic - North Atlantic - The Dark Ocean - BBC Earth

Ocean creatures migrate, some to wherever the winds and currents bring them. Others quite deliberately to where there is food. And they can breed and sometimes feed on other animals. I'm drawn to the elemental beauty of jellyfish. We're seeing increasing numbers of them in recent years, possibly due to a decline in predators who hunt them. Like turtles, they abound in our summer waters. Drawn to the life giving energy of the sun.

Barrel jellyfish are the largest in our waters. They can provide shelter for juvenile fish. And because of this, scientists now believe that the increase in the number of jellyfish may actually help fish stocks. Jellyfish are inescapably drawn to the sun. Living for just a few months, they strive to reach maturity, chasing the bounty of the early summer plankton bloom. Like most creatures, they appear to have two life goals. To reach maturity and reproduce. I doubt with this beautiful sh of compass. Jellyfish. In our warm summer waters they have come together to breed.

I ventured here to the mid Atlantic Ridge in search of fin whales. I believe they may come here to feed. These underwater mountains are known as seamounts and they can be hugely fertile areas. Because of their shape in the middle of the ocean, they cause nutrient rich water to well up from the deep, creating oasis of life in the open ocean. In places they rise within a few meters of the surface. In other areas they May Peak at 40 or 50 meters deep.

I dive in a seamount almost 100 kilometers. Maniland Shoals of barracuda gather here to feed on smaller fish, as do these trigger fish. They even try a bite of me shs a small snipe. Fish gather in numbers and squeeze together to form bait balls. The larger trigger fish, barracuda and other smaller fish arrive to feed on this open ocean bounty. Blue sharks migrate here annually because they know there'll be fish in the relative barrenness of the open ocean. The seamounts of the Mid Atlantic ridge are an oasis of life for sea creatures.

It's funny. The sea can be so much more stable at depth than it is at the surface. The whales can sense the presence of the herring and dive in pursuit. Holding my breath, I dive to film the action. They're not easy to find in the darkness. Tiny bubbles rise from the deep like a gas. Then I see a cloud of them and a course like a massive shoal of fish emerge from the deep. Thousands and thousands of herring killer whales have found them and driven them up from the deep.

With their sudden change of pressure. Gases burst from their swim bladders which control their buoyancy. The whales work together to Squeeze the fish into an even tighter ball. Gulls have spotted the killer whales push the herring up, but the humpbacks will be there to profit from this. The whales flick their tails into the herring shoal to stun the fish. The animals briefly surface, only to catch breath. Birds have learned to be in the right place. But then the humpbacks, with their enormous mouths and cooperation, take the lion's share. And after less than 30 minutes, it's all over, and the animals leave to search for more herring shoals.

In Sunny Atlantic waters 30km south of Ireland, I'm searching for open ocean sharks. Sadly, most all of the 40 species of sharks in Irish waters are now in trouble. Unlike basking sharks, most others are predatory sharks, that is, they have teeth and strong jaws to eat fish. They're curious animals. Blue sharks are the most common predatory shark in Irish waters. They are highly evolved hunters in their own ocean environment. The pores around their heads are sensors filled with gel that can sense the tiniest movement of fish or other prey. And humans are of no interest to these animals.

They migrate all around the North Atlantic, visiting Ireland in the summer months to feed, then traveling to these oars and America. In the last decade, however, their numbers have dramatically fallen because of chronic overfishing. These blue sharks have more than likely circumnavigated the North Atlantic. They migrate with the seasons. I guess you could say they live by the seasons. And they come into Irish waters in mid to late summer when the water warms up a bit, to feed. I guess, you know, sharks have been around for 400 million years.

There was a shark fossil found in the burn dated to 300 million years ago. But what I find incredible is that about a hundred million years ago, most shark species actually stopped evolving because more than likely, they'd reached the perfect form to hunt and to live and survive in the ocean. They've likely come into our bays and our shallow waters for hundreds, if not thousands of years. Then I can find no credible record of a shark attacking anybody in Ireland or any place close. But they're really curious. They come right up to the camera. What a privilege to share the water with these creatures. Look at this one.

Absolutely beautiful animals. On St Brendan's voyage, the monks wrote of having arrived at a coagulated sea, a place where the water appeared oily and absolutely no wind. All they could do was wait. I go for a swim in clear blue water. Salps are a chain of creatures living together. They suck seawater through their bodies to filter plankton. And this also Propels them forwards. A mother in very small calf. This doesn't feel like Ireland. We're here finally, on the edge of the continental shelf, 250 kilometers southwest of Ireland.

This place is called the Porcupine Seabite. What's incredible about here is that the seabed as you come west of Ireland, it's about 200 meters deep. And then suddenly it just drops down to a thousand meters, then 2000 meters and then eventually to 5000 meters. The abyssal plain that's more than half the height of Mount Everest. And you can see the conditions are just. I mean, it's surreal. It's absolutely beautiful here. And the water, it's blue, crystal clear and blue. Not like the coastal waters we get in Ireland, which are green because there's so much organic matter and plankton in there.

Here it's blue and we can see for maybe 15 meters. What we're hoping to find here is the fin whale. We've managed to film them in the inshore waters close to Ireland and other parts of the North Atlantic. And if we can find them here and maybe film or photograph the back of their heads, the chevron and the blaze pattern that's unique to every individual fin whale, a bit like our fingerprints are to us, then maybe, maybe we can confirm some migration routes of these animals or at the very least show the different areas where they're feeding and they're moving around and try to protect them in all those areas and the areas in between.

Right here on the edge of the continental shelf to the west of Ireland, it's one of the most fertile places in all of the North Atlantic. And this is where they're likely to be. For thousands of years, shoals of herring had gathered in the small bays of our North Atlantic coast. For several winters now, I've been trying unsuccessfully to find shoals of herring in our inshore waters. December is the key month when shoals would aggregate in these protected bays before spawning and also when they were fished. The cold water at this time of year helps with spawning.

The further north we go, the colder and darker it gets. But this can lead to more fertile waters. In the fishing port of Killibegs, County Donegal, I go to sea like many a man before in search of these herring shoals. I'm using scuba, as herring usually stay deeper and these are cold, dark waters. At 20 meters depth, it's more or less dark. Looking down, after a few days effort, I sense movement and look towards the sun. Harry. Thousands of them. They scatter from my dive bubbles. And seem to move in sync.

They never allow me to get close. It's wonderful to find some herring after several winters of trying. But what a fabulous fish they are. The old folk call them the king of fishes. But they were also hugely important for the ocean ecosystem, because herring feed on plankton and fish larvae and effectively convert that energy into the rich, fatty fish that they become. But I have to wonder what these babies looked like maybe 100 years ago, when the herring shoals were reputed to be, you know, two kilometers long, and what the wider ocean looked like at that time compared to now.

West of the clear coast, some ocean giants have arrived. I wonder what St. Brendan and the early seafarers in their open boats would have made of these creatures. Basking sharks. I can only imagine how many sharks they would have encountered in the Atlantic waters a thousand years ago. Did the sharks terrify them? Or did they perhaps spend time getting a sense of the animals and their quiet nature? We see basking sharks for maybe a week or two every year in sunlit spring waters when they arrive to feed on plankton, and then, just sporadically over the summer, they then disappear in early autumn for another eight months.

Where do they go? We're really not sure. There are almost no winter sightings of basking sharks in our inshore waters. They appear to be gentle giants, but we really only see them when they're feeding on plankton at the water's surface, gliding gently to catch as much plankton as they can, filtering it from the seawater with their gill rakers. But I'm not convinced. They're just docile creatures. At up to 10 meters and 5 tonnes, these are intimidating animals to meet in the open ocean.

It's my chance to document these animals. It would be my first time in years of trying to film a fin whale underwater. Being in the water with whales this size is something I've learned to do safely over many years now. But it's still scary. I think about my ancestors and wonder what they would have made of this. The fin whale swallows an enormous mouthful of sprat and dives, coming within a few short meters of me. An awesome animal. Water visibility is justified. Few meters. What an incredible moment.

To my knowledge, it's the first time anyone has filmed a fin whale underwater in Ireland. And then a humpback whale. But this is no ordinary humpback whale. I can recognize from the tail and dorsal fins that this is Boomerang, a whale that has been coming to our south coast for 20 years now and for some reason always associates with Fin whales. He blows a single line of bubbles, perhaps to herd the sprat, and lunges from below. The water usually blow circles of bubbles to entrap fish. But this animal is just blowing a line.

Perhaps he's competing with the fin whales. Again and again they rise, one giant mouth after another. Four fin whales feeding. Oh, my God. They're 20 meters and up to 80 tons weight. That's two fully loaded articulated trucks. 16 elephants. Holding my breath, I free dive to the action. One whale swims under his shoulder sprat, which drives the fish up to the surface. Common dolphins have also found this shoal, but the minkes are the dominant force here. I keep my distance so as not to interfere.

The minkies sometimes blow a short line of bubbles near the shore of sprat. I've never seen this behavior before. It seems the whales could be using the bubbles to partly herd the sprat. After half an hour, it's all over. The birds take off, perhaps searching for more shoals. Oh, my gosh. You can actually smell the fertile areas in the ocean because phytoplankton give off a gas known as dimethyl sulfide. DMS and seabirds have an incredible sense of smell, and I wonder if they use that to find the fertile areas in the ocean and the shoals of fish.

Maybe even whales and other animals could follow concentrated flocks of seabirds feeding. There's so much that we don't know still, but when you think, you know, a shoulder fish might be 20 meters wide in an area of the ocean, it could be tens of thousands of square kilometers. It's quite a feat for these animals to find them. So maybe the sense of smell is what's driving the whole thing. But what a wonderful scene. Thousands of seabirds, common dolphins and more than a dozen minke whales, all feeding on shoals of sprat and sand eel, who themselves are here to feed on the plankton.

Marine Life, Ecosystem, Migration, Science, Technology, Inspiration, Bbc Earth