from the world's big
The ocean's largest shark relies on vision more than previously believed.
- Japanese researchers discovered that the whale shark has "tiny teeth"—dermal denticles—protecting its eyes from abrasion.
- They also found the shark is able to retract its eyeball into the eye socket.
- Their research confirms that this giant fish relies on vision more than previously believed.
A. Anterior view of the whale shark, showing the locations of the eye (arrows). Note that whale shark eye is well projected from the orbit. Photo was taken in the sea near Saint Helena Island. B. Close-up view of the left eye of a captive whale shark (Specimen A).<p>Considering their dietary habits, vision was not thought be that important for whale sharks. This species is unique for not having any sort of eyelid or protective mechanism—until now, that is. Not only do dermal denticles protect their vision, the team, led by Taketeru Tomita, discovered that whale sharks have another trick:</p><p style="margin-left: 20px;">"We also demonstrate that the whale shark has a strong ability to retract the eyeball into the eye socket."</p><p>The researchers studied these massive sharks in an aquarium, offering them a rare look at one of the ocean's largest fish (They also studied deceased sharks). The eye denticle is different from the rest of the scales covering their body: they are designed for abrasion resistance, not ocean stealth. </p><p style="margin-left: 20px;">"The covering of the eye surface with denticles in the whale shark is probably useful in reducing the risk of mechanical damage to the eye surface." </p><p>Despite their massive size, whale sharks have relatively small eyes, measuring less than 1 percent of their total length. Their brain's visual center is also relatively small. With this discovery, the researchers realized vision plays a more important role than previously assumed. </p><p style="margin-left: 20px;">"The highly protected features of the whale shark eye, in contrast to the traditional view, seems to suggest the importance of vision in this species. Interestingly, Martin showed that whale shark eyes actively track divers swimming 3–5 m away from the animal, suggesting that vision of the whale shark plays an important role in short-range perception." </p><p>While you likely won't bump into a whale shark while swimming just off the coast, this is yet another reminder of how species adapt to their environment. </p><p><span></span>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
Scientists are befuddled by where the shark gets most of its food.
- A University of Sydney research team found that the great white shark spends an unexpectedly large amount of time feeding close to the sea bed.
- The group examined the contents in the stomachs of 40 juvenile white sharks and found the remains of a variety of fish species that typically inhabit the sea floor or are buried in the sand.
- The scientists hope that the information gained from this research will assist conservation and management efforts for the species.
Fresh findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzM5MjMyNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNjY5NDExM30.3JLqvvn4iB0F29jWuRMnEdmSwY6avTsmo6AP3LgXMxQ/img.jpg?width=1245&coordinates=0%2C333%2C0%2C334&height=700" id="362cb" class="rm-shortcode" data-rm-shortcode-id="f21b84cc3825bf4ac53454c6c4bbb09f" data-rm-shortcode-name="rebelmouse-image" />black shark in blue waterPhoto by Gerald Schömbs on Unsplash<p>A research team from the University of Sydney looked at sharks off the east coast of Australia and found that in their stomachs were remains from a variety of fish species that typically inhabit the sea floor or are buried in the sand. Specifically, the group examined the contents in the stomachs of 40 juvenile white sharks, scientifically known as <em>Carcharodon carcharias</em>, who were caught in the NSW Shark Meshing Program. </p><p>"This indicates the sharks must spend a good portion of their time foraging just above the seabed," explained lead author Richard Grainger, a Ph.D. candidate at the Charles Perkins Centre and School of Life and Environmental Sciences at the University of Sydney, <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">in a press release</a>. "The stereotype of a shark's dorsal fin above the surface as it hunts is probably not a very accurate picture." </p><p>The study was published on June 8, World Oceans Day, in the journal Frontiers in Marine Science<em>. </em>It's an important step forward for scientists trying to better understand the great white's diet and migratory behavior. </p><p>"We discovered that although mid-water fish, especially eastern Australian salmon, were the predominant prey for juvenile white sharks in NSW, stomach contents highlighted that these sharks also feed at or near the seabed," <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">said Vic Peddemors</a>, Ph.D., a co-author from the NSW Department of Primary Industries (Fisheries). </p><p>The research team compared this new dietary information with published data on great white feeding habits from other parts of the world where the sharks make home, mostly South Africa. From there they were able to establish a nutritional framework for the species. </p>
What's in a great white's diet?<p><a href="https://www.frontiersin.org/files/Articles/532445/fmars-07-00422-HTML/image_m/fmars-07-00422-t001.jpg" target="_blank">According to the research</a>, the juvenile great white sharks' diets relied primarily on pelagic — mid-water ocean swimming — fish, such as Australian salmon. This made up 32.2 percent of the shark's diet. Bottom-dwelling fish like stargazers, sole or flathead made up 17.4 percent; batoid fish such as stingrays 14.9 percent; and reef fish, like eastern blue gropers, 5 percent.</p><p>The remaining species eaten by the sharks were unidentified fish or less abundant prey. Grainger pointed out that other marine mammals, sharks, and cephalopods — squid and cuttlefish — were eaten at lower rates. </p><p>"The hunting of bigger prey, including other sharks and marine mammals such as dolphins, is not likely to happen until the sharks reach about 2.2 meters in length," <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">Grainger said</a>.</p><p>Another discovery was that bigger sharks tended to have diets that were higher in fat. Similarly to other animals, this is likely an adaptation to their higher energy needs for migration. Great white's migrate seasonally along Australia's east coast, traveling from southern Queensland to northern Tasmania. The range of distance covered increases with age. </p><p>"This fits with a lot of other research we've done showing that wild animals, including predators, select diets precisely balanced to meet their nutrient needs," said co-author Professor David Raubenheimer, Chair of Nutritional Ecology in the School of Life and Environmental Sciences.</p>
Species conservation and management<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="7bb54774f7a5b923690ad15c2e979aca"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/O2FInaOCqoo?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Ultimately, the scientists hope that the information gained from this research will assist conservation and management efforts for the sharks, who are considered a vulnerable and declining species due to overfishing and accidental catching in gill nets.</p>Of particular interest to scientists is better management of relations between humans and great whites. According to <a href="https://www.nationalgeographic.com/animals/fish/g/great-white-shark/" target="_blank">National Geographic</a>, of the over 100 annual shark attacks that happen worldwide, a whopping one-third to half can be attributed to great whites. Yet, research has found that the sharks, who tend to have a curious disposition, are often just taking sample nibble before releasing their human prey. So, at least we know humans aren't a great white delicacy.
Non-avian dinosaurs were thought terrestrially bound, but newly unearthed fossils suggest they conquered prehistoric waters, too.
Unearthing a mystery in the desert<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE4MDU1OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNzI1NTExM30.1L90N5rrjAiYqBzRa72_b3hmP8Bq20MdZ3KtdfSgUTg/img.jpg?width=1245&coordinates=0%2C24%2C0%2C262&height=700" id="765d6" class="rm-shortcode" data-rm-shortcode-id="45a87235d3fe79b339ade44f58f9818c" data-rm-shortcode-name="rebelmouse-image" />
Stromer's holotype of his original Spinosaurus specimen.
A digital resurrection<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE4MDU1OS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTU5NTM2MTExOX0.YuUzxvnm_mHQYTvH2e_Xjq4pKjE_U7R5HEf-xc1TfVc/img.png?width=1245&coordinates=92%2C0%2C93%2C0&height=700" id="c2e6e" class="rm-shortcode" data-rm-shortcode-id="b58ca0abb324db9a0fd7851490615a89" data-rm-shortcode-name="rebelmouse-image" />
An illustration of a Spinosaurus skeleton with its thinner, more traditionally therapod-like tail.
A study of lost tails<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="0530ef75d9bc4d29b2bc7c7802ba98e9"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/fDhofM81RQE?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>But something was missing: a means of propulsion. How did a giant like Spinosaurus catch slick and quick prey while paddling like a duck on two stumpy hind legs? It didn't add up.</p><p>"The big thing we were missing was a propulsive structure because you can't really be an aquatic predator unless you have some way to catch prey in the water and move through the water," <a href="https://www.youtube.com/watch?v=fDhofM81RQE&t=66s" target="_blank">Ibrahim told <em>Nature</em></a>. "That's what we now found."</p><p>Between 2015 and 2019, on a grant from the National Geographic Society, Ibrahim and his team traveled to the Kem Kem region of the Moroccan Sahara to unearth further Spinosaurus fossils. During their dig, they discovered Spinosaurus tail vertebrae that were "characterized by extremely long spines."</p><p>Ibrahim's previous reconstruction of Spinosaurus featured a thin tail borrowed from other therapods. But such a tail would make traveling through the water unwieldy—think paddling a canoe with a walking stick. The new vertebrae revealed a fin-like tail, similar in appearance to a newt's, and could more easily propel the dinosaur through the water.</p><p>To test his hypothesis, Ibrahim's colleagues at Harvard crafted plastic models of the Spinosaurus tail. They attached it to a robot system that mimics swimming and measured its thrust and efficiency. They then compared the Spinosaurus tail's performance against two other therapod tails and extant aquatic animals.</p><p>Spinosaurus's results were consistent with the aquatic animals and superior to the terrestrial therapods. Ibrahim and his team published their results in <a href="https://www.nature.com/articles/s41586-020-2190-3" target="_blank"><em>Nature</em></a>. </p><p>"This discovery is the nail in the coffin for the idea that non-avian dinosaurs never invaded the aquatic realm," <a href="https://www.eurekalert.org/pub_releases/2020-04/ngs-nfr042920.php" target="_blank">Ibrahim said in a release</a>. "This dinosaur was actively pursuing prey in the water column, not just standing in shallow waters waiting for fish to swim by. It probably spent most of its life in the water."</p><p>But as is the case in science, not everyone is yet convinced.</p><p>Donald M. Henderson, the curator of dinosaurs at the Royal Tyrrell Museum, believes Spinosaurus likely lived at the water's edge, scooping up fish as they swam by. As he told <a href="https://www.nytimes.com/2020/04/29/science/spinosaurus-dinosaur-tail-swimming.html" target="_blank">the <em>New York Times</em></a>, he does not believe Spinosaurus would be a powerful swimmer.</p><p>"My first thing is, they haven't actually demonstrated that this tail could produce enough force to propel a six-and-a-half-ton body through the water," Henderson said. He added that the researchers had yet to provide that Spinosaurus had enough muscle power to move such a tail or compensate for the drag of its sail.</p>
Dinosaurs are alive! Here’s how we know, and why it matters<div class="rm-shortcode" data-media_id="nTfwl0kS" data-player_id="FvQKszTI" data-rm-shortcode-id="67c76febbfb51d2231c6bcef00459388"> <div id="botr_nTfwl0kS_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/nTfwl0kS-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/nTfwl0kS-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/nTfwl0kS-FvQKszTI.js"></script> </div> <p>As new fossils are found and new ideas to test emerge, we'll see if Henderson's concerns capsize the aquatic hypothesis or not.</p><p>Even if Spinosaurus is thrown out of the pool, that doesn't mean dinosaurs will forever remain grounded. As <a href="https://www.nytimes.com/2017/12/06/science/duck-dinosaur-swim.html?action=click&module=RelatedLinks&pgtype=Article" target="_blank">reported by the <em>New York Times</em></a>, a dinosaur fossil called <em>Halszkaraptor escuilliei</em> has features that suggest a partial aquatic lifestyle. These include "a neck like a swan, a snout like a goose, and forelimbs like flippers," but the specimen is so unusual that its authenticity remains a matter of debate. </p><p>And what is revealed in these debates will change our understanding of dinosaurs—both those that are gone and those that are still with us.</p>
O.T. Olsen's gorgeous 'Piscatorial Atlas' (1883) describes a world now destroyed and forgotten
- In little more than a century, fish stocks in the North Sea have declined by 99%.
- For people living today, a grey and exhausted sea is all they know.
- O.T. Olsen's Atlas of the North Sea's fish species is a reminder of the richness that once was.
"Specialist and magnificent"<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1OTM3Mi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzOTM0MzMzMX0.PkQGcBkP0cmequpopd2aYgZJizI7c0emU37M_iXFwEE/img.jpg?width=980" id="6c165" class="rm-shortcode" data-rm-shortcode-id="43899a08c2e50c095db89f66e1919b99" data-rm-shortcode-name="rebelmouse-image" alt="In red, an oyster bank the size of Wales, between the Dogger Bank and the coast of northern Netherlands." />
In red, an oyster bank the size of Wales, between the Dogger Bank and the coast of northern Netherlands.
Image: Wellcome Collection. Public domain.<p>Ole T. Olsen's 'Piscatorial Atlas' is a masterclass in data presentation, and it doesn't half look bad either. As <a href="https://bryarsandbryars.co.uk/whats-that-got-to-do-with-the-price-of-fish-ole-theodor-olsens-piscatorial-atlas/" target="_blank">map guru Tim Bryars says</a>: "The late nineteenth century was the heyday of the thematic atlas, but I have rarely seen one quite so specialist or as magnificent." <br></p><p>But the atlas does more than be clever and look cool. It's also a window into a world that's now destroyed and forgotten: one in which the <a href="https://earthobservatory.nasa.gov/images/86176/the-north-sea-abloom" target="_blank">North Sea</a> – the body of water between the British east coast and the European mainland – teemed with life. Published in 1883, the atlas devotes one map each to 40-odd species of fish and crustaceans, describing their habits and habitats, and how and when to catch them. Less than a century and a half later, all are now greatly reduced, and some are functionally extinct in the North Sea. </p>
Shifting baselines<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1OTM3My9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMDAwMDc4MH0.H-B14UvMLU8dlKrZUN2DaqQSlJsFuXdRBLsQX7fvxyU/img.jpg?width=980" id="149a8" class="rm-shortcode" data-rm-shortcode-id="6bc4326d87080399ccae41952ad7c29b" data-rm-shortcode-name="rebelmouse-image" alt="\u200bEach map legend details when the species spawns, when and how they can be caught, what they eat, how much they weight, and what their qualities are. Anchovy, for example, is "excellent for sauce"." />
Each map legend details when the species spawns, when and how they can be caught, what they eat, how much they weigh, and what their qualities are. Anchovy, for example, is "excellent for sauce".
Image: Wellcome Collection. Public domain.<p>We think of our environment as 'normal', but that's because we don't know any better – by definition, we weren't around to experience the 'normal' from before we were born. This phenomenon is called <em>Shifting Baseline Syndrome</em>, and it's no coincidence that this psychological term has <a href="https://oceana.org/blog/daniel-pauly-and-george-monbiot-conversation-about-shifting-baselines-syndrome" target="_blank">found wide currency in fishery science</a>. Because only SBS and the 'generational blindness' it implies can explain how the virtual extinction of global fish stocks over the past century took place with such little notice.</p><p>Consider for a moment the North Sea's waters – grey and soupy today, as everyone thinks they've always been. But thronging its seabeds were once so many oysters, each of which <a href="https://onetrack.club/blogs/news/bringing-back-ocean-biodiversity-with-the-solent-oyster-restoration-project" target="_blank">can filter up to 200 litres of water</a> each day, that the sea must have been a lot clearer, as well as healthier for other marine species.</p><p>The North Sea's native European oysters (<em>Ostrea edulis</em>) have been a prized delicacy for millennia. They were shipped in quantity all the way to Rome, and tasty enough to be mentioned by Pliny the Elder and Juvenal. In more recent centuries, they were the street food of the urban poor. Back in the 1850s, half a billion oysters were sold each year at Billingsgate fish market in London, harvested from the oyster beds that ringed Britain and Ireland. <br></p>
Loss of biodiversity<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1OTM3NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNzE0OTY5OX0.9yWhhNi6Ecofzmpl2AVKj5jAyH8jBxy72oMuNUIkb3E/img.jpg?width=980" id="93a3a" class="rm-shortcode" data-rm-shortcode-id="525458bddf78572c78010bf3c54826a1" data-rm-shortcode-name="rebelmouse-image" alt="\u201cThe conger is very voracious, will attack man in the water, is very prolific, and its youg furnish a great amount of food for other fish. It is also used for isinglass.\u201d" />
"The conger is very voracious, will attack man in the water, is very prolific, and its young furnish a great amount of food for other fish. It is also used for isinglass (a gelatin obtained from fish, used in making jellies, glue, etc. and for fining real ale - Ed)."
Image: Wellcome Collection. Public domain.<p>In particular, Olsen's atlas shows one giant oyster area bigger than Wales, hemmed in by the Dogger bank and the northern coast of the Netherlands. That patch is now gone. As it turned out, Olsen composed his atlas jut before industrial fishing would start to decimate the marine species of the North Sea.</p><p>By the end of the 19th century, the oyster catch started to dwindle, due to overfishing and pollution. By the 1970s, the Pacific rock oyster had to be introduced into the North Sea to satisfy demand. By the 1980s, the European oyster had all but vanished. Heroic efforts are being made to <a href="https://www.ft.com/content/e08e8f16-ea29-11e9-85f4-d00e5018f061" target="_blank">bring back the native oyster</a>, but current stocks are barely 5% of what they were 200 years ago.<br></p><p>Compounding the loss of the oysters themselves is the loss of the reefs they build: these help regulate marine ecosystems, build a habitat for biodiversity – by providing food, nursery grounds and refuge for many fish species. Many of those reefs were destroyed by industrial trawling, which has proved equally devastating for other marine species in the North Sea. </p>
94% decline<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1OTM3NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxODkwOTI5Mn0.9N2Rdw9HsZqI0wOsc9LPcMKusK9Qa0VhsOhkRIEjbVY/img.jpg?width=980" id="5a1ce" class="rm-shortcode" data-rm-shortcode-id="cbe3b19f0e9b1bae6e6d88a268fd8206" data-rm-shortcode-name="rebelmouse-image" alt="\u200bThe mackerel was thinly spread across the North Sea, and more numerous to the west, in the Irish Sea and in the Bristol and English Channels." />
The mackerel was thinly spread across the North Sea, and more numerous to the west, in the Irish Sea and in the Bristol and English Channels.
Image: Wellcome Collection. Public domain.<p>Between 1889 and 2007, a <a href="https://www.nature.com/articles/ncomms1013" target="_blank">statistical study of historical fish catch data</a> shows, fish landings from bottom trawl catches in England and Wales declined by a jaw-dropping 94%. In other words: the modern fish stock in the North Sea is just one-seventeenth the size it was in the late Victorian era. That implies "an extraordinary decline in (…) fish and a profound reorganization of seabed ecosystems", the study says. No prizes if you guess what caused the decline: more than a century of industrialised trawling.</p><p>This figure applies to so-called 'demersal' (or bottom-dwelling) species like cod, plaice, haddock and halibut. In particular, haddock had fallen to less than 1% of its former volume, halibut to one-fifth of 1%. Another study suggests that the current biomass of large fish in the North Sea is up to 99.2% lower than if no fishing had occurred. <br></p><p><a href="https://www.youtube.com/watch?v=BnmGbDN278Y" target="_blank">Bottom-trawling</a> is the main method of catching bottom-living fish today. First attested in the 14th century, the process was industrialised from the late 19th century, first with the advent steam trawlers, and greatly expanded in the 20th century. Already in 1885, the UK government examined claims that industrialised fishing depleted stocks and damaged habitats. But conservation efforts came to nothing, among others by the absence of hard data. </p>
Common Fisheries Policy<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1OTM3OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0OTIyMTUwNn0.KkkS0oI13wfLSSE45FW-OABBx0Mwth9c3E0v_fUo_hA/img.jpg?width=980" id="7e01e" class="rm-shortcode" data-rm-shortcode-id="b85473e1dc68bc4e44081b9a1634d15e" data-rm-shortcode-name="rebelmouse-image" alt="\u200bShrimp fishing grounds all hug the coast - but are largely absent from the Norwegian and Danish coasts." />
Shrimp fishing grounds all hug the coast - but are largely absent from the Norwegian and Danish coasts.
Image: Wellcome Collection. Public domain.<p>In fact, the increasingly effective methods of industrial fishing have masked the negative effects they have had on fish stocks. According to the study cited above, the recent history of fishery in England and Wales can be divided into four phases:</p><ul><li>From 1889 to the onset of WWI: the fishery fleet is converted from sail to steam. Fishing is rapidly industrialised and intensified. Stocks start to decline, but this is compensated by massive expansion of the catch areas.</li><li>The interbellum (1919-1939): In a second wave of expansion, fishing vessels go as far away as the Arctic and West Africa, managing to increase catches until the late 1950s.</li><li>From the end of WWII to the early 1980s: fast-declining fish stocks in the North Sea and beyond. As a protective measure, Iceland and other countries declare Exclusive Economic Zones of 50, then 200 miles.</li><li>From 1983: the UK (and Ireland) join the European Economic Community, and must adhere to the <a href="https://ec.europa.eu/fisheries/cfp_en" target="_blank">Common Fisheries Policy</a>.</li></ul><p>The CFP is a compromise, forcing EU member states to adhere to fish quotas in order to allow the stocks to recover from overfishing. However, it is estimated that quotas have always been up to 35% higher than the levels advised by scientists as sustainable. In order to minimise displeasure of the fishing industry, the CFP has prioritised maintaining catch levels over maintaining stock levels. <br></p>
Fighting over a comb<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE1OTM4OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMzY2MDM3Nn0.6bdUKCerxaFtiGJ_1LUf6IjijchMG5Hbwmlz5mteRIg/img.jpg?width=980" id="da47c" class="rm-shortcode" data-rm-shortcode-id="6b687bada474d9da86a6d1a7f1ad9c21" data-rm-shortcode-name="rebelmouse-image" alt="\u200b"Very wholesome, nutritious and savoury," the herring is "as pleasing to the eye as the taste is grateful to the palate. It is also food for all fish."" />
"Very wholesome, nutritious and savoury," the herring is "as pleasing to the eye as the taste is grateful to the palate. It is also food for all fish."
Image: Wellcome Collection. Public domain.<p>As a result, it is estimated that stocks of demersal fish in the North Sea have declined by 42% since the early 1980s. "In many cases, today's fisheries are sustained by populations of species that should be considered commercially extinct," says the study. The end of the line has been a long time coming:</p><ul><li>In 1889, Britain's sail-powered fishing fleet landed twice as many fish as today's highly sophisticated vessels.</li><li>In 1910, British fishermen landed four times as many fish as they do today.</li><li>The peak year for North Sea fishing was 1938, when 5.4 times more fish were landed in the UK than today.</li><li>Mackerel fishing ceased in the 1970s due to overfishing. The same could soon happen for herring, cod and plaice. </li></ul><p>For the Leave campaign in Britain's 2016 Brexit referendum, the British fishing industry and its perceived suffering at the hands of EU bureaucracy was a major issue. Brexit meant 'taking back control' of British waters and the fish that swim in them, doing away with the limiting quotas imposed by Brussels. </p><p>But the baseline has shifted; the piscatorial richness that informed Olsen's atlas and which once filled the North Sea has gone. And duelling with the European Union over those dwindling fish stocks feels a bit like <a href="https://en.wikiquote.org/wiki/Falklands_War" target="_blank">what Borges said</a> about the absurdity of the Falklands War: "a fight between two bald men over a comb."<br></p>
The relatively quick evolution of nine unusual shark species has scientists intrigued.
- Living off Australia and New Guinea are at least nine species of walking sharks.
- Using fins as legs, they prowl coral reefs at low tide.
- The sharks are small, don't be frightened.