Swordfish as oceanographers: Satellite tags facilitate research of ocean's 'twilight zone' off Florida

NOVEMBER 5, 2019

by Hannah Hickey, University of Washington

Researchers from the University of Washington are using high-tech tags to record the movements of swordfish—big, deep-water, migratory, open-ocean fish that are poorly studied—and get a window into the ocean depths they inhabit.

The researchers tagged five swordfish in late August off the coast of Miami: Max, Simone, Anthony, Rex and Oliver. Their movements can now be viewed in near-real time. And although swordfish are a prized catch, these ones aren't at higher risk, researchers say, since the website updates only every few hours and these fast-swimming fish spend most of their time far from shore.

"These are animals that migrate into the ocean's twilight zone that we know next to nothing about," said Peter Gaube, an oceanographer at the UW Applied Physics Laboratory. "Swordfish in different regions have very different behavior. We hope to learn more about these amazing animals and their environment as they migrate between regions."

This is the first time satellite position tags have successfully been placed on swordfish caught off the coast of the United States.

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Dinosaur-era 'swordfish' discovered in outback Australia

14 October 2016

"Extremely rare" fossils from a swordfish-like creature which lived 100 million years ago have been discovered in the Australian outback.

Two families on holiday unearthed the prehistoric predator at a free fossil-finding site in north-west Queensland.

The remains are thought to be from the Australopachycormus hurleyi, a 3m-long ray-finned fish with a pointed snout.

"Part of what makes this specimen so special is that it is so complete," Dr Patrick Smith told the BBC.

Continued  http://www.bbc.co.uk/news/world-australia-37652333

Secret to Swordfish's Speedy Swimming Found

By Mindy Weisberger, Senior Writer | July 7, 2016 07:02am ET

A swordfish's impressive saber-like bill might inspire visions of swashbuckling fencers wielding flashing blades. But in reality, this protruding proboscis is more vulnerable than you might expect.

There is a weak spot at the base of the bill where it joins the skull. The bone thins at this spot to make room for an oversized gland. Scientists have just discovered what this mysterious gland might be used for — faster swimming.

Researchers have found that the gland produces oil that covers the swordfish's head with a slippery coating. By generating this greasy film, the gland could reduce drag and help the fish cut through the water more efficiently, contributing to its swim speed.

Built for speed

Swordfish have powerful yet streamlined bodies that are literally built for speed. They are thought to be the fastest swimmers on Earth and have been clocked at an estimated 62 mph (100 km/h), according to the study authors.

A swordfish uses its signature bill — which can reach up to 40 to 45 percent of its body length — in sweeping motions to slash and stun its prey. But it also plays a part in swimming. The bill's surface is porous and rough, the authors noted — a feature that previous studies had linked to drag reduction.

However, recent studies had also revealed a noticeable weakness at the bill's base that puzzled the scientists, prompting them to take a closer look. 

Luckily, the study's lead author, John Videler, a biologist and professor at Groningen University in the Netherlands, had scanned a pair of adult swordfish in 1996 and 1997 using magnetic resonance imaging (MRI). He captured 657 images showing the insides of the fish, from the tips of their bills to the ends of their tails.

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Illegal Med fishing claims up to two tons of swordfish per boat per day

Inadequate controls and monitoring off Italian coast could lead to collapse of swordfish population in next three years, warn conservationists

Arthur Neslen in Brussels

theguardian.com, Wednesday 29 October 2014 16.24 GMT

A rampant lack of controls is allowing fishing boats in the Mediterranean to illegally pluck huge quantities of swordfish from waters off the Italian coast, according to an internal report by EU fishery inspectors.

One boat can catch up to two tons of swordfish per day.

The detailed investigation, conducted in March last year and obtained under a freedom of information request, found poor enforcement of fishing season closures by local authorities in southern Italy, with very few landing inspections of the active fleet.

Swordfish catches were often authorised by officials after the season’s close, and swordfish meat was visibly on sale in local shops and markets, and easily available in local restaurants.

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Decades of overfishing causes swordfish decline

Overfishing has caused swordfish numbers to decline considerably since the 1980s and the population is now 70 percent lower than what is considered sustainable, the marine conservation charity Oceana has warned the EU.

They are asking the European Union to urgently adopt a Mediterranean swordfish management plan that will restore the stock to sustainable levels before it is too late. This the charity says should include the setting of a catch limit take measures that will ensure its recovery

“The European Union is blatantly ignoring its obligation to manage stocks at sustainable levels by 2015, or by 2020 at the very latest,” said Maria Jose Cornax, Fisheries Campaign Manager for Oceana Europe.

“By not adopting measures now, the EU would be duplicating the same costly mistake that brought bluefin tuna to the verge of collapse in the past.” 

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Swordfish catch in River Tyne 'very rare'

A swordfish usually found swimming in the clear, warm waters of the Mediterranean has been caught by a surprised fisherman in the River Tyne.

The fish, which measures about 1.2m (4ft) long from the tip of its sword to its tail, was caught in salmon nets close to South Tyneside.

It has now been taken to Latimer's Fishmongers in Whitburn to be filleted.

Owner Rob Latimer believes the fish had been "chasing" mackerel or salmon down the river when it got caught.

"It must have fancied a holiday in Whitburn I think - I can't blame it," Mr Latimer said.

Swordfish are normally associated with warmer waters like the Mediterranean sea.

Chief executive of the National Federation of Fishermen's Organisations (NFFO), Barry Deas, said: "I have never heard of this before.

"They are definitely a warm water fish, this is very rare."

http://www.bbc.co.uk/news/uk-england-tyne-23816569

Swordfish reported on a beach in Somerset

Swordfish in the Bristol Channel

July 2013. Wildlife Extra has found a few very small reports that a dead swordfish washed ashore on Berrow Beach in north Somerset at the end of June. The fish measured approximately 6-7 feet long, plus its sword, and apparently washed away on the next tide.

Second swordfish

Despite the rarity of this event, it is actually the second swordfish to have been found in this area. Another swordfish washed ashore on Barry Island, just across the Bristol Channel, in 2008. Amazingly, just a few weeks later, a Blue marlin was found washed ashore on another Welsh beach.

Grow up to 16 feet - One of the fastest fish

Swordfish can grow to 4.6 metres (16 feet) and weigh over 600 kg, so this one was small in global terms. They are often called a Broad-billed Swordfish, but there is only one species in the world. They are found throughout the tropical and temperate waters of the world but appear to prefer sea temperatures of 18°C to 22°C, migrating to cooler waters to feed in the summer.

These oceanic fish chase herring and mackerel and are among the fastest fish reaching 56 mph. This is in part due to their being warm-blooded, which allows not only their muscles but also their brain and eyes to work more efficiently.

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Small steps for tuna, sharks and swordfish

Measures to prevent illicit fishing of Mediterranean bluefin tuna have been strengthened at the annual meeting of governments involved in the industry.

The International Commission for the Conservation of Atlantic Tunas (Iccat) decided to implement an electronic system for recording bluefin catches.

Research shows catches have been far higher than skippers have declared.

The meeting, in Turkey, also gave extra protection to the silky shark, whose numbers are falling because of fishing.

Tuna boats often snare this species by accident; and now, fishermen will have to release them alive.

Government delegates also voted through a minimum legal size for swordfish, and will draw up a comprehensive recovery plan in 2013.

But proposals for protecting the porbeagle shark, classified as vulnerable to extinction on the internationally recognised Red List, were rebuffed.

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