Archive for the ‘Eat it or not’ Category

The State of Fish

Thursday, April 28th, 2016
(nature.com)

(nature.com)

We’ve known for a few decades now that we’ve been fishing the oceans at unsustainable levels. We have also over that time developed reasonable management strategies to help overfished stocks recover. So where are we now?

Global catch of fish, in millions of tons. It levels off, even delcines slightly, which looks hopeful - but it isn't: more boats search harder for fewer fish (worldoceanreview.com)

Global catch of fish, in millions of tons. It levels off, even delcines slightly, which looks hopeful – but it isn’t: more boats search harder for fewer fish (worldoceanreview.com)

A more accurate picture of the reported global catch, separating industrial from artisanal and recreational fisheries, and including the bycatch currently estimated to be about 10 million metric tons per year as well as the illegal unreported catch that reached about 30 mmt at its peak (nature.com)

A more accurate picture of the reported global catch, separating industrial from artisanal and recreational fisheries, and including the bycatch currently estimated to be about at about 10 million metric tons per year as well as the illegal unreported catch that reached 30 mmt at its peak (nature.com)

A new and remarkably inclusive report on the status of over 4500 of the world’s capture fisheries – that’s about 78% of them – indicates that most of them are in poor shape, overfished and heading toward collapse. No surprise there. About a third are in tolerable biological shape – which means not collapsing toward extinction, but not necessarily in good economic shape. So the overall picture is bleak, everywhere.

There are exceptions – on the coasts of some countries such as the US and Australia fisheries are recovering under strictly enforced regulations. On the other hand, China has indicated it wants to increase fish consumption by 50% within 6 years, and it already is the most voracious of the fishing nations.

The report then asks how each fishery would fare under four distinct recovery approaches, and models the outcomes. The first is the famous ‘business-as-usual’ don’t change anything scenario that we know leads to oblivion – everything dwindles and collapses. The second is if some modest conservation practices are accepted – and the outcome here is only a little better

The third approach is also familiar, the maximum-sustainable-yield model that has been used to manage many fisheries for decades. It is certainly is a lot better than open access, unregulated fishing, but few fisheries have actually recovered very much under it.

The fourth is ‘rights based fisheries management’ – more difficult, with short-term pain, but a long-term impressive benefit. It would involve reducing fishing effort to sustainable levels, stabilizing overfished stocks, reducing or eliminating the ‘race to fish’, maximizing economic value through product quality and market timing.

The 4 scenarios, all possible. Lowest: Business-as-usual. Next: some conservation. Next: Long-term maximum sustained yield. Top: Rights-based-fisheries-management (PNAS.org)

The 4 scenarios, all possible. Lowest: Business-as-usual. Next: some conservation. Next: Long-term maximum sustained yield. Top: Rights-based-fisheries-management (PNAS.org)

Of course this 4th approach is the one we should favor – who could disagree? The model predicts rapid recovery of most stocks (again, there are exceptions, like NW Atlantic cod) – 10 years on average should be sufficient. The total global annual catch should also increase by about 17% up from the current 98 million metric tons. Because of higher product value, this should add about $50 billion to the value of the total catch. Such management obviously involves a lot of regulation, cooperation and enforcement.

In this more perfect world, illegal fishing and Wasteful bycatch would be eliminated. Fishing fleets would be smaller. The report ends with this: “Commonsense reforms to fisheries management would dramatically improve overall fish abundance along with food security and profits.”

If only commonsense existed.

Even if we do somehow change our fishing practices, recovering fish stocks will still face the additional stresses of ocean warming and the related community disruption that is underway, and we have the immense challenge of feeding the additional 4-6 billion people we are likely to share the planet with by the end of the century.

For global fisheries to be sustainable, more abundant, and more valuable, we need to achieve the same global culture change that we have recognized is necessary to convert us to using abundant renewable energy, and to radically reduce both our consumption and class inequality.

What a dream!

But if we do not achieve this commonsense dream or something close to it, then we are left with the nightmare of business-as-usual that has brought us to the brink where we now stand.
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Traditional Chinese Medicine

Tuesday, March 29th, 2016

Perhaps you know about the impact that Chinese Traditional Medicine – TCM – has had on seahorses.

In TCM, dried seahorses have been consumed pretty well forever, mainly as an aphrodisiac for men. A legal, unregulated market exploded in the 1990s, and seahorses were stripped from reefs, mangroves and grass beds around the world – perhaps as many as 150 million collected, dried, and eventually sold per year for about $600 per kg. And even if aphrodisiacs were a defensible argument for killing other species – and they certainly aren’t – there is no evidence that dried seahorses have any such effect. The same is true of course for all the other traditional marine aphrodisiacs – sea turtle eggs, oysters, abalone, seal penises, lobsters, shark fins, an almost endless list of marine species.

A pregnant male pot-bellied seahorse, one of the largest species, giving birth (livescience.com)

A pregnant male pot-bellied seahorse, one of the largest species, giving birth (livescience.com)

More than 50 seahorse species exist, diverse, alien and beautiful. We almost lost most of them, particularly the larger species, more valuable in TCM. Finally protected in 2004 by CITES in 2004, their import, sale and export is now regulated, even in China. Yet in Taiwan, Hong Kong, mainland China, Vietnam, Korea, Japan, and in Chinese communities in cities around the world, dried or powdered seahorses remain easy to find in Chinese medicine stores: the black market never closes.

A seahorse called a seadragon, a poor swimmer like all seahorses, is difficult for predators to see when entangled  in algae (brooklyncyny.edu)ed in algae (

A seahorse called a seadragon, a poor swimmer like all seahorses, is difficult for predators to see when entangled in algae (brooklyncyny.edu)ed in algae (

True, extinction is now less likely – captive seahorse farming is improving, marine protected areas are often actually protected, ecotourists like to see seahorses alive in their natural habitats, and of course Viagra has helped. Unfortunately, even harmful traditions can be very slow to die.

If only we learned from such an example to avoid repeating it on others. Yet amazingly in the past few years, the gill rakers of manta and mobula rays have become extraordinarily popular as a new source of Chinese medicines. This time though it isn’t even traditional – instead it is a case of highly aggressive and successful industry marketing. People are trusting, probably ignorant of what exactly they are ingesting as medicine, but they are persuaded that the ground up gill rakers may cure just about everything: chicken pox, cancer, swine flu, throat and skin ailments, male kidney issues, fertility problems, immune system depletion, excess toxins, circulation challenges.

Manta rays are huge, feeding on plankton they sieve from the water as they swim (engineeringwellness.com)

Manta rays are huge, feeding on plankton they sieve from the water as they swim (engineeringwellness.com)

Looking into the open mouth of a plankton-feeding manta ray: you can see the rows of gill rakers where the plankton is raked from the water that is pushed out through the gills (wwvortex.com)

Looking into the open mouth of a plankton-feeding manta ray: you can see the rows of gill rakers where the plankton is raked from the water that is pushed out through the gills (wwvortex.com)

The truly discouraging aspect of this is that, just as with seahorse aphrodisiac properties, there is no evidence of any health benefits. None. Yet the rays are caught, the gill rakers cut out, the bodies discarded, and the populations are decimated.

Mobula rays, closely related to manta rays, leap from the water - perhaps to disturb ectoparasites, perhaps for mating purposes, perhaps by chance - we really have no idea (worldsbestdives.com)

Mobula rays, closely related to manta rays, leap from the water – perhaps to disturb ectoparasites, perhaps for mating purposes, perhaps by chance – we really have no idea (worldsbestdives.com)

Of course we all want want to be healthy humans. But is it too much to ask that there be good evidence the health products we select are actually beneficial? Should we not know or care that we are driving other species to extinction, disrupting ecological communities? And why, after all the experience we have had with marketing and advertizing, do we believe any of it?

Naturopathy and Traditional Chinese (Korean, Vietnamese, Japanese) Medicine are thriving. The nutraceutical industry is booming. Where it’s herbal and sustainable, perhaps the lack of supporting evidence doesn’t matter so much. But to wantonly kill animals – and the list is very long – for their non-existent health benefits is madness.

Tradition is not the problem: it’s our greed and ignorance, and we know better.

And in this case, taking action is incredibly easy: we just stop.

The pygmy seahorse, very small, very well camouflaged (lovethesepics.com)

The pygmy seahorse, very small, very well camouflaged (lovethesepics.com)

Invasion of the King Crabs

Friday, November 20th, 2015

We’re increasingly familiar with the idea that in the marine world as the sea gets warmer, organisms will move north (or south) to higher latitudes to escape the growing heat. Much less familiar is the idea that in some places animals from very deep water will move into more shallow areas, and create havoc with the ecosystem existing there.

Enter King Crabs. These are large, sometimes huge, made at least a little famous by Alaskan King Crabs that starred in the reality show The Deadliest Catch. Around the globe, they tend to live in very cold, deep water, preying on bottom living mollusks, echinoderms and other crustaceans by crushing them.

Alaskan King Crabs are abundant on the sea floor of the Gulf of Alaska, the target of one of the world's more risky fisheries (freerepublic.com)

Alaskan King Crabs are abundant on the sea floor of the Gulf of Alaska, the target of one of the world’s more risky fisheries (freerepublic.com)

A couple of other species live on the Continental Slope along the West Antarctic Peninsula, seaward of the more shallow Continental Shelf, mostly at depths between 2000 and 800 meters where water temperature varies from 0.4 degree C up to a balmy 1.16 degree C.

Like other King Crabs, they can tolerate very cold water, but there is a limit. They function well down to about 1 degree centigrade, but when the temperature is colder than about half a degree C, their magnesium physiology breaks down and they become paralysed and die.

Antarctic King Crab, Neolithodes yaldwini. The male is the larger one, guarding a female who he will mate with as soon as she molts (Katrien Heinman, nature.com)

Antarctic King Crab, Neolithodes yaldwini. The male is the larger one, guarding a female who he will mate with as soon as she molts (Katrien Heinman, nature.com)

Though that is certainly cold, sea temperatures on the adjacent more shallow Antarctic Continental Shelf remain even colder, a little below zero in all seasons, creating a lethal ceiling above the King Crabs deeper on the Slope.

This is all a relatively recent phenomenon. About 40 million years ago when the force of continental drift finally pushed Antarctica free from South America, the Antarctic Circumpolar Current formed, isolating the Southern Continent from the influence of more northerly warmer water, freezing the glaciers on the continental mass, and super-cooling the shallow seas on the Continental Shelf.

The Antarctic Circumpolar Current formed 40 million years ago, isolating and freezing Antarctica (globalspec.com)

The Antarctic Circumpolar Current formed 40 million years ago, isolating and freezing Antarctica (globalspec.com)

For 40 million years, King Crabs have not been able to penetrate the colder shelf waters, and nor have predatory bony fish, sharks or rays, also unable to tolerate such cold temperatures. For 40 million years, the bottom living animals, mostly suspension feeders except for some predatory starfish and worms, have become lightly skeletized, soft, in the absence of the shell-crushing predators.

They remind us of the bottom living Paleozoic community last seen before fish (and King Crabs) evolved, 350 million years ago, a rare and possibly unique ecosystem today.

The animals living on the sea floor on the Antarctic Continental Shelf are unusual, soft-bodied echinoderms, mollusks and worms, susceptible to predation by King Crabs (nature.com)

The animals living on the sea floor on the Antarctic Continental Shelf are unusual, soft-bodied echinoderms, mollusks and worms, susceptible to predation by shell-crushing King Crabs (nature.com)

But of course now things are changing. The Antarctic seas, especially around the West Antarctic Peninsula, are warming unusually quickly. Stronger winds, driven by climate warming, intensify the Antarctic Circumpolar Current, lifting warmer, denser, saltier water up from 4000 m over the lip of the Shelf and spilling into deeper canyons.

Marguerite Bay, West Antarctic Peninsula, where King Crabs have begun to appear in the deeper water canyons on the Shelf (pnas.com)

Marguerite Bay, West Antarctic Peninsula, where King Crabs have begun to appear in the deeper water canyons on the Shelf (pnas.com)

King Crabs are moving up into some of these canyons. The cold water ceiling above them on the Shelf is still there, but it is rising. Over the next decades – perhaps sooner than later – King Crabs will invade the rest of the Shelf.

The diverse deskeletized animals now living there will be then be history for they have no defenses against the King Crabs. The current fragile ecosystem will be disrupted, shifting toward something probably very similar to deep cold-water ecosystems elsewhere where King Crabs thrive.

At depths where King Crabs are common (black bars) potential prey (the other bar graphs) are greatly reduced (pnas.com)

At depths where King Crabs are common (black bars) potential prey (the other bar graphs) are greatly reduced (pnas.com)

This loss of an unusual ecosystem will be unfortunate, but there are obvious limits to our ability to be the stewards we might like to be. Clearly we have much more immediate and pressing problems to deal with. Still, we do know that there is so much that we but dimly understand about our current ecosystems, and as a result much of the change that lies ahead is simply unpredictable.

At least we can now add to the mix the idea that marine ecosystem change can come from any direction, including from below.

Enjoy your King Crabs – they look like survivors.

Enjoy your meal (clubnews.com)

Enjoy your meal (clubnews.com)

Swordfish revival

Saturday, July 25th, 2015

Is there a better taste than a perfectly grilled swordfish steak, lightly seasoned, practically melting in your mouth? Hard to imagine any.

swordfish steaks, lightly grilled, lightly seasoned, a taste and texture to die for (flikr.com)

swordfish steaks, lightly grilled, lightly seasoned, a taste and texture to die for (flikr.com)

Swordfish, like other billfish and tuna, are apex predators. They are pandemic – pretty well everywhere – but they prefer water that is 18-22 degrees C. During the night they rise to shallower, warmer water; during the day they forage at greater depths. They migrate great distance seasonally, following both prey and preferred water temps.

Swordfish fish in during the day, at depths of 2-300 meters, using their bills to slash and incapacitate their prey (arkive,com)

Swordfish fish in during the day, at depths of 2-300 meters, using their bills to slash and incapacitate their prey (arkive.com)

In the 1990s swordfish, heavily fished around the world, seemed to be declining toward extinction. Now, with the exception of the Mediterranean stock, they aren’t: IUCN has recognized the Atlantic and Pacific stocks now as ‘adequately managed’ rather than ‘overfished’ as they used to be.

This is good news. How did it happen?

Starting in 1999, a lot changed, driven not surprisingly by the US market. It started with hundreds of chefs across the US, along with and the encouragement of SeaWeb, agreeing not to serve swordfish. They called their initiative ‘Give Swordfish a Break’, mobilized consumer support, sustained it for two and a half years, and stimulated a formal 10 year recovery plan that actually seems to have worked.

Global landings of swordfish rose rapidly until the late 90s (wikipedia.com)

Global landings of swordfish rose rapidly until the late 90s (wikipedia.com)

The decline of global stocks (again, the Mediterranean is the exception) has stabilized, and generally risen to levels that fisheries scientists think can be fished sustainably. The bycatch of endangered sea turtles, which used to be horrendous, has declined by about 90%.

So the new regulations are effective.

Quotas were reduced, and are reconsidered every year. Limited access to licenses now controls the size of the fishing fleets.
Minimum size limits of individuals caught should allow them to breed at least once before their final capture. Observers must be carried whenever requested, vessels are monitored by satellite tracking, and there are time and area closures, protecting breeding and juvenile fish. An impressive array of regulations.

Bycatch of sea turtles, the other great concern, has also been taken very seriously. Long-lines with their hundreds of hooks, the dominant method of fishing, must be set only at night, at appropriate depths. Length of long-lines cannot be greater than 20 nautical miles (!). Fishing ships must move away when endangered sea turtles are seen. Larger circle hooks, much less damaging to sea turtles are mandatory.

Altogether, swordfish appears to be a fine example of an environmentally responsible pelagic fishery.

Or is it? IUCN still designates the overall population as ‘declining’. The Mediterranean stock, like so much in that sad almost enclosed sea, remains overfished. Some of the global catch is also certainly unreported. And the average length that is caught commercially is 1.2 to 1.9 meters, which seems quite large – but 50 years ago far larger swordfish were still common.

A swordfish captured in 1953, weighing in at 1182 pounds. (pinterestcom)

A swordfish captured in 1953, weighing in at 1182 ponds (pinterest.com)

So what should we do, knowing that we should thoroughly protect such marine apex predators rather than eat them? Faced with that grilled steak of a freshly caught swordfish, we’ll probably first swallow our misgivings, and then enjoy the extraordinary taste.

But swordfish are not really recovering – they just aren’t declining to oblivion any longer.

A fearsome and  famous skeleton at eh Nation Museum of Natural History in Washington  (enwikipedia.org)

A fearsome and famous skeleton at eh Nation Museum of Natural History in Washington (enwikipedia.org)

Opah, the Warm-Blooded Fish

Thursday, June 4th, 2015

We have a new fish to contemplate. It is truly warm-blooded, a fish with whole-body endothermy. This is unexpected, and quite amazing.

Opah, Lampris gutattus, is disc shaped, generally orange, grows to 1-2 meters in length, and lives well below the surface, chasing down squid (noaa.org)

Opah, Lampris gutattus, is disc shaped, generally orange, grows to 1-2 meters in length, and lives well below the surface, chasing down squid (noaa.org)

The swiftest and largest predatory fish – tuna, some sharks, billfish like marlins – warm their swimming muscles a few degrees warmer than the surrounding water, and thereby get the extra speed they need to race down prey. Though the rest of their bodies are mostly unwarmed, the same temperature as the water around them, it is a remarkable adaptation.

Tbey do this through a complex heat-exchange tangle of arteries and veins (rete mirabile) near their swimming muscles, conserving the heat instead of losing it all when when the blood flows through the gills where it is cooled to the ocean ambient temperature while it is re-oxygenated. These fish usually also tend to stay near the surface, where it is warmer, dropping down into deeper colder water only to hunt.

But a fish with whole-body endothermy? Brain, eyes, muscles, heart, the works? No one thought any existed.

Now we know that at least one species, the Opah Lampris guttatus, is endothermic. Not as hot as as mammals and birds are, but surprisingly warmer than the water around them. In 10 degree C water, in a 40 kg fish, muscles and internal organs are about 5 degrees warmer, and the brain and eye muscles a couple of degrees even warmer than that.

Opah also avoid surface waters: they are mesopelagic, living circumglabally at depths 50 to 400 m below the surface. And they are predators, apparently of squid, though they lack the streamlined form we expect of predatory fish.

On the left, internal temperatures, 5 cm below the skin, of a 40 kg Opah in 10.5 degree C water. On the right, temperature of pectoral muscles of a free swimming Opah (red) at depths of 70 meters or more (temp blue, depth black) (science.org)

On the left, internal temperatures, 5 cm below the skin, of a 40 kg Opah in 10.5 degree C water. On the right, temperature of pectoral muscles of a free swimming Opah (red) at depths of 70 meters or more (temp blue, depth black) (science.org)

How do they stay so warm? Their heat is generated by their pectoral muscles, and they too have rete mirabile heat-exchange system, but unlike all other fish, theirs are in their gills, the harshest place they could be. To help conserve their body heat, their skin is unusually thick, and under their skin they have an unusual layer of insulating fat.

The warmer muscles, brain, sense organs and heart all give Opah the advantages of a warm blooded predator in a cold blooded world – more alert, faster. Its body shape is puzzling though – what kind of predatory fish has a body shaped like a disc? Perhaps we don’t know enough about this yet.

What’s ahead for this species in a world where we eat as many fish as we can catch? Though it lives where it is relatively safe from us, it not uncommon as bycatch on the hooks of longline fishers. It also is turning up now in fish markets, and apparently makes for good sushi.

Circumglobal range of Opah (also known as Moonfish).  Red denotes regions where it most common. *chefs-resources.com)

Circumglobal range of Opah (also known as Moonfish). Red denotes regions where it most common. *chefs-resources.com)

But it doesn’t form vulnerable schools, it keeps away from surface waters, its range is very large, and as long as its own food supplies persist, it isn’t severely threatened. Or so it seems, anyway.

It would be nice to understand it better but otherwise, really, let’s just leave it alone, and hope it makes it through these challenging times.

So let’s agree not to hunt this one.

Let’s agree not to sushify it.

Eating Octopus Alive

Monday, March 30th, 2015
A couple of young, live octopus experiencing there last moment together (weirdasiannews.com)

A couple of young, live octopus experiencing there last moment together (weirdasiannews.com)

A Japanese restaurant in Toronto has recently begun to offer live octopus on its menu. I didn’t know anyone anywhere would eat octopus live, but apparently it is a not-uncommon dish in South Korea, where it is called San nachi or Sannakji.

Those of us who are carnivores eat a lot of cooked seafood, probably some raw – sushi, for instance, and perhaps on occasion some newly shucked and still living oysters, or even perhaps some raw sea urchin gonads.

But live octopus?

Only young, small octopus are eaten alive – you don’t need to imagine some huge monster in a bowl of water in front of you, ready to eat you back. And you don’t need to imagine how you are going to cut it up while it is roaming around the bowl – it is small enough that you can stuff the whole animal into your mouth and chew it up there.

What does this really look like? Here’s a video of someone eating one for the first time, and she clearly needs more practice at it. And then this video of someone somewhat more experienced.

Some places just offer freshly amputated and still writhing arms.

There is at least a very small risk that the suckers of one of the octopus arms will latch onto your palate, and when you try to swallow the rest of it, you will choke to death. But that isn’t why I have such a problem with the whole event.

The common octopus , Octopus vulgaris - intelligent, solitary predator (sites.google.com)

The common octopus , Octopus vulgaris – intelligent, solitary predator (sites.google.com)

An octopus isn’t an oyster or a sea urchin. It has eyes very similar to ours, a bigger brain for its size than any other invertebrate, and a habit of changing colors according to its probable emotional state. It is a stealthy, solitary, intelligent predator. When a female lays her eggs, she sits and guards them until they hatch, and then she usually dies. Altogether, an alien life-form to admire and co-exist with. Not to eat.

So, though I love to eat lobsters and fish, I don’t intend to eat any octopus, dead or alive. I also really don’t want to eat any animal that is still alive, even though octopus, or lobster, or fish or other non-human predators obviously eat their own prey still fresh and alive.

Famous blue ringed octopus, small and lethally toxic (marinebio.org)

Famous blue ringed octopus, small and lethally toxic (marinebio.org)

To make my hypocrisy even more blatant, lobsters usually die an ugly death before when they are cooked, fish have probably suffocated slowly to death after capture, and we know far too much about what most of our chickens, pigs and cattle go through before we eat them, yet still I eat them all with enthusiasm.

Faced with a young octopus in a bowl of seawater in front of you looking at you looking at it, eager to make a run for it, would you wrap it up on your fork and eat it?

Revenge of the octopus: beardart. (dailymail.co.uk)

Revenge of the octopus: beardart. (dailymail.co.uk)

Eating Dead Jellyfish

Friday, February 13th, 2015

Eating living jellyfish is hard enough to imagine – they are mostly water, they usually have piles of sting cells, and seem neither nourishing or appetizing. Unusually, Loggerhead Sea Turtles and Ocean Sunfish eat them out of choice. Even some people claim to: there are quite a few recipes for things like jellyfish crisps to go with your beer. But really, who really would eat them if there were decent alternatives around?

Jeelyfish blooms appear to be occurring more frequently. Ocean Sunfish and Loggerhead Sea turtles are among their predators (fao.un.org)

Jeelyfish blooms appear to be occurring more frequently. Ocean Sunfish and Loggerhead Sea turtles are among their predators (fao.un.org)

Jellyfish usually come in blooms, a nice name for the immense aggregations that frequently occur in coastal waters around the world. So what happens when a bloom of jellyfish matures, sheds its eggs and sperm, and dies? The dead mass of jellyfish sinks to the bottom of the sea and we have assumed it decays there, slowly consumed by bacteria, smothering the sea bottom, rendering it unfit for most other organisms.

Periphylla, the jellyfish used in the bottom feeding experiment, is a deeper water species that occurs in large blooms world wide p(planktonportal.com)

Periphylla, the jellyfish used in the bottom feeding experiment, is a deeper water species that occurs in large blooms world wide (planktonportal.com)

We’re wrong. An elegant study published several months ago has surprised everyone. Dead jellyfish were fastened to 50x50cm ‘landers’ and sunk, along with similar landers laden with yummy bits of mackerel, to the bottom of Sognefjord in southern Norway, 4000 feet below the surface. The results were filmed.

Surely the community of bottom scavengers would selectively eat the mackerel, and pay little attention to the jellyfish carcasses.

Atlantic Hagfish scavenging on the dead jellyfish (natureworldnews.com)

Atlantic Hagfish scavenging on the dead jellyfish (natureworldnews.com)

Instead, dense aggregations of scavengers moved in on the jellyfish just as quickly as they did on the mackerel. First came Atlantic Hagfish, attractively know as slime eels, which burrowed into the mass of dead jellyfish and selectively ate the spent gonads.

Atlantic Hagfish, also called slime eels (seasky.org)

Atlantic Hagfish, also called slime eels (seasky.org)

Then came the crustaceans – particularly a long-clawed crab called a galatheid which in the video look to be aggressive, each protecting its piece of jellyfish from others, spaced out over the lander. Then came a decapod shrimp and lyssianasid amphipods. The scavengers eliminated the jellyfish in 2 1/2 hours, which is extraordinarily fast.

When the hagfsih leave the jellyfish carcasses, galatheid crabs move in (natureworldnews.com)

When the hagfsih leave the jellyfish carcasses, galatheid crabs move in (natureworldnews.com)

Galatheid crabs are common members of the deep water scavenging community (marlin.ao.uk)

Galatheid crabs are common members of the deep water scavenging community (marlin.ao.uk)

In fact the whole event is quite extraordinary.

When a whale dies and sinks the bottom – we call it a whale fall – it becomes a major source of nourishment for the bottom scavenging community. Now it seems that when a jellyfish fall occurs, the same thing happens. The dead jellyfish contribute to the food web in ways we did not expect – and carbon is transported from pelagic organisms near the sea surface to the scavengers foraging on the sea bottom.

This is all good to learn. In recent years jellyfish blooms appear to be larger and more frequent, often in places already stressed by low oxygen or overfishing. But they remain part of the food web instead of smothering part of it when they die, and we did not know this. It makes them less of a threat to marine ecosystem stability than we thought.

By why any crab – or hagfish for that matter – would pass up mackerel flesh for dead jellyfish jelly remains a mystery.

The Shrimp of Shrimps

Saturday, July 26th, 2014

Shrimp are now the most popular seafood in North America. More than lobsters or tuna or even salmon.

Whiteleg Shrimp: Who can resist this?fiveinthechamber.com)

Whiteleg Shrimp: Who can resist this?(fiveinthechamber.com)

Getting shrimp to us has become infamous for all the collateral damage it has created. Shrimp trawlers, trawling for adults in the shallow tropics and sub-tropics of the world, have damaged bottom habitats and tossed out an immense load of unwanted bycatch – both features that should continue to condemn the method to oblivion.

Farming shrimp in coastal tidal ponds creates a whole different suite of equally damaging effects: mangroves are destroyed to make the ponds, and the ponds are moved every few years leaving behind nothing but devastation; pollution and waste are extensive; lethal disease is frequently widespread; salination of the underlying water table occurs; and in some regions people who do the farming or collect the fish for fishmeal may work in close to slave conditions, provoking concerns about human rights and social justice. It’s pretty well all bad.

One species in particular, the Whiteleg Shrimp (Litopanaeus vannamei) has become the species of choice for farms from Mexico and the Caribbean to India, Thailand, Vietnam, China, Indonesia and the Philippines. It is native to the warm Pacific coastal waters of Central America from Sonora Mexico south to Peru, and it grows faster, requires less protein to grow, and is more resistant to disease than other species. Everyone wants it.

Adult Whiteleg Shrimp, Litopanaeus vannamei (regisbador.com)

Adult Whiteleg Shrimp, Litopanaeus vannamei (regisbador.com)

In 1990 a modest annual Whiteleg fishery of 90,000 tons existed. Then, as the mangrove farms in Asia embraced the species, the fishery grew huge, reaching 3.2 million tons in 2012, dominating the market.

In 2010, because of the mangrove destruction and the human rights abuses, Greenpeace designated Whiteleg Shrimp a Redlist species. A reasonable conclusion would surely be to say sayonara to the whole sorry mess of shrimp farming and trawling.

But all is not yet lost.

Gradually, ‘intensive’ farming has begun, moving the ponds away from the shores, though still dealing with water supply problems, contamination, and disease. Not great news, but better.

Then, in the past few years, a new method of ‘superintensive’ farming has emerged, and it is very promising. The shrimp are bred and the larvae are grown in hatcheries, and post-larvae are then shipped to inland culture facilities. At their best, these facilities grow the shrimp to market size in a few months in biosecure tanks under controlled temperature conditions, using recirculated sea water, requiring no pesticides or antibiotics.

Whiteleg Shrimp larvae are grown in hatching facilities and then sent to the super-intensive tank farms. (intechopen.com)

Whiteleg Shrimp larvae are grown in hatching facilities and then sent to the super-intensive tank farms. (intechopen.com)

One of these super-intensive farms near Boston was featured recently in the NY Times, but 22 others are scattered across the US – in Iowa, Minnesota, even one near Las Vegas. This is revolutionary. Suddenly many of the problems associated with trawling or coastal pond culture disappear. No habitat destruction, no pollution, no added chemicals, no abused humans.

The Blue Oasis superintensive tank farm for Whiteleg Shrimp, near Las Vegas (lasvegassun.com)

The Blue Oasis superintensive tank farm for Whiteleg Shrimp, near Las Vegas (lasvegassun.com)

There’s sophisticated science to all this of course: selective breeding of Whiteleg adults to produce disease resistant larvae requires great care and patience. The largest breeding companies are now in Florida and Hawaii – the one on Molakai for instance. Comparable facilities in Vietnam and China now do their own selective breeding of Whiteleg for farms, but super-intensive tank culture is still uncommon there.

Meanwhile, the companies that have started tank farming in the US are quite excited. Should they be?

Their main remaining challenge is cost, and mostly they supply high end restaurants. But people in America are increasingly concerned that their food is produced in the least damaging way, agreeing to pay more for it where they need to.

Tank farmed Whiteleg Shrimp has now won the highest rating from Monterrey Bay Aquarium Seafood Watch. So let’s buy this stuff. Let’s insist on shrimp that have been raised in tank farms.

Then the tank farms will flourish and spread, replacing mangrove farms and shrimp trawls. The warm water coastal ecosystems will be far better off, bycatch will be radically reduced, and mangroves will not be destroyed for farming shrimp.

Everyone wins.

Krill and Omega 3

Friday, April 25th, 2014

TV ads, pharmacy shelves, it’s hard to miss bottles of Omega 3 capsules, derived from krill, promising relief or protection from cardiovascular and other diseases.

Krill oil pills are marketed far too well (leehayward.com)

Krill oil pills are marketed far too well
(leehayward.com)

There are two serious problems with this. One is the impact this will have on krill populations, and the other is the validity of the evidence of the benefits.

Antarctic krill, Euphausia superba, is the primary source of krill oil (healthyplanetcanada.com)

Antarctic krill, Euphausia superba, is the primary source of krill oil (healthyplanetcanada.com)

First the source. The main source is Antarctic Krill, Euphausia superba. It grows to 5cm long, and lives in huge schools in the the near-ice regions around Antarctica. Much of its food comes from the algae growing on the under side of the ice. Its predators? Pretty well every marine vertebrate living or hunting in the Southern Ocean: baleen whales, seabirds (penguins), most of the seals, many fish species, and now humans.

A small school of Antarctic krill - you can see how easily trawled the shrimp are (healthpost.co.nz)

A small school of Antarctic krill – you can see how easily trawled the shrimp are (healthpost.co.nz)

In our illustrious past as hunters in the Southern Ocean, we eliminated the Antarctic fur seals by 1900, most of the great whales by the 1930s, pelagic fish by the 1970s, and bottom finfish by the 1980s. That has left krill.

Krill trawling began in the 1970s, and didn’t look promising: the animals had to be processed within hours of capture to avoid rapid enzymatic breakdown releasing toxic flourides. Now, however, ships process the krill quickly, rapidly removing the oil, and freezing or drying the meat.

The Southern Ocean is remote, hard to protect, and under stress (underwatertimes.com)

The Southern Ocean is remote, hard to protect, and under stress (underwatertimes.com)

We don’t actually eat krill meat – that goes into fish meal for chickens – but during the past decade the oil has become an increasingly popular source of Omega 3 as a human dietary supplement.

The current level of krill fishing in the Southern Ocean may appear to be sustainable, but the signs of ecosystem stress are everywhere. Apart from Southern Humpbacks, the great whales have not recovered; Adelie and chin-strap penguin populations are in decline; in warmer water areas of the West Antarctic Peninsula non-nutritious gelatinous salps are outcompeting krill; and in areas where sea ice is shrinking, less under-ice algae exists for krill to feed on.

Penguin populations are in decline, an indirect indication of a stressed ecosystem (noaa.com)

Adelie Penguin populations are in decline, a direct indication of a stressed ecosystem (noaa.com)

The Southern Ocean ecosystem depends on krill, but even without our krill fishing, something is clearly very wrong. The deepest, newest threat to the krill is our desire for Omega 3, for we are too numerous, too obsessed by our health, and too susceptible to sophisticated marketing. We are insatiable.

Now, to complicate things, and just published in The Annals of Internal Medicine, comes a meta-study of 72 studies of the dietary use of Omega-3 fatty acids in treating coronary disease, altogether involving 600,000 participants from 18 countries. Its conclusion? No support actually exists for cardiovascular guidelines that promote high consumption of Omega 3.

We are extracting oil from Antarctic Krill for medical benefits for ourselves that are dubious at best, to supplement fish meal which is ecologically short-sighted, and to supplement what we feed our pets. None of this is necessary, and appears in fact have no true value for any of us: chickens, cats, dogs or humans.

This isn’t a hard situation to resolve: we can stop krilling. At stake is the viability of an immense, critical and threatened ecosystem.

Iconic Southern Humpack in the Southern Ocean (earthtimes.org)

Iconic Southern Humpack in the Southern Ocean (earthtimes.org)

Myths of the Giant Oarfish

Wednesday, December 11th, 2013

Giant Oarfish (Regalecus glesne) have been in the news again recently. Two washed up dead on the coast of California in October, one at Santa Catalina, the other near San Diego. They are lousy swimmers, and probably got caught in coastal currents they couldn’t fight successfully.

A dead giant oarfish is still a remarkable thing. These two were 4-5 meters long, but they can grow to as long as 11-12 meters No other bony fish species grows longer.

About 20 men holding up one giant oarfish (wikipedia.com)

About 20 men holding up one giant oarfish (wikipedia.com)

They are also rarely seen by humans, so every corpse is a new source of amazement. Normally the fish are pelagic, living well off shore, probably usually in deep water – their large eyes suggests adaptation to the deep dim world a few hundred meters below the surface.

And there the mystery of this fish remains. Cruising through the science articles that mention them usually just describe another dead animal that has washed up somewhere new.

The little information we have suggests they spend their time hovering vertically in the water, propelled slowly by a long and undulating dorsal fin while the rest of the body doesn’t move. You really need to see this to believe it: a robot camera captured one a couple of years ago.

Dead medium sized oarfish lying beside living child. The long dorsal fin is typically red (strangesounds.org)

Dead medium sized oarfish lying beside living child. The long dorsal fin is typically red (strangesounds.org)

We know they they are toothless, lack scales, and have small mouths. As they hover vertically, they are probably feeding, sucking in plankton and euphausids or krill and straining them from the water they push through their gill-rakers. Perhaps they somehow eat small fish. They certainly can’t chase down prey, and they grow too large to be prey for most other fish besides sharks. Somehow they don’t turn up in fishermen’s nets very often, and in fact seem able to avoid the nets.

A living oarfish, rarely seen (ferrebeekeeper.wordpress.com)

A living oarfish, rarely seen (ferrebeekeeper.wordpress.com)

What else? Their meat tastes mushy, gelatinous, so they are safe from human predation. There are perhaps 4 different oarfish species of different sizes around the world. They have been observed, usually dead, most often in warm-temperate waters. An old quote: “A dead oarfish is about as tough as wet cardboard.”

A very small juvenile oarfish, a very rare find. Captive,offered for sale, it soon died (reefbuilders.com).

A very small juvenile oarfish, a very rare find. Captive, offered for sale, it soon died (reefbuilders.com).

And the myths? Perhaps they change gender as they grow larger (many fish do). Perhaps they shed the ends of their tails the way some lizards do (maybe the ends just fall off more quickly from dead animals). Perhaps they are the source of mariners’ tales of huge sea serpents (those seen at the surface are usually sick or dying, and could perhaps have inspired the mariners). Perhaps they are especially sensitive to Earth tremors – for example, before the 2011 tsunami in Japan, 20 beached themselves and died (who knows?).

Probably none of these are true, but we really lack the facts that dispel most myths.

What we have here is a most bizarre fish, rarely observed alive and healthy, of no commercial value to us. It probably isn’t endangered, though it certainly is not abundant. It shares this planet with us, mostly out of our view, which is the safest place for it to be. It is a reminder that life on Earth is incredibly diverse, and that not only do we not know everything about everything, but that in fact perhaps we don’t need to know.

It just is.