Marine Extinctions - Paper!

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Finally!

Years ago, I posted several pieces about marine extinctions.

In brief, they postulated that compared to the terrestrial biota, there had been comparatively few - and that after having had a closer look at two controversial species, I could find zero evidence for any marine Fishes that had gone extinct during the anthropocene.

But obviously there has been a grave reduction in numbers all the way to local extinctions, meaning that many populations are now so severely depleted that they have accumulated extinction debt; and having thus lost much of their resilience and faculty to adapt, an environmental catastrophe like Climate Change could well push them over the brink.

And now this is largely being confirmed in this paper.

Synopsis here.

And I cite.

Conclusions 

On many levels, defaunation in the oceans has, to date, been less severe than defaunation on land.
Developing this contrast is useful because our more advanced terrestrial defaunation experience can serve as a harbinger for the possible future of marine defaunation (3). Humans have had profoundly deleterious impacts on marine animal populations, but there is still time and there exist mechanisms to avert the kinds of defaunation disasters observed on land. Few marine extinctions have occurred; many subtidal marine habitats are today less developed, less polluted, and more wild than their terrestrial counterparts; global body size distributions of extant marine animal species have been mostly unchanged in the oceans; and many marine fauna have not yet experienced range contractions as severe as those observed on land.

We are not necessarily doomed to helplessly recapitulate the defaunation processes observed on land in the oceans: intensifying marine hunting until it becomes untenable and then embarking on an era of large-scale marine habitat modification. However, if these actions move forward in tandem, we may finally trigger a wave of marine extinctions of the same intensity as that observed on land. Efforts to slow climate change, rebuild affected animal populations, and intelligently engage the coming wave of new marine development activities will all help to change the present course of marine defaunation. We must play catch-up in the realm of marine protected area establishment, tailoring them to be operational in our changing oceans. We must also carefully construct marine spatial management plans for the vast regions in between these areas to help ensure that marine mining, energy development, and intensive aquaculture take important marine wildlife habitats into consideration, not vice versa. All of this is a tall order, but the oceans remain relatively full of the raw faunal ingredients and still contain a sufficient degree of resilient capacity so that the goal of reversing the current crisis of marine defaunation remains within reach. 

The next several decades will be those in which we choose the fate of the future of marine wildlife.

Indeed, there is hope.

And like I said back then, there is a role, small or big, that each of us can play in order to ensure that the worst case scenario does not eventuate.

And what about the Sharks?

Re-read this report by the IUCN and this paper by Christine!

Let' do it!

H/T The Ambassador aka the Saffron Pimpernel!

Marine Conservation - the principal Issues!

Just in case we lose sight of the context here.
Barring cataclysmic cosmic or geological events, these are the biggest threats to marine biodiversity - once again, very simplified.

First and foremost: there are too many people!
We are seven billion now and probably we will get as high as 9 billion, both of which is just not sustainable.
Moreover, billions of people are attempting to attain what they consider to be better life conditions, meaning that their ecological footprints are increasing as they progressively consume more resources and produce more waste. Even if we managed to stabilize or even turn around population growth, this will continue to exert tremendous pressure on biodiversity.
Those are monumental challenges indeed - solutions???
These are the root causes of all that follows.

The biggest anthropogenic threats to marine biodiversity are.

• Global Warming
• Ocean Acidification
• Pollution
• Habitat Degradation
• Overfishing including Bycatch & Discards

When it comes to Overfishing.
As far as can be ascertained, anthropogenic extinction rates so far have been substantially lower in the oceans than in terrestrial ecosystems. In fact and despite of our best efforts, there is probably not a single documented case of us having fished a marine Fish to extinction - and should there be one, it would be the exception and not the rule.
This is cause for hope.

But that's of course not the whole story.
Several Fishes have become locally extinct and the populations of many marine Fishes that have been targeted commercially are severely depleted and but a shadow of what they used to be.
There is a line of thought stipulating that those populations have accumulated extinction debt and that they could be driven into extinction by an environmental catastrophe.
That environmental catastrophe could be Global Warming.

Sharks?
They are obviously subjected to the same pressures.
In particular, several larger species are being severely overfished and although to my knowledge this has not been specifically documented, it also stands to reason that Shark populations will be affected by the overfishing of their direct prey or of even lower trophic levels like forage Fishes.
Some of those larger Sharks are also apex predators and keystone species and there is research documenting that their removal can ripple down through the trophic levels via cascading effects, hence exacerbating the ecological consequences of their demise.

This as far as I can see are the principal issues.
The problems are enormous and eminently intractable as documented by the frustratingly slow progress of conservation and above all, by the many conservation setbacks and defeats. Yes there have been many successes - but alas, everything points to the fact that in the big scheme of things, those successes are simply too small and the pace, simply too slow. Especially if we don't get a handle on Global Warming, the future for marine biodiversity looks very bleak indeed.

Solutions?
If we so wish, there is a role for each of us to play - the most basic one being that it behooves all of us who live in relative opulence to reduce our ecological footprint, including limiting our carbon emissions! And those of us who want to do more and get involved in advocacy will find unlimited opportunities to make a difference as e.g. discussed here in the case of Shark conservation.

Orgs I personally like: Shark Foundation and Save our Seas Foundation for sponsoring research; Shark Trust, Shark Savers and Shark Defenders for advocacy; Pew Environment for all of the above.

But please, let us be rational and credible.
Let's please stop the esoteric balderdash and the pseudoscience.

The sooner we do that, the sooner we will be able to effect real, positive change.
Yes?

A Glimmer of Hope?

Another fantastic collage by Vitaly - using a pic of Predator by Lill!

Found this message in my in-box this morning.

My marine conservation sensei is of course absolutely correct.
Although some highly depleted but thankfully, largely local as opposed to global Fish populations may have accumulated extinction debt and may be pushed over the brink by the double whammy of Global Warming and Ocean Acidification, we are still to unequivocally document the extinction of a single marine Fish - meaning that there is hope that most of the Fishes could indeed survive in some MPAs (Assumption 3, Solution A).
But my sensei is heavily invested genetically and has no choice but to be optimistic about the future prospects of his grandchildren. And, the next 100 years is a mighty long time - just think of all that has happened, and of the havoc we have wreaked since 1911!

Anyway, here is the message, unabridged.
Wise words indeed - but that's why he is my sensei!

Your blog of 2011/05 was a bit of a wail of despair and your facts per se are hard to refute, but one might paint many different pictures from the same pigments of fact.

Yes, consumerism is the dirty secret of modern social, economic and political stability.
Like our relatives the chimpanzee, we humans are driven to compete for the biologically important things in life, like breeding rights with Alphas of the opposite gender, by amassing resources. Glittering status things, Ferraris, and Rolex watches do work. Societies with strong economies that foster consumerism out-compete other societies, and governments that allow people the freedom to compete for and amass resources can even get away with political repression, as in China. However consumerism that draws lightly upon the accumulated resources of Earth or does not overtax the compensatory mechanisms that maintain the equilibrium of the biosphere may be compatible with maintaining a healthy natural world.
Clean energy technology may be the sort of straw that an optimist might grasp here.

The big problem, as you pointed out, is population.
Yes there are presently too many people worldwide and the inexorable spread of consumerism will only increase the strain on natural systems. However, the demographic transition, which affects all modern first world societies, is an unexpected miracle with long term effects impossible to ignore. More and more countries are moving from zero population growth to negative growth, as in Japan and southern European countries. Even many third world countries are experiencing a dramatic reduction in the number of children per family, and education and empowerment of females in patriarchal societies promises continuing demographic changes. The inertia of population growth will certainly cause grave strain on natural systems throughout this century, but the Long Run may not be bleak if we can get through this bottleneck. Nature has its own ways of controlling overpopulation as well, and the Four Horsemen of the Apocalypse could saddle up yet again for another winnowing. Perhaps they have even started their ride in Africa now.

It is probably an unrealistic goal to protect all habitats or to maintain large populations of species like sharks everywhere.
The future of, say, Triaenodon populations in places like Cocos Island may be bleak. It may be more effective to allocate resources to protect species and key habitats, with the hope that species that can “ark” through the next 100 years and then repopulate the spaces a more enlightened humanity sets aside for them. Education does change attitudes in the long run. I am encouraged that large areas of marine environment have recently been protected. Enforcement is always a problem, but some vast areas like the Northwestern Hawaiian Islands are effectively protected by the might of the US government, others like the southern Line Islands by remoteness. Species is such areas, including Triaenodon, should get through the bottleneck OK.

The SRMR is the sort of project that can play a vital role in protecting species and habitats.
Even though you seem to despair for the future, interpretation is everything and according to the guardedly optimistic picture I have painted from facts and trends, the work you and others are doing may yet provide our descendents the resources necessary to help restore balance in the natural world.

Weekend Rant!

Time for a rant!

From a message by a friend

Agree that there is much breathy hyperbole and blatant nonsense written about sharks and conservation, but I suppose that this is inevitable when concern is high but facts are few, with the most solid data residing in relatively inaccessible scientific papers.

Generally I take a sanguine or even charitable view toward the popular Jeremiads you have castigated since the goals of the authors are generally in concordance with mine, and these often painfully well-intentioned folks are far more able to communicate values effectively and educate a large audience than someone who uses words like sanguine or Jeremiad, no?
And education does seem to work in the long run.

Totally agree – BUT!
I’m getting terminally irritated that people who purport to be Shark conservationists and are perceived to represent the whole movement continue to make public statements containing ludicrous assertions and statistics.
This is not only not helpful - it directly undermines our efforts by allowing the other side to assert that we’re nothing but a bunch of lunatics who operate with false claims.
Is that what we want?

Yes it’s an old grievance of mine – but enough is enough.
So there.

But first, check out this piece of equine manure!
Very timely indeed – thank you!



Wow!
Pure sharkitarian snake oil!

There are no Shark attacks?
Right!
Please re-read this!

Sharks?
When talking conservation, talking about “Sharks” is utterly useless!
The fact is that “Sharks” are neither threatened with extinction, nor are "they" apex predators – only a small minority of species are apex predators, let alone keystone species, and the species that are particularly at risk of extinction are several large predatory Sharks, many of which are pelagic; possibly some deep water Sharks; and maybe Whale Sharks – full stop!
Other species are doing no better and no worse that any other Fish that is not subjected to exceptional fishing pressure – meaning not particularly great but not particularly catastrophically, either.
List here (search for "Sharks"), criteria here.

The numbers?
The numbers are just that, numbers.
If one does not put them into context by comparing them to what we know about individual species in specific locations, they say nothing about sustainability which is the only thing that counts.
Yes we all know without having to resort to peer reviewed science that many local, and possibly even some global populations of some Sharks have been severely depleted, and that their disappearance is of concern – but for the time being, that’s basically all we can assert.

So far, there has been one single paper trying to shed a light on the actual numbers being caught, and this only based on data from the Shark fin trade. Read it!
The paper is based on a series of (probably plausible) assumptions that are heaped upon more assumptions, and consequently, the results are merely expressed in orders of magnitude. Specifically, the authors come to the conclusion that the fins traded annually came from between 26 and 73 million Sharks, with a median number of 38 million.
Does that really allow us to honestly state that up to 73 million Sharks are being killed each year, as everybody and his dog has started to assert?
Kudos to Seafood Watch for doing it right: It's estimated that tens of millions of sharks are killed around the world each year for their fins is much better - but then again, have they been killed for their fins?

As I said, the above numbers are only about the global Shark fin trade alone.
They do not cover many other Shark fatalities due to bycatch or targeted food fisheries where the fins are not being introduced into the fin trade. Also, that was then and the trade has very likely increased since. It is thus entirely plausible to assume that the “real” number is higher, and it is perfectly OK to say so.
It is however totally unacceptable to make up numbers on the fly, be it as many as 100 million, let alone over 200,000 million (!!!) which is just plain ludicrous and quite frankly, a total disgrace! Yes, I'm being frank! :)
The good news is that I know that somebody is working on a peer reviewed paper about the global number of Shark being killed – but once again, unless put into context, those numbers will mean absolutely nothing!

And what about the Rate of Depletion?
Is it really true that 90% (or 99, or 70 – whatever!) of global Shark stocks have already been wiped out? Compared to which original baseline count, done when, where and by whom?
Where are the data?

And is it really true that Some marine biologist have suggested as soon as 2020 these magnificent creatures may be extinct – and if so, who is claiming such utter baloney?
Those endangered species of Sharks will become commercially extinct long, long before they will become biologically extinct! But there's a caveat: it is however probable that some local populations may have shrunk to the extent that they may have accumulated extinction debt and that they may be too small to be able to withstand the pressure of a large environmental shock, like the current anthropogenic Climate Change – re-read this post!

Shark Finning?
Shark finning does not equal catching Sharks. It is a specific, particularly wasteful and particularly cruel harvesting technique and for these reasons alone, it certainly needs to be stopped.
But is everybody aware that stopping the finning does not necessarily stop the fishing? The most widespread remedy against Shark finning is to legislate that the Sharks must be landed with their fins attached. This reduces the number of Sharks that are being killed as the carcasses take up a lot of space in the hold of the vessels – but as many examples show, Sharks are still being landed with their fins attached in what clearly appear to be unsustainable numbers.
Also, in many third world countries, local fishermen (and poachers!) have already wiped out many of the traditional food fisheries and as a consequence, many people have added Sharks to their menu, meaning that there is a substantial and increasing Shark food- , as opposed to Shark fin fisheries.
Thus, if we want to save Sharks stocks from overfishing, Stop Shark Finning! petitions alone are simply not adequate – we must also campaign for their protection!

Also, not every fin that is being sold has been finned!
Statements like over one hundred million sharks are caught and finned alive are thus doubly misleading!

Cascading Effects?
Yes there is a seminal paper by Myers et al. that essentially shows how the removal of large predatory coastal Sharks in the Northwest Atlantic led to the explosion of the population of Cownose Rays who in turn wiped out the Scallops, and the industry depending on them, in Chesapeake Bay. More details here.
Great paper – but it has one weakness: nobody was harvesting those Cownose Rays!

But in the real world, coastal Sharks are not being selectively removed alone.
Instead, fishermen target both the apex- and the mesopredators (and the prey), meaning that asserting that removing the big Sharks will inevitably lead to a population explosion of mesopredators (many of which are incidentally Sharks!) who in turn will wipe out the grazers which in turn will lead to an explosion of algae who in turn will smother the reefs can be totally wrong.
In a way, it is now us who have unwittingly assumed the role of apex predators and are keeping the lower trophic levels in check – see many terrestrial habitats where most apex predators have all but disappeared but where there has not at all been a total collapse of the system!
I’m not saying it is not so: I’m just saying that the empirical evidence is scarce and that once again, those effects will vary according to habitat and species composition.
See Ferretti et al. for more details!

As to the role of Sharks in their habitat and the widespread explanation that they weed out the sick and dying and thus keep the gene pool of their prey healthy, etc?
Certainly intuitively plausible: but to my knowledge, whereas there is plenty of research about the role of terrestrial predators, such effects have not been conclusively documented for Sharks – yet!

Which brings me straight over to Climate Change and Oxygen Production!
Check this out.



Did you hear that?
Who has come up with the glorious idea of linking Shark conservation to the Oceans’ production of oxygen?
Yes the Oceans provide for about half of the planet’s oxygen production through the photosynthesis by phytoplanktonic Algae and Cyanobacteria (but then again, probably not!). This (incidentally, to a very small extent), and the sea water’s capacity to dissolve CO2 make it that the Oceans are also Earth’s largest active carbon sink.
It is also certainly true that the Oceans have a great influence on the weather, and that millions of people depend on them for food.

But this got nothing to do with Sharks!
The principal threats to oceanic ecosystems are probably Climate Change, Acidification, Overfishing, Pollution and Habitat Degradation – not the fisheries for Sharks!
It is just not plausible and there is certainly no scientific evidence indicating that if one selectively removed all Sharks
- the oxygen production would cease due to the disappearance of phytoplankton
- the oceans would cease to be a carbon sink
- the weather would change
- fisheries would collapse and humankind would starve
or any other similar stupidities that happen to be en vogue among some Shark activists!

Shark Intelligence?
This very much smells like the newest up-and-coming Shark conservation fad.
Does the fact that some Sharks migrate and that they are capable of memorizing locations automatically mean that they are particularly intelligent? Why are some quarters asserting that it is so, when this is in no way being claimed by the authors of those migration papers?
Sorry Richard – I still think you rock! ;)

Are Monarchs particularly intelligent? Wildebeest?
What about Bees who are not only capable of finding and memorizing the location of a food source, but then also fly back to the hive and convey that information to the other bees – so effectively. that those other bees can find the food without being guided there by the finder?
Hell, that’s even smarter than what we know about the so much hyped Dolphins!

Frankly, I dunno.
My gut tells me that migration and spatial orientation are not good indicators for intelligence. Yes it is amazing behavior – but animals doing amazing things are more often than not simply well adapted to their ecological niche, and behavior that comes across as being remarkably clever is often hard wired and the result of evolutionary selection as opposed to volition.
Example? The amazing Anglerfish!
Perfectly camouflaged and provided with an ingenious lure, they are highly successful at ambushing their unsuspecting prey. Totally clever – and yet one of my ichthyological gurus assures me that they dispose of the lowest brain-to-body mass ratio of all Fishes!

Sharks BTW have a relatively high brain-to-body mass ratio, somewhere between Teleost Fishes and Mammals..
But although we all intuitively know what intelligence means conceptually, it is nevertheless difficult to define, especially in animals - and even more difficult to compare, see the Bees and the Dolphins!

When it comes to Sharks, the one person who knows most about the topic is probably Doc who has demonstrated remarkable learning and problem solving capacity in Lemons, very much in line with what we experience daily with our Bulls.
My gut feeling is that as always, different species will display different abilities, and that those predatory species with the widest trophic niches requiring the widest range of predatory strategies and thus the highest adaptive capabilities will be perceived as the most intelligent - but then again, a friend may be on to something when he remarks
Incidentally, since humans filled a generalist predator niche at one time before we graduated to planetary predator class, would we not inevitably tend to think that other generalist predators like sharks are particularly intelligent?
Yes, it's complicated!

Still, I fully agree with Wolfgang that Tiger Sharks come across as being way smarter than, say, Whale Sharks that I incidentally perceive as being particularly dumb - and who incidentally migrate like crazy!

But those are clearly personal perceptions, not objective data.
Whereas I’m convinced that all of our Bull Sharks have distinct personalities and that they develop affinities to specific persons, I also know that we humans have a fatal propensity for anthropomorphism, i.e. for attributing human faculties to animals.
So, yes, let’s love them like crazy – but let us not assert that our feelings are being equally reciprocated, or the like!
Yes Emma very much appears to love Jim (and there’s absolutely no doubt whatsoever that Jim loves Emma!) – but she is very likely being bribed with massive amounts of juicy handouts and is just being the opportunistic feeder Tiger Sharks are!

Having said that, there appears to be clear evidence that the behavior of some Sharks goes well beyond that of mere automatons that are solely driven by genetic programming.
In fact and going back to, say, Tigers and Bulls, aren’t high flexibility and adaptive capability precisely what we would expect evolution to select for in a generalist predator – meaning that some of what we perceive as being intelligent behavior may be genetically encoded, but that there must also be scope for individual decision making, individual learning, individual preferences, individual personality, etc. which may indeed be good indicators for intelligence.
Again, I don’t know - but precisely because of that, I would never proffer any strong statements one way or the other!

Long story short?
If we want to be credible Shark advocates, we got to do our homework and first of all, be informed about the animals we love!
Science is always in flux and today’s insights may quickly become tomorrow’s fallacies, meaning that we must keep abreast of the latest research results and not base our knowledge on old publications and approximate hearsay.
Most importantly, we the amateur naturalists should never make up things on the fly, nor should we idly re-interpret what is considered to be the accepted consensus.

This does not mean that we should not challenge the current status quo, as that is precisely the process by which knowledge is being advanced!
BUT: the only accepted technique for doing so is the Scientific Method and as always, let me warn against the siren calls and intellectual shortcuts of the self promoters, quacks and charlatans - see on top!

All researchers I’ve ever met have always been eager to engage in informed discussions and to entertain different hypotheses, if adequately supported by according observations.
Those researchers are neither omniscient nor omnipresent and often, observations by common mortals like us have greatly contributed to the advancement of scientific insights - so even if you have no academic background, don’t be shy and speak up!
But do your home work first!

Or, as I said before .

Can we maybe just be a little more humble and less righteous, the more since Conservation is so complicated?
Maybe progress towards more facts and less truthiness (read this!)?
Can we maybe just open our eyes and wonder at the magnificence of what IS instead of trying to make things up?

We are the amateurs.
Can we please listen to what the professionals are telling us – the principal message being that extreme positions (on both sides!) are inhibiting Conservation and appropriate Management measures?
Recent example? Right here – like it or not, the man has a point!

If we want to educate others – let’s educate ourselves first!

And here endeth the weekend rant!

PS Patric's take: WOW!!!

Marine Extinction - four

白鱀豚

John C. Briggs in 2001.

In this article, I argue that the species changes at the K-T boundary were neither sudden nor catastrophic. They were most likely caused by a regression of seal level that led to a decrease in primary production.

The catastrophic extinction under way today as the result of human destruction of the biosphere is far faster and greater than the events of 65 million years ago.

J. C. Briggs ten years later.

Marine extinctions and conservation

Abstract

In contrast to the large number of terrestrial extinctions that have taken place over the past 12,000 years, there have apparently been very few marine extinctions.
But these small losses should not be reason for complacency. During the past 50 years, government supported, commercial fishing has resulted in the collapse of about a thousand populations that once supplied most of the world’s seafood.

For the collapsed species, now existing as small remnants of their former population sizes, the future is bleak.
They suffer from loss of genetic diversity, inbreeding depression, and depensation. Because marine species were eliminated by historic climatic changes, continued global warming is likely to result in the extinction of small populations that already have a precarious existence. They may be considered evidence of an extinction debt that must be paid as the climate change becomes more severe.

For some of the remnant species, extinction can be avoided if there is a rapid management conversion to the use of more marine protected areas (MPAs) and extensive ocean zoning where fishing is prohibited.

From the Introduction

Ceballos et al. (2010), in their article on the sixth extinction crisis, observed that extinctions caused by human activities are thousands of times greater than the background rate.
Indeed, many other articles have also concluded that we are in the midst of the world’s sixth, great mass extinction. Most such articles, in discussing the rate of global extinction, are actually referring to the terrestrial (and freshwater) habitat and not the marine waters that cover 71% of the earth’s surface.

What about the marine environment?
Does the alarming rate of land extinctions also extend to marine species?

From Species at Risk

Although extinctions have been few, this should not detract from the fact that uncontrolled exploitation (overfishing) has drastically reduced most populations of large marine animals from their sizes prior to human exploitation (historic baselines).
Hutchings and Reynolds (2004) examined data from 230 marine fish populations and found a median reduction of 83% in breeding population size from known historic levels. Lotze and Worm (2009) similarly investigated records of 256 exploited populations and found an 89% decline. In the latter study, the groups most severely affected were
(1) diadromous fishes (salmon and other species that migrate to and from freshwater),
(2) ground fishes (large demersal species such as cod and halibut),
(3) reef fishes,
(4) deep sea fishes, and
(5) sea turtles.
All of these groups had suffered declines of 90% or more from their pre-exploitation abundance.

As noted, most of the major global fisheries are severely stressed, but in some areas, the situation is demonstrably worse.
For example, in the western North Atlantic, the populations of almost all the large-sized, predatory fishes have collapsed (Essington et al. 2006). Included are the ground fishes such as the cod, flounder, haddock, and halibut as well as pelagic species such as blue marlin, sailfish, bluefin tuna, and albacore.

All of the fishery crises, demonstrated by a thousand or more collapsed populations that are presently at risk, have occurred with the past 50 years.

Overfishing still continues, often due to scientific advice being ignored by politicians in charge of setting the fishery regulations. But the main drivers are generally identified as an oversupply of fishing vessels and, perhaps more important, government subsidies to fisheries estimated at about $30 billion per year (Pauly 2009).

From Extinction Later?

Of all the reef denizens, the fishes are by far the best known, and, in places such as the Florida Keys or Hawaii, any extinctions occurring during the past 50 years would have been noticed.
Worldwide, only two marine fishes are known to have become extinct (Dulvy et al. 2008): the Galapagos damselfish, Azurina eupalama, last recorded in 1982, and the Mauritius green wrasse, Anampses viridis, missing since 1839. (But please re-read this!)
The New Zealand grayling, Prototroctes oxyrinchus, is also extinct, but it resided primarily in freshwater. Each of the extinct marine species had been found only around a small, oceanic island and was probably represented by a small population. Species with small geographic ranges and low population densities are likely to have an enhanced extinction risk (Purvis et al. 2000).

Aside from the fishes, a few other marine species are known to have become extinct during the past 12,000 years: four mammals, eight birds, four mollusks, and one algae (Dulvyet al. 2008).

When these losses are considered against the total marine species diversity of at least one million, the rate of species extinction has been exceedingly low.

From Conservation

The conservation movement needs to focus on the small populations that are currently at risk.

In the marine habitat, the greatest risk is borne by about a thousand small populations produced by overfishing over the past 50 years.
They have demonstrated a remarkable tenacity in being able to hang on, despite handicaps such as the loss of genetic diversity, depensation (Allee effect), and inbreeding depression.Although some populations that have collapsed may have lost the capability to rebound, those that still consist of many individuals, thousands rather than hundreds, may be able to recover.

There are two conservation alternatives for fishery science and management, one is to continue business as usual and the other is to convert to an ecosystem-based management program (Pauly 2009).
The transformation will require extensive use of ocean zoning, spatial closures, and no-take marine protected areas (MPAs). MPAs presently cover only 0.7% of the world’s oceans, but international agreements have called for at least 10%. If we wish to re-establish functional ecosystems where uncontrolled exploitation has obliterated them, these changes must take place more rapidly than is currently envisioned.
MPAs that are appropriately supervised would benefit most species, while broad no-fishing zones would help the wide-ranging species.

The current pace of global warming indicates that another global extinction is on the horizon.
This means that our small marine populations, remnants of once larger ones, are at risk because, among other handicaps, they may no longer possess the genetic diversity necessary to cope with environmental change, i.e., they represent an extinction debt that has been built up during the past 50 years.

We cannot afford to sit back and lose several hundred of the large fish species that provided the bulk of our seafood only 50 years ago.
In addition, there is now a myriad of smaller fish and invertebrate species that have also been overfished and need to be restored to the food web.

Conclusions

Marine species extinctions are spasmodic, occurring primarily in response to drastic environmental changes.
Over the long run, most extinctions have taken place in the temperate zones, probably because these areas have been subjected to more climatic changes than the tropics. But there is also contemporary evidence that extinction patterns have originated in the high diversity center of the tropics, even though the final elimination of the species concerned may eventually take place in peripheral areas.

After a quiescent period of 1.5 million years, global warming has taken the world to the edge of another precipitous extinction episode.
In the marine environment, there are a thousand species or more that overfishing has reduced to small remnants of their former population sizes. These species are already at risk because of the handicaps of small populations and that risk will greatly increase with the environmental change that lies ahead. As things now stand, they represent an extinction debt that almost certainly will be paid as warming proceeds.

But many of them can still be saved if management of marine fisheries is shifted to an ecological basis.
MPAs must be at the core of a new management philosophy, but at present, they cover only 0.7% of the world’s oceans when they should cover at least 10%. But MPAs cannot solve the entire problem because some species, especially those that are wide-ranging, will need to be protected by broad ocean zones where fishing is prohibited.

Amen to that, brother!

Marine Extinction - three

Remember this post?
In it, I postulated that we haven't managed to cause the global extinction of a single marine Fish - yet!

Well, I might have been wrong.
Enter the 2003 paper Extinction vulnerability in marine populations in general and Azurina eupalama, pictured above, the Galapagos Damsel or Blackspot Chromis in particular. A small, drab planktivorous Fish, it apparently went extinct when the 82/83 El Niño eliminated the local plankton production for a year.

But then again, as usual, things may be way more complicated.
I am truly blessed in being able to access a network of unbelievably knowledgeable and smart people, and having asked the question, one of my Fish gurus commented as follows.

This little known species was the subject of much discussion between Dr. Ross Robertson of STRI, myself and others on our ichthyological expeditions in the Tropical Eastern Pacific, or TEP.

Our consensus was that it would be premature to pronounce Azurina eupalama extinct for several reasons:
It may be a “boom or bust” species existing in very low numbers until conditions are propitious for a population explosion. Being drab, small and unexceptional-looking it would pass unnoticed by all but a few knowledgeable scientist divers, who might never encounter remnant, small, scattered populations.
The ocean is a big place!

Luzonichthys earlei is a species in Hawaii with extreme population fluctuations and there are others like that here.
Like its sibling species north of the equator in the TEP, A. hirundo, it is a cold water species.
In places like the Galapagos it may usually live at great depths, or retreat to cool depths in warm or even normal temperature regimes. Richard and I recently published a paper describing 5 new damselfish species we found with rebreathers, all from below 80 meters. The family does go deep.

Finally, and to me most importantly, the center or core of the population of this species could very well be elsewhere, likely in the relatively faunally unknown areas of the TEP along the coast of Equator and northern Peru, spreading to marginal habitat areas like the Galapagos or Cocos Island under certain transient conditions, only to disappear when conditions revert to the norm.

There are also analogs for this pattern in Hawaiian fauna.
Species of fish and mollusks present in the cooler waters of the Northwestern Hawaiian Islands have historically appeared in the main Hawaiian Islands for awhile and then vanished utterly. If we only had collecting experience from Kauai to the Island of Hawaii it would certainly look like several species of endemic Hawaiian cowries such as Cypraea rashleighana or C. burgessi have become extinct within the last 30 years.

This idea of a core population existing outside its historically recorded range is a testable hypothesis, of course.
Ross and I tried to get permission to take the STRI RV Urraca to Isla de la Plata off Equator, a likely core area well-situated to seed areas down current like the Galapagos.
Alas we were unsuccessful.

Life is resilient and adapted by evolution to the conditions and even the extremes of conditions in its habitat.
The thought that a marine species existing through long eons of geological time would crash utterly during one single recent weather event is hard for me to swallow.
I shave with Occam’s Razor.

Methinks the question of marine fish extinctions in recent times remains open…….though I will admit that I am losing hope regarding the Placoderms!

Me too!
But there's still hope for Megalodon! :)

Back to the marine extinctions, please read this.
Amid a sad list of local, regional and alas, global extinctions of various marine organisms, I find Anampses viridis, the Mauritius Green Wrasse, possibly a victim of sedimentation and nutrient pollution . It is once again an endemic which makes it particularly vulnerable and according to this equally sad list of most recent extinctions, it has not been reported since 1839. But then again, as witnessed by several spectacular range extensions that we have documented on Shark Reef, the published geographical distribution of Fishes remains always in flux, and there's a slim chance that it may suddenly turn up elsewhere.
If the Bull Sharks of Tonga have managed to remain hidden until 2006 despite probably being a breeding population, so can a small green Wrasse!

Not hopeful - but fingers crossed!

PS when I sent him this post, my guru commented

Anampses viridis, the Mauritius Green Wrasse, is a mystery fish, known only from a few dried specimens and last collected before 1840 when described by Valenciennes.

One wonders if it is a valid species, where and from what depth it was actually collected (collecting data can be unreliable from that era…note the range of Amblyglyphidodon curacao), and, if a valid species presently extinct, what factors contributed to its extinction.
Not much human marine impact in that area in the early 19th century.

Extinction is a natural process and the fate of all species.
Man may not necessarily be implicated in all recent extinctions………one hopes.

So there!

Marine Extinction - two

I'm talking about us!
Us, the baby boomers - me, I learn, being a Joneser.

One of the most interesting topics of discussion at this year's DEMA was how population dynamics are affecting our industry.

It is very much us the boomers who have pioneered SCUBA diving and who have developed it from the initial passion of a select few intrepid adventurers to a world wide movement that has become universally accessible. It is very much us who have discovered and developed most destinations, opened the first dive centers, built the first liveaboard vessels, established the accepted diving procedures and developed the modern dive gear.
And most passionate, committed, wealthy and experienced clients hail from our ranks - especially those who book trips on liveaboard vessels.

But now, we're getting ever older and ever more frail, and dying.
Gone are the glorious days of hard core diving in some remote corner of the world - nowadays, it's Old Farts' Diving, as Bob Halstead calls it: no more schlepping of tanks, no more currents, no more risks, no more reckless adventure and exploration.
Enter the global recession that has wiped out most 401Ks and by the time we’ve managed to re-coup our losses, it will be too late - for us and for the conventional liveaboard industry.

Because the next batch is nothing like us.
To them, diving is just one among many other activities one can pursue during one’s holiday. They care not for dive dive eat dive dive eat dive sleep, the rather basic food, the occasional roach infestation and the constant rocking whilst trying to fall asleep on a narrow hard bunk .
They want to be able to play a couple of rounds of golf, sip a cocktail at the pool, have a massage, download their mail and watch news, go sightseeing and shopping and sleep in a proper bed.
Plus, more often than not, they tend to be accompanied by a non-diving and boat-o-phobic partner and a bunch of kids for whom diving is something un-cool that only old people do.
Not the kind of people who book traditional, old-style liveaboards, that’s for sure.

For that very specialized industry segment to survive, it will have to evolve, and very fast on top of that.
I believe that with the exception of very select destinations that will always remain iconic and attract a loyal following, like Cocos and the Galapagos where land based diving is really not an option anyway, the trend will have to be substantially shorter trips coupled with a much wider range of activities and services. Think “very small adventure cruise ship” offering a wide range of aquatic and land based activities including several X-activities like kayaking, surfing, hiking, canyoning and cross country biking along with cultural immersion and shopping - and even the all-important yoga, wellness and spa! And the connectivity! And the luxury!

Impossible?
Not really – but it will imply a change of mind set, strategy and marketing. And substantial investments on top of that, something I fear only few will be able, or willing to shoulder in these challenging times. Having talked to quite a few, many just can't be bothered and will just sell their vessels and retire.

Le Roi est mort - vive le Roi!

Marine Extinction - one

Talking about getting the facts right.

When writing that post, I was reminded of a recent lunch with a fellow Shark conservationist.
We were comparing the image of terrestrial vs aquatic apex predators and he looked at me and said that contrary to the fishermen, the hunters had never led to the extinction of a species.
Passenger Pigeon (mass ornicide) anybody? Quagga, pictured above?

I of course went looking and found these lists.
Heaps upon heaps of terrestrial animals, be it Mammals, Birds, Reptiles, Amphibians and even Insects! And freshwater Fishes! Many of which certainly hunted, and fished to extinction! But of course the man was partly right: modern hunters have indeed changed their ways and don't do those things anymore - and I may add, contrary to the game fishermen who still target pregnant Sharks in their stupid quest for trophies!

And how about the Ocean?
How many marine Mammals have gone extinct during the Holocene, i.e. from approx. 12,000 years ago til now? Steller's Sea Cow (hunted to extinction). Caribbean Monk Seal (overhunted). Japanese Sea Lion, possibly only a sub-species (hunted to extinction). Sea Mink, more coastal than marine (hunted to extinction - even before being scientifically described!).
Incidentally, I could not find any marine Cetaceans - yet.

Marine Reptiles?
Can anybody name a single one?

And how about a single marine Fish, Sharks included?

Don't get me wrong: I'm by no means suggesting that the situation is OK.
It is certainly very dire and we must continue working very hard in order to prevent what appears to be the imminent collapse of some of the most threatened species, like the Northern Bluefin, the Flapper Skate, many Sharks and the whole sad lineup on the Red List, many of which Corals. Still, the Ocean is a very very big place and it appears that so far and despite of our very best efforts, its Fishes have managed to dodge everything we've thrown at them, from reckless overfishing to reckless pollution.

Let's just keep that in mind when faced with the apparent hopelessness of our efforts.
It is not hopeless, and we can turn things around.