Human Effects on Oceans

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http://www.nature.com/nature/journal...ture04385.html
Slowing of the Atlantic meridional overturning circulation at 25° N

Here we analyse a new 25° N transatlantic section and compare it with four previous sections taken over the past five decades. The comparison suggests that the Atlantic meridional overturning circulation has slowed by about 30 per cent between 1957 and 2004. Whereas the northward transport in the Gulf Stream across 25° N has remained nearly constant, the slowing is evident both in a 50 per cent larger southward-moving mid-ocean recirculation of thermocline waters, and also in a 50 per cent decrease in the southward transport of lower North Atlantic Deep Water between 3,000 and 5,000 m in depth.

http://www.sciencedirect.com/science...f3db581898b053
Early summer thermohaline characteristics and mixing in the western Weddell Sea

The first, Modified Weddell Deep Water (MWDW), comprises the permanent pycnocline and was less saline than a decade earlier, whereas Weddell Sea Bottom Water (WSBW) was horizontally patchier and colder. Near-bottom temperatures observed in 2004 were the coldest on record for the western Weddell Sea over the continental slope.

Versus
http://www.nature.com/nature/journal...l/448844b.html

Suggestions of a substantial decline in the Atlantic Ocean circulation that carries warm tropical water northwards seem to be largely unfounded. New data — recorded between the Bahamas and the Canary Islands — show that the seemingly dramatic reduction discovered two years ago in the strength of the Atlantic meridional overturning circulation (MOC) is easily within the range of huge seasonal variability.

But
http://www.npr.org/templates/story/s...oryId=87959035

The region of the ocean known as "the desert of the sea" has expanded dramatically over the past decade, according to a new study.

Scientists studying climate change have predicted this kind of change. But the sea desert has been spreading 10 times faster than climate scientists predicted. So Polovina is a bit cautious — this could be a shorter-term fluctuation, not a permanent change.

Ocenic desertification is related to the reduction in upwelling, downwelling (or deepwater creation) is reduced, flow is reduced, but the thermohaline current is not stalling, it is all just noise. OK so it might possibly be natural variation, but there is also a possibility it is not just noise.

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http://www.sciencemag.org/cgi/conten...cience.1183517
Effect of Ocean Acidification on Iron Availability to Marine Phytoplankton
Dalin Shi,* Yan Xu, Brian M. Hopkinson, François M. M. Morel

The acidification caused by dissolution of anthropogenic CO2 in the ocean changes the chemistry and, hence, the bioavailability of iron (Fe), a limiting nutrient in large oceanic regions. Here, we show that the bioavailability of dissolved Fe may decline due to ocean acidification. Acidification of media containing various Fe compounds decreases the Fe uptake rate of diatoms and coccolithophores to an extent predicted by the changes in Fe chemistry. A slower Fe uptake by a model diatom with decreasing pH is also seen in experiments with Atlantic surface water. The Fe requirement of model phytoplankton remains unchanged with increasing CO2. The ongoing acidification of seawater is likely to increase the Fe-stress of phytoplankton populations in some areas of the ocean.

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http://assets.panda.org/downloads/ha...ne_turtles.pdf

ABSTRACT: Marine turtles occupy a wide range of terrestrial and marine habitats, and many aspects of their life history have been demonstrated to be closely tied to climatic variables such as ambient temperature and storminess. As a group, therefore, marine turtles may be good indicators of climate change effects on coastal and marine habitats.

The cumulative indications from these previous
studies indicate that future research should focus on: (1) climate change effects on key habitats upon which turtles depend; (2) factors that influence nest site selection; (3) the consequences of skewed primary sex ratios; and (4) the effect of climate change on turtles at sea, for example range shifts and dietary breadth. Although it is too early to give detailed management recommendations, careful protection of coastlines along which turtles nest should be considered, as should the protection of beaches that produce male hatchlings, which may be of increased importance in the future. More active management approaches, for example translocation of eggs to suitable yet vacant nesting beaches, may be necessary to consider under worst-case scenarios.

Compounding the threat of sea level rise is the likelihood of an increase in fortification of coastal areas to protect human settlements (using e.g. sea walls, groynes and other hard sea defences). Such ‘shoreline
protection’ is already in widespread use

Although some beaches may be inundated and lost, one possible result of climate change is an increase in thermally suitable nesting habitat, both geographically and temporally. With an increase in mean air, and
therefore beach sand temperatures, previously unsuitable habitat, for example beaches at higher latitudes than current nesting areas, may become suitable for successful egg incubation. This has apparently occurred in the past, when warmer temperatures in interglacial periods facilitated the expansion of loggerhead sea turtles

Marine turtle clutches are sensitive to temperature changes and typically incubate successfully only between 25 and 35°C (Ackerman 1997, Carthy et al. 2003), with embryos incubating at high temperatures becoming females and those at lower temperatures becoming males, and 50% of either sex produced at the ‘pivotal temperature,’ between 28 to 31°C

A link from Kate at Climate Sight

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http://www.mcclatchydc.com/2010/07/0...k=omni_popular

It's not just BP's oil in the Gulf that threatens world's oceans

WASHINGTON — A sobering new report warns that the oceans face a "fundamental and irreversible ecological transformation" not seen in millions of years as greenhouse gases and climate change already have affected temperature, acidity, sea and oxygen levels, the food chain and possibly major currents that could alter global weather.

"This is further evidence we are well on our way to the next great extinction event," said Ove Hoegh-Guldberg, the director of the Global Change Institute at the University of Queensland in Australia and a co-author of the report.

Among other things, the report notes:



•The average temperature of the upper level of the oceans has increased more than 1 degree Fahrenheit over the past 100 years, and global ocean surface temperatures in January were the second warmest ever recorded for that month.


•Though the increase in acidity is slight, it represents a "major departure" from the geochemical conditions that have existed in the oceans for hundred of thousands if not millions of years.

•Nutrient-poor "ocean deserts" in the Pacific and Atlantic oceans grew by 15 percent, or roughly 2.5 million square miles, from 1998 to 2006.

•Oxygen concentrations have been dropping off the Northwest U.S. coast and the coast of southern Africa, where dead zones are appearing regularly. There is paleontological evidence that declining oxygen levels in the oceans played a major role in at least four or five mass extinctions.

•Since the early 1980s, the production of phytoplankton, a crucial creature at the lower end of the food chain, has declined 6 percent, with 70 percent of the decline found in the northern parts of the oceans. Scientists also have found that phytoplankton are becoming smaller.

Bruno said a 50-year time frame to consider changes in the ocean was way too short, however.

"I am a lot more worried about 200 to 300 years out," he said.

Read more: http://www.mcclatchydc.com/2010/07/0...#ixzz0st0q7K00

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http://climateprogress.org/2010/11/0...comment-305930

And if you want to get really depressed look at the embedded TED talk.

I ask myself what would the early stages of a Canfield State look like and realise Peter Ward (Under a Green Sky) might have been too optimistic.

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http://www.sciencedaily.com/releases...1111133220.htm
Oceanography Researchers Discover Toxic Algae in Open Water

ScienceDaily (Nov. 13, 2010) — Louisiana State University's Sibel Bargu, along with her former graduate student Ana Garcia, from the Department of Oceanography and Coastal Sciences in LSU's School of the Coast & Environment, has discovered toxic algae in vast, remote regions of the open ocean for the first time.

Harmful algal blooms, or HABs, are reported as increasing both geographically and in frequency along populated coastlines. Bargu's research shows that the ubiquitous diatom Pseudo-nitzschia -- an alga that produces the neurotoxin, domoic acid, or DA, in coastal regions -- actually also produces DA at many locations in the open Pacific. The presence of these potent toxins in deep water environments is worrisome, given that in coastal waters, where the phenomenon has been studied, DA can enter the food chain, forcing the closure of some fisheries and poisoning marine mammals and birds that feed on the contaminated fish. The main concern, though, is that the adding of iron to ocean waters -- one of the most commonly proposed strategies to reduce global warming -- appears now to likely result in promoting toxic blooms in the ocean.

Their findings show that iron enrichment indeed promotes high levels of toxins in the open sea, sometimes as high as those in coastal regions, where deaths of seabirds and mammals occur.

Dumping tons of iron dust in the ocean just might not be a good idea.

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Dead Whales: Argentina
http://www.youtube.com/watch?v=GuZLsx9PHww&feature=sub

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http://www.skepticalscience.com/Cora...n-you-die.html
Coral: life's a bleach... and then you die
Posted on 13 January 2011 by Rob Painting

Despite what you may read or see in the mainstream media, out in the real world, massive and rapid changes are taking place in many ecological systems as a result of global warming. The Earth seems to be already convinced of global warming and is responding quickly.

Once vast stretches of colourful reefs teeming with marine life are being reduced to lifeless rubble covered in seaweed or slime. Many areas are not recovering, and the scale and frequency of bleaching worldwide is getting worse. In fact, early reports suggest 2010 may have witnessed the largest single bleaching event ever recorded.

So how does hot water kill coral?. It requires both high water temperatures and sunlight. Oxygen is released as waste during photosynthesis and like all chemical processes this is affected by temperature, speeding up as more energy (warmth) is applied. When water temperatures rise too high the protective mechanisms to prevent heat damage, employed by the coral and the algae, are overwhelmed. The zooxanthellae algae produce high levels of oxygen waste which begin to poison the coral polyp. In acts of self-preservation the coral kick out the algae, and in doing so become susceptible to starvation, opportunistic diseases, competitive seaweeds and macroalgae

Ecologically speaking the value of coral reefs is even greater because they are integral to the well being of the oceans as we know them. It might serve to picture them as the undersea equivalent of rainforest trees. Tropical waters are naturally low in nutrients because the warm water limits nutrients essential for life from welling up from the deep, which is why they are sometimes called a "marine desert". Through the photosynthesis carried out by their algae, coral serve as a vital input of food into the tropical/sub-tropical marine food-chain, and assist in recycling the nutrients too. The reefs provide home and shelter to over 25% of fish in the ocean and up to two million marine species. They are also a nursery for the juvenile forms of many marine creatures .

The critical issue with global warming induced coral bleaching, as it is for many eco-systems, is the speed of warming. They are simply not being given sufficient time to evolve tolerance.

There are many links to papers embeded in the text of the original Skeptical Science posting.

One more sign that we are way overdoing things and are in trouble.

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http://www.sciencedaily.com/releases...0121103748.htm

ScienceDaily (Jan. 21, 2011) — Around one in four Montrealers take some kind of anti-depressant, and according to new research, the drugs are passing into the waterways and affecting fish.

Lead by Dr. Sébastien Sauvé at the University of Montreal's Department of Chemistry and André Lajeunesse, a PhD candidate, the research team found that the drugs accumulate in fish tissues and are affecting the fish's brain activity.

Sauvé was quick to point out that there is no immediate danger to humans. "The amount of anti-depressants being released into our river works out to roughly the equivalent of a grain of salt in an Olympic-size swimming pool," he said. "That's not enough to affect people, should they are brave enough to go fishing out there -- I'd be more worried about the trace metals!

It is a serious issue and all I want to do is make jokes.

[gaiasdaughter]

Originally Posted by 776281

http://www.sciencedaily.com/releases...0121103748.htm It is a serious issue and all I want to do is make jokes.

Tony, jokes, even tasteless ones, are good for the soul. It helps relieve stress to laugh a bit now and then

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http://dsc.discovery.com/news/2009/0...tery-blob.html

July 22, 2009 -- A huge mat of oily goo caught everyone by surprise when it showed up off the shore of Wainwright, Alaska nearly two weeks ago. Since then, the mysteries have only deepened.

Initial reports indicated that it was a substance that resembled heavy oil, crude oil or intermediate fuel oil," Hasenauer told Discovery News.

Preliminary testing showed that the goo was made of algae, even though it looked like an oil spill.

Things are changing," RaLonde said. "I don't expect that this is the last time we will see something like this."

Rember that last bit, and now

http://www.heraldtribune.com/article...orts?p=1&tc=pg

From a distance the toxic goo looks like oil, but up close it smells like rotten eggs and wiggles like jelly. Scientists have no idea what it is or how it wound up in the northern Gulf of Mexico, near Perdido Pass.

Scientists are trying to determine if oil from last year's Deepwater Horizon disaster led to the glob. But tests so far have found no sign of oil.

He speculates that a bloom of algae may have feasted on something - possibly oil - ran out of food and then died. The decaying algae might have then sucked all the oxygen out of the water and killed whatever was in the way.

http://www.newscientist.com/article/...d-at-last.html

Marine biologists have definitively shown that the "Chilean Blob" and other similar mysteries are simply the remains of whales.

That was from 2004, have to find a new explanation now

Desdemona Despair, is what got me started on this
http://www.desdemonadespair.net/2011...mystifies.html

Full of not so good news
http://www.desdemonadespair.net/2011...ing-under.html
Arctic fishing underreported.
http://www.desdemonadespair.net/2011...worldwide.html
Oysters functionally extinct in many eco regions

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http://climateprogress.org/2011/03/13/over-fishing/

Many fisheries scientists were sure there was no way humans could make a dent in the seemingly endless abundance of fish in the ocean as late as the middle of the 20th century. But our fishing industries were already well on their way to proving them wrong. It now seems that the problems facing our fisheries are as plentiful as cod once were on the Grand Banks off Newfoundland and throughout the Gulf of Maine.

This column will endeavor to help fishery managers, industry members, and environmental advocates engage in a desperate search for two aspirin and a tall glass of cold water that will dull the pain of payback and put America’s oldest industry back on a path to a healthy, vibrant future.

The responses are worth reading

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Proc. Natl. Acad. Sci. U.S.A. 108, 10.1073/pnas.1015782108 (2011).

Jelly Takeover
Caroline Ash

Jellyfish are unpalatable to most potential consumers, apart from the hardiest. As the numbers of sea turtles and large fish have plummeted and phytoplankton blooms have increased, the jellies have moved in, and increasing numbers and volumes of jellyfish blooms are being reported. Locally, jellyfish can vacuum up a wide range of swimming prey, thus tipping food web dynamics and potentially altering biogeochemical outputs. Condon et al. have discovered that jellyfish blooms in tributaries of the Chesapeake Bay generate large quantities of low nitrogen–high carbon—content dissolved organic matter: jelly-DOM. This in turn selects for normally rare (in the marine environment) microorganisms, like gamma-proteobacteria, which apparently outcompete other microbial taxa to consume the jelly-DOM rapidly. However, their metabolic efficiency is poor, and they respire 45 to 73% of the dissolved carbon generated during a bloom, rather than recycling the carbon in the food web or allowing it to fix and sediment. So the consequences of shifting marine food webs to a preponderance of gelatinous creatures may affect not only fisheries but also atmospheric warming.

My bolding

Another climatic tipping point that we (at least I) didn't know about.

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http://www.skepticalscience.com/Ocea...ering-Sea.html
Ocean Acidification: Corrosive waters arrive in the Bering Sea
Posted on 14 December 2011 by Rob Painting

You've probably read it before, some aspect of global warming is happening much faster, or sooner than anticipated by the scientific community. Well, this is one of three blog posts that continue in that vein. This time the bad news is corrosive seawater brought about by global warming's evil twin - ocean acidification. Something once considered to be some decades away is already here, and may be killing marine life.

A number of recently published scientific papers (Feeley [2010], Pfister [2011], Mathis [2011a], and Mathis [2011b]) have revealed that, rather than being some far-off future threat, corrosive seawater (from ocean acidification) is making its presence felt, both in the coastal waters of the US/Canadian North Pacific, and the eastern Bering Sea. As well as putting the finishing touches on the struggling oyster farming industry in the US states of Oregon and Washington, ocean acidification is likely to seriously impact the valuable US fishing catch, almost 50% of which (by weight) comes from the Bering Sea. See figure 1.

What does this all mean for the lucrative fishing industry based in the Bering Sea? It's too early to say for certain. The dire threat posed by ocean acidification, rather embarrassingly, has only crept into mainstream scientific awareness in the last decade or so. Therefore few long-term records or baseline studies exist, and marine scientists are, more-or-less, scrambling to quickly find out the implications.

The acid test
So to summarize the key points:

Rather than some far-flung concern for future generations, ocean acidification is already here and affecting marine life.
In the near-polar regions, such as the eastern Bering Sea, natural factors accelerate the 'unnatural' fossil fuel-derived input of carbon dioxide into seawater.
These natural factors include: cold water being able to absorb more CO2, and melting sea ice, and thaw over land, flushing more acidic water into the coastal Bering Sea. But the most significant contributor is the marine 'carbon pump', the export of CO2 to the seafloor through the 'rain' of organic debris from phytoplankton blooms and subsequent die-off. This greatly speeds up acidification near the seafloor.
Mathis (2011b) calculated that, without human CO2 contributions, the eastern Bering Sea would not have reached calcite undersaturation, and would have been aragonite undersaturated in Fall, at one location only. Therefore these corrosive waters are ultimately the result of human activities.
If phytoplankton blooms increase, or further melt-induced warming feeds more nutrients into the sea, (from organic matter flushed out of rivers, stimulating such blooms), then acidification in this region could accelerate.
Further fossil fuel burning will eventually cause subsurface waters to be persistently corrosive, and deep winter mixing will ensure that the entire water column is also persistently corrosive. This is likely to happen by mid 21st century.
The eastern Bering Sea is one of the most productive seas on Earth, and these waters provide almost half of the US fish catch.
Although research on the effects of ocean acidification on local marine life is almost non-existent, one of the foundation blocks of the local food web, the 'sea butterfly,' has an aragonite shell that dissolves in corrosive seawater. Furthermore, lab experiments show that corrosive and also warm seawater both contribute to higher mortality. Therefore projected acidification, and ocean warming may have profoundly negative consequences for the area, and for the United States fishing industry.

There are many embedded links in Rob Painting's post.

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Do you ever read a headline and think "well duh"? But even what is seemingly obvious needs to be researched and shown, all to often what everybody knows, or think they can see, turns out to be wrong.

http://www.sciencedaily.com/releases...0301143735.htm
Ocean Acidification Rate May Be Unprecedented, Study Says
ScienceDaily (Mar. 1, 2012)

The world's oceans may be turning acidic faster today from human carbon emissions than they did during four major extinctions in the last 300 million years, when natural pulses of carbon sent global temperatures soaring, says a new study in Science. The study is the first of its kind to survey the geologic record for evidence of ocean acidification over this vast time period.

Stands to reason. We have changed the atmospheric concentration of CO2 well over an order of magnitude faster than anything previous, therefore we would expect the ocean CO2 measure to have changed much faster than anything previous.

The oceans act like a sponge to draw down excess carbon dioxide from the air; the gas reacts with seawater to form carbonic acid, which over time is neutralized by fossil carbonate shells on the seafloor. But if CO2 goes into the oceans too quickly, it can deplete the carbonate ions that corals, mollusks and some plankton need for reef and shell-building.

And we already know phytoplankton is way down.

That is what is happening now. In a review of hundreds of paleoceanographic studies, a team of researchers from five countries found evidence for only one period in the last 300 million years when the oceans changed even remotely as fast as today: the Paleocene-Eocene Thermal Maximum, or PETM, some 56 million years ago.

That did not go too well did it?

More catastrophic events have shaken earth before, but perhaps not as quickly

For those who like the referenced science
The Geological Record of Ocean Acidification. Science, March 2, 2012 DOI: 10.1126/science.1208277

Same message spelt out a little differently. More on the consequences not on the rate.
http://www.sciencedaily.com/releases...0825093651.htm
Acidifying Oceans Spell Bleak Marine Biological Future 'by End of Century', Mediterranean Research Finds

A unique 'natural laboratory' in the Mediterranean Sea is revealing the effects of rising carbon dioxide levels on life in the oceans. The results show a bleak future for marine life as ocean acidity rises, and suggest that similar lowering of ocean pH levels may have been responsible for massive extinctions in the past.

'At a mean pH level of 7.8, calcified organisms begin to disappear, and non calcifying ones take over. We are headed towards that being the case in this century. The big concern for me is that unless we curb carbon emissions we risk mass extinctions, degrading coastal waters and encouraging outbreaks of toxic jellyfish and algae.'

And the jellyfish plagues do seem more common now. But not according to the Sydney Morning Herald.

Jellyfish still the same - it's interaction that's different

http://www.smh.com.au/environment/je...#ixzz1nupUj9zz

But then
http://phuketwan.com/tourism/jellyfi...-patong-beach/

To his knowledge, there had never been an invasion like it before, although algae attributed to pollution had been a problem on Patong beach at the close of high seasons recently.

And if you Google Jellyfish plague you get many, many, recent stories from around the world.

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http://www.sciencemag.org/content/ea...24836.abstract
A Global Pattern of Thermal Adaptation in Marine Phytoplankton

Rising ocean temperatures will alter the productivity and composition of marine phytoplankton communities, thereby affecting global biogeochemical cycles. Predicting the effects of future ocean warming on biogeochemical cycles depends critically on understanding how existing global temperature variation affects phytoplankton. Here, we show that variation in phytoplankton temperature optima over 150 degrees of latitude is well explained by a gradient in mean ocean temperature. An eco-evolutionary model predicts a similar relationship, suggesting that this pattern is the result of evolutionary adaptation. Using mechanistic species distribution models, we find that rising temperatures this century will cause poleward shifts in species' thermal niches and a sharp decline in tropical phytoplankton diversity in the absence of an evolutionary response.

This is so much more significant than it first appears, not unexpected but not good news.

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Are jelly fish going to rule the oceans?
http://www.sciencemag.org/content/339/6117/251.1.short

One strand of evidence for the deterioration of Earth's oceans is the perception that the seas are becoming overwhelmed by jellyfish. In fact, there has been little global analysis of jellyfish populations and the jellyfish ocean perception as made on the basis of a few scattered reports

Although strong 20-year oscillations were revealed by the analysis, in fact only a weak upward trend has been observed since 1970. The authors acknowledge that this could be a false negative, but unless more data are collected from more sites, the jury is still out on whether jellyfish will take over the increasingly anthropogenically affected oceans.

Perhaps not just yet, but the ocean's chemistry is changing and so longer term jelly fish will probably dominate.

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http://www.sciencedaily.com/releases...0723134743.htm
'Red Tide' Species Is Deadlier Than First Thought
July 23, 2012

A University of Connecticut researcher and his team have discovered that a species of tiny aquatic organism prominent in harmful algal blooms sometimes called "red tide" is even deadlier than first thought, with potential consequences for entire marine food chains

Alexandrium tamarense contains not one but two different types of toxins, one that's deadly to large organisms and one that's deadly to small predators.

"These small predators that are being affected by the reactive oxygen species are the things that typically eat large amounts of the algae and keep them from growing like crazy," says Dam. "This brings up a whole new line of inquiry for us: What will actually control these algae in the future?"

Dam notes that although harmful algal blooms have been linked to human activities, such as pollution runoff from rivers, there are many different factors that could affect the blooms, and scientists still aren't sure exactly how they begin. He speculates that the algae may have become more toxic over time, which has led to their proliferation.

Just to brighten your day.