The Incredible Voyage of Neodenticula Seminae

This article from a publication called DW-World was recently brought to my attention as iron-clad proof of unprecedented Arctic melting due to AGW…

Seems pretty cut and dried… But, I had never heard of DW-World, so I looked for some sort of confirmation of this startling discovery. My first stop was Nature

Nature Reports Climate Change Published online: 18 October 2007 | doi:10.1038/climate.2007.61

Atlantic invaders

The melting of Arctic sea ice is blurring the biological boundaries between Pacific and Atlantic.

It was in May 1999, during routine monitoring, that the tiny diatom was first found drifting in the ocean currents. Not an unusual observation on a plankton survey, only the species was in the wrong ocean. The north-west Atlantic was thick with phytoplankton of a Pacific species on its first visit for 800,000 years.

[…]

Reid’s explanation — based on analyses of sea ice coverage — is that Neodenticula seminae migrated from the Pacific to the Atlantic via the Arctic as a direct consequence of the Arctic’s diminishing ice cover. Melting of ice is now opening up the Northwest Passage between the Arctic and Pacific Oceans during summer and could result in a seasonal ice-free state in the region as the climate continues to warm.

[…]

Since its arrival, the diatom, commonly found in the most northerly reaches of the Pacific and the Bering Sea, has colonized the Labrador Sea between Greenland and Canada, as reported by Reid and colleagues in the September issue of Global Change Biology 2. “An [ice] gate was opened in 1998 which has probably been closed for thousands of years and then it closed again immediately afterwards,” he explains. “[The plankton] would have moved through the Bering Strait, through the [normally icy] Canadian archipelago and [south] into Baffin Bay.” The completely open seawater in the summer months of that year — blown by winds accelerating the general east-west current flow — would have provided ideal conditions for the phytoplankton to grow and proliferate, he argues.

[…]

But there is another potential explanation for how Neodenticula made the trans-Arctic trip into Atlantic waters: as a stow away in a ship’s ballast water on a route that took the Zebra Mussel and many other invasive species to world domination. Reid and colleagues are confident that this is not the case, though they cannot completely discount the route. They argue that few ships take the Northwest Passage and any ice breakers using the route are unlikely to risk exchanging their ballast water in transit or in the open waters of the Labrador Sea.

[…]

Neodenticula’s journey may also reveal new evidence for the unprecedented nature of today’s warming climate. Fossil records show the only other time the species appeared in the north Atlantic was between 1.2 million and 800,000 years ago, introduced during an interglacial period. “It died out probably because of severe cooling,” explains Reid, adding that oddly there is also no evidence of its presence in the north Atlantic during the Pliocene ‘trans-Arctic interchange’ of about 3.5 million years ago, when there was a huge extinction as Pacific species invaded the Atlantic. Martin Head, a palaeoclimate expert from Brock University in Canada, points out that it hasn’t appeared in the last 800,000 years despite plenty of interglacials during this time. The Eemian interglacial of about 130,000 years ago was thought to have been much warmer than today, for example. “It is telling us that something very unusual is happening during this [current] interglacial,” says Head. “The reason could be those interglacials were not as warm as now.”

Zoe Corbyn is a freelance science writer based in London, UK. Nature

The paper, Reid et al., 2007, is behind a paywall. The abstract says that the “the exceptional occurrence of extensive ice-free water to the North of Canada” enabled N. seminae to be “carried in a pulse of Pacific water in 1998/early 1999 via the Canadian Arctic Archipelago and/or Fram Strait;” arriving in the North Atlantic for the first time since the mid-Pleistocene. The incredible voyage of N. seminae was also hyped up in this “plenary paper” by Burkhill & Reid. The obvious Warmist conclusion was that “interglacials were not as warm as” the present day. This one little diatom obviously trumps all of the evidence that the last interglacial was significantly warmer than the current interglacial.

Three questions came to mind:

  1. How strong is the evidence that the Arctic climate was significantly warmer during the last interglacial?
  2. Could N. seminae have transited the Arctic in one melt season?
  3. Did N. seminae really go extinct in the North Atlantic 800,000 years ago?

Evidence of Eemian/Sangamonian Warmth

The last interglacial stage (often referred to as Marine Isotope Stage 5, the Sangamonian or the Eemian) was considerably warmer than the current interglacial and sea level was 3-6 meters higher than modern time. The Sangamonian was particularly warmer in the Arctic. Oxygen isotope ratios from the NGRIP ice core indicate that the Arctic was significantly warmer at the peak of the last interglacial (~135,000 years ago). If N. seminae could be blown from the Bering Sea through the Chukchi Sea, the Beaufort Sea, the Canadian Archipelago and Baffin Bay, without leaving any evidence of its transit, during one warm summer, it would have done so many times over the last 800,000 years. It also appears that it was significantly warmer in the Arctic during the Holocene Climatic Optimum (~7,000 years ago) than modern times. The Arctic was routinely ice-free during summer for most of the Holocene up until about 1,000 years ago. McKay et al., 2008 demonstrated that the modern Arctic sea ice cover is anomalously high and the Arctic summer sea surface temperature is anomalously low relative to the rest of the Holocene…

Modern sea-ice cover in the study area, expressed here as the number of months/year with >50% coverage, averages 10.6 ±1.2 months/year… Present day SST and SSS in August are 1.1 ± 2.4 8C and 28.5 ±1.3, respectively… In the Holocene record of core HLY0501-05, sea-ice cover has ranged between 5.5 and 9 months/year, summer SSS has varied between 22 and 30, and summer SST has ranged from 3 to 7.5 8C (Fig. 7).

McKay et al., 2008

The evidence against the modern warming being anomalous in the context of the Quaternary Period appears to be overwhelming.

You Can’t Get There From Here

Could N. seminae have transited the Arctic in one melt season? The short answer is no.

If N. seminaerecently migrated into the Atlantic from through the Northwest Passage and Canadian Archipelago, there ought to be some evidence of their transit in the Beaufort Sea and Baffin Bay; but there isn’t…

There’s not much evidence of anything transiting the Northwest Passage and Canadian Archipelago.

Driftwoodtakes the long route from the Pacific to the Atlantic because it follows the prevailing circulation patterns. The transit time from the Bering Strait to the Labrador Sea is about 6 years.

Driftwood takes the long route and about 6 years to transit the Arctic.

It’s amazing that the authors and uncritical commenters in the Nature article simply discounted the possibility that maritime activity might just have carried N. seminae into the North Atlantic… While proposing a preposterous scenario in which N. seminae traveled on the winds and currents from the Bering Sea through the Chukchi Sea, the Beaufort Sea, the Canadian Archipelago and Baffin Bay into the Labrador Sea, without leaving any evidence of its transit, during one warm summer.

But there is another potential explanation for how Neodenticula made the trans-Arctic trip into Atlantic waters: as a stow away in a ship’s ballast water on a route that took the Zebra Mussel and many other invasive species to world domination. Reid and colleagues are confident that this is not the case, though they cannot completely discount the route. They argue that few ships take the Northwest Passage and any ice breakers using the route are unlikely to risk exchanging their ballast water in transit or in the open waters of the Labrador Sea.

“Reid and colleagues” must be unfamiliar with nuclear submarines… Not to mention bilge pumps.

In 1969, the modified oil tanker SS Manhattan made a Northwest Passage round-trip, accompanied by two icebreakers… 10,000 nautical miles in 90 days… ~100 miles per day. Most Arctic currents have a surface velocity of 1-2 miles per day. If N. seminae drifted on ice-free summer currents, it would have taken at least 6 summers to travel from the Bering Sea to the Labrador Sea, spending nine months in hibernation each year. Yet the Warmists are confident it made the trip in one summer and didn’t hitch a ride on a ship or other anthropogenic vessel.

“I’m not dead yet!”

Did N. seminae really go extinct in the North Atlantic 800,000 years ago?

N. seminae did not just appear in the North Atlantic during an interglacial and then disappear due to “severe cooling.” It spanned several full glacial cycles during the mid-Pleistocene transition.

N. seminae is an important mid-Pleistocene biostratigraphic marker in the North Atlantic. Enhanced N. seminaeproductivity is associated with a transition to “cool, low-saline, surface waters” in the mid-Pleistocene…

Raymo, M.E., Jansen, E., Blum, P., and Herbert, T.D. (Eds.), 1999 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 162 51

4. HIGH-RESOLUTION PLEISTOCENE DIATOM BIOSTRATIGRAPHY OF SITE 983 AND CORRELATIONS WITH ISOTOPE STRATIGRAPHY

Nalân Koç,2,3 David A. Hodell,4 Helga Kleiven,2 and Laurent Labeyrie5

ABSTRACT

High accumulation rates and the presence of well-preserved, abundant diatoms in Site 983 sediments from the Gardar Drift gave us the opportunity to refine the Pleistocene diatom biostratigraphic resolution of the high- latitude North Atlantic. Eight Pleistocene diatom datum events are identified and, for the first time, tied directly to the oxygen isotope record and paleomagnetic stratigraphy of Site 983. These datum events are (1) the last occurrence (LO) of Proboscia curvirostris at 0.3 Ma, (2) the LO of Thalassiosira jouseae at 0.3 Ma, (3) the LO of Nitzschia reinholdii at 0.6 Ma, (4) the LO of Nitzschia fossilis at 0.68 Ma, (5) the LO of Nitzschia seminae at 0.84 Ma, (6) the first occurrence (FO) of N. seminae at 1.25 Ma, (7) the FO of Proboscia curvirostris at 1.53 Ma, and (8) the FO of Pseudoeunotia doliolus at 1.89 Ma. Most of these datums are found to be synchronous between the middle and high latitudes of the North Atlantic and the North Pacific. On the basis of these datums, four high-latitude North Atlantic diatom zones are proposed for the Pleistocene. The record of diatom abundance and preservation at Site 983 gives evidence for the influence of fluctuating Pleistocene climatic conditions on diatom productivity in the high-latitude North Atlantic.

[…]

Presence of significant diatom production during glacial stages 18, 20, and 30 indicates open-marine conditions over Site 983 during these times. High diatom production during glacial stages 18 and 20 is also recorded from Site 919, which suggests that the North Atlantic was free of sea ice during these glacial periods (Koç and Flower, 1998). These glacial stages are within the first 100-k.y. cycles after the Mid-Pleistocene Transition. As indicated by the benthic oxygen isotope records, they were not as severe as the late Quaternary glacials (Mix et al., 1995). Neodenticula seminae is part of the modern diatom assemblage of the middle- and high-latitude North Pacific (Barron, 1981; Sancetta, 1982). Our results indicate that this species is limited to the interval 0.84–1.26 Ma in the North Atlantic. Baldauf (1986) had interpreted the occurrence of N. seminae in the North Atlantic as the presence of cool, low-saline, surface waters in the central North Atlantic during the early Quaternary. The interval of N. seminae in the North Atlantic straddles the transition from the dominance of 41-k.y. cycles in the climate records to the dominance of 100-k.y. cycles. It is, therefore, possible to interpret the first occurrence of N. seminae in the North Atlantic as a sign for cooling, which started at 1.26 Ma, leading to the establishment of the 100-k.y. cycles with severe glacial periods. The presence of N. seminae in the North Atlantic is, therefore, attributable to the unique conditions related to the Mid-Pleistocene Transition.

[…]

LINK

Now here’s the million dollar question. If N. seminae first evolved ~1.2 million years ago in the North Atlantic and then became locally extinct 800,000 years ago… Where was N. seminae from 800,000 years ago up until 250,000 years ago?

Did it re-evolve in the North Pacific 250,000 years ago? Was it truly extinct? Or was its productivity so low that it wasn’t noted in the fossil record?

The answers are no, no and yes.

N. seminae has been present in the North Pacific since at least the beginning of the Pleistocene (~2.6 MYA). The N. seminae biostratigraphic zone starts with the last occurrence of P. curvirostiris. So, it did not reappear in the North Pacific 250,000 years ago.

Shimada & Tanimura, 2005 noted that “N. seminae has been reported in subtropical gyres in the Indian Ocean and the North Atlantic, its occurrences there seem to be quite sporadic and episodic. Semina (1981) reported fewer than 100 specimens/L from low latitudes in the North Atlantic, in contrast with up to 3.3×10^7 specimens/L in surface seawaters from the subarctic North Pacific Ocean and its surrounding seas.”

I’m not 100% certain… But, I think that N. seminae was named after G. I. Semina… The researcher who noted N. seminae’s presence in the Indian Ocean and North Atlantic back in 1981.

Conclusions

  • Neodenticula seminae did not go extinct in the North Atlantic 800,000 years ago.
  • Neodenticula seminae could not have transited the Arctic in one melt season.

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