These conditions seem to favor diatoms, a more toxic form of plankton to marine life, over dinoflagellates…. Save the dinoflagellates!

Eeek, no! Long live the diatoms! I realize the first summary gives the impression that diatoms are more toxic than dinoflagellates, but I think we’re missing some important context from the quotes (unfortunately, there’s an embargo on the full article so I can’t access it yet).

There are about 2 dozen or so different dinoflagellates that cause harmful algae blooms, and they tend to be the most common and most severe blooms. In contrast there’s only 1 (AFAIK) species of diatom that’s a common cause of HABs. Diatoms also tend to be a much more important part of marine food webs than dinoflagellates.

This paper just published yesterday is highly relevant: Changes in marine dinoflagellate and diatom abundance under climate change (summarized here and here).

Climate change includes wind that is also altering how nutrients mix in the warming surface waters of the North Atlantic. These conditions seem to favor diatoms, a more toxic form of plankton to marine life, over dinoflagellates.

I’ve been tracking die-off news on the Facebook page, Anthropocene Mass Extinction. I’ve seen evidence there are ongoing unexplained marine die-off events happening in numerous other species that may be related…. butI’m probably over my link quota for this post. The history of news posted on that FB page tells the grim story.

Save the dinoflagellates!

BLARRGH!

See also :

http://blogs.discovermagazine.com/80beats/2009/03/10/no-more-speculation-scientists-prove-ocean-acidification-is-already-underway/

&

http://www.oceanclimatechange.org.au/content/index.php/site/report_card_extended/category/phytoplankton

&

http://www.neaq.org/conservation_and_research/climate_change/effects_on_ocean_animals.php

From which we find – if you scroll down to the bit about right whales :

Between 1997 and 1999, zooplankton numbers plummeted. Over 50 years of observation, scientists have learned that zooplankton are abundant when the North Atlantic Oscillation (NAO) Index — which charts variations in atmospheric pressure centers over the North Atlantic — is predominantly positive. When it becomes negative, the numbers decline. Right whales illustrate the dramatic “downstream” significance of NAO conditions. … (snip) .. The big drop occurred in 1998; it took two years before the 1996 drop in the NAO Index had its effects on the zooplankton population downstream in the Gulf of Maine, where it dropped tenfold. By 1999 the zooplankton numbers were climbing back up again. However, because of the right whales’ long reproductive cycle, the consequences of this climatic event were not over yet for the whales. In 1999, only one right whale calf was born, the lowest on record (there were 21 born in 1996). But in 2001, two years after the abundance of the zooplankton increased, 30 right whale calves were born, the most recorded since 1982.

Where does all this fit into global warming? Some scientists suggest that increased climate variability or a prolonged period of negative NAO index, which are both expected under a global warming scenario, would undermine the already tenuous recovery of the North Atlantic right whale.

To find a lot more do a google search : “studies that show the measured effects of climate change on plankton”.

That’s what I found in about two minutes.

The cold Benguella and warm Agulhas currents collide off Cape Point, near Cape Town, which is further east than Cape Agulhas itself, which is correctly indicated as the Southernmost tip of Africa.

There may be spirals of cold Benguella dragged off up along with the warmer Agulhas current along the East coast of SA but these soon dissipate. As far as I know, there is no warm water dragged up the West coast.

The picture as shown has the Atlantic to the bottom, not to the right. Technically, because of the two currents split off Cape Point, the Atlantic and Indian Oceans meet at Cape Point, which is hidden by cloud in the picture.

That’s a gyre.