Lucifer I is over

Phase I of the Lucifer project is over. The objectives of the study are the biogeochemical consequences of (1) the vertical mixing and the consequent planktonic bloom in the oceanic subtropical waters around the Canary Islands, (2) the influence of the lunar cycle observed in zooplankton in the transport of organic carbon towards the mesopelagic zone, and (3) the process of natural fertilization with iron promoted by the deposition of Saharan dust which is produced in several events during winter around the Canary Islands. During phase I, we performed a weekly sampling in the oceanic waters north of the Canary Islands from February to June 2010 in order to study the so-called late winter bloom in subtropical waters. We also studied the effect of a strong event of dust deposition, increasing production in synchrony with the lunar cycle.

Temperature, salinity and fluorescence were measured using a CTD SeaBird 25 and an in situ fluorometer. Primary production as 13C, chlorophyll, abundance of bacteria, phytoplankton cells, microzooplankton abundance, and mesozooplankton, biomass, gut fluorescence, electron transfer system (ETS), and aminoacyl t-RNA sinthetase (AARS) activities were also measured at four oceanic stations to the north of Gran Canaria Island. We also collected dust particles using active samplers near the study site for the measurement of metal composition (iron, nickel, cadmium, manganese,..).

Figure 1. True color image of the dust storm observed over the Canary Islands the 18th March, 2010. The image was provided by NASA/GSFC, MODIS Rapid Response through http://rapidfire.sci.gsfc.nasa.gov.

During March 2010, an important event of Saharan dust (Figure 1) took place around the islands. Values of dust particles smaller than 10 µm (PM10) reached values of 300 µg•m-3 in Gran Canaria Island, near our sampling area. Preliminary data showed no response of phytoplankton biomass to the massive dust deposition, at least at a weekly timescale. However, we measured a sharp increase of zooplankton biomass after this event. The bloom lasted for more than one month, indicating an important influence of the dust over the area. Flow citometry, 13C, microzooplankton and proxies of metabolic activity in zooplankton are being measured but our preliminary results show that the effect of this dust deposition event did not promoted any increase in chlorophyll, similar to some common results reported in the literature.
However, we wonder whether the increase in productivity is rapidly transferred to higher trophic levels through micro- and mesozooplankton in this warm water environment, avoiding the accumulation of phytoplankton biomass in the mixed layer. The consequences of this finding will restrain the use of remote sensing data to assess the effect of dust fertilization in the ocean. Finally, the active carbon flux promoted by the diel vertical migrants is a scarcely studied mechanism of the biological pump. Predation by this fauna upon the zooplankton crop observed after the dust deposition, shunted this epipelagic biomass to the mesopelagic zone. This transport will be the objective of Lucifer phase II which will start next November.

Santiago Hernández-León
IMBER Newsletter, Issue No. 15, September 2010

IMBER endorsement

The IMBER (Integrated Marine Biogeochemistry and Ecosystem Research) endorsement sub-committee sent us a letter last week informing about their acceptance of the LUCIFER project. The endorsement will serve to help coordinate national and regional IMBER research activities and to share data among scientists. It will also serve as a recognition that our objectives are under the umbrella of IMBER international project. If you are interested in looking at the endorsed projects by IMBER please visit http://www.imber.info/endorsed_projects.html.

Below are some pictures of the sampling activities carried out recently on board the "Atlantic Explorer". Thanks to Alejandro Ariza for the photos.

Federico Maldonado at work with the double WP-2 net

Federico again with the microplankton net

The Bongo net

Idem

Alejandro Ariza deploying the 30 liter Niskin bottle

Almudena Folgado, Alejandro Ariza and Mar Benavides in a democratic attitude

The oceanographic team. From left to right: Laia Armengol, Mar Benavides (biting the apple...), Almudena Folgado, Sabrina Sánchez and Federico Maldonado

Idem with Alejandro Ariza. Nice team

Victor Sepúlveda at work

Alejandro, Federico and Almudena

Sabrina, Almudena and Federico

Dust composition

Our colleague Mar Benavides sent us a nice paper about the composition and age of dust in Northwest Africa by Eglinton et al. Thank you very much. Below is the abstract. The paper is available on request and it is of interest for those working on the geology and chemistry of dust.

The introduction of the paper is really very original as they quote the first description of the dust clouds from the Sahara. The citation is from somebody named Charles Darwin who sail this area on board a ship called H.M.S. Beagle. Below is the text.

Nice description, like in a blog.

Meeting

Next week, those engaged in sampling during the project (oceanography and aerosols) are invited to a new meeting. Next Thursday at 10:00 a.m could be a good day and a good time to start, but you have to send an e-mail to the IP in order to agree with this date. If some of you are not able to come this day, the IP will look for another day.

The IP will give a short talk about the history and objectives of the project for the new members and he will present the dueties before sampling and the sampling program.

Do not forget to e-mail the IP.

Remember important dust events

After a long period without news, Lucifer strikes back again. Today an interesting paper by Viana et al. (2002) in which we found that during the famous dust event from February 2000, there was somebody measuring the dust deposition in Gran Canaria (prima!). Therefore, we can have an idea of the amount of dust promoting a bloom in the ocean, the one we measured at that time. This data is really interesting for the now starting project. The paper is available on request (as usual). Somebody knows somebody from this research group?

Two interesting papers

Below are the abstract of two interesting papers. The first one is a nice paper by Benoit-Bird et al. about the influence of the lunar cycle in the nigthtime vertical position of the deep scattering layers. Observe the technology they are using to measure the biomass of micronekton. Impressive. The second one is a remote sensing paper dealing with the dust deposition in the Mediterranean and the increase or not in chlorophyll. They conclude that increases in chlorophyll is an artefact of the remote sensing measurements. So, dust fertilize or not? Interesting question.

Saharan Dust Storms and Plankton in the Ocean

The number of June 19, 2009 of ScienceDaily published the effort made by German and Cape Vert institutions to disentangle the relationship between dust storms and plankton fertilization. As you can see, we have good competence in the study of the effect of dust. They have money, good equipment and a boat. For the followers of this blog, below is the content of the article. I think we can benefit from their work very south of the Canaries. Perhaps, we should start to think about a join meeting to discuss our results.

As our colleague Gara Frachy saids, they are using the same kind of picture we use here but in their area of research. Perhaps, we follow the same objectives...

The tropical Atlantic waters around Cape Verde are very low in plant nutrients. Nitrogen is in especially short supply and limits the growth of the phytoplankton, the tiny plants that are at the basis of the food chain in the ocean. In this area, the nutrients fall out from the sky: Trade winds carry Saharan dust rich in iron and phosphorus which can fertilize the surface of the ocean.
This was one of the reasons for the IFM-GEOMAR and other German and UK institutions to establish an observatory on the Cape Verde island Sao Vicente. The Tenatso Observatory now supports long-term measurements of dust and greenhouse gases as well as an oceanographic mooring and regular sampling expeditions by the small Cape Verdean research vessel Islandia.
“We’re testing whether Saharan dust can promote the growth of a particular type of microbe, a cyanobacteria. These cyanobacteria can fertilize the surface of the ocean by fixing the abundant nitrogen gas that is dissolved in seawater”, says Prof. Julie LaRoche from IFM-GEOMAR, co-leader of the expedition.
There is plenty of nitrogen gas in the atmosphere but it needs to be "fixed" so that it turns into a fertilizer which is available to phytoplankton. The enigmatic cyanobacteria UCYN-A seems to be a very special nitrogen fixer. In contrast to other cyanobacteria, it is probably incapable of producing oxygen. This in turns enables it to fix nitrogen during the day while others cannot.
The Trade Winds and frequent dust storms that make this area so important for ocean research also complicate the scientists’ work. Dust samples are collected with filters on top of the atmospheric observatory. The collection of the water samples, however, requires sailing on the Islandia for several hours to the ocean observatory located 130 kilometres offshore in a surrounding water depth of 3600 metres. The samples are returned to laboratories that have been established at Cape Verde’s “National Institute for Fishery Development” where the dust experiments are conducted.
"The working conditions are difficult and some trips on the Islandia are like a roller coaster. But overall it’s a very positive work experience, thanks to our supportive Cape Verdean colleagues, the crew of the Islandia, and the general ambience on the islands “, says Stefanie Sudhaus , Ph.D. student at IFM-GEOMAR and member of the last expedition. Loaded with plenty of data from their experiments and confident that the experiments will deliver new discoveries, the scientists have returned to Kiel. During the expedition they were accompanied by scientists from the Max Planck Institute for Marine Microbiology, the Alfred Wegener Institute for Polar and Marine Research, Leibniz Institute for Baltic Sea Research and the Leibniz Institute for Tropospheric Research.

Research Project at the Cape Verde

Scientists from German and Cape Verdean institutes have started collecting data at Cape Verde Observatory Tenatso in 2008, measurements that they hope to continue in order to follow the effect of global change in the tropical Atlantic Ocean. Their research is part of the SOPRAN project (Surface Ocean Processes in the Anthropocene) that is largely supported by the German Federal Ministry of Education and Research (BMBF).

Nitrogen fixers and UCYN-A

There is plenty of nitrogen gas (N2) in the atmosphere but only few organisms are able to "fix" it so that it turns into a fertilizer with biologically useful molecules. Cyanobacteria or blue-green algae are amongst the most important nitrogen-fixers. Until recently scientists thought that single-cell organisms could only fix the nitrogen during the night because during the day, oxygen is released through photosynthesis and inhibits nitrogen fixation by poisoning the enzyme responsible for it.
The cyanobacterium UCYN-A doesn’t seem to work like that. It lacks the genes for photosystem II that are needed for the oxygen release and apparently cannot fix carbon dioxide into sugars. Thus, it may utilize light energy in other ways and forgoes photosynthesis, as is normally carried out by land plants and other algae. Although this organism has never been isolated in pure culture, an initial characterization of its genome was published in 2008 by the group of Jonathan Zehr at University of Santa Cruz (Zehr et al. 2008, Science Vol. 322 no. 5904, pp. 1110-1112).

Update

Today, another talk of the series "Perspectives in Oceanography" about Living light in the darknes by Dr. Michael Latz. Enjoy the lecture.



Below some additional papers to update our PhD. Students. The first is about grazing in the Arctic. Very, very interesting. Look at the detailed description of the dilution method. For those who are revising grazing values in the ocean, give a look to this data. Values are not so high as the data given by Calbet and Landry.

For those working in grazing and metabolism of polar mesozooplankton, the paper by Campbell et al. is of interest.



Finally, those working in the Oxygen Minimum Zone have to read this paper by Dr. Escribano from Chile.

More and more papers

Two more interesting papers (AOR). The first one is related to the vertical migration of sonic scattering layers. Interesting to see that Uda in 1956 also observed the effect of moonlight on the vertical position of the deep dwellers. The second is an interesting experiment about the effect of nutrients on picoplankton. This is an important paper to those working on the annual cycle of micro- nano- and picoplankton.

Interesting paper

Today, a very interesting paper about the vertical migration of zooplankton and micronekton. Exploring the literature, I found a paper describing the movements of the deep scattering layers (DSLs)in relation to illumination. The interesting thing was the observation made by the author, Hilary Moore, about the effect of the lunar illumination on the vertical distribution of the DSLs. She found that at full moon the DSLs move downward because of the increase in light at the surface layers. The most impresive is that this paper was published in 1950!! So, now, almost 60 years after, we are starting to understand the consequences of this migration. Compulsory for those interested in the lunar cycles (AOR).

Dilution method

New paper about the dilution method. Very interesting description of the procedure and calculation of grazing and phytoplankton growth rates. Compulsory for those working on grazing.

More interesting papers

First, an important paper by Evan et al. published in Science about the effect of aerosols in maintaining the ocean temperature and the importance of dust in this process. They present a time-series of ocean temperature and estimate the cooling effect of the long-term decrease in dust over the area.

To those working in fish larvae and fisheries oceanography, the trailer of a coming review paper by Edward Houde about one of the most important issues in oceanography: recruitment variability. Once we have the paper, we will announce its publication. Please, keep your interest in our blog.

Dear Mr. President

Some weeks before, I posted a nice song. The project followers delighted those little things in life that make us happy every day. Today nothing about papers or brainy videos. I post another song this time dedicated to those who had a bad and sad childhood, and now when they become adults try to recover the past doing nasty things to the people. They are happy promoting badness. We live every day with them but there are some icons in the history. This song is dedicated to the last one but much more are on the way. Please, help to stop this people by sharing this video. Thanks Alex (playadelhombre.blogspot) for let me know this wonderful song.

Nice paper about microzooplankton grazing

The paper of today is a very recent publication sent to me by Claire Schmoker (thanks Claire) written by Teixeira and Figueiras about the dilution method to estimate microzooplankton grazing. This is a really important paper about the methodology and the problems normally observed in those experiments. Compulsory for the microzooplankton team.

See feeding currents in copepods

Today a video about the zooplankton. Most of you know a lot about the zooplankton but I encourage you to see this video in order to watch some beautiful images about how copepods move or feed. Enjoy the video.



The paper of today is a recent publication by Isabel Reche and co-workers about the effect of Saharan dust on bacterial biomass and production in lakes. Interesting to our work in the ocean.

Some more references

Below is the abstract of a paper by Hirst and Bunker which is a revision of growth rates in relation food, temperature and body weight. Interesting paper for those working in growth rate in the field and in modeling studies.

New paper by Lidia Yebra in Deep-Sea Research I (congratulations Lidia). The publication is related to the mesoscale physical variability and AARS activity of zooplankton as a proxy for growth rate.

Some interesting references

Today, some new references appeared in the literature. Probably, you will identify the interest for your work of every one but I will give some ideas.

Probably somebody working in top-down effects in the ocean would be interested in this paper. This is a clear message.

This paper was sent by Marta Moyano (thank you) and it is an interesting review about recruitment and Hjort´s hypothesis. Important for those interested in fisheries oceanography.

Finally, another interesting paper by Jaspers et al. about metazoan microzooplankton in the Indian Ocean. Interesting for those wishing to know more and more about those tiny organisms, but especially for those thinking about to build an apparatus to concentrate microzooplankton from a Niskin bottle. Somebody has to ask Dr. Jaspers because the description of the toy is not already published.

New Blog for the WG in Biological Oceanography

Dear Luciferinos,

Today I announce the start of a new blog for the biological oceanography working group of the University of Las Palmas. Therefore, I strongly recommend to change to this new blog (biologicaloceanography.blogspot.com), because in a short time we will have access to the different projects of the group and you can easily see if a new entry has been posted and when... In fact, this Lucifer blog is announced right now in the new blog. So, general information will be shown in the biological oceanography blog, while the more specific information about each project will appear in their respective blogs. Long life to the new blog!!

Santiago

Migrations into the Ocean's Interior

Today, an interesting talk by Dr. Mark Ohman (Scripps Institution of Oceanography) about the vertical migrations in the ocean. Look at the audience during the talk. The same problem as in our Universities. Where are the young people? Perhaps, watching talks in internet.

Deep Sea Part IV

Below the part IV of the deep sea movie.