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Bioécologie

Articles avec #oceanographie

Marine animals like corals and starfish

23 Février 2015,

Publié par Bioécologie

Sandro Bocci a diffusé cette vidéo d’animaux marins filmés en macro et parfois en timelapse comme accroche d’un prochain film.

Sandro Bocci:

"Meanwhile in a world far, far away ...

This is a short film created during the "Porgrave" shooting, the latest film by Sandro Bocci, that will be released in late 2015. ...Meanwhile... shows the world of marine animals like corals and starfish at high magnification and during long time span through the timelapse. The music almost alien and disturbing has been joined to the images that stimulate mental associations to create a contrast, stimulate synesthesia and feelings do not necessarily harmonics and assonant.
This is an infinitesimal part of the wonderful world in which we live and of which we should take better care. A trip through a different perspective that would encourage reflection on the consequences of our actions on each scale of space and time.
Enjoy the visio
n...

Images and editing: Sandro Bocci - Original Music: Maurizio Morganti - Featured: Protoreaster linckii, Scolymia , Fungia, Trachyphyllia, Symphyllia, Euphyllia divisa wilde, Zoas mix, Alien eye zoas, Tridacna maxima. A special thank's to: Nicola Musacchio, Mario Fagioli, Julia Set Collection.

…Meanwhile… è un cortometraggio sperimentale che mostra il mondo di alcuni animali marini tropicali come coralli e stelle marine ad alto ingrandimento ed attraverso lassi di tempo condensati. Il cortometraggio vorrebbe stimolare una riflessione sulle conseguenze delle nostre azioni su altre scale spazio-temporali mostrando le meraviglie nascoste e spesso impercettibili ad occhio nudo attraverso l'utilizzo di tecniche come il timelapse ed alti ingrandimenti ottici. La musica quasi aliena e disturbante è stata affiancata alle immagini che stimolano associazioni mentali per creare un contrasto, stimolare sinestesie e sensazioni non necessariamente armoniche ed assonanti.

Buona visione..."

Ferrando A., Gonzalez E ., Franco M., Commendatore M., Nievas M., Militon C., Stora G., Gilbert F., Esteves JL. & Cuny P. Spill effects on macrofaunal communities and bioturbation of pristine marine sediments (Caleta Valdés, Patagonia, Argentina): experimental evidence of low resistance capacities of benthic systems without history of pollution

18 Février 2015,

Publié par Bioécologie

Ferrando A., Gonzalez E .,  Franco M., Commendatore M., Nievas M., Militon C., Stora G., Gilbert F., Esteves JL. & Cuny P. Spill effects on macrofaunal communities and bioturbation of pristine marine sediments (Caleta Valdés, Patagonia, Argentina): experimental evidence of low resistance capacities of benthic systems without history of pollution

The Patagonian coast is characterized by the existence of pristine ecosystems which may be particularly sensitive to oil contamination. In this study, a simulated oil spill at acute and chronic input levels was carried out to assess the effects of contamination on the macrobenthic community structure and the bioturbation activity of sediments sampled in Caleta Valdés creek. Superficial sediments were either noncontaminated or contaminated by Escalante crude oil and incubated in the laboratory for 30 days. Oil contamination induced adverse effects on macrobenthic community at both concentrations with, for the highest concentration, a marked decrease of approximately 40 and 55 % of density and specific richness, respectively. Besides the disappearance of sensitive species, some other species like Oligochaeta sp. 1, Paranebalia sp., and Ostracoda sp. 2 species have a higher resistance to oil contamination. Sediment reworking activity was also affected by oil addition. At the highest level of contamination, nearly no activity was observed due to the high mortality of macroorganisms. The results strongly suggest that an oil spill in this protected marine area with no previous history of contamination would have a deep impact on the non-adapted macrobenthic community.

http://link.springer.com/article/10.1007%2Fs11356-015-4167-6

Pufferfish make seafloor circles to attract mates

17 Décembre 2014,

Publié par Bioécologie

Changes in the circular structure constructed by male pufferfish. (a) Early stage; (b) middle stage; (c) final stage; and (d) after spawning of the same circular structure. Photograph by Y. Okata on 23, 27, 29 June, and 6 July 2012, respectively.

Changes in the circular structure constructed by male pufferfish. (a) Early stage; (b) middle stage; (c) final stage; and (d) after spawning of the same circular structure. Photograph by Y. Okata on 23, 27, 29 June, and 6 July 2012, respectively.

The male pufferfishes (Torquigenersp., Tetraodontidae) construct large geometric circular structures on the seabed that play an important role in female mate choice. See this scientific publication for more information, and videos below.

Dans les vidéo présentées ci-dessous, découvrez cette incroyable structure géométrique réalisée par un poisson. Il s'agit d'un nid construit pas un mâle.

Les femelles se basent sur la "qualité" de ces structures pour "décider" ou non de se reproduire avec un mâle. Les œufs sont déposés au centre du nid. Lire cette publication scientifiquepour en savoir plus.

NOAA'S AERIAL SURVEYS OF ARCTIC MARINE MAMMALS PHOTOGRAPH WALRUS HAULOUT SITE - SCIENTISTS CALL BEHAVIOR A NEW PHENOMENON

4 Octobre 2014,

Publié par Bioécologie

A walrus hits the ice with its tusks near Baffin Island, Canada by Paul Nicklen
A walrus hits the ice with its tusks near Baffin Island, Canada by Paul Nicklen

Author: Julie Speegle, NOAA Fisheries, September 30, 2013 (Image ©Paul Nicklen)

NOAA scientists participating in this year's annual Aerial Surveys of Arctic Marine Mammals project in Alaska say they have photographed an area where thousands of Pacific walruses haul out of the ocean on a remote barrier island in the Chukchi Sea, near Pt. Lay.

This study is being funded and co-managed by the Bureau of Ocean Energy Management (BOEM)'s environmental studies program.

Scientists say it is difficult to provide an accurate count of the number of walruses densely packed together on coastal haulouts. Using aerial photographs, scientists estimated that this year's haulout at Pt. Lay initially contained 1,500 to 4,000 animals on Sept. 12. The number of walruses had increased to 5,500 to 8,000 when sighted on Sept. 22, and on Sept. 27, biologists estimated that there were approximately 10,000 walruses.

In 2011, scientists estimated that 30,000 walruses were hauled out along one kilometer of beach near Pt. Lay.

"Large walrus haulouts along the Alaskan coasts in the northeastern Chukchi Sea are a relatively new phenomenon," said Megan Ferguson, marine mammal scientist with NOAA Fisheries. "NOAA's research doesn't typically extend to studying walruses, since this is a species managed by the U.S. Fish and Wildlife Service (USFWS), so you can imagine how exciting it was for us to be able to collect such valuable data for our partner agencies."

Conserving and restoring protected species such as whales is one of NOAA Fisheries' core missions. The goal of the surveys is to document the distribution and relative abundance of bowhead, gray, minke, fin whales, beluga whales and other marine mammals in areas of potential oil and natural gas exploration, development and production activities in the Alaskan Arctic.

"In addition to photographing the walrus haulout area, NOAA scientists documented more bowhead whales, including calves and feeding adults in the Beaufort Sea this summer compared to 2012," said Ferguson. "We are also seeing more gray whale calves in the Chukchi Sea than we have in recent years."

Documenting the walrus haulout near Pt. Lay was a bonus for the scientists, since this information provides useful data for partners studying walruses in the Arctic. One of the reasons photograph documentation of the walrus haulout areas is so important is because seeing so many along the beaches is a relatively new phenomenon.

In the past, walruses used sea ice habitat offshore in the northern Chukchi Sea as resting platforms in between dives to the bottom of the shallow Chukchi Sea where they feed on their preferred prey, including clams, snails and worms, during the summer and autumn. Due to loss of ice in offshore areas, walruses are foraging in more coastal areas and using beaches for resting (hauling out).

The first large beach haulout in this region formed in 2007 near Pt. Lay, coinciding with an unprecedented loss of sea ice across the Chukchi Sea. Subsequent haulouts formed in northwestern Alaska near Icy Cape and Cape Lisburne in 2009, and near Pt. Lay in 2010, 2011 and 2013. During 2008 and 2012, remnants of sea ice offshore in the Chukchi Sea were sufficient for walruses to rest on between foraging bouts.

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