Modelando el hábitat de especies transzonales y migratorias (Conferencias organizadas por la Sociedad Nacional de Pesquería)

Ponencia

Cuantificando el hábitat del juren usando datos VMS (Conferencias organizadas por la Sociedad Nacional de Pesquería)

Ponencia

Anchovy biofouled plastic treatment

El Niño 2. Beginning of El Nino --V1.25--

Is El Niño Developing? A NASA News

Data from ocean-observing satellites and other ocean sensors indicate that El Niño conditions appear to be developing in the equatorial Pacific Ocean. Conditions in May 2014 bear some similarities to those of May 1997, a year that brought one of the most potent El Niño events of the 20th century.

During an El Niño, easterly trade winds in the Pacific falter and allow giant waves of warm water—known asKelvin waves—to drift across from the western Pacific toward South America. Surface waters in the central and eastern Pacific become significantly warmer than normal, altering weather patterns and affecting fisheries along the west coasts of the Americas. El Niño also can have a significant influence on weather and climate far from the tropics.

The maps above show the ten-day average of sea surface height centered on May 2, 1997 (left), and May 3, 2014. Shades of red and orange indicate where the water is warmer and above normal sea level. Shades of blue-green show where sea level and temperatures are lower than average. Normal sea-level conditions appear in white. The 1997 map was assembled from data collected by the TOPEX/Poseidon satellite, while the 2014 data comes from the Ocean Surface Topography Mission/Jason 2 satellite.

The height of the sea surface is a good indicator of the amount of heat stored in the water. As the ocean warms, the surface rises; as it cools, its falls. This is due to thermal expansion and contraction; the molecules in warmer water are farther apart than in cooler water. Above-normal sea surface heights in the equatorial Pacific indicate El Niño conditions, while below-normal heights indicate La Niña. (You can see an example of La Niña here and El Niño here.)

“What we are now seeing in the tropical Pacific Ocean looks similar to conditions in early 1997,” said Eric Lindstrom, oceanography program manager at NASA headquarters. “If this continues, we could be looking at a major El Niño this fall. But there are no guarantees.” Observations from a network of sensors within the Pacific Ocean support the satellite view, showing a deep pool of warm water that has been sliding eastward since January.

More information:  http://earthobservatory.nasa.gov/

Sustainable Yield in Fisheries

It is very difficult to achieve this goal. Typically, fisheries undergo stocks permanently at different temporal and spatial scales of exploitation that exceeds the biological capacity and ecological recovery of the species. On the other hand, the fishery always begins without further study of the population which will be exploted. When these studies exist, and these are more intensive, the population has already changed to another phase, ie, the response is delayed (Figure 1).

Figure 1. Evolution of changes in a fishery.

One factor that clearly shows these effects are average sizes of the populations subjected to exploitation. Body sizes of fish as well as the quality and quantity of their eggs, are subject to biological changes. Drastic natural events, and fishing pressure, can severely affect the exploited stocks (Figure 2). 

Figure 2. Some changes in a fish population during its inappropiate exploitation.

Generally, these changes can be observed after several years of inappropiate fishing pressure, but in some cases may occur over short periods due to a combination of several factors. Fisheries also have problems due to these changes, yields may decrease while the exploited population undergoes various changes (Figure 3). It is necessary to apply the ecosystem approach to fisheries management, through a comprehensive and multidisciplinary study taking in account all parts involved.

Global ocean ecosystem dynamics, integrated marine biogeochemistry and ecosystem research, China

Dates
Symposium: 22-24 November 2011
Training course: 25 November 2011

Venue
East China Normal University
3663 Zhongshan Road North
Shanghai, China

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Mid-Term Strategy meeting: Air-Sea Gas Fluxes in Eastern Boundary Upwelling Systems and Oxygen Minimum Zones (OMZs)

Background

Among the new initiatives approved by the SOLAS Scientific Steering Committee, the theme of air-sea exchange of short- and long-term radiatively-active gases in the Eastern Boundary Upwelling Systems (EBUS) and
Oxygen Minimum Zones (OMZs) has been discussed during the SOLAS Open Science Conference in Barcelona (November 2009).
This initiative focuses on the co-existence of specific mechanisms, which are inducing a perturbation of biogeochemical cycles (for instance nitrogen loss, acidification) and acting as an "engine" producing and/or
consuming climatic gases: O2, CO2, N2O, CH4, halogenous compounds. The scientific issues are:

1) Which is the complete influence of the OMZs-EBUS on climate change, taking into account the impact of the greenhouse gases, cloud formation and control of O3 and O2?
2) Which are the responsible mechanisms associated with a bio-, photo-, or chemo-degradation of organic matter (including CDOM) for the production of greenhouse gases, e.g. the switch from an aerobic
(O2-respiration) to an anaerobic (via NO3, SO4, methanogenesis, IO3, Fe) remineralization?

In order to answer these questions in the tropical OMZs-EBUS, the initiative focuses on the eastern tropical Pacific, which corresponds to the largest OMZ.

The workshop, including one day of short presentations and one day and a half for discussion, aims to stimulate an experimental oceanic and atmospheric effort, coordinated at the international scale from 2011-2012. 

More information: web site

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