1
On almost any ocean there is day after day when scarcely
a bird, beast, or fish appears to break the monotony, and
contrasted with this, here and there a few minutes or hours of
teeming abundance, when every field of the binoculars shows a
dozen birds or a hundred, and porpoises, orcas, or that cynosure of all passengers’ eyes, “real whales,” are seen on every
hand. Why should things be so badly arranged?
(Brooks 1934)
Abstract Marine fronts are part of the structural complexity of the sea; they
are narrow boundaries separating different water masses. Fronts are caused by
diverse forcing and occur throughout the world ocean at several spatial and temporal scales. Unlike terrestrial ecotones, they show high biological production,
affecting pelagic and benthic organisms of all trophic levels; consequently they
are important for fisheries. Solar energy stimulates biological production in the
entire biosphere, but in the sea it needs to be complemented by auxiliary energy
to replenish plant nutrients; a significant quantity of mechanical energy becomes
available for biological production at fronts. Global change is redistributing auxiliary energy in the oceans; consequently fronts are ideal sites for early monitoring
of global change effects. Fronts also provide retention mechanisms for plankton
in the highly dispersive marine environment; and become landmarks and beacons important for migrations or meeting of some species in a traceless realm.
Keywords Biological production · Plankton retention · Climate change ·
Migrations · Ecological boundaries · Ecotones
Though not immediately perceived, oceans are characterized by a profusion of
patterns which cover several scales of space and time. A few decades ago Le Févre
(1986) began his review on shelf tidal fronts stressing that “A common-sense view
of the marine environment as a fluid medium would probably imply progressive
changes and smooth gradients in physical properties. Sharp boundaries, however,
Chapter 1
Introduction
© The Author(s) 2015
E.M. Acha et al., Ecological Processes at Marine Fronts,
SpringerBriefs in Environmental Science, DOI 10.1007/978-3-319-15479-4_1
On almost any ocean there is day after day when scarcely
a bird, beast, or fish appears to break the monotony, and
contrasted with this, here and there a few minutes or hours of
teeming abundance, when every field of the binoculars shows a
dozen birds or a hundred, and porpoises, orcas, or that cynosure of all passengers’ eyes, “real whales,” are seen on every
hand. Why should things be so badly arranged?
(Brooks 1934)
Abstract Marine fronts are part of the structural complexity of the sea; they
are narrow boundaries separating different water masses. Fronts are caused by
diverse forcing and occur throughout the world ocean at several spatial and temporal scales. Unlike terrestrial ecotones, they show high biological production,
affecting pelagic and benthic organisms of all trophic levels; consequently they
are important for fisheries. Solar energy stimulates biological production in the
entire biosphere, but in the sea it needs to be complemented by auxiliary energy
to replenish plant nutrients; a significant quantity of mechanical energy becomes
available for biological production at fronts. Global change is redistributing auxiliary energy in the oceans; consequently fronts are ideal sites for early monitoring
of global change effects. Fronts also provide retention mechanisms for plankton
in the highly dispersive marine environment; and become landmarks and beacons important for migrations or meeting of some species in a traceless realm.
Keywords Biological production · Plankton retention · Climate change ·
Migrations · Ecological boundaries · Ecotones
Though not immediately perceived, oceans are characterized by a profusion of
patterns which cover several scales of space and time. A few decades ago Le Févre
(1986) began his review on shelf tidal fronts stressing that “A common-sense view
of the marine environment as a fluid medium would probably imply progressive
changes and smooth gradients in physical properties. Sharp boundaries, however,
Chapter 1
Introduction
© The Author(s) 2015
E.M. Acha et al., Ecological Processes at Marine Fronts,
SpringerBriefs in Environmental Science, DOI 10.1007/978-3-319-15479-4_1